Improvements in the Manufacture of Aerated Bread and Cakes.
Year: 1893

page_text: Date of Application, 8th July, 1893
Complete Specification Left, 7th Apr., 1894-Accepted, 7th July, 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Aerated Bread and Cakes.
I, JAMES CHILDS, Heathcroft, Putney Hill, in the County of Surrey, Gentleman,
do hereby declare the nature of this invention to be as follows:-
In the process of making aerated bread as heretofore carried out a mixing vessel
in which flour has to be mixed with aerated water or other liquid is put in
connection with a vessel containing a supply of the liquid used. Air is first
expelled from the mixing vessel by filling it with carbonic acid, allowing the air
to escape through an opening at the top and then closing this opening. Carbonic
acid gas is also pumped into the vessel containing the liquid to be aerated, all
gas not absorbed by the liquid passing on to the interior of the mixing vessel
and the pumping is continued until the pressure in the two vessels has been
raised to the required degree-when this has taken place the liquid now aerated'
by the gas which it has absorbed is allowed to flow down into the mixing vessel
and is mixed with the flour which that vessel contains.
The aeration of the liquid in the above way is not so complete as is desirable
and practicable-and in addition considerable plant is required for manufacturing
the carbonic acid gas and for pumping the gas into the vessels containing the
liquid to be aerated so rendering this way of making bread and the like unsuitable
except for large establishments.
The object of my invention is to provide apparatus which can not only be used in
small establishments but by which also the manufacture of bread and the like is
greatly improved.
In the manufacture of bread cakes and the like from dough prepared with
aerated liquid it is of great importance that the liquid with which the flour and
other ingredients are admixed should not only be thoroughly aerated but that it
should be aerated with pure carbonic acid gas unadmixed with any atmospheric
air in order that when the dough is taken from the mixing vessel and relieved
from pressure it may not only rise sufficiently but also gradually and uniformly
whereas if atmospheric air be admixed with the carbonic acid the giving off of
gas takes place much too rapidly for the dough to rise into a uniform minutely
divided spongy mass.
To ensure that the carbonic acid gas employed shall not be admixed with atmo-
spheric air I cause the liquid to be aerated with carbonic acid from bottles
containing this gas in a liquid state and to ensure the thorough aeration of the
liquid with the gas I construct the apparatus in such a way that the liquid
before being admixed with flour &c. shall be kept agitated for a considerable
time in an aerating vessel. The aeration may be effected either by rocking the
vessel or by a revolving agitator. The vessel may either be the vessel in which
the amount of liquid required for each charge of dough is measured before being
admitted to the dough mixing vessel or it may be an aerating vessel of much
greater size, than is required for containing this quantity of liquid. When a
large aerating vessel is used I also provide a measuring vessel into which the
requisite quantity of aerated liquid to be delivered into the dough mixing vessel
for each charge can be drawn off from the large aerating vessel and from
which the liquid can be passed to the dough mixing vessel without loss of gas.
The large aerating vessel I preferably fit with a shaft passing into its interior

page_text: and having blades projecting from it inside the vessel to agitate the liquid, whilst
outside the vessel I provide for giving to the shaft a continuous revolving motion.
I also provide for keeping this vessel constantly supplied with gas under pressure
from bottles containing liquid carbonic acid, the admission of gas from the bottles
to the vessel being controlled by a small stop valve so that an approximately
constant pressure of gas may be maintained within the vessel. In this way the
liquid may be kept agitated for a long time even for hours in presence of gas under
pressure before being used for mixing with the flour.
The more perfect the aeration of the liquid the more perfectly will the dough
formed with it pass into a minutely divided spongy state.
By using bottles containing liquid carbonic acid the amount of plant required
For an establishment for making bread or cakes or the like is much reduced and can
be used by any baker without the assistance of a skilled engineer.
All the pressure requisite for aerating the liquid used and for expelling the aerated
dough from the mixing vessel into the moulds can be obtained from the pressure
upon the gas within the bottles.
To avoid waste of gas when a fresh charge of flour or material is to be placed
into the dough mixing vessel the charge of flour or material may as described in
the Specification of a former Patent granted to me No. 3607 of 1889 be first
placed into a vessel which is separated by a valve from the dough mixing vessel
and then when the vessel into which the flour has been placed has been closed the
valve may be opened and the flour &c. allowed to drop down into the dough mixing
vessel or if this arrangement be not adopted the gas under pressure in the dough
mixing vessel may be allowed to flow off into a bag or receiver before the dough
mixing vessel is opened for a fresh charge of flour or material to be fed into it.
The power requisite for revolving the mixer of the mixing vessel and the agitator
of the aerating vessel can be obtained from a small gas engine or otherwise or hand
power may be used.
Improvements in the Manufacture of Aerated Bread and Cakes.
I, JAMES CHILDS, of Heathcroft, Putney Hill, in the County of Surrey,
Gentleman, 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 aud
by the following statement:-
In the process of making aerated bread as heretofore carried out a mixing vessel
in which four has to be mixed with aerated water or other liquid is put in connec-
tion with a vessel containing a supply of the liquid used. Air is first expelled from
the mixing vessel by filling it with carbonic acid, allowing the air to escape through
an opening at the top and then closing this opening. Carbonic acid gas is also
pumped into the vessel containing the liquid to be aerated, all gas not absorbed by
the liquid passing on to the interior of the mixing vessel and the pumping is
continued until the pressure in the two vessels has been raised to the required
degree when this has taken place the liquid now aerated by the gas which it has
absorbed is allowed to flow down into the mixing vessel and is mixed with the flour
which that vessel contains.
The aeration of the liquid in the above way is not so complete as is desirable
and practicable and in addition considerable plant is required for manufacturing the
carbonic acid gas and for pumping the gas into the vessels containing the liquid to
be aerated so rendering this way of making bread and the like unsuitable except
for large establishments.
The object of my invention is to provide apparatus which can not only be used

page_text: in small establishments but by which also the manufacture of bread and the like is
greatly improved.
In the manufacture of bread cakes and the like from dough prepared with
aerated liquid it is of great importance that the liquid with which the flour and
other ingredients are admixed should not only be thoroughly aerated but that it
should be aerated with pure carbonic acid gas unadmixed with any atmospheric air in
order that when the dough is taken from the mixing vessel and relieved from
pressure it may not only rise sufficiently but also gradually and uniformly whereas
if atmospheric air be admixed with the carbonic acid the giving off of gas takes
place much too rapidly for the dough to rise into a uniform minutely divided
spongy mass.
To ensure that the carbonic acid gas employed shall not be admixed with atmo-
spheric air I cause the liquid to be aerated with carbonic acid from bottles containing
this gas in a liquid state and to ensure the thorough aeration of the liquid with the
gas I construct the apparatus in such a way that the liquid before being admixed
with flour &c. shall be kept agitated for a considerable time in an aerating vessel.
The aeration may be effected either by rocking the vessel or by a revolving agitator.
The vessel may either be the vessel in which the amount of liquid required for
each charge of dough is measured before being admitted to the dough mixing vessel
or it may be an aerating vessel of much greater size than is required for containing
this quantity of liquid. When a large aerating vessel is used I also provide a
measuring vessel into which the requisite quantity of aerated liquid to be delivered
into the dough mixing vessel for each charge can be drawn off from the large
aerating vessel and from which the liquid can be passed to the dough mixing vessel
without loss of gas.
The large aerating vessel I preferably fit with a shaft passing into its interior
and having blades projecting from it inside the vessel to agitate the liquid, whilst
outside the vessel I provide for giving to the shaft a continuous revolving motion.
I also provide for keeping this vessel constantly supplied with gas under pressure
from bottles containing liquid carbonic acid, the admission of gas from the bottles
to the vessel being controlled by a small stop valve so that an approximately
In this way the
constant pressure of gas may be maintained within the vessel.
liquid may be kept agitated for a long time even for hours in presence of gas under
pressure before being used for mixing with the flour.
The more perfect the aeration of the liquid the more perfectly will the dough
formed with it pass into a minutely divided spongy state.
By using bottles containing liquid carbonic acid the amount of plant required
for an establishment for making bread or cakes or the like is much reduced and can
be used by any baker without the assistance of a skilled engineer.
All the pressure requisite for aerating the liquid used and for expelling the
aerated dough from the mixing vessel into the moulds can be obtained from the
pressure upon the gas within the bottles.
To avoid waste of gas when a fresh charge of flour or material is to be placed
into the dough mixing vessel the charge of flour or material may as described in
the Specification of a former Patent granted to me No. 3607 of 1889 be first
placed into a vessel which is separated by a valve from the dough mixing vessel
and then when the vessel into which the flour has been placed has been closed the
valve may be opened and the flour &c. allowed to drop down into the dough mixing
vessel or if this arrangement be not adopted the gas under pressure in the dough
mixing vessel may be allowed to flow off into a bag or receiver before the dough
mixing vessel is opened for a fresh charge of flour or material to be fed into it.
The power requisite for revolving the mixer of the mixing vessel and the agitator
of the aerating vessel can be obtained from a small gas engine or otherwise or hand
power may be used.
Figure 1 of the drawing annexed shews an elevation of apparatus arranged
according to my invention. Figure 2 is a side elevation of the aerating vessel
sod

page_text: A is the aerating vessel, B a pipe extending to the bottom of the interior of this
vessel from a bottle C containing liquid carbonic acid.
Da tap for controlling the passing off of gas from the bottle through the pipe B.
E a pipe passing from the bottom of the vessel A to a measuring vessel F. F' a
gauge glass fitted to the measuring vessel. G is a mixing vessel in which measured
quantities of aerated liquid are mixed with flour and other ingredients for making
bread, cakes and the like-H a mixing blade revolved within the mixing vessel.
The water or liquid to be aerated is run into the aerating vessel A from an
elevated cistern or is forced into it by a force pump.
A shaft I which passes through the aerating vessel and has agitating blades
standing out from it is then made to revolve and carbonic acid is passed into the
vessel from the bottle C by opening the tap D until the pressure in the aerating
vessel has risen to the extent required-the pressure in the vessel is indicated by a
pressure gauge J. The liquid is kept agitated in this way in presence of carbonic
acid under pressure for a considerable time previous to its being used.
When a charge of dough is to be mixed-the requisite quantity of flour and other
ingredients is placed into the mixing vessel through the door G-the air in this
vessel is then expelled by the admission into it of carbonic acid through a pipe K
from the upper part of the vessel A by opening the taps K1 K2. The door G¹ is
then closed and more carbonic acid is admitted to the mixing vessel and from it to
the measuring vessel until the pressure in these vessels is nearly but not quite up
to the pressure in the aerating vessel.
The tap L' on the pipe L which connects the bottom of the measuring vessel
with the mixing vessel is then closed and also the taps K' K' on the pipe K.
Afterwards the taps E' E2 on the pipe E are opened and aerated liquid allowed to
pass into the measuring vessel from the aerating vessel.
When the measuring vessel contains the required quantity of aerated liquid the
tap E' is closed and the tap L' is opened--the aerated liquid then flows down from
the measuring vessel into the mixing vessel-the slight excess of pressure in the
measuring vessel helping it to do so. The tap L is now closed and the mixing
blade is kept revolving within the mixing vessel until the dough is thoroughly
mixed. When this has been done the dough is drawn off into moulds in the ordinary
manner through the tap M.
When all the dough has been drawn off from the mixing vessel carbonic acid
may be allowed to pass off from this vessel through a pipe N by opening a tap N'
upon it.
When the pressure of gas in the vessel has in this way been reduced the door G¹
may be opened and a fresh charge of flour and ingredients placed into the vessel
and the operation repeated. The carbonic acid allowed to pass away by the pipe N
may either be allowed to escape into the air and be wasted or it may pass into an
elastic bag or other form of gasometer and be pumped from thence back into the
aerating vessel.
In place of the charge of flour and other ingredients being introduced into the
mixing vessel through a door G¹ as above described it may as has before been
proposed by me be first placed into a smaller vessel O which as shewn in Figure 3
is shut off from the mixing vessel by a valve P. Before introducing the charge into
the mixing vessel the smaller vessel O is closed at the top by a cover Q-the
valve P is then opened and the charge allowed to drop into the mixing vessel which
may already have had a charge of aerated liquid introduced into it.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
In apparatus used in the manufacture of aerated bread cakes and the like the
combination of a mixing vessel in which flour and other ingredients can be mixed
with aerated liquid, an aerating vessel for aerating water or other liquid supplied
with carbonic acid under pressure from a bottle containing liquid carbonic acid, a

page_text: measuring vessel for measuring the requisite quantity of aerated liquid to be mixed
with each charge of flour or other ingredient put into the mixing vessel and passages.
fitted with valves between the aerating vessel and the measuring vessel and between
the measuring vessel and the mixing vessel substantially as described.
Dated this 31st day of March 1894.
JAS. CHILDS.