Improvements in the Method of and Apparatus for Preparing Milk so as to Enable the same to be Preserved Indefinitely.
Year: 1889

page_text: Date of Application, 12th Apr., 1889-Accepted, 12th Apr., 1890
COMPLETE SPECIFICATION.
Improvements in the Method of and Apparatus for Preparing Milk
so as to Enable the same to be Preserved Indefinitely.
We JOHANN FRANZ HUGO GRONWALD, Pharmaceutical Chemist of 6* Lietzmann
Strasse, and EMIL HEINRICH CONRAD OEHLMANN, Engineer Dresdener Strasse 70, both
in Berlin, German Empire, do hereby declare the nature of our said invention for
"IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR PREPARING MILK SO AS
TO ENABLE THE SAME TO BE KEPT INDEFINITELY" and in what manner the same is
to be performed to be particularly described and ascertained in and by the following
statement:-
The object of the present invention is to prepare milk in such a manner as to enable
it to be preserved in its natural normal condition for indefinite periods. The said
invention is valuable both from economic and hygienic reasons.
It is well known that when milk is preparod for consumption by boiling and by
reason of the accidents frequently occurring when this is done (such as boiling over
and burning) and by deterioration of the milk when it is kept for some time, particu-
larly in warm weather, waste of time and money is caused which in the aggregate
represents a not inconsiderable loss. To prevent such losses must necessarily be
beneficial to the general public.
By this invention the losses above referred to are avoided; the milk prepared as
hereinafter stated is ready for consumption & requires no further boiling it will not
turn even by continued application of heat above summer temperature (30° C.) and the
advantage of using such milk, the price of which will be about equal to that of the
milk usually sold, is obvious.
A further important consideration is the following: It is a well established fact that
milk is not unfrequently a vehicle for disease-germs which are capable of transmission
from the organism of animals to that of mankind.
Tuberculosis and scrofula are amongst these. It is also acknowledged by medical
men that the diarrhoea so frequently occurring in an epidemic form in summer and
which decimates infants is caused by infection through milk. Thus damage to health
and loss of human life, consequent upon consumption of diseased milk are by no
means slight and have caused competent authorities to utter urgent demands for germ-
free milk.
Milk treated according to this invention fulfils this requirement being free from
all infectious matter all micro-organisms contained in the milk, whether ferments or
disease gernis, are killed in the treatment.
The hygienic importance of the said invention must therefore also be acknowledged.
In other respects the quality of the milk is not affected, the separation of the casein
and fatty matters takes place by the same manipulations as with fresh milk.
The taste of the milk prepared according to this invention is also better than that
of ordinary boiled milk the latter always having a peculiar taste. In accordance with
this invention good milk is first examined as to the amount of alkaline matter it
contains. It is required that the milk should be neutral, if there is acidity this is
corrected by the addition of bicarbonate of potassium. The milk is then exposed to
circulating aqueous vapour of 100° C. temperature during a definite time, is then
under pressure filled into suitable vessels contained in a hermetically closed receiver
& likewise sterilised by aqueous vapour of 100° C. and the vessels are then hermetically
closed.
The principal features of the new process are ;
1.) Neutralisation of the milk.
2 1000
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page_text: 3.) The separate sterilisation of the receptacles for receiving the milk and of the
closing devices therefor.
The first operation is neutralisation of the milk. Owing to unsuitable feeding of
the cattle froin which the milk is derive the latter usually shows acid reaction and
contains free lactic acil. This has to be remedied as the acid in the milk would
cause, even, in milk free from gerius separation of the proteins, and consequent
coagulation of the milk.
Separate sterilisation of the receptacles for the milk and of the devices for closing
the same is obtained by circulating aqueous vapours of 100° C. temperature in a sterile
· vessel, hermetically closed against the atmosphere as it is by this means alone that
freedom from gerius of the receptacles, and especially of the closing devices can be
ensured.
The apparatus for carrying this process into practice are represented in the accom-
panying drawings in which
Fig. 1 is an elevation of the apparatus for preparing the milk.
Fig. 2 shows the filling & closing apparatus in section.
Figs. 3 to 8 show various details of the same and
Figs. 9 & 10 illustrate an apparatus for filling large vessels such as casks or
barrels.
The entire apparatus for preparing the milk consists of the pan or boiler A and the
filling and closing apparatus B. The pan or boiler A is of known construction and
has a steam jacket and the closely fitting lid is provided with an inlet funnel, pressure
guage, & thermometer.
When a given quantity of milk has been measured off (say
for instance 100 liters) and poured in by the funnel a into the pan A, the two way
cock of the steam-pipe c is so set that steam passes through pipe c into the steam-
spaco of the pan A (the jacket) and heats the milk to 100°. When this is done the
steam outlet d on the upper part of the jacket is opened and the steam-supply so
adjusted that the temperature of 100° is not exceeded to any considerable extent.
The steam escaping from the steam outlet passes by pipe d into the lower part of
pipe c and thence to the filling apparatus (which, thus far is not supplied with direct
steam) and heats the same.
The steam for heating the milk is purified before use, being to this end passed
through a purifying vessel e' filled with charcoal or other suitable purifying agents.
Simultaneously with the operation last heroinabove mentioned, the stop cock e is
opened and the branch pipe on pipe c admits fresh steam into the pan A and upon
the milk, so that the milk is surrounded by boiling steam, the boiling will therefore
not affect its composition. The milk is maintained at the temperature of 100° for as
long a time as appears requisite to enable it to be kept.
During these operations the filling and closing apparatus is prepared for further
manipulation of the inilk.
The filling and closing apparatus consists of a bottom portion g and a lid h so
secured thereto as to be readily removable but yet steam tight. In the bottom
portion g is arranged the platen or table D supported on brackets i and serving for
the reception of the receptacles for the milk say bottles. The table D (figs. 2 & 4)
,consists of a solid plate K and an upper part capable of being heated (see figs 2, 5,
& 8). The lid (the upper part) is fitted with as many shells boxes or frames m (made
say of copper) as bottles are to be filled at one operation. If for instance the apparatus
is to work up 100 litres of milk at each operation & fill it into litre bottles there will
be 100 boxes or shells m. The pipe e supplies steam for the table D and the steam,
guided by a spiral partition n (figs. 3, 4) passes round all the shell or boxes m and
ultimately issues through the aperture o (fig. 3) into the body of the apparatus B. In
each box or shell there is a bottle fitted preferably with a stoppering device of the
construction hereinafter set forth and the bottles are evenly heated to 100° C.
The stoppers of all bottles are open and rest on stout rings F (see fig. 5). Four
such rings are provided in an apparatus of the dimensions above stated and as shown
in fig. 4 they are so arranged that the stoppers of all the bottles can readily be rested
thereon. The rings F are connected with the star shaped plate G by rods p which

page_text: pass through stays making tight joint with the interior of table 1) and into holes or
recesses in the plate G.
The plate G is capable of vertical motion, it is connected with a stout plunger g
(fig. 2) passing through a stuffing box H in the lower portion g of the apparatus.
This plunger is carried by the short arm of a lever J. The latter is operated by a
screw spindle and wheel K and by those means the plate G can be raised and
lowered.
T
By the rising and falling of the plate G the insertion and securing of the bottle
stoppers is effected. To this end angle pieces (fig. 5) are so secured upon the rings F
that one such angle piece is inserted between the strap carrying each stopper and the
levers on the bottle.
When the bottles placed in the shells on the table D have been filled, the lever J
is depressed and plate G raised (see fig. 6). Consequently the angle pieces r raise
the stoppers and these, retained by their wire-straps, are placed on the mouths of the
corresponding bottles
The lever J is next raised and plate G now descends, the angle pieces bear on the
levers s, depress the same and thereby tighten the stoppers and their packing so that
all the bottles are simultaneously closed with removal from the apparatus. Before
the bottles are filled they are also sterilised by circulating steam. To this end a
tube L, tinned and fitted with a valve t (figs. 7 & 8) is inserted into each. All the
tubes L are attached to the filling vessel M so suspended in the upper part of the
filling apparatus as to be vertically movable. They are held in position by guide
cones on the sheet metal plate N.
Into the upper portion h, above the filling vessel M steam is also admitted, through
the branch cock o and elbow-pipe w Fig. 2. When the valves t are open the steam
or aqueous vapour passes through the pipes or tubes L to the bottom of the bottle and
then escapes through the mouths of the bottles to the interior of the apparatus so that
all the bottles are sterilised in their interior also. The said valves t in the tubes L are
opened by lowering the filling vessel M. Every valve has a prolonged stem pro-
jecting somewhat beyond the end of the tube L. Consequently each valve t is closed
when the vessel M is at such level that the stems
bottles (Fig. 7). The steam however passes freely
vessel M is lowered sufficiently to cause the stems
bottles raising the valve t (fig. 8).
are clear of the bottom of the
through the tubes L when filling
to bear upon the bottom of the
When the apparatus B has been thoroughly sterilised, by the aqueous vapour
circulating within it, the stopcock o is so set that access of steam through pipe v
to the part is prevented whereas connection is made between that portion of the
apparatus (through pipe R and syphon S) and pan A. The filling vessel M being
first raised so far that all the valves of the tubes L close. The steam acting from
above upon the milk in the pan A causes the same to flow through syphon S, pipe R
cock o and elbow pipe W the latter passing (so as to make a tight joint) through the
sleeve I on the bottom of the filling vessel M. The entire quantity of milk passes
from pan A to the vessel M. By the guage-glass U (fig. 1) can be ascertained
when the milk has passed and then the vessel M is lowered whereby the valves
in the tubes L are caused to rise and the milk flows uniformly into all the
bottles.
When the vessel M is empty and all the bottles are full (which is ascertained by
a guage U) the wheel P is turned and vessel M raised until it touches the top
portion h, pawl V then takes into the notch 2 and the hand wheel is stopped.
All the tubes L are thus raised out of the bottles being guided by the plate N
which is not raised. The bottles are now in the position shown by fig. 5. The plate G
is then raised and all the stoppers are turned over onto the bottle mouth and by a
downward motion of the plate the projections on the rings F fasten the stoppering
device. The bottles being thus filled and closed the connections between the top &
5 bottom portions of the apparatus are released, the pawl V is raised clear of the notch
and the hand wheel P being turned will further raise vessel M which as stated already
bears against the lid h and the latter is carried upwards its rollers guiding it on

page_text: suitable uprights and the table D becomes readily accessible to the operator who
having fixed wheel P in position by pawl V, can easily remove the bottles from the
apparatus, and set the same aside to be cooled slowly.
The sequence of operations therefore is as follows:
The apparatus being empty & steam & milk inlets closed, the upper portion / is
raised so that the bottles may be put into place. The bottles are set in the shells or
boxes M the operator beginning preferably with the inmost row and the stoppering
devices are made to rest on the rings F as shown in fig. 5. This done pawl V is
released and the lid is carefully lowered until it bears upon the portion g and the
centering studs on the flanges pass into the holes for their reception.
By further gradual turning of wheel P the receiver or vessel M begins to descend
the tubes L pass into the bottles and the pawl falls into the first notch on handwheel P
so that the wheel stops. The connections between lid & bottom portion are now
fastened pawl V is released and the vessel M lowered until it rests on the plate N.
This causes the rods to touch the bottom of the bottles, the valves t rise and tubes L
are opened.
Now cocks band o are now so adjusted that steam flows from_pipe C into the
table D and over the filling vessel M, fills the interior of apparatus B and the bottles
and so heats all the parts at the same time sterilising the same.
The wheel P is then turned until pawl V engages with the notch 1. This raises
the vessel M and by the valves t closes the tubes L. The cock o is then reversed and
the milk, meanwhile prepared in the apparatus A, as described is brought over at a
temperature of 100°. The pan A now empty is refilled and the milk in M is allowed
to settle. When all agitation in the milk contained in the filling vessel has ceased
pawl V is set free and vessel M gradually lowered this causes the valves t to open so
that the milk flows evenly into all the bottles and fills all of them alike.
When the bottles are full band wheel P is turned raising vessel M and tubes L until
the engagement of the pawl shows that the tubes L are withdrawn from the bottles.
The wheel K is now operated to depress the long arm of the lever J consequently the
plate G rises and the projections of the rings F place the stoppers on the bottle
mouths. When the operator has ascertained the completion of this operation by
looking through sight u' he reverses wheel k raises the long arm of lever I and so
brings down plate G with considerable force. The projections on rings F will
consequently force down the levers s of the stoppering devices securing all of the latter
& closing all the bottles hermetically.
This completes the operation and the steam-inlets being closed and the lid raised
the bottles are removed for the introduction of a fresh supply.
For large vessels such as casks and the like the described form of apparatus
is not convenient and the modification shown in figs. 9 & 10 has been devised for
this purpose. The pan remains unaltered.
The filling apparatus B (figs. 9 & 10) has hermetically closing door by which the
cask or the like is introduced and placed on the truck Y. This apparatus is divided
into two compartments I and II, the upper for receiving the milk before it is allowed
to flow into the barrel. Into the lower portion I fitted with a perforated false bottom Z
a branched steam-pipe C is fitted one branch leading below the perforated bottom Z
in order to distribute the steam properly.
The upper branch can admit steam into the cask or barrel by pushing back the
spring-back pressure valve in the latter, this makes the interior of the cask sterile.
Suitable Ushaped pipes conduct steam from the compartment I to the compartment II
for a like purpose. Pressure guages safety valves & thermometers serve to control
tension & temperature of the aqueous vapour. When the interior of the apparatus
and the cask are thoroughly sterilised the cock o is opened and the milk is, through
pipe E & branch w passed into compartment II. A glazed & graduated sight hole U
in the side of the apparatus shows the quantity passed into the compartment II and
this allows to close the cock o when just that quantity of milk has flown into com-
partment II as will exactly fill the cask introduced into compartment I. This done
the truck Y is drawn forward by the rod a (passing through a stuffing box in the side

page_text: Υ
of the apparatus) until the upper branch C of the pipe is clear of the cask and the
valve opened by such pipe, has closed again. This will bring the back-pressure valve
in the head of the barrel (fig. 10) under the tap h¹ which is vertically adjustable.
Rods guide this tap, its outlet is secured in the bottom of the compartment by a
stuffing box and at its lower end it has outlot slots. On the plug of this tap a rod
is provided which passes an air tight stuffing box on the top of the apparatus and is
fitted with a stop within the compartment and a handle outside of the same. When
the cask is in the proper position, which can be ascertained by a sight hole in the
compartment I the rod y and by it the tap h¹ is lowered into the position shown in
figs. 9. The outlet of the tap depresses the back pressure valve and passes into the
cask but without establishing communication with the compartment II. This only
takes place when the handle on the rod is turned acting on the plug of tap '. The
milk now flows through tap ', past the back pressure valve into the cask.
When the cask is full, the rod y is turned back and this closes the tap h¹.
as the tap is raised again by rod y the back-pressure valve closes automatically
and the milk is hermetically enclosed. The door of the apparatus is now opened & the
cask removed.
As soon
When the milk is to be drawn from the cask, the draw-off cock & is opened (the
vent ¹ in the lid having first been opened. The vent & carries a casing or chamber
filled with sterilised wadding or cottonwool so that all air passing through it is filtered
& likewise sterilised. Any desired quantities may therefore be successively be drawn
from the cask without affecting the keeping quantity of the remainder. To obtain
greater security as to the keeping of the milk than the filtration of air by sterilised
wadding offers, sterilised air is compressed in the cask which then contains only so
much milk as will be expelled by cock by the compressed air it contains after the
back pressure valves are closed.
The apparatus described permit, as will be seen, to fill suitable vessels of any size
with appropriate quantities of sterilised milk and to preserve the latter indofinitely.
Having now particularly described & ascertained the nature of the said inven-
tion, & in what manner the same is to be performed we declare that what
we claim is
1.) A method or process of preparing milk enabling the same to be preserved,
which process consists in neutralising the milk, then subjecting it to flowing aqueous
vapour of 100° temperature during a sufficient time under exclusion of the atmosphere
filling it into and sealing it in separately sterilised vessels, likewise under exclusion of
the atmosphere, substantially as set forth.
2.) For filling milk prepared as above specified into bottles or the like, the apparatus
having the plate or table D, the movable plate G carrying rings F fitted with pro-
jections for supporting and operating the stoppering devices, arranged in conjunction
with suitable accessory parts, all as set forth & shown in the drawings.
3.) For filling casks barrels or the like with milk prepared as specified, an apparatus
divided into compartments I and II the compartment 1 serving for the reception of
the cask or receptacle and the compartment Il for the milk, the said apparatus, being
fitted with devices for sterilisation and for transferring the milk, the cask or
receptacle being fitted with suitable valves & cocks, the whole as described and shown
in the drawings.
TOLL
CA
1009
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicants.