INVESTIGATION AND REPORT ON THE MANUFACTURE OF DESSICATED MILK BY THE ANDREWS PATENT PROCESS AS COVERED BY UNITED STATES PATENT NUMBER 1,012,578 AND BY MANY FOREIGN PATENTS FREDERIC BUCH ENGINEER 43 EXCHANGE PLACE, NEW YORK CITY NOVEMBER 1, 1913 A ex h Copyrighted, 1913, by Habry Irving Andrews. y ©CI.A3588f}J[ INDEX Diagram — Whole Milk Required to Produce One Pound of Butter — Skimmed Milk Remaining — Cost OF Reducing Same to Milk Powder — -Clear Profit 3 How Milk Powder is Made 4 Diagramatic Layout of a Typical Milk Powder Plant and Table Showing Routing of Milk 5 Table of Operating Costs and Clear Profits Per Day for Reducing any Quantity of Skimmed Milk up to 60,000 Pounds Per Day 6 Table for Estimating Clear Profit on One Plant P 7 General Expenses : Estimated Overhead and Fixed Charges Per Plant, Per Day — Other Estimated Operating Costs Per Day er Year, With the Milk Supply Varying 8 Description of Evaporator 9 Sectional Views of Evaporator 10 Sectional Views and Description of Drum 11 Estimated Cost of One Plant 11 Chart for Determining Amount of Horse Power Required and Running Hours of Plant for any Quantity of Milk up to 60,000 Pounds Per Day 12 Milk Powder Plant — Plan and Elevation 13 Some Milk Powder Products 14 S i d - I ^ CA o £: Q O Pi <: o . b CO _ h- S c» Cd O w o pa = X -J/ o (O V f iii...V.ii;,ii <0 ^ "^ii 00<-a ^ o > «3 e wuo < rt .-H lO HOW MILK POWDER IS MADE TYPICAL MILK POWDER PLANT By referring to the accompanying diagram a comprehensive working knowledge of a milk drying plant will be had, the diagram showing a layout of the machinery, apparatus, vats, tanks, etc., through which the milk must pass from the time it first enters the plant until it is packed in barrels, boxes, or cartons ; the finished product, ready for shipment. PROCESS OF MANUFACTURE Milk enters the plant immediately after being weighed on the wagon scales and is dumped from the milk wagons so that it will flow by gravity into cold storage vats, where it is accumulated until the quantity becomes sufficient to start the plant. The milk is then caused to flow into a regulating tank, located just above the cream separators, as shown. By means of this tank the flow of the milk into the separators is adjusted and controlled as desired. Milk and cream are now separated, and, if butter is to be made, the cream led to a cream storage tank and thence to the butter-making' machinery, while the skimmed milk passes through a degermer where bacteria is destroyed and the milk purified by a patent process. The skimmed milk now passes into the main evaporator, where evaporation is affected until it becomes about the same consistency as the pure cream in the cream tank, or ordinary condensed milk. This condensed milk now flows into the mixing or revitalizing tank, where it is revitalized by the introduction of pure filtered air, and, if no butter is to be made, the cream and condensed milk are here united. The two, now being of the same consistency, may be forced together into the secondary evaporator or drum, where the remaining moisture is quickly evaporated and carried off, the milk and cream, or milk only, now forming chips or strips of a yellowish appearance. These milk strips and chips, being very damp, are next passed into a tumbler directly under the drum,, where they are broken into particles and brought into contact with hot dry air, to be dried out as completely as possible before being allowed to enter the pulverizer or grinder, for the final grinding into milk flour or powder of a suitable fineness desired by the trade. That nothing may be lost or wasted, the grinder is enclosed in an air-tight casing and connected by a powerful suction fan to a dust collector, where every particle of the powdered milk is collected and then allowed to flow into barrels or boxes to be removed to the store room or shipping platform. For this purpose a mechanical conveyor may be brought into use if desired, as indicated in the diagram, but as the average grinder or pulverizer now on the market could hardly produce more than one barrel (360 pounds) of powder per hour under the most favorable conditions, it will be seen that a conveyor is hardly a necessity. From the foregoing it will be seen that, if based on the right principles, the process is simple indeed, and that if the machinery is properly designed and proportioned no skilled labor will be required, as every- thing is arranged to work automatically and with a mechanical precision that smirks of the best efforts of the trained or skilled hand. THE ACCOMPANYING TABLE To give a still clearer outline and better understanding of the process just described, the table under the diagram has been added. The consecutive numbers in the first column give exactly, in running order, the routing of the milk through the plant, while the second and third columns give the names of the various apparatus or parts, and their respective functions. OTHER MECHANICAL EQUIPMENT Engine and boiler, air heater and dryer, air compressor, the various piping systems and other minutae have been purposely omitted from the diagram as the interest here is centered on the process of manufacture rather than on mechanical details, which in some instances need but slight consideration, as they already form part of a plant to which the milk powder machinery may be added. Note. — If this process was not based on the right principles, the German patent would not have been allowed — and the German Government protects its basic patent grants. — Inventor. S5S.UVir«a. WA>&ON SCALES © v^xa. © Reil (D © .EstoiiRSiiEtii j © To a-no^t KooMS DIA>6RAMAT\C L.NYQOT er APPARRTU3 AND P)PtH<5 fOR COMPLETE MILK POWDER PL/^NT SHOyvtNG E-y^CT TRAVEL OF HlUK IN BEIf1G> TREfyTCP HOTE - AFtr^OWS llSC>tCft>T& PlRg.CT •• J Si £1 £ l/l N « - O rn ^ *^ f^"^ Q o ^ o d pi '1^ \j • w - S ^ <« 1 m >5 i«i _: sS " «NVSlo - N m i?S spr-K«o» N tMP> ^ 19 rt JO ^ 4) (VI VI e « 9 9 4 9 N Mc4 — — — — w ci c^ §ggsl SH^^ O o o o o P <5 o ^ o Q "5" v6 «0 d ^CO o cMi^ 'T "T 10 S I f e< c4 CMcvi ff> « N VJ"^ «) «n -^ ^6 In O 'i !h, 2 r 3 N N d a v» N ® «47 o frj F] fj jw ,0 Q O ^ oQ rf ijo I f i vS ©( Jj t^fJS O O Q - N " ^li O n od o» 6 N rt tM CJ i»> « •») Tj- 0} c^ (J q «} Q 0) f^ d 9 9 ■ « 9 9 c^ * vj «9.6 >r •«• ^ o (9 »l t) — - N rvl ■•3 & sfe.s c ^ ^ « ?:; R H U)0 ni' -CM bj3 : >o ccvio (M

fj ^;j ," V rs !<^ ^ OJ cJ c-J CJ 19 f^ a W ^V) ^Z^^^ lost ^*- >0 000 0> CMOOCN-^ IC- . . . ^^ C^ ^ .— ' CO 00000 ™ CD CDiO o o Ji ■zo < g >S .^ o 2 B £ -^ ^ £ S "^ g 0_ _aj Ji! o O O -^ ^ O o CNi ." ^^ CD ^ ■P "^ ^ -r .. g x C ^ 9 ti _ c -a O C —' n! — o" O L, " 3 >, U £ r- 3 "r^ O *:! '^ / 0.^0-^ > ' 3 . o "^ < ^ w B g E E J, CO c o fO C ro CM "*-i GENERAL EXPENSES Overhead and Fixed Charges Salary of principal $6.00 Traveling expenses of principal .... 4.00 Advertising Gifts to customers SO Interest on capital (5% on $7,000) . . 1.00 Interest on borrowed money Rent (assumed at 8% on value of property) 2.63 Stationery, postage, telephone, tele- graph 50 Insurance : Fire— $30 per 1.000 on $12,000 property 1-98 Credit 2.00 Partnership Casualty Bonds Liability Depreciation of plant 1.00 Repairs 1.00 Unjust claims of customers (1% on $100,000) 2.73 Damage, loss, freight and express charges on returned goods... Collections 2.73 Bad debts 2.73 Factory supplies and equipment .... 2.00 Office supplies and equipment 50 Lighting 50 Taxes (assumed at $18 per M) 35 Legal expenses 50 Maintaining three horses 1.50 Refrigeration 5.00 Charity SO Miscellaneous expenses .35 Total $40.00 per day. Note. — The above is a fair estimate for average con- ditions. Close inspection may show, however, that not all the items taxed above will enter in every condition, and the overhead and fixed charges may therefore be even less than the quoted $40.00 per day. Various Operating Charges LABOR— Machinist in charge $4.00 salary. Night watchman. . . Fireman 2.50 per day. Driver Men at grinders — 2 at $2.S0 5.00 per 10-hour day or less. Total $11.50 ESTIMATED HORSEPOWER— Evaporator 2 h. p. Drum and Tumbler 1 Air Compressor 10 Hot air exhauster 10 Air dryer and heater 2 Pulverizer or grinder 15 Total, with 1 grinder 40 h. p. with 2 grinders 55 h. p. COST OF FUEL— Coal assumed at $5.00 per ton of 2,000 fbs. Eight (8) fbs. of coal per h. p. per hour. This gives cost of coal at 2 cents per h. p. per hour. MILK SUPPLY— Price of skimmed milk assumed at 25 cents per 100 lbs. BARRELS FOR PACKING FINISHED POWDER— Barrels assumed at IS cents each when bought in lots. 360 tbs. of powder per barrel, 2.77 barrels per 1,000 lbs. This gives 41J/2 cents, say 45 cents, per 1,000 lt>s. ROYALTY— In order to obtain the exact clear profit, over and above all ordinary possible expenses, the royalty is here included with the operating expenses. The royalty amounts to one (1) cent per pound of milk powder. EVAPORATOR The evaporator shown in the accompanying illustration serves to reduce skimmed milk to the consist- ency of condensed milk, by evaporating about 75% of the moisture. This should be accomplished without the milk reaching 156 degrees F, as at that temperature the albumen is coagulated and a cooked taste acquired. In the Andrews System this difficulty is overcome by rapid alternating heating and chilling of the milk, instead of a heating process alone (as is the case in all other methods, none of which are a complete success), the slight chilling always occurring just as the milk reaches the maximum allowable temperature before boiling or burning, thus automatically preventing overheating of the same. The illustration shows the evaporator in section, both from the front and side. It consists mainly of a sheet metal casing carried by an angle iron frame made up practically air-tight, with inlet pipes at the top for the skimmed milk to be treated, and outlets at the bottom through which the condensed milk passes to the re-vitalizing tank. There are also large inlet and outlet connections for the hot dry air used to absorb and carry off the moisture evaporated from the milk. Access doors are provided on three sides for cleaning and inspection purposes. These are closed air- tight when the evaporator is in operation. The perforated spread pipes at the top serve to evenly distribute the incoming milk. The slightly inclined corrugated plates directly under the spread pipes are of wired glass for sanitary reasons. Their pur- pose is to heat the milk to a certain desired temperature so that evaporation may immediately commence when the liquid strikes the upper hot rollers. The plates are heated from the iron pipe coils shown directly underneath. The rollers, over which the milk must pass, are also of wired glass, or, they may be made of cast iron with a heavily nickeled surface to resist the corrosive action of the heated milk. They are hollow so that steam or electric heat and ammonia gases may be passed through alternate rollers, thus causing a perfect hot and cold process for treating the milk. The inlet pipes to these rollers are fitted with thermometers, pressure gauges, and instantly adjustable pressure regulating valves, thus allowing the minutest adjustment of temperatures. The rollers rotate with the inlet and outlet pipes acting as the shafts — they are driven by a sprocket chain on the outside of the casing. Each roller is fitted on the under side with an automatic scraper, held tight against the same by adjust- able springs. These springs prevent the milk from clinging to the surface of a roller beyond the specified time. The machine is so proportioned that the layer of milk on the surface of the upper rollers will be approximately 1/32" in thickness, while on the successive rollers it will necessarily be proportionately less. The temperatures and speed are carefully adjusted at the first operation and are thereafter constant, making the entire process of evaporation a mechanical one with no need for skilled or specially trained help. The rotating pipe ends of the rollers are connected to the inlet and outlet pipes with special stuffing boxes and extra long glands, so there can be no escaping of steam or gases and all oil bearings are located on the outside of the casing of the machine. The outlets at the bottom, through which the condensed milk must pass, are fitted with test cocks so that samples of every run of milk may be taken, if desired, and thus an absolute check kept on the high quality of the product. sp»i».r PIPE CORRU (D <<3) toWP' f*otVEsi I HOT t>«T fttf? 1 ' . ' i WaaT Ofl'T l'*1 Ri?-^ B. V 1 B H A T R 1. Milk enters from the degermer through the pipes shown at the top. 2. It is spread and evenly distributed by passing through the small holes in the spread pipes. 3. The milk now flows slowly in a very thin sheet, ov er the heated and slightly inclined corrugated plates, the temperature rising to approximately 90 degrees F. 4. It now falls from the plates to the upper or first hot rollers (one on each side), and passes half way round the same in an even layer about 1/32" thick, at the same time rising to about 140 degrees and giving off part of its moisture which is immediately absorbed by the hot dry air passing through the apparatus at a high speed. 5. The milk is next forced from the under side of the hot rollers to the cold rollers. This is accomplished by the knife-edge scrapers. 6. It passes half way around the cold rollers and is thus slightly cooled. 7. It is again scraped off and passes to the next hot rollers, where evaporation is again caused with the temperature reaching 140 F. 8. The milk is again cooled on the cold roller. 9. It now passes over the final (bottom) hot rollers where more moisture is evaporated at the temperature stated above. Scraper blades force it from these rollers as from the preceding ones to prevent boiling, burning or overheating. About 75% of the moisture in the milk has now been evaporated without the milk at any time heing overheated, the immense volumes of hot dry air passing over the rollers greatly assisting in the process of evaporation. The milk is now the consistency of condensed milk, and may, if desired, be sold as such, after passing through a re-vitalizing process with pure filtered air. If milk powder is to be made, the re-vitalized condensed milk passes to the drum, described on the following sheet. No milk is allowed to accumulate in the bottom of the evaporator, the product being forced, by air blast, into the re-vitalizing tank as fast as it falls from the bottom rollers. 10 ^Ct\51>^G -I DRUM The drum shown herewith consists of a revolving shell running on the two fixed heads, with a light metal casing enclosing the entire apparatus. This shell is driven by gear wheels, not shown. The condensed milk from the re-vitalizing tank is forced into the spread pipe by compressed air heated to a high temperature, and is spread in fine streams, at a temperature of approximately 140 F, on to the hollow revolving cylinder, which is kept to about 32 degrees F by refrigeration. The heat contact is very limited. The heated milk, coming in sudden contact with the very cold surface of the roller, instantly congeals the milk into ribbons and strips. These ribbons and strips are continually scraped from the cold roller and the inner surface of the revolving shell (upon which they subsequently fall) and carried through slots in the revolving shell to be passed into the tumbler. The latter, which is a very simple apparatus for breaking up the ribbons and strips, is located imme- diately under the drum. Hot dry air is forced through this tumbler in great quantities to further dry out the milk. It is drawn off by the air exhaust fan through the two pipes shown in the cross section. Tumbler and drum have the same capacity as the evaporator, so that no storing of the condensed milk will be required. COST OF MACHINERY Evaporator $ 750.00 Drum 250.00 Tumbler 50.00 Degermer 150.00 2 Pulverizers at $1,140.00 2,280.00 Air heater box and pipe coils 50.00 Air exhaust fan 320.00 Air compressor 350.00 (Estimated costs Air receiver tank 25.00 being given as Revitalizing tank 25.00 maximum, the Flow regulating tank 25.00 actual cost will be Steam and water piping 50.00 less than total of Hot dry air piping 100.00 $5,375.) Millwrighting (shafting, pulleys, etc.) Inn nn Machinery foundations ^nn'nn Erection of machinery 500.00 Total $5,375.00 Additional working capital 1.625.00 Grand Total $7,000.00 NOTE. — It is assumed that the plant is annexed to a creamery which will furnish the power required, steam heat, refrigeration, pure fresh water, etc. 11 DIAGRAM FOR CALCULATING RUNNING TIME OF MACHINERY AND TOTAL H. P. CONSUMED FOR ANY QUANTITY OF MILK FROM 1 TO 60,000 LBS. INCLUSIVE. NOTE :— ONE QUART OP MILK EQUALS TWO POUNDS. tx/KftPufc : - It i& DESiR.t^P TO Fiiso thb ^truAu. TOTAU HDCStr POWC^ NCQOIWEJC, AND iSajNNlHCi HOvJBS pF rT>.CHiNCRY. TO REC>UCE 'J.O.ooo ^.K .OP SKIM MILK. CNTer^ TftBue *.T the ooTroro -Eo. ooo i_B. Anp P51.1.0VV THE Oii>TTEt5 Uir-rC (;i,HOWN HERC; f=DR DGI-TOf* ^BATloH . P«!P<3&C'S> ONl.Y^ TO TH6 tolACONAL^ LIMS. TMCM HOEJ-ZOMTWl-l-X, Xa. T^ C BUGH-T Ca£lAD 300 KORSE rS' Moopr & , EJStM . tmc -roT(Sl. M.P. COJ-LSUf-rifiJ* WILX. t5U;tr\AU*-'TME..S^riE. z^- SKin niLK us pouMDa TO Be RECuJCeo To COWOER.. i i n ! 'Ill FUTURE eiJTE'HSfOM OF STOf?e f^OOMS m c>^3 Ik)-- LH,.,J^ DEfpERrJlER. I iO|- I MRiri FLOOR PURN. CR03S - SECTION 13 SOME MILK POWDER PRODUCTS PRODUCT USE PACKED IN SOLD TO METHOD 1 MILK POWDER General Barrels Bakers Confectioners Direct 2 MILK FLOUR Home Use Cartons Grocery Trade Jobbers 3 MILK FLAKES " " " 4 MILK DOMINO CRYSTALS " " " 5 MILK JELLY " Glass Jars " 6 MILK CUBES Tourists Soldiers Tins Grocers Confectioners 7 MILK GRANULES Infants Invalids Bottles Drug Trade 8 MILK POWDER CAPSULES Invalids Glass Jars " 9 MILK WAFERS Confectioners Wax Paper Druggists Confectioners 10 MILK STICKS " " " 11 MILK FLESH FOOD General Boxes Drug Trade 12 TOILET MILK PREPARATIONS " " 1§ !3!3 LIBRPRY OF CONGRESS 000 891 022 A