Improved Apparatus for Sterilizing Liquids, applicable also for Heating, Cooling, Condensing, Distilling, and other similar Purposes.
Year: 1894

page_text: Date of Application (in United Kingdom), 19th May, 1894
Complete Specification Left, 22nd Jan., 1895-Accepted, 23rd Feb., 1895
PROVISIONAL SPECIFICATION.
Improved Apparatus for Sterilizing Liquids, applicable also for
Heating, Cooling, Condensing, Distilling, and other similar
Purposes.
I, PAUL MARIE FRANÇOIS LAURENT, of 1 Rue Jacquier, Paris, France,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to an apparatus for enabling temperatures to be exchanged
between two or more fluids and it consists essentially of two or more spirally
coiled sheets of metal between which the fluids are caused to circulate. The
apparatus is more especially intended for use in sterilizing liquids by means
of heat.
It is known that by maintaining water, for example, at a temperature above
100 degrees C. for a sufficient length of time, the whole of the germs contained
will be destroyed. The difficulty has been to restore to the water its initial
temperature; as it will be easily understood that if the temperature of water be
raised a few degrees only it is no longer potable since no one would like to drink
tepid water. Every degree corresponds to an expenditure of one unit of heat
per litre, and if extraneous means are employed to cool the liquid, much
complication results as well as very considerable expense.
My improved apparatus enables these objections to be obviated.
The accompanying drawing illustrates in an elementary manner the principle of
the invention.
Figure 1 shows in perspective and before being coiled the metal sheets and
intermediate strips or distance pieces of which the apparatus is composed.
Figure 2 is a transverse section of the apparatus.
Figure 3 is a similar section of a modification.
Figure 4 is a longitudinal section.
Figure 5 is a longitudinal vertical section of the apparatus as applied for a
particular purpose.
Figure 6 is a transverse section of the heat exchanging apparatus properly so
called.
Figure 7 is a transverse section of the heater.
The apparatus is constructed as shown in Figure 1 of two sheets of copper,
brass, tinplate, galvanized iron, or other metal a, b, thin enough to admit of being
coiled. These metal sheets are superposed and held at a suitable distance apart by
any suitable means, such for example as strips è of any suitable material, applied
along the longitudinal edges of the sheets a, b. These strips should be thin
enough to allow of their being coiled up together with the sheets, a certain
number being superposed so that the sheets a, b, will be separated by intervening
spaces forming passages d and e, of suitable width.

page_text: The whole system of sheets and intermediate distance pieces is coiled upon
itself around a central tube f. The convolutions thus formed require to be drawn
very closely together and it is necessary that they should be sufficiently flexible to
be coiled and that the coiling apparatus employed should apply considerable
pressure. For this purpose the ends of the sheets a, and', and distance strips c
are fixed to the central tube which is mounted upon a horizontal mandrel
supported on a strong framing and having keyed thereon a toothed wheel operated
by a worm. The sheets and strips pass between guides carried by the framing and
between metal plates or clamps tightened by bolts so that strong pressure is
exerted upon the sheets whereby on rotating the worm the resistance due to
friction will cause the sheets to be tightly coiled. The ends of the spiral passages
between the sheets are closed as shown in Figures 2 and 3 and to each of the
spaces de, are connected the pipes g, h, g, h, de therefore form two passages of
rectangular section which can have no connection with each other. If a liquid be
introduced by pipe g it will circulate through passage d and pass out by pipe g¹,
while if a second liquid be introduced by pipe h¹ it will circulate in the reverse
direction through the passage e and escape by the pipe h. These two liquids
exchange their temperatures through the walls a band owing to the thinness-and
large area of those walls the two liquids will always have at two adjacent points
sensibly the same temperature so that the exchange of heat is almost perfect.
When it is required to sterilize a liquid, the passages de would communicate
with each other at point as shown in Figure 3 and the central tube would be
heated internally by any suitable arraugement. The water to be sterilized enters
by pipe y circulates in passage e from the circumference to the centre becomes
heated around the central tube by which it is raised to the temperature desired
and then returned through the second passage e where its heat is transmitted to the
water which enters and escapes through the pipe h. The temperature of the water
on exit will more nearly coincide with that on entry the greater is the superficial
area of the two passages de. To facilitate the circulation cords m are disposed
within the passages d and e forming separate channels opening into the general
passage and which prevent all buckling of the plates, preserve their distance apart,
and ensure a regular circulation of the liquid.
In order to render the joints of the distance pieces or strips water-tight, a cord 7
or band of suitable material such as india-rubber, cotton impregnated with some
suitable composition &c. is placed just within the said distance pieces and after
coiling the spaces between the outer edges of the plates, which project slightly
beyond the strips, are filled with solder or cement suited to the conditions of
working of the apparatus. In this manner an absolute water-tight joint is
obtained and when low pressures only are employed the strip may be dispensed
with, a simple cotton plait sufficing to ensure the spacing of the plates as well as a
water-tight joint.
In a large number of cases the water in order to be completely sterilized must
be kept for a certain time at a temperature exceeding 100 degrees C. and as the
capacity of the apparatus must be proportionate to the delivery and the length of
time the water is required to remain at this temperature, the apparatus is in this
case divided into two parts viz. :-an exchanger apparatus E and a heater C both
these parts of the apparatus being constructed on the principle of that hereinbefore
described.
The exchanger only differs from the heater in that it is not heated internally.
The central tube is made in two parts 1, f, between which the ends of the plates
are clamped as shewn in Figure 6 and then soldered. The strips care fixed to
collars and the coiling is performed in the manner before described. The
central tube is provided with rings k suitably perforated to permit of the liquid
circulating throughout the apparatus. The central tube of the heater may be
constituted of two concentric tubes f³, f, the space between them being filled
with a suitable liquid forming a bath, which prevents the liquid to be sterilized'
from coming in contact with a surface which may be accidentally overheated. One

page_text: of the plates a of the heater is fixed to a transverse plate m and the other plate
is fixed upon the central tube itself. The plates and strips are coiled. and. fixed in
the manner previously described, and when the coiling is terminated, the collecting
tubes p, q, p, q, are solderedion.and the whole is then consolidated by means of
hoops or other suitable means.
The heat exchanger and the heater communicate with each other by means of
the connecting pipes r, The water bath of the heater is heated by means of a
gas burner &, the internal tube being furnished with a diaphragm beneath
which the flame is caused to pass after having heated the upper part for the
purpose of heating the lower part of said tube before passing to the chimney s¹.
The supply of gas is controlled by a temperature regulator i formed of a tube
filled with air which is immersed in the liquid to be sterilized, the variations in
volume of the air consequent on the differences of temperature, causing the opening
or closing of the gas inlet pipe t', the gas being admitted by the pipe t' which dips
in the liquid contained in the vessel t, to which the pipe t is connected. The
water to be sterilized enters at pipe g and circulates through the space & from the
centre to the circumference, and becomes heated by the water which circulates in
the reverse direction and attains a temperature of about 100 degrees C. on leaving
the first apparatus, from which it passes through pipe r to the heater C. The
water entering this apparatus at a temperature of about 100 degrees C. circulates
in space d' from the circumference to the centre, being constantly heated by the
liquid circulating in the reverse direction and by the central tube whereby it is
raised to the temperature necessary to completely sterilize it; the water then
returns through the space e' from the centre to the circumference gives up a part
of its heat to the inflowing water, and passes out of the heater at a temperature of
about 100 degrees C. into the heat exchanging apparatus in which. it circulates
from the circumference to the centre through the space e and is discharged at pipe /
after having yielded up the whole of its heat to the inflowing water. The
dimensions of the heating apparatus would be regulated according to the
temperature to which the water is to be raised and the time during which it is to be
maintained at this temperature.
My apparatus admits of the employment of very thin metal. sheets of large
superficial area, and the heat is readily transmitted in a methodical manner so that
the water before its exit.from the apparatus delivers up the whole of its heat to
the inflowing water. The whole of the heat is thus utilized, the consumption of
fuel is very small, hence the apparatus is very economical, and the water may be
employed immediately on leaving the apparatus without requiring to be passed
through a cooler, which is a great advantage since tepid water is distasteful. for
drinking.
The apparatus possesses great strength and no risk of explosion is incurred.
All the joints being exposed there can be no communication between the two
currents and in, no case can the sterilized water be contaminated by. impure
water.
My apparatus is placed upon the water supply pipe, its action being dependent
on the rate of consumption while the temperature regulator renders its action
entirely automatic and dispenses with the necessity of any superintendence. The
relative dimensions and the number of heaters and heat exchangers are dependent
upon the consumption and available pressure while their arrangement.and grouping
would vary according to the nature of the application and the conditions of each
particular case.
It may happen where large quantities of water are to be supplied at a low
pressure that the time necessary for sterilizing may be so long that the delivery
will be very slow. In this case the heater may be replaced by an ordinary boiler
heated by any suitable means and in which by means of a system of partitions the
water is constrained to follow a regular course which ensures its remaining for the
required time at the necessary temperature. The apparatus of my invention is also
applicable to the sterilization. of wine, beer, milk, etc. As a heat exchanging

page_text: apparatus it may also be applied to the condensation of vapors, and as a refrigerator
or heating apparatus etc.
In certain cases a larger number of passages are required and for this
it
purpose
is only necessary to coil a number of sheets corresponding to the number of
passages required. In the distillation of alcoholic liquids for example there are
three fluids in circulation viz., the liquid to be distilled, the vapor to be condensed,
and the spent liquid. The liquid to be treated requires to be brought to the
highest temperature before being conducted into the evaporating boiler and in this
case a heat exchanger is employed having three passages, in one of which the liquid
to be distilled circulates, while in the two others the vapor and spent liquor would
circulate in the reverse direction.
1004
P. M. F. LAURENT,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.
Improved Apparatus for Sterilizing Liquids, applicable also for
Heating, Cooling, Condensing, Distilling, and other similar
Purposes.
I, PAUL MARIE FRANÇOIS LAURENT, of 1, Rue Jacquier, Paris, France,
Engineer, 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 apparatus for enabling temperatures to be exchanged
between two or more fluids, and it consists essentially of two or more spirally-coiled
sheets of metal between which the fluids are caused to circulate. The apparatus is
more especially intended for use in sterilizing liquids by means of heat.
It is known that by maintaining water, for example, at a temperature above
100 degrees C. for a sufficient length of time, the whole of the germs contained
will be destroyed. The difficulty has been to restore to the water its initial
temperature, as it will be easily understood that if the temperature of water be
raised a few degrees only it is no longer potable, since no one would like to drink
tepid water. Every degree corresponds to an expenditure of one unit of heat per
litre, and if extraneous means are employed to cool the liquid, much complication
results as well as very considerable expense.
My improved apparatus enables these objections to be obviated.
The drawing accompanying my Provisional Specification illustrates, in an
elementary manner, the principle of the invention.
Figure 1 shews in perspective and before being coiled the metal sheets and
intermediate strips or distance pieces of which the apparatus is composed.
Figure 2 is a transverse section of the apparatus.
Figure 3 is a similar section of a modification.
Figure 4 is a longitudinal section.
Figure 5 is a longitudinal vertical section of the apparatus as applied for a
particular purpose.
Figure 6 is a transverse section of the beat exchanging apparatus properly so
called.
Figure 7 is a transverse section of the heater.
The apparatus is constructed as shewn in Figure 1 of two sheets of copper, brass,
tinplate, galvanized iron, or other metal, a, b, thin enough to admit of being
coiled. These metal sheets are superposed and held at a suitable distance apart

page_text: by any suitable means, such, for example, as strips c, of any suitable material,
applied along the longitudinal edges of the sheets a, b. These strips c should be
thin enough to allow of their being coiled up together with the sheets, a certain
number being superposed so that the sheets a, b, will be separated by intervening
spaces forming passages and e of suitable width.
The whole system of sheets and intermediate distance pieces is coiled upon itself
around a central tube f. The convolutions thus formed require to be drawn very
closely together and it is necessary that they should be sufficiently flexible to be
coiled and that the coiling apparatus employed should apply considerable pressure.
For this purpose the ends of the sheets a and b and distance strips c are fixed to the
central tube which is mounted upon a horizontal mandrel supported on a strong
framing and having keyed thereon a toothed wheel operated by a worm. The
sheets and strips pass between guides carried by the framing and between metal
plates or clamps tightened by bolts, so that strong pressure is exerted upon the
sheets whereby on rotating the worm the resistance due to friction will cause the
sheets to be tightly coiled. The ends of the spiral passages between the sheets are
closed, as shewn in Figures 2 and 3, and to each of the spaces d, e, are connected
the pipes g, h, g', '; the spaces d, e, therefore, form two passages of rectangular
section which can have no connection with each other.
If a liquid be introduced by pipe g it will circulate through passage d and pass
out by pipe g', while if a second liquid be introduced by pipe it will circulate in
the reverse direction through the passage e and escape by the pipe h. These two
liquide exchange their temperatures through the walls a, b, and, owing to the
thinness and large area of those walls, the two liquids will always have at two
adjacent points sensibly the same temperature, so that the exchange of heat is
almost perfect.
When it is required. to sterilize a liquid, the passages d, e, would communicate
with each other at point i, as shewn in Figure 3, and the central tubo would be
heated internally by any suitable arrangement. The water to be sterilized enters
by pipe g, circulates in passage d from the circumference to the centre, becomes
heated around the central tube f by which it is raised to the temperature desired,
and then returns through the second passage e where its heat is transmitted to the
water which enters and escapes through the pipe h. The temperature of the water
on exit will more nearly coincide with that on entry, the greater is the superficial
area of the two passages d, e. To facilitate the circulation, cords m are disposed
within the passages d and e, forming separate channels opening into the general
passage and which prevent all buckling of the plates, preserve their distance apart,
and ensure a regular circulation of the liquid.
In order to render the joints of the distance pieces or strips water-tight, a cord /
or band, of suitable material, such as india-rubber, cotton impregnated with some
suitable composition, etc., is placed just within the said distance pieces and after
coiling, the spaces between the outer edges of the plates, which project slightly
beyond the strips, are filled with solder or cement suited to the conditions of
working of the apparatus. In this manner an absolute water-tight joint is obtained
and when low pressures only are employed the strip may be dispensed with, a
simple cotton plait sufficing to ensure the spacing of the plates, as well as a water-
tight joint.
In a large number of cases the water, in order to be completely sterilized, must
be kept for a certain time at a temperature exceeding 100 degrees C. and as the
capacity of the apparatus must be proportionate to the delivery and the length of
time the water is required to remain at this temperature, the apparatus is, in this
case divided into two parts viz. :-au exchanger apparatus E aud a heater C, both.
these parts of the apparatus being constructed on the principle of that hereinbefore
described.
The exchanger only differs from the heater in that it is not heated internally,
The central tube is made in two parts f,, between which the ends of the plates
are clamped, as shewn in Figure 6, and then soldered. The strips c are fixed to

page_text: collars, and the coiling is performed in the manner before described. The
central tube is provided with rings & suitably perforated to permit of the liquid
circulating throughout the apparatus. The central tube of the heater may be
constituted of two concentric tubes,, the space between them being filled with
a suitable liquid forming a bath, which prevents the liquid to be sterilized from
coming in contact with a surface which may be accidentally overheated.. One of
the plates a of the heater is fixed to a transverse plate n.and the other plate bis
fixed upon the central tube itself. The plates and strips are coiled and fixed in the.
manner previously described, and when the coiling is terminated, the collecting
tubes p, q, p, q, are soldered on, and the whole is then consolidated by means of
hoops or other suitable means.
The heat exchanger and the heater communicate with each other by means of
the connecting pipes, r². The water bath of the heater is heated by means of a
gas burner s, the internal tube being furnished with a diaphragm beneath
which the flame is caused to pass, after having heated the upper part for the purpose
of heating the lower part of said tube before passing to the chimneys. The
supply of gas is controlled by a temperature regulator t formed of a tube filled with
air which is immersed in the liquid to be sterilized, the variations in volume of the
air consequent on the differences of temperature, causing the opening or closing of
the gas inlet pipe t', the gas being admitted by the pipe t' which dips in the liquid
contained in the vessel to which the pipe t is connected. The water to be
sterilized enters at pipe g and circulates through the spaced from the .centre to the
circumference, and becomes heated by the water which circulates in the reverse
direction and attains a temperature of about 100 degrees C. on leaving the first
apparatus, from which it passes through pipe to the heater C. The water
entering this apparatus at a temperature of about 100 degrees C. circulates in
space from the circumference to the centre, being constantly heated by the
liquid circulating in the reverse direction and by the central tube, whereby it is
raised to the temperature necessary to completely sterilize it; the water then
returns through the space el from the centre to the circumference, gives up a part
of its heat to the inflowing water, and passes out of the heater, at a temperature of
about 100 degrees C. by pipe 2, into the heat exchanging apparatus in which it
circulates from the circumference to the centre through the space e and is
discharged at pipe h, after having yielded up the whole of its heat to the inflowing
water.
The dimensions of the heating apparatus would be regulated according to the
temperature to which the water is to be raised and the time during which it is to
be maintained at this temperature.
My apparatus admits of the employment of very thin metal sheets of large
superficial area, and the heat is readily transmitted in a methodical manner so that
the water before its exit from the apparatus delivers up the whole of its heat to the
inflowing water. The whole of the heat is thus utilized, the consumption of fuel is
very small, hence the apparatus is very economical, and the water may be
employed immediately on leaving the apparatus without requiring to be passed
through a cooler, which is a great advantage, since tepid water is distasteful for
drinking.
All
The apparatus possesses great strength and no risk of explosion is incurred.
the joints being exposed, there can be no communication between the two currents
and in no case can the sterilized water be contaminated by impure water.
My apparatus is placed upon the water supply pipe, its action being dependent
on the rate of consumption, while the temperature regulator renders its action
entirely automatic and dispenses with the necessity of any superintendence. The
relative dimensions and the number of heaters and heat exchangers are dependent
upon the consumption and available pressure while their arrangement and grouping
would vary according to the nature of the application and the conditions of each
particular case.
It may happen, where large quantities of water are to be supplied at a low

page_text: pressure, that the time necessary for sterilizing may be so long that the delivery
will be very slow. In this case the heater may be replaced by an ordinary boiler
heated by any suitable means and in which by means of a system of partitions the
water is constrained to follow a regular course, which ensures its remaining for the
required time at the necessary temperature.
The apparatus of my invention is also applicable to the sterilization of wine, beer,
milk, etc. As a heat exchanging apparatus it may also be applied to the condensa-
tion of vapours, and as a refrigerator or heating apparatus, etc.
In certain cases a larger number of passages are required and for this purpose it
is only necessary to coil a number of sheets corresponding to the number of
passages required. In the distillation of alcoholic liquids, for example, there are
three fluids in circulation viz. :-the liquid to be distilled, the vapour to be
condensed, and the spent liquid. The liquid to be treated requires to be brought to
the highest temperature, before being conducted into the evaporating boiler, and in
this case a heat exchanger is employed having three passages, in one of which the
liquid to be distilled circulates, while in the two others the vapour and spent liquor
would circulate in the reverse direction.
.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1st. A system of apparatus enabling two or more fluids to exchange their
temperatures by causing them to circulate between two or more sheets of metal or
other material coiled spirally around a central tube which may or may not be
provided with a suitable heating arrangement, the apparatus being so arranged
that the fluid emerging shall have sensibly the same temperature as
entering.
that
2nd. The combination of two or more apparatus arranged as hereinbefore claimed
and united by a suitable system of tubing, all substantially as and for the purpose
specified with reference to the annexed drawing.
Dated this 22nd day of January 1895
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.