Improvements in Process of and Apparatus for Condensing and Preserving Milk.
Year: 1894

page_text: Date of Application, 31st July, 1894-Accepted, 31st Aug.. 1895
COMPLETE SPECIFICATION.
Improvements in Process of and Apparatus for Condensing and
Preserving Milk.
I, BYRON FLOYD MCINTYRE, of East Orange, in the County of Essex, and
State of New Jersey, United States of America, Chemist, do hereby declare the
nature of this invention and in what manner the same is to be performed, to
be particularly described and ascertained in and by the following statement:-
This invention relates to the process of and apparatus for preparing condensed
or concentrated milk, in a semi-liquid or powdered form, and adapted for the trade
and general use as condensed milk, and especially adapted for use as a fond
for infants and invalids.
My milk product is prepared by subjecting fresh milk to a process of
concentration by first freezing out the watery portion and separating the remaining
constituents in a semi-liquid condition, from the ice crystals, with a centrifugal
machine, or by other means, till reduced to the desired specific gravity or
consistence, then sterilizing the product by freezing it in thin flakes at a suitable
temperature below zero to destroy pathogenic germs, then continuing the operation
of drying the partially concentrated product at a comparatively low temperature,-
about 100° F.-in a vacuum pan; then moulding the resulting semi-solid product
at or below a freezing temperature so as to form blocks or cakes, then shaving or
chipping such blocks into thin chips or shavings, then completely drying such
shaving by means of dry, warm carbonic acid gas, or equivalent non-oxidizing gas,
circulated over and through them while contained in trays in close chambers,
and finally powdering the product and filling it into cans or jars from which air
is excluded and in the presence of carbonic acid gas or other non-oxidizing gas.
The object of my invention is to produce an improved condensed or powdered
milk product, without changing or toughening the albumninoids, as is ordinarily the
cuse by the boiling process, but, on the contrary, preserve them in their natural
soluble condition; also to prepare the milk without discoloration and without
imparting to the product an unnatural and unpleasant cooked odor and taste, but on
the contrary preserve its natural, sweet pleasant flavor; also to avoid melting and
bursting the globules of natural milk fat or cream, and therefore preserve it in the
pure agreeable form in the concentrated product; also to sterilize and preserve the
finished product in the presence of a non-oxidizing gas, whereby deterioration and
rancidity are avoided, and a more agreeable and nutritious product is presented to
the consumer.
One of the special objects of my invention is to provide for rapidly and
economically freezing milk in flakes or thin layers by subjecting the surface of the
milk to artificial refrigeration and periodically removing the films or layers of ice
from the surface of the milk, so as to facilitate the operation of freezing the milk
and avoid the non-conducting action of a layer or body of ice between the
refrigerating surfaces and the liquid.
I will now describe the details of my process and apparatus in connection with
the accompanying drawings which illustrate an apparatus suitable for use in
carrying out the main steps or operations of the process, and in which,-
Figure 1 represents a vertical longitudinal section of my refrigerating
anbaratua •

page_text: Fig. 2 is a vertical transverse section thereof;
Fig. 3 is a view of the apparatus partly in elevation and partly in vertical
transverse section ;
Fig. 4 is a view of the apparatus partly in side elevation and partly in longitudinal
vertical section ;
Fig. 5 is a top plan view of one of my ice racks or grids;
Figs. 6 and 7 represent side or edge views of the ice grid;
Figs. 8 and 9 represent details of construction;
Fig. 10 represents a view partly in elevation and partly in section of a vacuum
pan and devices for sterilizing the product by refrigeration and comminuting
or chipping it by a knife or scraper;
Fig. 11 represents a drying apparatus partly in elevation and partly in vertical
section.
The freezing closets, A, in my apparatus, are constructed with thick non-
conducting walls of wood or other material and divided by horizontal partitions, a,
into comparatively shallow chambers A', one above another, as shown in the
drawing, and any desired number of chambers or compartments may be constructed
in a vertical series. The front walls of the chamber A', are provided with
openings, which, in practice, are closed by tight fitting doors, a', and the doors are
provided with sight openings, a, closed by glass plates. The refrigerating
coils, B¹, for the circulation of ammonia, or other refrigerating fluid, are arranged
adjacent to the tops of chambers, A', extending practically over their entire area,
and are provided with supply pipes B, having valve,, for admitting, shutting off.
or regulating the supply of the refrigerant. The trays, or pans, C, for holding the
liquid to be frozen or concentrated, are made broad and shallow, as shown, and are
preferably constructed of galvanized iron. They may be made twelve feet long,
four feet wide and ten inches deep. The pans are preferably mounted on small
wheels, c, running upon the rails, and at their front ends are provided with short
spouts, having valves, c', which may be gate valves, or of other convenient form
for drawing off water or the partially frozen liquid, containing granular or
comminute ice.
Above the pans C, I arrange my devices for agitating the liquid and for raising
and lowering the racks or grids for removing the cakes or layers of ice, and such
devices are constructed as follows: Trucks D, constructed with transverse axles,
having at their outer ends grooved wheels, d, rest upon the side rails, a",
as shown
in Figure 2, and each axle is provided at the middle portion with a box, d', through
which extends the longitudinal rod D', connecting the axles and extending through
the front wall of the chamber, where it is provided with a hand wheel, ". In each
of the boxes, d, is arranged a pinion, , upon rod D', which pinion engages with
a short vertical toothed rack bar, supported and guided in box, d, and such
rack bar, e, connects at its lower end with a cross bar C, which at its outer end,
is connected by means of adjustable bolts or hangers, ', with the rack or grid E,
which is made of the proper length and width to neatly fit into the pan C.
In each chamber or compartment A', I preferably provide two trucks or axles, D,
fitted with boxes, d', vertical rack bars, c", and pinions, d, as shown in Figure 1,
so that the racks or grids, E', may be connected at four points on its sides or edges
and raised up and down, while it is maintained in horizontal position. By means
of the above devices, the racks, E', may be evenly raised and lowered through the
medium of the rod, D', and hand wheel, d". When the rack bars, cl, are raised,
as shown in Fig. 3, their upper ends project into the recesses all, formed in the
tops of the chambers. In practice the doors, a', may be made the full height and
width of the chambers, A', so that truck D, carrying the grid, E, supporting a
cake of ice, may be run directly out of a chamber on to rails outside thereof and
conveyed away to a convenient place where it is broken up. In case, however, that
the trucks, D, are not run out of the chambers, the grid may be detached from the
cross bars, C, by means of the detachable bolts or hangers, b', and the grid with
its cake of ice is removed separately.

page_text: The four bangers, b', extending from the cross bars, C', of the truck to the
grids, E', are apt to become frozen solidly in the ice above the grid, and in order to
At the
loosen them therefrom, I provide the gearing shown in Figs. 8 and 9.
upper ends of the shaft, are attached toothed worm wheels, 6, and adjacent to
such wheels, I provide rods, having worms, &, which mesh with the teeth of the
wheel and serve for turning the hangers, , so as to loosen them from the ice.
To facilitate the operation, the hangers, b', are made tapering as shown. The
rods, carrying the worms, b, may extend longitudinally through the closets, A'.
In treating the milk for concentrating it, I may periodically, or at short intervals,
agitate it during the freezing operation, so as to break the films or ice crystals
formed on the top surface into flakes or granules, and for this purpose I provide
agitating rakes with teeth, ". Rake teeth, g, having suitable heads may be
dropped through holes in the cross bar, C¹, as shown in Fig. 3, in which arrangement
the rack or grid, E', is at, that time, detached from the cross-bars.
I may also
suspend rake heads, C", having teeth, y", from the tops of the chambers by means
of swinging links, ", and connect such rake heads by a longitudinal rod, N1, passing
through the wall of the chamber, as shown in Figure 4, for agitating the liquid
while the racks or trays, E', is submerged in the liquid. In this arrangement the
rack or tray, E', is preferably made with a perforated bottom, so as to hold granular
or finely comminuted ice, and the handle, N¹, is given a reciprocating motion, at
suitable intervals, for breaking the ice as it forms upon the surface of the liquid.
When the
Any suitable gearing may be provided for operating the handle, N¹.
rake teeth, g, are inserted through the holes in the cross bar, C', then the rakes
are reciprocated by means of the rod, D, connecting with the trucks D, running
upon the side rails, a". In case the suspended rake heads, el, are used, they may
be raised and held out of the way when the racks E', are to be inserted into
the pans.
For the purpose of detaching and supporting large cakes or layers of ice,
from an inch to two inches thick, and covering the entire surface of the
liquid in a pan, I preferably construct the racks or grids, E, as shown in
Figures 5, 6 and 7, in which the outer frame, e", is provided with sharp
cutting points,, projecting upward, as shown, for cutting through the ice,
as the grid is raised. The outer frame,, is connected by numerous cross
bars, e provided with upwardly projecting knobs, k, arranged so as to be in
line between the cutting points, .
The cutting points, , on the rack, E', should be higher than the knobs, k, so
as to cut or fracture the ice from the side walls of the pan and then allow it to
rest upon the knobs.
In connection with my ice rack, I use a crusher or breaker composed of a
frame and cross bar which are provided with knobs, which knobs are preferably
so placed as to break joints with the cutting points, i', and knobs, A, on the rack;
that is, so that the knobs of the breaker will be arranged in a position corresponding
with the marks, &, shown in view of the grid (Fig. 5). The crusher, in practice,
may be arranged to work up and down in vertical guide ways in a frame, so as
to be dropped down upon the cake of ice resting upon the grid, E', and break it
iuto small lumps, as indicated above.
In case it is desired to freeze the water in viscous liquids, such as milk, the liquid
during the refrigerating operation is agitated at short intervals, so as to break
the ice films into flakes or granules, and thus keep the liquid surface exposed to
the refrigerating coils. When the body of liquid becomes filled with ice crystals
or granules, the thick magma is preferably withdrawn from the pans and placed in
a centrifugal machine, where the remaining liquid portion is separated from the
ice crystals by centrifugal force. The liquid this removed may be again subjecte.
to the freezing and agitating operation and be separated in a centrifugal machine
until it is concentrated to the desired density.
In some cases the liquid is subjected to the refrigerating operation until a cake
or sheet of ice is formed from one-half to an inch or two inches in thickness, during

page_text: which operation the rack or grid, El, is submerged in the liquid; then, when the
sheet of ice is of the desired thickness, the rack is raised, by means of the pinion
and rack bars, causing the cutting points, , to cut through the sheet of ice and
detach it from the side walls of the pan, and then the rack is raised above the pan
and may be drawn out from the closet while suspended from the trucks D, which
may run out upon rails outside of the closets. The racks, E¹, are then detached
from the trucks and placed in any suitable frame under a crusher, after which the
crusher is allowed to fall with sufficient force to break the ice into small lumps
which will fall through the bars, ell, of the rack. The rack may now be lifted
away from the ice and again adjusted in position below the trucks and placed in the
freezing closet within the pan of liquid, and then the operation of freezing a thin
sheet of ice is repeated.
In the above described process, it will be seen that there is a frequent exposure
of fresh liquid to the refrigerating coils and prompt economical results are obtained.
With my apparatus the ice is fractured to any size required at very small expense,
and is prepared for use in the most favourable form.
In practice, my freezing closets, are operated in rooms, which are cooled to or
below 32° F., so that the freezing operation within the closets may be quickly
performed at about zero.
The elevation of the sheet of ice above the pan and water contained therein and
in close proximity to the cooling pipes, freezes the drip water adhering to the
ice, so that it can be removed from the closets in a dry and convenient form to
handle.
My refrigerating, sterilizing devices, in connection with a vacuum pan, are
illustrated in Fig. 10. The vacuum pan, E, (which may be of a kind in general
use) is mounted upon the frame X, and is provided with an annular water jacket, e,
containing heating coils, d, and also with a separate water or steam jacket, e¹¹, at
the bottom, containing a heating coil, . The pan is provided with a stirring
device, F, which in practice, has knife-edged bars, f", for scraping the surface of
the pan.
The shaft F, to which the stirrer is attached extends down through a
gland, f, at the bottom of the pan, and is provided with a large beveled gear
wheel, t, which meshes with a beveled pinion, ie, secured upon the horizontal shaft.
The bottom of the pan is provided with an opening or spout, 1, extending through
the lower jacket and having a closing stopper or plug, 6", to permit the removal
of the condensed semi-solid milk product. The dome of the pan is
the usual sight opening, a, a man hole and lid, ', and vacuum gage y¹.
provided with
Adjacent to the pan, or at any suitable distance therefrom, I arrange a
refrigerating casing G, having at the top a funnel, G', which is tapered at the
bottom to form a narrow discharge mouth, g', for distributing the milk upon the
freezing cylinder H, just below it. The freezing cylinder, H, is made hollow, and
in practice is provided with suitable hollow journals, with which connect pipes,
such as I, having a valve, i, for circulating the refrigerating liquid, such as ammonia,
brine or glycerine. The journal has also a belt pulley, h, around which may pass a
belt for revolving the cylinder. At one side of the casing, and preferably near
its top, there is secured a pivoted knife or scraper K, which is adapted to bear
at its cutting edge upon the surface of the cylinder H, and the shaft of such
knife is provided with an arm, k, to the outer end of which is attached the
weights, k, for causing the edge of the knife to bear more closely upon the
periphery of the cylinder and cut or scrape therefrom the films or layers of ice in
the form of flakes or chips. The knife or scraper is made adjustable and can be
thrown out of contact with the cylinder when desired, so that the operation of
cutting or sharing the ice can be made intermittent.
A revolving, cutting or chipping device, may be used for removing ice from the
freezing cylinder. The freezing cylinder H, will in practice be provided with an
inlet and an outlet pipe, one at each end, for conveying cold glycerine or other
refrigerant. The casing, G, connects by pipe, L, with the top of the vacuum pan,
and by a pipe, L', having a gate valve, l, with the top of the box or other receptacle, M,

page_text: for the chipped or comminuted ice removed from cylinder H. Box, M, is provided
at one side with a large tight fitting lid, m, and at the bottom with a depression or
well, m', and at the side with a liquid gage, s. A heating coil, J, having an inlet
valve.j, is preferably arranged below the box, M. A steam inlet pipe, N, having
valve, n, connects with the bottom of the box, M, and an outlet pipe, O, having
a valve, o, connects with the top thereof.
a
The gate valve, l, being closed, the vacuum in ice box, M, may be broken by
opening valve, o. Air may be driven out and the vacuum produced by admitting
steam through pipe N, which condenses in contact with the solid contents and
surfaces of the walls.
A liquid transfer pipe, P, having valve, p, extends down through box, M, into
the well, m', and connects the latter with the interior of the racunm pan, E, for
conveying liquified milk into the vacuum pan, where the further operation of
drying out and reducing the product to a semi-liquid or viscous consistency takes
place at the low temperature of about 100° F.
When watery vapors only are condensed and frozen upon cylinder H, and then
scraped therefrom, the resulting ice takes may be removed from box M, by
opening the door, m, at suitable intervals, care being taken to first close the
valve, 1, and the valve, p, so that the vacuum may not be broken in the pan E.
A steam supply pipe, having valve. p", connects with pipe P, for admitting steam
to drive out air from the vacuum pan at the commencement of the operation.
My cooling and drying apparatus is illustrated in Fig. 11, in which R designates
a casing divided by horizontal partitions, r, into separate chambers or closets, R',
which are provided at one end with tight fitting doors, v. Below the drying
chamber R, I place a warming chamber, R", containing steam or hot water
coils, S', having a supply pipe, S, provided with a valve, s', and an outlet pipe
having a valve, s". In connection with my drying chamber, I use a refrigerating
casing G", containing a revolving freezing cylinder having a pulley, h, like those
described above with reference to Fig. 10. The casing G, commects by pipe, L',
having a valve, l, with an ice box M', constructed like the one heretofore described.
A large pipe P, leads from the top of box M', to the exhaust pump, Q, which
connects by pipe P, having a valve, 9, with the warming chamber R. A pipe, J',
having a valve,, connects with pipe P, for admitting thereto carbonic acid
gas or any suitable non-oxidizing gas such as nitrogen or carbonic oxide, or a
mixture of any two or more of these gases such as carbonic acid, carbonic oxide,
and nitrogen, for circulation through the warming chamber, thence through the
drying chambers, and thence through the refrigerating chambers in contact with
the freezing cylinder for condensing and removing any contained moisture.
The warming chamber, R", connects by pipe T, and branches T¹, T", T, with
the drying chambers, and a pipe, U, connects by suitable branch pipes, having
valves, u, u. and u", with the drying chambers for conducting off moist gas and
vapor, which is conveyed by pipe, L", to the cooling casing G. The drying
chambers, R', are provided with cleats or guideways w, secured to the side walls
for receiving and supporting the trays, W, containing moist food shavings to be
desiccated, as will be hereinafter more fully described.
I will now describe my process under three principal heads or divisions :-First,
separation of water from milk solids mainly by freezing to form ice crystals or
granules, and separation of the remaining unfrozen coustituents containing milk
solids from said crystals or granules; sccond, sterilization, drying and reduction
to powder; third, filling the finished product into jars or cans and preservation
thereof in the presence of carbonic acid gas or other non-oxidizing gas.
Heretofore concentration of milk has been effected by a process of boiling, usually
in a vacuum pan, produced by vacuum pumps and vapor condensers, and by appli-
cation of high pressure steam heat to the jacket of the pan. This is necessarily
done as quickly as possible, but with the most approved apparatus, the milk is
subjected to a long process of boiling and chemical changes are wrought by the
heat, which diminish and change the nutritive value of the milk constituents, and

page_text: impart a cooked milk odor and taste to the product. The prolonged heating of
the milk, at the comparatively high temperature employed also ruptures the fat
globules, changing them in their physical appearance, and instead of being granular,
they become salvey, and are more easily made rancid by exposure to atmospheric
air. My cold process insures the integrity of these globules, and under the
condition detailed in this process, the milk fat is preserved in the original form,
less the water required for their suspension as in milk.
In treating a large volume of milk, it is previously first subjected to centrifugal
action in a separating machine to separate the cream or milk fat therefrom, and
such separated cream is reserved and added at a further stage of the process, as
will be described below. Ordinarily the separated milk only need be subjected to
the freezing process, for the purpose of producing a concentrated semi-liquid
product. The separated milk is filled into the pans, C, which are placed in the
freezing closets and the doors of the latter tightly closed. The brine or other
refrigerant, is circulated in the coil, and the operation of freezing the milk started.
After the ice crystals begin to form, the rakes or stirrers, C¹, or C, Figs. 3 and 4.
are started into operation for breaking up the ice as it forms upon the surface and
changing it to a granular or crystalline form. The freezing and agitation is
continued until the whole body of milk in each pan has been changed to a soft
granular condition, after which the mixture is transferred to a centrifugal
machine where the unfrozen portion containing the milk solids, is separated in a
liquid or semi-liquid form from the ice crystals or granules. During the
operation of the centrifugal machine the crystals may be washed with fresh milk
which has been previously cooled to 32° F. Live steam, may, at any time, be
momentarily projected against the wall of granular ice in the machine until the
crystals are free from all adhering milk. This treatment with steam is important
and prevents the regelation of the crystals or granules of ice and the consequent
locking up of milk solids within their interstices. Instead of treating the mass of
granular milk received from the freezing trays in a centrifugal machine, it may
be placed upon a tray having a screen or false bottom of wire netting and
connecting below with an exhaust pump or other suction device. Live steam
may then be momentarily projected against the layer of granular ice during the
operation of the suction device, so as to remove the coating of milk in liquid
form from the ice crystals.
The crystals after having been freed from the milk can be used for cooling
purposes in future operations.
The partially concentrated milk is preferably subjected repeatedly to the
refrigerating operation (two or three times if desired) and separation in a centri-
fugal machine or by other means until the product is of a syrupy consistence
containing from 0% to 95% of solids.
When the milk product has been reduced to this consistence, it is then subjected
to the sterilizing operation at a temperature below zero.
The freezing cylinder, II, (Fig. 10) having been reduced to a very low tempera-
ture by cirenlation of cold glycerine or other refrigerating medium through it,
the dense concentrated milk is supplied to the funnel G', and permitted to flow
by gravity in thin streams upon the surface of the freezing cylinder H.
As the milk freezes in thin films or layers on cylinder II, it is scraped off by
knife K. or other device in the form of chips or flakes. The cylinder H, is
preferably revolved slowly and the operation of freezing the milk there on in thin
layers and removing it by a scraper may be continuous; or, if desired, the con-
centrated milk may be distributed upon cylinder H, for a few moments, while the
scraping knife is out of contact therewith, then the supply of milk cut off and the
scraping knife K, made to bear against the cylinder until the film or layer of ice is
removed in the form of chips or flakes. Cylinder II, is pre'erably cooled to a
temperature ranging from 10° to 20° F. below zero, and always sufficiently low to
destroy all pathogenic germs.
By means of direct expansion aminonia coils, properly arranged in a tank, very

page_text: low temperatures can be obtained; and by using glycerine, which remains fluid
at an extremely low temperature, as a medium of transmitting the cold, the freezing
cylinder can be readily cooled as above described.
I prefer to discharge the frozen milk flakes into the tight box, M, until it is
filled and then melt the contents by means of steam circulated in coil J, at which
time valve, 1, should be closed. The chamber, M. having been filled with melted
milk product, valve, p, in pipe P is opened and the contents discharged into
vacuum pan E. To perform this operation a partial vacuum is previously created
in pan E, as described below.
A full charge of milk product having been supplied to the vacuum pan, live
steam is forced into the pan by means of pipe p", over the milk to expel all the
air, so that the pan will contain only condensed milk and vapor,-valve, p, and
the other inlets to the pan are closed and the cooling cylinder H started and
the vapor cooled to about 100° F. The warm vapor rising from the milk condenses
perfectly on the cooling cylinder and the condensation produces a sufficient and
effective vacuum without the use of a pump.
Hot water is run through the jacket of the pan, or the water in the jacket is
heated by the coil, so as to maintain a uniform vapor temperature not to exceed
100° F. or sufficient to vaporize the water in the milk product, and the vapor is
continuously condensed by contact with the freezing cylinder. Evaporation and
concentration of the milk is preferably continued until the product is reduced
to a semi-solid consistence or to such a consistence as will produce when cold,
a solid mass suitable for shaving when cold. The operation having been completed
in the vacuum pan, the vacuum is preferably broken by using carbonic acid gas
instead of atmospheric air, so as to avoid any oxidizing effect. The warm semi-
solid product is run into molds and thus formed into cakes or blocks which are
preferably allowed to cool at a low temperature. The process up to this stage
produces condensed and sterilized milk and the product has been preserved in an
atmosphere of carbonic acid gas.
My improved method of condensing and sterilizing milk is designed particularly to
preserve the natural aroma of the milk and the integrity of the milk constituents.
To modify the composition of the milk and reduce the proportion of albuminoids
when required, milk or cane sugar is added to the condensed milk, using only a
saturated solution of sugar. After making a saturated solution of sugar it should
be heated in a tight kettle until the pressure gage registers about four pounds,
where it should be held for ten minutes at or near a temperature of 220° F. to
destroy all micro organisms. The syrup after sterilization is cooled and then run
into the condensed milk in the vacuum pan and the stirrer put in motion as well
as the cooling cylinder.
After the milk has been concentrated to a semi-solid condition such proportion
of cream is added as will produce a product containing the desired per centage
of milk fat, preferably from ten to twenty-five per cent. Further condensation is
then made to the desired condition. Previous to evaporation of cream with milk
solids, it may be sterilized on the cooling cylinder in the same manner as the
condensed milk solids.
After addition of the saturated sugar solution and the cream and evaporation
of the whole batch to a semi-solid consistence when hot, the batch is drawn off
into molds and cooled at a low temperature, so as to form blocks or cakes, as before
explained.
The solid blocks or cakes of chilled milk are then, by suitable mechanical means,
shaved into thin shavings or chips, which are then placed upon the trays, w, which
are inserted into the driving chambers R', as shown in Fig. 11. The trays are
constructed with bottoms of wire netting and covered with cloth so that the warm,
dry carbonic acid gas may pass up through the contained shavings, as well as over
the trays. The refrigerating cylinder is put in operation, steam is passed through
the coils S¹, in the warming chamber R", carbonic acid gas is admitted by pipe J',
to pipe P¹, and the pump Q, put in operation.

page_text: Vapor is drawn off from the drying chambers, through pipes, U and L", into the
cooling chamber, G", where all moisture is condensed. The dry carbonic acid gas
passes thence through pipe P', through the pump, and is warmed by contact with
the coils S', in warming chamber R", from which it passes through pipe T and its
branch pipes, and their valves into any one or more of the drying chambers R'.
When the contents of any one chamber R', has been thoroughly dried, the valves
on the inlet and outlet pipes of such chamber are closed, and the trays removed
through the door, r. During the drying operation, the doors, v, of each chamber
is tightly closed or sealed. The carbonic acid gas or other non-oxidizing gas, is
preferably heated to a temperature of about 100° F., and, after leaving the drying
chamber, it is deprived of its moisture, and returns again through the warming
chamber and passes thence through the drying chamber, being continuously
circulated by the pump. Fresh carbonic acid gas is admitted by pipe J', as
required. The ice formed upon the freezing cylinder in chamber G, is scraped
off and deposited in box, M', from which it is periodically removed.
gas,
After the milk shavings have been perfectly desiccated in the drying chamber,
they are preferably cooled by circulation of cold dry carbonic acid gas, the
steam at that time being shut off from the coils S. The dry products and carbonic
acid gas are then discharged into a receptacle previously filled with carbonic acid
and provided with cooling pipes to maintain the temperature below 32° F.
From this receptacle the product is discharged through air tight tubes into the
powdering mills, which are preferably operated in rooms cooled to 32° F. The
milk fat contained in the product, is at this temperature a hard and easily
pulverized solid, when in combination with the other milk solids, and can be readily
sieved in a well known manner.
The powdered product which constitutes my infant's food, or milk powder,
together with carbonic acid gas, is then discharged into a receptacle from whence
it is filled into bottles or cans which have been previously filled with carbonic acid
gas without admixture of air, and which are, afterwards, hermetically sealed. The
carbonic acid gas acts as a preservative by excluding air and preventing oxidation
of the milk fat, and, in addition to its preservative effect, exerts a bleaching or
decolorizing effect that is of marked value, and that in no way deteriorates the
product.
My prepared milk product, as prepared above, is white, has a fresh milk odor
without rancidity or a cooked odor or taste, is quite soluble, forming with water an
opaque white mixture, resembling milk in appearance, and the albuminoids are
preserved therein without marked change. The proportions of albuminoids, milk
fat, and sugar can be varied to make a product adapted for different uses.
The partially concentrated product may be drawn off from the vacuum pan and
filled directly into cans or jars in the presence of carbonic acid gas, so as to present
a product like ordinary condensed milk.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manuer the same is to be performed, I declare that what I
claim is :-
1. The process of concentrating or condensing milk and producing ice which
consists in subjecting milk to a freezing temperature, and at the same time
agitating it, thereby freezing the watery portion and breaking the ice into flakes
or granules, and then separating the remaining constituents containing the milk
solids from said flakes or granules of icc.
2. The process of concentrating or condensing milk which consists in freezing
the watery portion by refrigeration at the exposed upper surface of the milk,
simultaneously breaking the ice crystals as formed, by suitable means, into flakes
or granules, thereby avoiding the locking up of milk solids in the ice crystals, and
then separating the remaining unfrozen portions containing milk solids from said
ice flakes or granules by centrifugal force or other means.
3. The process of concentrating or condensing milk which consists in freezing

page_text: the watery portion by refrigeration at the exposed upper surface of the milk,
simultaneously breaking the ice crystals, as formed, by suitable means into flakes
or granules, thereby avoiding the locking up of milk solids in the ice crystals, and
then separating the remaining unfrozen portions containing milk solids from said
ice flakes or granules by centrifugal or other force, and then continuing the con-
centration in racu) at about 100° F., until the product is reduced to the desired
density or consistence.
4. The process of concentrating or condensing milk, which consists in freezing
the watery portion and breaking the ice, as formed, into flakes or granules, then
separating the remaining constituents containing the milk solids, from said ice
flakes or granules by centrifugal force, and in such operation projecting against
the ice granales a current of steam, thereby preventing regelation and consequent
locking up of milk constituents in the interstices of said granules.
5. The process of condensing and preserving milk which consists in freezing the
watery portion and breaking the ice as formed into flakes or granules, then
separating the remaining constituents containing the milk solids from said ice flakes
or granules by suitable means, and then sterilizing such product by freezing it in
films or flakes at a suitable temperature below zero to kill pathogenic germs.
6. The process of condensing and preserving milk, which consists in freezing the
watery portion and breaking the ice into flakes or granules, then separating the
remaining constituents containing the milk solids from said ice flakes or granules,
distributing the resulting semi-fluid product in films upon a freezing cylinder and
freezing it thereon at a temperature below zero to kill pathogenic germs and
shaving or cutting the frozen films from said cylinder in the form of flakes
or chips.
7. The process of condensing and preserving milk, which consists in freezing the
watery portion and breaking the ice into flakes or granules, then agitating the
remaining constituents containing milk solids from said flakes or granules, then
sterilizing the resulting product by freezing at a suitable temperature below zero
to kill pathogenic gerins and then drying the product in vacuo to the desired
density or consistence.
8. The process of condensing and preserving milk, which consists in freezing the
watery portion and separating the ice crystals from the remaining constituents,―
sterilizing the resulting semi-fluid product at a suitable temperature below zero,
then drying the product in vacuo, and then moulding into blocks or cakes at a low
temperature.
9. The process of condensing and preserving milk, which consists in removing
the watery portion in the form of ice crystals from the solid constituents, drying
the semi-fluid product in vacuo, to the desired density or consistence, moulding
such product into blocks, then shaving or comminuting the mass and drying the
shavings by means of dry carbonic acid gas or other non-oxidizing gas circulated
over and through them, and finally powdering the dry shavings.
10. In the art of manufacturing condensed milk the process of preserving it
which consists in subjecting the shavings or chips of the condensed product to the
drying action of dry warm carbonic acid or other non-oxidizing gas circulated
through and over them, then powdering the dry shaving at about a freezing
temperature, and filling into receptacles in the presence of carbonic acid or other
non-oxidizing gas.
11. The process of manufacturing condensed milk which consists in first separating
from fresh milk the cream or fat, then concentrating the milk by freezing out the
water and separating the resulting ice from the remaining constituents till reduced
to the desired density, then sterilizing the semi-fluid product by refrigeration,
partially drying the resulting product in vacuo at a temperature of about 100° F.,
and then adding the separated cream and continuing the drying operation till the
product is reduced to the desired consistence.
12. The process of manufacturing condensed milk which consists in first
separating from fresh milk, the cream or fat, then concentrating the milk by
B

page_text: freezing out the water and separating the resulting ice from the remaining
constituents till reduced to the desired density, then sterilizing the semi-fluid
product by refrigeration, partially drying the resulting product in vacuo at a
temperature of about 100° F. separately sterilizing the cream by refrigeration
and adding it to the partially dried product in the vacuum pan and continuing
the drying operation till the product is reduced to the desired consistence.
13 In the manufacture of condensed milk the method of producing ice which
consists in subjecting the exposed surface of the milk to artificial refrigerating
surfaces, periodically removing the ice in thin sheets, and repeatedly exposing the
surface of the liquid to artificial refrigeration.
14. In apparatus for condensing and preserving milk, the combination with a
tight freezing closet a pan for containing liquid, a refrigerating coil above such
pan and means for periodically agitating the liquid and breaking the ice crystals
or films during the refrigerating operation.
15. In apparatus for condensing and preserving milk, the combination with a
tight freezing closet, of a pan for containing liquid, a refrigerating coil above said
pan, a rack or perforated tray submerged in the liquid in the pan, and means for
raising said rack or tray, for periodically removing the ice, substantially as
described.
16. In apparatus for condensing and preserving milk, the combination with a
tight freezing closet, a pan for containing liquid and a refrigerating coil, of an
adjustable ice rack or tray, having cutting points at its outer edges, and cross bars
provided with knobs, and mechanism for raising and lowering said rack, for the
purpose of cutting a sheet of ice from the pan and removing it from the closet,
substantially as described.
17. In apparatus for condensing and preserving milk the combination with a
tight freezing closet, containing a pan for liquid and a refrigerating coil, of trucks
having wheels resting on side rails and also provided with vertical rack bars,
pinions meshing with said bars, and a tray or rack connecting with said bars and
adapted to be submerged in the liquid in the pan or to be raised therefrom,
substantially as described.
18. In apparatus for condensing and preserving milk, the combination of a
vacuum pan, a hollow refrigerating cylinder or other body, having inlet and outlet
pipes, for the circulation of the refrigerating fluid, means for scraping the ice from
such refrigerating body, a box or receptacle, as M, for containing the ice chips, a
chamber or casing, as G, enclosing the refrigerating body and connecting with
the vacuum pan and also with the ice box and having a valve, l, substantially as
described.
19. In apparatus for condensing and preserving milk the combination with the
vacuum pan, of a refrigerating cylinder, having inlet and outlet pipes, an ice
scraper or cutter therefor, a feed trough and an ice box, pipes connecting the
vacuum pan and ice box with the casing which encloses the refrigerating cylinder, a
valve between the casing and ice box and a transfer pipe, as P, having a valve, p,
convecting the ice box with the interior of the vacuum pan, substantially as
described.
20. In apparatus for condensing and preserving milk, a drying closet having an
inlet for dry carbonic acid gas and an outlet for gas and vapor, in combination
with a refrigerating casing, containing a hollow cylinder or other body, having
inlet and outlet pipes for circulating through it a refrigerating fluid, pipe connections
between the refrigerating casing and the drying closet and a valved pipe for
admitting carbonic acid gas, substantially as described.
21. In apparatus for condensing and preserving milk, the combination with a
drying closet, having an inlet pipe and au exhaust pipe, a condensing and
refrigerating casing, a revolving refrigerating cylinder in said casing and having
an inlet and outlet pipe for circulating a refrigerating fluid, a cutter or scraper
bearing upon the surface of said cylinder for scraping off the frost or ice therefrom,
a receptacle for the ice chips, a warming chamber, containing a heating coil, and

page_text: pipes connecting the ice receptacle with said warming chamber and also with the
drying closet, substantially as described.
22. In apparatus for condensing and preserving milk, the combination with a
drying closet, having a tight fitting door, suitable trays, a valved inlet pipe and a
valved outlet pipe, of a refrigerating casing connecting with the closet and
containing means for circulating a refrigerating fluid, means for scraping or cutting
the ice from the refrigerating surfaces, an ice receptacle, and a valved pipe
connecting the refrigerating casing with said receptacle, an exhaust pump, a warming
chamber, containing a heating coil and valved pipes connecting said chamber with
the pump and with the drying closet, substantially as described.
Dated this 31st day of July 1894.
HASELTINE, LAKE, & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.