HEATING - - OIL BURNERS A SUMMARY of tnC MOST APPROVED PRACTICE IN THE APPLICATION OF AUTOMATIC OIL HEATING to the MODERN BUILDING aj'-.v■ V....... ■ r; '.■■■ ■■• '■> ■'■ lmm.r :f: |p#SS'f ■' , Prepared by ELECTROL INCORPORATED ST. LOUIS, U. S. A. Manufacturers of ELECTROL The ALL-ELECTRIC OIL BURNER WITH THE MASTER CONTROL 30gl Heating-'Oil Bumers"Electrol All-Electric Oil Burners I W ' /\;.vc. tt; ';, ■.. ■ .'■' r’ ..' i;,- ■%«'•#'/*•; 4 V'VV'"'' .rv'^?;'.i:^).;M , -/. ■ ■'■ J. ■,'/c> .' ' ' ■"'■ ' ■ ' ■ "' ' ■'t' '■■ ’ v'. v . ,.V . ' '.. ■ ■ ’ • ^' ' •^•,'- ^’-'V ■’••' ’ ' ■; , . , .■■;^ ■„> , •Ti ■ 'V' ■■''<. '■ < ‘ "' '! ‘■..>',rV : /•- , ... ^ j - . {A - • ■' '■* ' k''Ti .. I ." . ,• ... '".•' ■' ■ i ■ V. ' Vr? u s. ■ ■ •*- <-'..A-* V A SUMMARY OF THE MOST APPROVED PRACTICE IN THE APPLICATION OF AUTOMATIC OIL HEATING TO THE MODERN BUILDING Prepared by ELECTROL INCORPORATED St. Louis, U. S. A. Manufacturers of ELECTROL The AlhElectric Oil Burner With the Master Control Copyright 1928 Table of Contents Text Page Present Standards of Oil Burner Design. 5 l^asic Essentials of an Automatic Oil Burner Installation. 6 1 he Oil Burner. 6 Boilers for Oil-fired Heating Plants. 6 Wfiirm Air Furnaces Adapted to Oil Firing. . . 7 Fitting the Burner to the Heating Plant. 7 Chimneys. 7 Ventilation of Boiler Room . 8 Storage Tanks. 8 Multiple Installations. 8 Piping and Valves. 8 Electric Wiring. 8 Controls. 10 I he Part the Dealer Plays. 12 Supplementary Uses for the Oil Burner. 12 The Domestic Hot Water Supply. 12 a — Indirect Water Heaters. 12 h — Direct Method of Heating Domestic Water. 13 Garbage Incineration. 13 Fuel for Automatic Oil Burners. 13 The Cost of Oil Heating. 14 a — Installation Cost. 14 b—Operating Costs of Oil Heating Systems 14 Range of Application of Automatic Oil Heating Systems. 17 The Electrol Oil B urner. 18 General Description of Electrol Oil Burners. ... 18 Summary of Principal Features of the Electrol Oil Burner. 18 Principal Parts of the Electrol Oil Burner. 19 Nozzle. 19 Pump. 19 Diaphragm Valve. 19 Motor and Fan. 19 Pressure Regulating Valve. 19 Strainer. 20 Purolator. 20 Thermostat. 20 Ignition Transformer . 20 Radio Interference. 20 Relay. 20 Materials Used in Electrol. 20 Fhe Electrol Master Control. 21 Dimensions and Capacities of Electrol Burners 21 Oil Burner Service for Architects and Engineers 21 Page Specifications of Complete Equipment for an Electrol Oil Burner Installation in Accordance with the Underwriters’ Rules . 22 General .'. 22 Burner Guarantee . 22 Burner . 22 Pump . 22 Oil Atomization . 22 Regulating Valve . 22 Service . 22 Boiler Work . 22 Smoke Flue . 22 Tank . 22 Piping . 22 Testing . 22 Control Devices . 22 Safety Control . 23 Boder Controls . 23 Oil Gauges . 23 Electric Current . 23 Fire-proofing . 23 Permits . 23 Extracts from Underwriters’ Rules for the In¬ stallation of AutomaticOil BurningEquipment 23 Illustrations Tanks. 9 Thermostats Recommended for Electrol In¬ stallations . 10 Controls . 11 Hot Water Boder Control Warm Air Furnace Control Mercoid Controls. Electrol Installed in Steam Furnace . 12 Electrol Installed in Incinerator. 13 Oil-Consumption Charts . 16 Assembly of Model T Electrol Burner . 18 Nozzle . 19 Pump . 19 Diaphragm Valve . 19 Motor and Fan . 19 Pressure Regulating Valve . 19 Strainer . 20 Ignition System . 20 Continuous Electric Arc . 20 Chart of Dimensions and Capacities . 21 Diagram of Typical Electrol Installation . 24 f 2] Advantage of oil-fired heating systems, 17 Air leaks, 7 Air rotation, principle of, 18 American Oil Burner Association, 13 American Petroleum Institute, 13 American Society for Testing Materials, 13 Anti-siphon valve, 10 Architects and Engineers, service for, by Electrol Dealers, 21 by Electrol Engineers, 21 Atomization, mechanical, principle of, 5 First applied to domestic burner, 13 Automatic control of incineration, 13 Automatic control, system of, 10 Automatic water feeder, 22 Baffle, conditions necessitating construction, 7 Boiler feed controls, 10 Boilerstat part of regulating device for oil burners, 6 specified for Electrol installations, 22 Boiler thermostat, 12 Boiler work for Electrol installations, 22 Boilers capacity needed to carry domestic hot water heating system, 12 design which gives best results, 6 development, 6 standard types suitable to oil burner in¬ stallations, 7 Chimneys, 7 stack capacity for oil, 7 Clock thermostat specified for Electrol in¬ stallations, 22 Combustion chamber, designed for maximum efficiency, 6 proper construction of, 7 specifications for Electrol installations, 22 design, 22 material, 22 relation to boiler and nozzle, 22 Combustion completely controlled, 5 factors controlling, 5 roar of, eliminated, 5 Controls, system of automatic, 10 boiler feed, 10 domestic hot water, 10 emergency, 10 hot water, 10 low water cut-off, 10 Master, 21 steam, 10 thermostats, 10 vapor system, 10 warm air furnace, 10 Controls built as unit with burner, 6 not affected by room temperature, 6 correct installation necessary, 6 specifications in detail for Electro in¬ stallations, 22 Cost of heating domestic hot water by oil, 13 Cost of oil heating system installation cost, 14 principal items of expense, 14 quotations through dealers, 14 variation in different parts of the country, 14 operating costs, 14 design of burner important factor, 6 factors controlling cost of operating, 14 methods of estimating, 14 Cut-off valves, 12, 19 Dampers, 7 specifications for Electrol installation, 22 Index Dampers {continued) Underwriters’ rules for damper area, 23 Dealer important part in success of installation, 12 qualifications demanded of, 12 responsibilities of, 12 Diaphragm valve used on Electrol burner operation of, 19 purpose of, 19 Domestic hot water control, 10, 12 Domestic hot water supply provided by oil burner, 12 limits of indirect method, 13 Draft, 7 Duplex switch (low water cut-off and pres- surestat), 10 Electric current for Electrol installations, proper voltage, 23 Electric wiring capacity of supply outlets for different size burners, 10 installation—by recognized electrician, 10 —in accordance with Under¬ writers’ rules, 10 Electrol engineers contribution to standard practice in oil burner installation, 6, 18 improvements effected, 18 in touch with latest developments, 6 Electrol Incorporated, 18 budget for research, 19 Electrol Master Control, 21 conditions under which it functions, 21 purpose of control system, 21 Electrol oil burners capacities of, 21 complete specifications for installation of 22 boiler controls, 23 boiler work, 23 burner, 22 control devices, 22 electric current, 23 fire-proofing, 23 guarantee, 22 oil atomization, 22 oil gauges, 23 piping, 22 pumps, 21 permits, 23 regulating valve, 22 safety control, 23 service, 22 smoke flue, 23 tank, 22 testing, 22 dimensions and capacities of different models, 21 general specifications, 22 materials used in, 20 _ principal parts diaphragm valve, 19 fan, 19 ignition transformer, 20 motor, 19 nozzle, 19 pump, 19 _ , in pressure regulating valve, 19 purolator, 20 relay, 20 strainer, 20 thermostat, 20 product of a pioneer organization, 18 Electrol research laboratory, 18 Emergency controls. Underwriters’ rules, 24 !31 Fan used on Electrol burner operation, 19 size, 19 type, 19 Filling pipes equipment and location. Underwriters’ rules, 23 Fire-proofing of boiler room, 23 Fire protection required by Underwriters. 24 clearance for smoke pipes, 22 covering of combustible materials, 24 Flash point for fuel oil, 23 Flues cleanliness necessary, 7 defects must be corrected for Electrol In¬ stallations, 22 question of capacity, 7 reduction in size for oil, 7 Flue gas analysis necessary, 7 Fuel oil confusion of terms, 13 grades carried by distributors for convenience of users, 13 specifications according to A. O. B. A., A. P. I., 13 grade specified by Underwriters’ rules, 14 Fuel oil gauges, 10 Future supply of oil assured, 13 Garbage incineration flame of oil burner ideal for, 13 heat from, utilized for heating water for domestic purposes, 13 method of automatic control, 13 Guarantee of Electrol burner, 22 Heating coils necessary, 12 Hot air furnace, 7 any type adapted to oil firing, 7 should be gas-tight, 7 Hot water controls, 10 Hydrostat, 10, 12 Ignition, principle of, 18 Ignition transformer used on Electrol burner design, 20 purpose, 20 Infiltration of secondary air, 7 Installation of oil burner costs, 14 dual installations. 8 no limit to size of building heated, 17 for domestic hot water heating, 12 in steam and vapor boiler, 12 in hot water boiler, 12 for tank heater, 13 possible in any boiler of standard construc¬ tion, 6 standard practice developed by Electrol engineers, 5 Instruction card required by Underwriters, 24 Local ordinances installation of electric wiring, 10 installation of Electrol burners, 22 Low water cut-off, 10 Underwriters’ rules, 23, 21, Manholes, Underwriters’ rules for, 23 (See cut p. 9) Manual control of Incinerator recommended, 13 Manual restarting of burner, 6 Master Control, 21 Index—Continued Materials for wearing parts of burner, 6 used in Electrol burner, 20 Mechanical atomization, 5 principle of, 5 rotation, method of securing, 5 used on Electrol burner, 5 Mercury switches, 19 Motor used in Electrol burner size, 19 speed, 19 type, 19 Nozzle, 6 used on Electrol burner, 19 Oil atomization on Electrol burner, 22 Oil burners advantages for summer hot water, 13 approximate number in use, 5 basic principle—mechanical atomization of fuel, 5 care in selection of proper size, 7 design should fit type of heating plant, 6 durability of, judged by results, 6 Electrol Oil Burners dimensions and capacities, 21 general description of, 18 Master Control, 21 materials used in, 20 flame of, ideal for incineration, 13 features common to satisfactory oil burners, 5 flexibility responsible for success, 6 lines of present development in domestic oil burners, 5 improvements made by Electrol en¬ gineers, 5 perfection of accessory details, 5 standard practice developed by Electrol engineers, 5 modern and satisfactory types, 6 no longer new thing, 6 success due to sound engineering basis, 5 successful application other than domestic use, 5 supplementary uses for, 12 Oil-fired heating systems adapted to all types of buildings, 17 advantages, 17 not limited by size of building, 17 rapid increase in adoption, 17 Oil for fuel. Underwriters’ rules, 23 Oil gauges specified for Electrol installations purpose, 23 operation, 23 type, 23 Oil line controls, 10 Oil pump capacity, 6 integral part of burner, 6 on Electrol burner, 22 Oil piping for burner installations in accordance with Underwriters’ speci¬ fications, 23 materials specified for, 22 necessary parts of system, 22 Open circuit operation of safety control, 19 Operating costs of oil burner, 14 factors causing variation, 14 Orifice, 5 Permits for burner installations, 22 periodic charges borne by owner, 22 provided by contractor, 22 Pipe,_ piping swivel joints, 8 proper material for oil line, 8, 23 proper material for vent pipes, 8 sizes for suction and return lines, 8 Underwriters’ rules regarding, 23 Pressure atomization, see Mechanical atomi¬ zation Pressurestat— for steam system control, 10 for vapor system control, 10 Pressure regulating valve necessary for oil pump, 6 used in Electrol burner, 19 operation on Electrol burner, 22 Pump connection of, 18 type used on Electrol burner, 19 detailed description of, 19 capacity, 22 operation of, 19, 22 double purpose, 19 “Purolator” installation recommended, 10 used on Electrol burner, 20 purpose, 20 type, 20 Radio interference, 20 Regulating device for oil burner, 19 Relay on Electrol burner, 20 operation of, 20 Room thermostat, 10 purpose, 10 type used in Electrol burner, 20 Safety control specified for Electrol installa¬ tions, 23 (See Master Control, p. 21) conditions of operation, 23 unit with burner, 23 Servicing of Electrol burner what it consists of, 22 length of free service period, 22 Sirocco fan, 19 Shut-off valves, 8 Specifications for Electrol installation, 22 Steam system controls, 10 Storage tanks basement tank, 8 Storage tanks {continued) capacities determining location, 8 Underwriters’ rules, 23 excavation for, 8 filler pipes. Underwriters’ rules, 23 for sub-gravity installation, 8 location basement, 8 underground, 8 Underwriters’ rules, 23 relative costs for Inside and outside tanks, 8 specification of material for Electrol installations, 22 safeguarding underground tank, 8 testing of, 22 types,. 8 vents—• location, material, size, 22 wall type to feed burner, 8 Strainer used on Electrol burner operation, 20 purpose, 20 Suction lines, 8, 22 Switches, 22 Electrol installation mercury, 19 Systems of automatic control, 10 Tanks, oil, see storage tanks Tank heater, 13 diameter of fire-pot necessary for satis¬ factory operation, 13 Temperature control system for different types of boilers, 12 Thermostats types used in Electrol burner, 10, 20 Testing of Electrol installations, 22 Underwriters’ rules, extracts from, 23 damper, 24 emergency control, 24 fittings, 24 fire protection, 24 installation, 24 instruction card, 24 oil, 23 piping, 23 tanks, 23 Valves anti-siphon, 10 cut-off, 10, 19 diaphragm, 19 needle, 19 pressure regulating, 19 shut-off, 8 Valves and fittings, quality, 8 Vapor system controls, 10 Ventilation of boiler room, 8 Underwriters’ rules concerning, 24 Warm air furnace controls, 10 Wiring, electric, 10 Present Standards of Oil Burner Design HE extraordinary success of the domestic oil burner is largely attributable to the fact that its development was from the first based on a sound foundation of engineering knowledge. Oil burners have been successfully used in heating large buildings, in power plants, locomotives, and in ships, for the past thirty years. During this period a mass of information was accumulated and made available to engineers. As a result of this work the development of the present types of domestic oil burners consisted largely in eliminating the roar of combustion, which would be objectionable in a dwelling, and in working out the application of automatic control devices to a machine whose actual operation had already reached a high degree of efficiency. How well the problem has been solved is shown by the fact that there are at least 500,000 automatic oil burners now in use. Although differing greatlj^ in construction and in external appearance, the oil burners which have given satisfaction have in common the following features: a. A device for atomizing the oil mechanically. b. The application of the right amount of air at the point of combustion. c. Means for insuring thorough and complete mixing of air and oil supply. d. Means for igniting the mixture of oil and air and for maintaining the combustion. e. Means for automatically starting up or shutting down the burner. f. Means for immediately shutting off the burner and the oil supply whenever any unusual conditions arise. burthermore, m addition to these requirements of operation and construction, which are more rigorous and exacting than those required by any other heating method, the modern oil burner must operate at a high rate of efficiency. 1 he basic principle upon which all of the most suc¬ cessful oil burners have always operated is that of mechanical atomization of the fuel. This principle is as fundamental in oil burner design as ftielvapori- zation is to automobile engine design. In the mechanical system there are three funda¬ mental factors that control the proper combustion of fuel oil, (1) the atomization or breaking up of the oil into minute particles; (2) the introduction of air in just sufficient quantity and in such a f manner that it surrounds every particle of oil and causes complete combustion; and (3) a combustion chamber so constructed that the gases are kept above ignition temperatures until combustion is complete. The pressure or mechanical atomizer has been in use a number of years and is adopted by the United States Navy as standard. There are a number of pressure atomizers on the market, of which Electrol is a good example. All incorporate the principle of forcing oil under pressure through passages in the atomizer so arranged as to give the oil a high velocity of rotation. The rotation is ac¬ complished by means of tangential grooves discharg¬ ing into a small cylindrical chamber. The tip end of this chamber is coned out and at the apexof this cone is the orifice through which the oil is discharged. On leaving the orifice, the small streams of oil break up into very fine fog-like particles, resulting in a cone of finely atomized oil. At this point, the finely divided oil meets a cross current of air rotating in the opposite direction to the oil particles. These cross currents of oil and air become a turbulent mixture of air and oil fog. Just at this point, the turbulent mixture meets the ignition and is burned completely in a specially constructed firebrick enclosure before it is allowed to pass over the heating surfaces of the boiler. So long, therefore, as mechanical atomization forms the basis for oil burner construction, improvements in oil burners will be confined to further perfection of accessory details. Electrol engineers have always regarded mechan¬ ical atomization and electric ignition as essentials to satisfactory operation. Working from these as a basis, they have made improvements in electrical equipment, including both motors and trans¬ formers. They have eliminated the roar of com¬ bustion which was such a handicap in the earlier days of oil burners, by the introduction of air tangentially in an air receiver, thus cutting down 'the velocity, and eliminating the torch effect. They have effected improvements in overall design and in specification of materials for construction, which have resulted in economies of construction and reduction of maintenance costs. At the same time they have studied and success¬ fully coped with a great variety of installation problems in order to be able to work out standard installation methods representing the best possible practice for all sorts of conditions. 5! Basic Essentials of an Automatic Oil Burner Installation Present-day oil burner installations involve con- the single exception that pipe for oil lines should be siderable detail, as reference to the typical sped- black iron or brass and free from scale, fications for an Electrol Burner Installation Xhe peculiar elements of an oil burner installation (page 22) will show, concern the selection, arrangement and installa- However, a great number of these details are con- tion of the heating plant, storage tank, burner and cerned with piping and wiring, both of which boiler controls. The following discussion briefly have been reduced to a standard practice and summarizes the main points to be considered in present no problems peculiar to oil burning, with selecting or specifying this equipment. The Oil Burner The most modern and satisfactory type of oil burner is that which is fully automatic, combining mechanical fuel atomization and electric ignition. The oil should be completely atomized and inti- matel}^ mixed with air for combustion. The burner should be furnished with the proper sized nozzle to supply oil for combustion to the full capacity of the boiler. The combustion should be positively controlled in its operation so that if anything occurs to affect the safe operation of the burner the burner will stop immediately and not operate again until manually re-started. The control should be vested in an unfailing me¬ chanism built as a unit with the burner. It should be self-adjusting to the conditions of the installa¬ tion and not affected by room temperature. This control should render the oil burning installation safe under the conditions mentioned under the heading Master Control. 1 he oil pump should also be integral with the burner, and should be constructed to handle oil of any gravity between 28° and 45° Baume for the full capacity of the burner. It should lift oil directly from underground tank without auxiliary equipment. 1 he burner should have the following regulating devices: (I) A pressure-regulating valve in con¬ junction with the pump, so that the supply of oil to the nozzle may be carefully regulated to suit the combustion requirements of the boiler. (2) An electrically operated thermostat as recommended by the manufacturer, with the necessary connec¬ tions to make it a part of the complete control system. (3) A boiler or furnace control of design recommended by the manufacturer for the par¬ ticular type of boiler or furnace used. This con¬ trol should be properly wired and connected so it will be an efficiently operating part of the complete control system. The burner should be of a design that can be ap¬ plied to any type of heating plant such as steam, hot water, hot air or vapor. The operating cost of an oil burner will vary to some extent according to the individual installation—being affected by the type of heating plant, amount of heat required by the building’s occupants, the length of heating season, and other factors. But the design of the burner plays an important part in operating costs. (See detailed discussion of operating costs, page 14.) Good materials are also essential for the satisfac¬ tory oil burner. Nichrome alloy, pure nickel, semi-steel, monel metal, and brass are more ex¬ pensive than substitutes; but the use of such metals for certain parts of a burner adds much to its lasting quality. Laboratory tests alone are not enough to prove the best materials for use in oil burner construction. The durability of a burner should be judged by the known results of its use in actual operation over a period of years. Oil burners are no longer a “new thing.” The best makes have been on the market a number of years, proving their durability by 3 ^ears of satis¬ factory service. Boilers for Oil-fired Heating Plants All types of boilers are suited to oil burner installa¬ tions, 4'he use of oil fuels usually" increases the efficiency of the installation over that obtainable with coal. 4'he development of boilers designed for oil firing is progressing rapidly—so rapidly that the litera¬ ture on the subject is out of date almost as soon as It appears in print. Consequently no attempt can be made here to describe the situation. Electrol dealers and heating engineers are continually in touch with the latest developments in the field and can be relied upon to possess tbe necessary in¬ formation to insure the most modern heating plant and the most efficient installations. I6| In order to obtain all the heat in burning oil, it is necessary to have the combustion chamber and heating surface of the boiler so designed that (1) the oil and air may be thoroughly mixed before combustion takes place and (2) the heating sur¬ face will be large enough to allow for the absorp¬ tion of all the heat resulting from combustion. Although an oil burner installation will operate in almost any type of heating plant more efficiently than coal can be burned in it, best results are obtained where ample combustion space is avail¬ able and the heat-absorbing surfaces are of suffi¬ cient area. Warm Air Furnaces Oil burners have been successfully installed in any type of warm air furnace wherever the firebox can be made absolutely gas-tight, so that the products of combustion will not leak into the hot¬ air space and thence into the living quarters. The great flexibility of the oil burner is the factor which is responsible for the success which has been attained with installations made in equipment originally designed for coal firing. A skilled in¬ stallation man, knowing the equipment with which he must work, can install burner controls and construct the combustion chamber so that the heating plant will operate under most favorable conditions. As a general statement it can be safely asserted that an oil burner installation can be made in any boiler of standard construction with assurance that it will operate efficiently. Adapted to Oil Firing which of course are the same conditions as should apply when coal is burned. Practical examples of these installations may be found in nearly every community and the testimony of their owners is sufficient guarantee of the results rendered. Fitting the Burner to the Heating Plant Even where the heating plant is especially designed for operation with oil, there are individual prob¬ lems connected with each installation. Where maximum efficiency is to be obtained from an in¬ stallation made in a boiler originally designed for coal, the problems are great enough to require the high degree of skill which can only come from wide experience in this work. In order to properly fit the burner to the heating plant, the engineer in charge of the installation must first of all select the right sized burner for the heating plant. Then he must see that the proper controls are specified and correctly installed. The proper construction of the fire-brick combus¬ tion chamber is vital if complete combustion is to be obtained before the gases pass over the heating surface. Furthermore, the draft condi¬ tions must be studied in order to see whether or not the introduction of a damper m the flue is advisable (see Underwriters’ Rules, page 23). Even with a damper installed the rate of gas travel may be too great to allow proper transfer of heat to the heating surfaces. This must be determined and the condition corrected by the introduction of secondary baffles. Furthermore, the infiltration of secondary air must be pre¬ vented by stopping up all cracks between boiler sections, under the base or in the insulation. Air leaks that ma}^ occur here are often responsible not only for lowered operating efficiency but for noisy operation. After the installation has been completed the installation engineer must see that the proper ratio between air and oil is obtained when the burner operates, and if rate of oil consumption is too high it should be checked by flue gas analysis to see that the right amount of CO 2 is present in these gases. The temperature of flue gases should be checked to determine if they are not too high. Much heat can be lost if the flue gases are per¬ mitted to escape at too high a temperature. Chimneys In new buildings where oil is to be used, it is usually advisable to design the chimney as if hard coal were to be used in the boiler. This will give ample facilities for carrying away flue gases. When an oil burner is to be installed in an old flue that has been used for coal, it is seldom necessary to alter the flue; only be sure there are no stop¬ pages, and that the flue is swept clean. It is a well-known fact that a stack capacity inadequate for coal may prove ample for oil burning. If any question arises regarding flue capacity, it would be well to refer to handbooks on the subject, check over the design and rebuild according to the latest regulations, if necessary. Wherever possible the installation should be so planned that the oil-fired heating system has a separate flue with no other openings in it. If this is impossible special study should be given to local ordinances and the Underwriters’ Rules. 171 Ventilation of Boiler Room It is quite essential to have air (oxygen) for com¬ bustion of any material. It is therefore quite neces¬ sary that an oil burner installation should allow for a sufficient supply of air to properly burn the oil. The Undeiwriters’ Rules (page 23) are quite specific regarding this matter and care should be taken in planning the installation to see that all requirements are fully complied with. Storage Tanks Storage tanks are of two general types—those designed for installation within the building and those designed for installation underground. The Underwriters limit exposed basement tanks to 275-gallon capacity (see Rules, page 23). Outside underground tank capacities are not limited. However the Underwriters’ Rules indicate the posi¬ tion of each size of tank relative to buildings. In case oil can be readily obtained, basement tank installations are thoroughly practical. Since the cost for an inside tank and installation is con¬ siderably less than for underground tank instal¬ lations, It IS possible m many cases to reduce materially the total cost of an oil burner outfit. Oil will cost more in small deliveries and the owner must watch the supply closely to avoid run¬ ning out of oil. The drawings on page 9 give the dimensions of the tanks usually employed. Where tank capaci¬ ties exceeding 275 gallons are advisable, an under¬ ground tank must be used. I'he location selected should be as close to the building wall as the nature of subsoil and foundations will allow (see page 23, Underwriters’ Rules). The fill pipe should be run out to a point near the curb, so that the tank wagon need not come up the drive. The necessary excavation is usually simple, par¬ ticularly where an installation in a new build¬ ing is concerned. However, competent dealers are equipped to cope with any situation that may arise, from excavation in rock, quicksand, water, etc., to removal and replacement of turf with no injury to a lawn or danger of subsequent settling. Buried tank installations should be made with every precaution to make them last as long as possible. Tanks should be protected against corrosion, preferably by use of asphalt paint. This is usually a matter of routine on the part of dealers, but in any case it is a safeguard that should be insisted upon. Where outside storage tanks have to be installed at a considerable distance from the building, special means for pumping the oil may be necessaiy. Multiple Installations The installation of two oil burners in one furnace is permissible, provided each burner has its own safety device. For installation of burners in a group of boilers, it IS recommended that a switching device be pro¬ vided which will cut in an additional boiler as the outside temperature drops. Electrol Engineers are experienced in these installations and will gladly provide data covering any specific project. Piping and Valves Gejieral Specifications — Wrought iron or brass pipe should be used for all oil lines. Galvanized pipe for oil lines IS unsatisfactory because of scaling. For the vent pipe galvanized is recommended. \ alves and fittings should be the best obtainable, sufficiently rugged to stand jarring. Shut-off valves, if used, should have a good packing gland, in order to be sure that no leakage occurs here. Sizes — Pipe for suction and return lines should be of the same size. The following sizes should be specified according to the installation: Electric All electric wiring for oil burner use must be in¬ stalled according to the National Electrical Code and any local ordinances. It is suggested that for small and medium sized burners a supply outlet capable ol providing not less than 250 watts be Eor 275 gallon, inside tank, ^ inch pipe. Eor 1,000 gallon or larger tank underground in¬ stallation, % inch from tank to building wall; 3^2 inch from wall to burner. Where the location of the tank is 50 feet or more from the wa 11, M inch pipe should be used from the wall to the burner. Swivel Jomts —Where suction, return, vent and fill pipes emerge from underground tank, swivel joints should be installed as a safeguard against leakage in the pipe caused by settling of tank. Wiring located in an approved position near the oil burner installation. Eor the largest models an outlet must be provided capable of supplying 660 watts. All electrical work should be done by a competent electrician. Tanks:— Types and Specifications The square tank is a type that is used in the basement, and is de¬ signed to go readily through the majority of basement entrances. While it is practical in a great many instances, it does not have the strength that is found in the round tank. A round tank is not recommended, as a 250 gallon tank of this type will not go through many basement entrances. The illustration at left is of an underground tank. This type is used for a sub-gravity installation. The sketch gives the number and size of openings required. Note: Manholes are not sup¬ plied in stock tanks under 2,000 gallons’ capacity. (See Under¬ writers’ Rules.) Consult local ordinance on this subject. The obround tank is one which has been designed for oil burner use. It has the flexibility of the square tank but on account of its shape is very rigid and will readily pass through the average door¬ way. This type is recommended for inside tank installations where it is preferred to have the tank installed in the basement of the home, instead of underground in the yard. /f OBeOUND BBSBMENT 7?iNk: CB}RF)C/7y A B C PLflTE THiCPNE66 4.2" <2,0" Controls 1. Thermostats —All automatic oil burner systems should have a room thermostat to control operation and insure the maintenance of the desired tem¬ perature. A description of the thermostats used with the Electrol burner appears on page 20. 2. Steam System Controls —In addition to a thermo¬ stat, a steam system should be provided with an au¬ tomatic regulator (pressurestat), which will shut down the burner whenever the pressure in the boiler rises aboveapre-determined point (see cut,page 11). 3. Vapor System Controls —A type of pressurestat adjusted to work at pressures below atmospheric is provided to control the operation of this system (see cut, page 11). 4. Hot W^ater Controls —Hot water systems are controlled by a hydrostat attached to a riser as close to the boiler as possible. The hydrostat operates to shut off the burner when the tem¬ perature of the water rises above the temperature for which the hydrostat is set, regardless of the action of the room thermostat (see cut, page 11). 5. Warm Air Furnace Controls —The warm air fur¬ nace control operates to shut off the burner when the temperature m the hood rises above a predeter¬ mined figure, usually 250-300° (see cut, page 11). 6. Low Water Cut-off —The use of a low water cut-oft is an additional safeguard recommended for steam and vapor systems. The cut-off operates to shut down the burner if the water level in the boiler should drop below a fixed level. The low water cut-off and pressurestat may be intercon¬ nected and operated as a duplex switch (see cut). 7. Boiler Feed Controls —Several companies make automatic boiler feeders which will maintain the boiler water at a constant level. Where the city water pressure is greater than the pressure main¬ tained in the boiler, a boiler feeder may be used (see Undemriters’ Rules). However, a closed system with no steam leaks rarely requires this type of control. 8. Domestic Hot Water Control —See page 12 for discussion of control device necessary for control of the oil burner when it is used to provide domes¬ tic hot water indirectly. 9. Oil Line Controls and Accessories —The installa¬ tion of an anti-siphon valve in the oil line in order to prevent flooding in case of a broken pipe is mandatory if the tank is installed above the level of the burner. The inside 275-gallon tank feeding a burner by gravity is an exception to the rule. Various approved types of anti-siphon valves are now on the market, and one of them should be included in the proposal covering the installation, if the tank is above the burner. Fuel oil gauges are not compulsory, but they are a great convenience to the owner of the heating plant. There is generally an extra charge made for installing an oil gauge. Their use is recom¬ mended if the owner does not wish to gauge the tank periodically by means of the measuring stick ordinarily provided. The installation of a “purolator” is also recom¬ mended as a mam filtering device, to clean the oil as much as possible before it is bandied by the burner. Thermostats Recommended for Electrol Installations M inneapolis-II oneywell plain M inneapolis Honeywell Model 7710, Thermostat, low voltage, manually low voltage, with clock, for automatic set for constant temperature. temperature changes as set. Mercoid high voltage thermostat. Controls burner direct without a relay. Manually set. Furnace and Boiler Controls Recommended for Electrol Installations Warm Air Furnace Control. Duplex Mercoid Control. Combination Pressure Control and Low Water Cut-off. I 111 The Part the Dealer Plays No basis for the selection of an oil burner is sound if one fails to give consideration to the dealer from whom the equipment is bought and by whom the installation is made. For it has been rightly said that no oil burner installation is better than the dealer who installs it. Present installation practice makes the oil burner dealer responsible either as principal or sub¬ contractor for all equipment required lor the opera¬ tion of the oil burner, for the installation of the equipment and for any servicing that may be re¬ quired during the life of the burner. (For full details of installation requirements see complete specifications on page 22). In order to make sure that the owner will receive the kind of heating service that he has a right to expect from his oil burner, the dealer who installs it must possess the following qualifications: 1. A good grasp of the principles employed in the various types and makes of boilers and heating systems. 2. A complete knowledge of the application of the burner he sells to the type of heating plant which It IS to operate. 3. Knowledge of the latest approved methods of burner installation. 4. A knowledge of the different grades and kinds of fuel oil and their adaptability to the equipment. 5. An appreciation of the necessity of maintaining the burner in perfect operating condition at all times. 6. Sufficient business ability and financial respon¬ sibility to give every expectation that the service * facilities which he now offers will be maintained. Supplementary Uses for tlie Oil Burner The Domestic Hot Water Supply Indirect JVater Heaters —The oil burner may be advantageously used for economical heating of domestic hot water, during the summer months as well as in winter. In the steam or vapor boiler the installation is simple, requiring only the addi¬ tion of an oversize* indirect water heater and a boiler thermostat, ordinarily called a hydrostat, which IS set at a predetermined temperature of about 190 degrees and so connected to the burner that the boiler water temperature is maintained at that point. This boiler thermostat works independently of the room thermostat to maintain only the proper temperature of the boiler water to supply sufficient heat for domestic hot water. When heat is required the room thermostat will, of course, control the burner. In the case of a hot water boiler a slightly different application of the same method is used. The oversize indirect water heater is connected in practically the same manner. The burner in this case, however, is controlled exclusively by the boiler thermostat. When heat is needed in the house the room thermostat starts a separate con¬ trol motor which is connected to quick-closing valves installed m each riser. When the desired temperature is reached in the house the separate motor closes the valves and the circulation stops. * Oversize heating coils are recommended because of the intermittent operation of the oil burner and because most manufacturers’ ratings are based upon steam temperatures. The constant maintenance of the boiler water at ap¬ proximately 190°—a condition essential to obtain¬ ing proper temperature of domestic hot water— IS of real advantage m the operation of the heating plant. For circulation of hot water begins immedi¬ ately upon the opening of the valves in the risers. For entirely satisfactory operation under all con¬ ditions, the boiler, whether steam or hot water. FAectrol Installed in Steam Furnace should have a capacity slightly exceeding that required for maximum requirements of the stand¬ ing radiation. Some boiler companies desire two square feet additional boiler rating for each gallon of hot water heated per hour. Experience of users has shown that economy of operation is effected by indirect heating of domes¬ tic water by oil in comparison with the cost of heating the same water by gas. The cost of in¬ stallation is extremely moderate in cases where a hot water storage tank is already in use. During the winter heating season there is but slight expense for hot water service. In summer, th e very limited operation of the oil burner to provide hot water is inexpensive. Furthermore, the use of the burner during the summer months keeps both burner and boiler in good operating condition. When a burner is in constant use as a source of domestic hot water, a sudden cold snap will put the room thermostat in action and thus provide heat without attention from the owner. b. Direct Method of Heating Domestic Water — When the hot water requirements exceed 400-500 gallons per day, the indirect method is not recom¬ mended, because it would require an excessively large boiler to handle the load. A separate tank heater should be installed. In many cases a small sized oil burner placed in tbe tank heater can be used to heat domestic water at a considerable saving in fuel expense. The in¬ stallation cost IS low since no additional fuel tanks are needed. A hydrostat connected to the storage tank makes operation entirely automatic. This control will operate winter and summer to turn the oil burner on and off as hot water is required. For most satisfactory operation the tank heater should have at least a 16-inch diameter grate. Garbage Incineration 1 he intense heat of the flame from an oil burner IS ideal for incinerator operation. Complete com¬ bustion IS assured and smoke and odor are virtu¬ ally eliminated. Some incinerators are designed to burn up the garbage and utilize the heat given off for domestic hot water. For installations of this type, the oil burner operation should be controlled by the tem¬ perature of the domestic hot water. A hydrostat connected to the storage tank will make the opera¬ tion entirely automatic. When incineration is conducted in a specially con¬ structed furnace, using an oil burner for the heat, the burner should be controlled manually or by means of a furnace control described herein (page 10, Controls). Even where the furnace control is used, it is ad¬ visable to have an attendant on hand to turn off the burner when incineration is completed. Electrol Installed in Dicinerator Fuel for Automatic Oil Burners Fuel oil requirements for automatic oil burners are covered by the oil trade classification as distillates —ordinarily called gas oil and light fuel oil. Un¬ fortunately, these terms have been rather loosely applied and there has been considerable confusion among oil burner dealers, fuel oil dealers and the general public regarding them. In order to clear up this confusion and establish a standard method of grading oils used in automatic oil burners, specifications covering them have been drawn up by the technical committee of the Amer¬ ican Oil Burner Association, with the assistance of the American Petroleum Institute and of the Amer¬ ican Society for Testing Materials. These spec- -ifications have been adopted by the Underwriters’ Laboratories and are recognized by oil burner manufacturers and the leading oil companies. Under the classification thus established there are three grades of fuel oil which cover all requirements of burners of the automatic class with which we are concerned. These grades are the following: No. 1 Furnace oil—Light (36°M:0° Be.) No. 2 Furnace oil—Medium (32°-36° Be.) No. 3 Furnace oil—Heavy (28°-32° Be.) Three additional grades, light, medium and heavy fuel oil, have also been established, but they are not adaptable for use in automatic oil burners. Nos. 1, 2 and 3, light, medium and heavy fur¬ nace oil, are the oil fuels which are almost univer¬ sally used in automatic oil heating plants. All of the larger producers and distributors are in a posi¬ tion to make regular deliveries of these grades of oil in every section of the country. The owner ol an oil burner installation which is specified to operate with these grades need have no fears con¬ cerning oil supply. The Underwriters’ Laboratories, in setting the seal of approval on an oil burner, specify the grade of fuel oil which should be used. Owners of heating plants should be cautioned to adhere to the grades which fall within the limits specified. So long as the specified grade is used there will be no increase in insurance rate. So far as the future supply of fuel oil is concerned, there is nothing to fear. Mr. Frank Howard of The Standard Development Company recently stated that the supply of petroleum is now as The Cost of a. histaUatio7i Cost —The cost of the oil burner is only a small part of the items that make up an oil heating installation. The other principal items of expense are tank, controls, and other accessories, piping, wiring, excavation, alterations to heating plant necessary in order to fit the burner to the boiler, together with the expert mechanical labor required for installation. (See specifications page 22 for full details.) It is apparent that a large proportion of the in¬ vestment must be expended in these additional items and in work done upon the owner’s premises. Even the legal requirements for certain elements of the installation vary in different parts of the country. There are also variations in the cost of labor. Consequently it is impossible for a manu¬ facturer to establish a definite installation price which can be maintained over a wide territory. Most manufacturers prefer to quote on jobs only through their dealers. These local representa¬ tives are able to submit definite quotations or proposals at short notice and can be freely con¬ sulted at any time. b. Comparative Fuel Costs —^The most recent and in our opinion the most authoritative data on comparative costs of various fuels have been published hy the American Oil Burner Association, assured as the supply of an}^ other of our raw materials. Petroleum can now be produced in any quantity desired by opening wells already drilled but shut off during the period of over¬ production. Mr. Walter Teagle, president of the Standard Oil Company of New Jersey, recently wrote: “I have full faith in the ability of the oil industry to meet the growing demand for oil for domestic heating purposes. The experience of the last generation plus the best forecast which science can make for the coming generation justifies such faith. “The modern domestic oil burner gives a kind of household heating service which gas alone has supplied in the past, and in the country as a whole it gives that service cheaper. In my opinion, oil heating will not only supplant gas, which is its present sole competitor, but, like the gasoline automobile, establish a new standard of American home life and fix a level of comfort and convenience never before attained by any civilization, and at a price well below the limit of its economic value for that use.” Oil Heating Inc., in the “Handbook of Domestic Oil Heating.” The following paragraphs quoted from the book are reprinted here by permission of the Associa¬ tion. Unfortunately, space permits but brief extracts. We believe that the book will repay study by anyone interested in oil heating installa¬ tions. Regarding comparative fuel costs, the Handbook says, in part: “Comparative fuel costs are at the best estimates of performance based partialU upon known factors and partially on assumed factors that are supposed to represent average conditions. Cost comparisons are worthless unless accompanied by complete information as to the known factors and the assumed factors. The known factors are the cost per unit which may be pounds, gallons, cubic feet or kilowatt hours, the heat content per unit. The assumed factor is the efficiency with which the heat content of the fuel can be utilized. ‘‘Cost of Fuel —Coal is usually sold by the short ton or 2,000 pounds, although in some cases the long ton of 2,240 pounds is used. Oil is sold by the gallon, gas by the thousand cubic feet and electricity by the kilowatt hour. Regardless of which fuel is used the heat output would be mea¬ sured in B.t.u., consequently we must convert these units of measure to the B.t.u. basis. In order to do this we must have some information as to the heat content of various fuels. The fol¬ lowing Table 27 gives average figures for the heat content of various fuels: TABLE 27 Heating Value of Various Fuels FUEL B.T.U. Oils: Fuel Oil, Medium.149,000 per gallon Furnace Oil, Heavy.141,000 “ “ Furnace Oil, Medium.138,500 “ “ Furnace Oil, Light.136,000 “ “ Gases; Natural, California. . . Natural, Oklahoma. . Natural, Pittsburgh. . Coal gas. Coke-oven gas. Carbureted water gas. 850 per cubic foot 975 “ “ “ nyr n n a 650 “ “ “ 600 “ “ “ 575 “ “ “ Coals, Anthracite (as received) Broken. Egg . Stove . Nut . Pea . Buckwheat. Coals, Bituminous (as received) Kentucky cannel . Pennsylvania . Oklahoma . Ohio . Illinois . Indiana . Electricity 1 Kilowatt hour . 12,800 per pound 12.650 “ 12,600 “ 12,350 “ 12,150 “ 11,400 “ 13.750 “ 13,500 “ 13.500 “ 12.750 “ 11.650 “ 11.500 “ 3,415 “Fuel Equivalent on Heat Co?itent Basis —Fre¬ quently fuels are compared on a heat content basis: for example, it might be said that a gallon of oil is equivalent to so many pounds of coal or to a certain number of cubic feet of gas. For example, It is desired to know how many gallons of Furnace Oil—Medium would have the same heat content as a ton of anthracite stove coal. One ton of anthracite stove coal would contain 2,000 x 12,600 —25,200,000 B.t.u. If we divide this figure by 138,500 the number of B.t.u.’s in a gallon of Fur¬ nace Oil—Medium, we find that it would require 182 gallons of oil. This figure is a true comparison of the heat content of the two fuels, but is not a reliable index to the comparative cost as it does not take into consideration the efficiency with which the fuel is consumed. The efficiency is the measure of the amount of heat that is taken from the fuel for useful work as compared to the total heat content of the fuel. In some instances, conditions will be such that the increase will be much greater and in others where It will be less. A boiler, being operated at a very light load or excessive overload will not be as efficient as when operated near its rated capacit}^ “The average efficiency for oil burners installed in existing systems is between 60%-65%; when in¬ stalled in specially designed boilers this figure will be between 70%—75%. The efficiency of the aver¬ age coal burning system is approximately 50%. The average with gas in specially designed boilers is 70%-80% and in converted coal burning sys¬ tems is 50%-60%. “Estimating Comparative Fuel Consumption — When attempting to make an estimate as to the comparative consumption of two fuels in a given installation, it is desirable to have as much accu¬ rate information available as is possible. For ex¬ ample, if we have an installation in which the average coal consumption is 45 tons per season, using anthracite nut coal: Referring to Table 27 we can see that this coal averages 12,350 B.t.u. per pound. If the boiler and system are in average good condition, we can assume an efficiency of 50%. It is desired to install an oil heating system, using Furnace Oil—Heavy, which will average 141,000 B.t.u. per gallon and we can assume an efficiency of 65%. The following general formula gives the factors required in making this comparison. Let Xo = Gallons of oil required. C = Number of tons of coal used. He = B.t.u. per pound of coal. Ho = B.t.u. per gallon of oil. Ee = Efficiency of coal burning plant. Eo = Efficiency of oil burning plant. 2000 X C X He X Ee X„ =--- H„ X E„ “Substituting in this equation the values assumed for this example, we have 2000 X 45 X 12,350 X .50 Xo = —---= 6060 gals. Furnace Oil—Heavy. 141,000 X .65 “With Anthracite Nut Coal at ^15.00 per ton and Furnace Oil—Heavy at 8c. per gallon we have the following comparative fuel cost: 45x315.00 = 3675.00 6060x3.08 = 3484.80 Output B.t.u.’s absorbed by Boiler Efficiency =- =- Input B.t.u.’s in fuel “Furnace Efficiency —The only way of determining the efficiency of a given heating plant is to make an operating test. Under average conditions it can be assumed that the oil should be burned with an increased efficiency from 10% to 15% over coal. Saving in Fuel = 3190.20 190.20X100 —^-= 28% saving 675 “Charts 1 and 2 [page 16] are based on this formula and worked out one for gas, the other for coal in order to make it possible to obtain com¬ parative cost figures with a minimum of calcula- f 15 1 GAS C ONSUM PTI ON _ PER__SEASQN ' TH.Og_^ND^Or CU BIC FEET Read Equ ivalent Oil T o R ismt 0 r n o z (/) c 2 D -I 5 z I'O h bo m io r D iZ jCP GAS C ONSU MPTION PER SEASON THOUSANDS OF CUBIC FEET Re .^o_ Equivauent Oiu To Left Chart 2—Comparative Gas and Oil Consumption per Season 116 ] tion. A chart of this kind must be used with discretion, making due allowance for a higher or lower value coal or oil. “To use these charts, it is assumed that the coal or gas consumption per season is known; for example, 900,000 cubic feet of 550 B.t.u. gas. Locating 900 on the gas consumption scale, follow the vertical line to the 550 B.t.u. per cubic foot curve and reading horizontally to the left, we find that the oil consumption would be approxi¬ mately 4,325 gallons. “Assuming a gas rate of 80c. per thousand cubic feet, which is lower than the average for this quality of manufactured city gas, and the price of 8c. per gallon for Furnace Oil—Heavy, we have the following comparative fuel cost: 900x^.80 = 3720.00 4325 X .08 = 346.00 Saving with oil = 384.00 384 x 100 ^ . , . -^ 2 ^ = j 3% saving with oil when oil is replacing gas. If the gas is figured to replace oil we have: 384x 100 . ,, , -= 111% increase in cost ot fuel. “Other Cost Factors —There are other factors which enter into making a complete cost comparison between the two different kinds of fuel. In most cases these are all in favor of oil. Where coal is the competing fuel, we have additional charges for ash handling and removal and where a furnace man is employed his wages should be rightfully charged against the cost of maintaining the heating system. Compared with these charges against coal, there is an additional expense with motor- driven oil burners for the current used and also for a gas pilot where one is used. Under average conditions, an allowance of 3^c. per gallon will cover the cost of operating the motor and ignition. An allowance of Ic. per gallon will cover any but exceptional conditions. It can be readily seen that this figure will compare very favorably with the cost of a furnace man and the cost of handling and disposing of ashes. “Where gas is used, the differential in fuel cost is so great as to make the additional expense of operating the motor and ignition a negligible one.” Range of Application of Automatic Oil Heating Systems The installation of automatic oil heating is not limited to certain classes of buildings. In fact it is impossible to single out any class of building and point to it as representing a heating problem incapable of economical solution by means of the utilization of oil fuel. The reason for this condition lies in the number of advantages possessed by oil-fired heating sys¬ tems. In a majority of cases the reasons that have led to the installation of oil heat are as varied as the types of buildings in which it is used. For automatic oil heat provides uniform, healthful heat; it eliminates the necessity for personal attention to the heating plant, thereby saving owner’s time or hired labor as the case may be. It provides great economies in space and makes possible the use of the basement as a livable part of the house. And it operates so efficiently that results are secured at no greater expense than would be incurred in the operation of a coal-fired system. It is therefore not remarkable that modern homes, office buildings, theatres, churches, schools, hos¬ pitals, hotels and apartments are, m rapidly in¬ creasing numbers, adopting oil heat. The list of industrial uses for the oil burner is also long, and includes greenhouses, tobacco warehouses, cream¬ eries, dry kilns, etc., where the heating require¬ ments are intermittent, or automatic control of heat is peculiarly advantageous. Automatic oil burners are now in satisfactory operation in heating plants up to 10,000 square feet of radiation. There is no reasonable limit to the size of building which can be heated by multiple installations. Any building of such design that a thermostatic temperature control is satisfactory may logically have an automatic oil burner in¬ stalled in the heating plant. The Electrol Oil Burner General Description of Electrol Oil Burners The’Electrol Oil Burner is all-electric and fully automatic, combining mechanical fuel atomization and continuous electric ignition. Suitable for domestic installations in homes of all types, and for commercial installations in apartment buildings, churches, libraries, theatres, schools, banks, small office buildings, stores, bakeries, greenhouses and many types of industrial application. Summary of Principal Features of the Electrol Oil Burner (1) Mechanical draft supplied by a Sirocco fan on the motor shaft, fully automatic, with electric Master Control, built as a unit with the burner. (2) The exclusive shell-shaped air receiver produces a rotary movement of the air, giving a ball shaped flame that is extremely quiet and of high efficiency. (3) Listed to burn oil fuel not heavier than 28 gravity (A. O. B. A. Spec. No. 3), also Diesel oil (Pacific Coast) not heavier than 25 degrees Baume when viscosity is not more than 54 seconds (Saybolt- Universal at 100 degrees F.). (4) Oil delivery is accomplished by one pump directly connected to the motor shaft, which serves the double purpose of pumping oil from supply tank and main¬ taining the proper pressure for atomization. (5) Mechanical atomization is employed. This is accomplished by forcing the oil under pressure through a specially designed nozzle. (6) The atomized oil is mixed with the correct amount of air for proper combustion and ignited by a heavy spark produced by a special step-up transformer. (7) Flame adjustments are made at time of instal¬ lation to meet requirements of boiler or furnace. (8) Electrol automatic burners are installed in the present heating system, requiring only the removal of the coal burning grates and the building of a combus¬ tion chamber with refractory material in the ash pit. (9) Electrol automatic burners are manufactured in three sizes. The Model TJ, the Model T, and the Model TD. See page 21 for capacities. (10) Motor Sizes: Model TJ—1/6 H.P. Model T —1/6 H.P. Model TD—1/3 H.P. The Product of a Pioneer Organization I he Electrol Oil Burner is the sole product manufac¬ tured by Electrol Incorporated, of St. Louis— a pioneer m the development of automatic oil burners. 4'he contributions of Electrol engineers have not been confined solely to the Electrol. For the development took place along original lines and as a result of in¬ tensive experimental work Electrol engineers are re¬ sponsible tor the discovery of many principles and methods which have become standard practice in oil burner manufacture. tlectrol engineers pioneered in the following points: (1) The application of transformer generated ignition applied to oil burning. (Electrol was the first burner using this principle that was presented to and ap¬ proved by the Underwriters.) (2) The open circuit operation of safety control in¬ stead of closed circuit method. This is now standard because with it any electrical defect automatically shuts down the burner. (3) Cut-off valves. Dribbling of oil into the combus¬ tion chamber and faulty atomization due to low pres¬ sure atomization were causes of trouble in the early burners. Electrol engineers developed the first prac¬ tical application of the cut-off valve—a device which prevents the escape of any oil until proper pressure for atomization is built up by the oil pump. (4) Direct connection of oil pump. Belts, gears and other intermediate driving means between motor and pump add more moving parts to the assembly, in¬ crease expense and cause operating difficulties. The pump on the Electrol burner is packless and direct- driven by a slow speed motor. (5) Mercury switches. The Electrol burner was the first to be equipped with mercury switches making contact in a vacuum, thus eliminating switch contact in air and failure due to oxidation of these contacts. (6) Air for combustion. The principle of air rotation applied to domestic burners is original with Electrol. (7) Mechanical atomization. This method of atomi¬ zation was first applied to domestic burners by Electrol. (8) Development and research. Electrofs budget includes, annually, a very substantial sum for the purpose of development and research. A compre¬ hensive and well-equipped research laboratory is at all times trying new and improved methods. Principal Parts of the Electrol Burner Nozzle The nozzle screws into the stem of the diaphragm valve. A twirler is used and is ground into the shell forming a seat. The twirler Itself does not turn, but because of the eccentric position of the slots, the oil passing through the slots is given a twirling motion, which causes it to break up into a fine mist upon leav¬ ing the nozzle orifice. The nozzle on the Electrol oil burner is the only part that varies according to heating requirements. It is simple. Operates without springs. Nothing to get out of order. Pump The pump used on the Electrol oil burner is of very high efficiency and is directly con¬ nected to the motor by means of a fibre coup¬ ling requiring very little power. It serves the double purpose of pumping oil from the supply tank and maintaining the proper pressure for perfect atomiza¬ tion. It is of the rotary gear type, having one driven gear and one idling gear—self-sealing. No stuffing box, auxiliary pump or motor is required. The driving shaft is constructed with a bevel which runs on a seat in the pump housing. The bevel is forced against the seat by a small square shaft on which the driving gear floats, at the other end of which is a ball and spring pressing against it. The spring tension forms a thrust bearing and keeps the bevel on the drive shaft against the seat. Diaphragm Valve The diaphragm valve prevents oil from flowing by gravity from the pump and pressure regulating valve, through the nozzle and into the furnace. It also immediately shuts off the oil at the nozzle tip to prevent dripping when the motor stops and the pres¬ sure drops on the pump. The oil from the fuel line passes first through the diaphragm strainer and then presses against the dia¬ phragm. This pressure on the diaphragm overcomes the tension of a spring and indirectly raises the needle valve from its seat. When the needle valve is raised, the oil is forced through the tube and out of the nozzle. Motor and Fan The motor is small—1/6 horsepower—low speed with low current consump¬ tion, and is specially built for the Electrol burner. A six-inch Sirocco fan is used. The fan is directly connected to the motor shaft, furnishing the supply of air for combustion. In order to obtain more capacity for the TD burner? a 3/^ H. P. motor is employed. Pressure Regulating Valve This valve is bolted to the side of the pump. By means of a screw adjustment, different pres¬ sures can be applied to the spring. The spring applies a constant pressure against the disk. The disk presses against the needle valve, forcing it into its seat. When oil is forced into the chamber, it presses against the metal disk, cupping it up—the pressure on the needle valve is relieved and the spring causes the needle valve to open and allow the oil that is not used to return to the supply tank. duty spark which is truly an arc, it was necessary to design a transformer of sufficiently rugged con¬ struction to prevent overheating and breakdown of insulation. Strainer The line strainer is connected to the suction side of the pump. It consists of a strainer housing and strainer bowl, which screws into the housing. A screen assembly is fastened to the bowl. To clean the strainer, it is only necessary to unscrew the bowl from the housing and then unscrew the screen from the bowl, by hand. A sheet-brass line silencer is used, which takes out all singing in the suction and return lines. Purolator On all Electrol installations a Purolator is utilized for filtering oil from the supply tank. The Purolator is of similar design and construction to the models used for filtering lubricating oil in automobiles. This type of strainer takes out the very finely divided particles that are present in most fuel ods, thus en¬ suring absolutely clean oil. The Purolator is mounted against the cellar wall in the suction line. Thermostat Low voltage thermostats are used on the Model T. Only a series 10 thermostat can be used. When specified, an eight-day clock is furnished which will automatically control a different temperature during the night from that needed during the day, effecting a saving in fuel. High voltage controls are standard equipment on the Model TJ and TD Electrol burners. Ignition Transformer In the Electrol burner ignition is continuous while oil is being pumped. In order to supply a heavy Electrol Ignition System Continuous electric arc produced at electrodes and blown by the air current into the oil mixture, giving positive ignition without electrodes coming into contact with oil. Radio Interference —Because of the design there is rarely any trouble in this connection. However, in case there is a surge in the supply lines which might cause interference, a specially designed radio trap can be furnished which will eliminate any possibility of interference. Relay On the Electrol burner is supplied a relay which is operated by the room thermostat, using low voltage supplied by a step-down transformer in the control box. So long as the room thermostat is on (calling for heat) a failure of the electric supply will simply drop this relay by gravity and turn off the burner. When the supply voltage is turned on again this relay will pick up the load and restart the burner without attention from the owner. Materials Used in the Electrol Burner 1 he materials used in the Electrol burner have been selected after ten years of development and research work. Every part has been studied under the most rigorous operating conditions. As a result of this study the materials specified for each part of the burner are the best and most durable that can be obtained. 1 he quality of the material and the care exercised in the manufacture are such that it is possible to guar¬ antee every part in the Electrol burner against me¬ chanical failure. [ 20 ] The Electrol Master Control If complete automatic operation of an oil burner is to be accompanied with absolute safety, a control sys¬ tem is necessary. This control device must function to shut down the burner and place it in a non-operating condition if any abnormal condition occurs. In the Electrol burner, the safety control system is known as the Electrol Master Control. This system of operation was developed and patented by Electrol Engineers. The occurrence of any one of a number of conditions will cause the Master Control to function. The most important of these conditions are: Retarded fuel delivery through feed line; A break in the electric wiring, short circuiting, or ignition failure; Any condition which prevents motor from operating at normal speed; Operation of burner when oil tank is empty; Presence of water in the oil; No flame of burning oil; Any abnormal condition in the combustion chamber. Dimensions and Capacities of Electrol Burners Capacities of Electrol Burners Range: Square Feet of Actual C. I. Radiators Model Steam Heat Hot Water TJ 200— 800 350— 1,300 T 600—3,000 1,000— 5,000 TD 2,000—7,000 3,500—13,000 These ranges include piping and risers. Ranges for vapor jobs fall in between the steam and hot water capacities and vary according to the degree of vacuum under which the system is operating. Model Modcl-TJ Model' T Model'T D 2C4 4Zi III s£ Si' 3^5 M or foil, and installed in the basement in a convenient place. The Owner shall provide a convenient electric supply of the proper voltage to operate the burner. If necessary, the Owner, in co-operation with the Electric Company, will provide leads of sufficient capacity to prevent excessive drop in voltage from the outside source. Fire-proofing of the boiler-room, if required by the local fire ordinances, shall be completed by the Owner. All necessary permits that must be obtained from local governing boards will be provided by the contractor except that a recurring periodic charge by any governing board shall be borne by the owner. Extracts from Underwriters’ Rules for the Installation of Automatic Oil Burning Equipment 1. Oil. Oil used for fuel under these rules shall be a topped or distilled oil having a flash point of not less than 100 degrees F. closed cup. 2. Tanks. Storage tanks shall preferably be located outside, the top at least 2 feet underground. An inside exposed tank shall not exceed 275 gallons capacity. Inside tanks over 275 gallons shall be completely enclosed in concrete not less than 12 inches in thickness or its equivalent. A space of 6 inches must be left all around the tank. This space must be filled with sand or well tamped earth, with 12 inches of sand on top of tank. A concrete slab not less than 5 inches thick must be placed over this vault. In ordinary buildings, enclosed tank capacity shall not exceed 5,000 gallons. Tank capacity up to 50,000 gallons may be stored underground within 10 feet of any building when tank is above lowest floor of building. If tank is lower than all floors of build¬ ings, 75,000 gallons may be stored within a radius of 10 feet. Tanks shall be securely anchored or weighted in place to prevent floating, where conditions make it necessary. Minimum thickness of steel for tanks: 275 gals. 16 gauge metal 1,000 to 4,000 gals. 7 gauge metal 5,000 to 12,000 gals. 34 inch plate All vents must be of galvanized iron pipe. Minimum pipe size 1 inch. Increase the size of vent in propor¬ tion to size of tank, when capacity is over 1,000 gallons. The outer end shall be provided with a screened, weather-proof hood, terminating at a point outside of building not less than 3 feet from any window or building opening and preferably 12 feet above top of full line. A test well or gauging device must be designed to pre¬ vent the escape of oil or vapor when closed. Test wells shall not be located within buildings. Man¬ holes, if used, shall have covers securely fastened in order to make access difficult by unauthorized persons. All filling pipes shall terminate outside of buildings and when installed in the vicinity of any door or other building opening, shall be as remote therefrom as possible in order to prevent liability of flow of oil or vapor through building openings; terminal shall be provided with a metal cover or cap, which may be locked. 3. Piping. Standard, full weight, wrought iron, steel or brass pipe with substantial fittings shall be used and shall be carefully protected against mechan¬ ical injury in a manner satisfactory to authorities having jurisdiction. Do not use galvanized pipe for lines carrying oil. In all piping systems proper allowance shall be made for expansion and contrac¬ ts 1 tion, jarring and vibration. Piping shall be separated from exposed electric wiring, that is not enclosed in approved conduit as provided by the National Elec¬ trical Code. Copper tubing of not less than 1/16 inch wall thick¬ ness is approved for use where permitted by local authorities. Flexible metallic tubing of an approved type may be used to eliminate jarring or vibration, if installed strictly in accordance with the limitations on its approval. Piping shall be run as directly as possible and pitched back toward tank. Openings through masonry walls below the ground level shall be made oil-tight. 4. Ventilation. Adequate ventilation of boiler room shall be provided in order to insure proper combustion. 5. Dampers. Dampers which may entirely close the chimney up-take are prohibited. Damper area shall be carefully determined in each case, but in no case shall it be greater than 80% of the internal cross- sectional area of the up-take. 6. Emergency Control. A valve should be in¬ stalled in the suction line to shut off the flow of oil to the burner in the case of emergency. A switch in the power lines to the burner should be installed so that the power may be cut off in case of emergency. Signs indicating the purpose of these controls shall be located at the control device. It is recommended that in steam, vapor, or vapor vacuum systems an approved low water cutoff be Installed to guard against firing into a dry boiler or one in which the water line is dangerously low. An automatic water feeder may be used in this case when a positive water pressure is always available. 7. Instruction Card. A card giving com¬ plete instructions in regard to the care and operation of the system shall be permanently posted near the apparatus. 8. Fire Protection. Any woodwork, wooden lath and plaster partition or other combustible material within 4 feet of the sides or back or 8 feet from the front of the furnace shall be covered with approved plaster board or other approved incombustible mate¬ rial. Smoke pipes shall be located with minimum clearances to ceilings, partitions, etc., in accordance with the following table: Minimum Clearance if Unprotected Woodwork. 24" Plaster on wood lath.. 18" Plaster on incombus¬ tible lath, wooden beams or studs... . 9" Minimum Clearance if Protected 12 " 9" 'jr The protection required by the above table shall consist of a sheet of metal or equivalent covering placed at least 1 inch from the surface to be pro¬ tected, extending the full length of the smoke pipe and at least 12 inches beyond it on both sides. Recognizing the value of first-aid fire-extinguishers near furnaces or other forms of heating plants irre¬ spective of the fuel used, so located as to be con¬ venient for use in emergency, there shall be provided an approved hand fire-extinguisher of a suitable type. 9. Installation. Oil burning equipment shall be installed only by properly qualified mechanics ex¬ perienced in this kind of work. •••• ■ ■ HU * .. . ' ■» | J jL > Showing typical installation of an Electrol burner. [ 24 ] Printed in U. S. A.