IMPROVEMENTS IN APPARATUS FOR CONCENTRATING SYRUPS OF SUGAR, APPLICABLE ALSO IN OTHER MANUFACTURES
Year: 1878

page_text: LETTERS PATENT to Sydney Pitt, of Sutton, in the County of Surrey, for
the Invention of "IMPROVEMENTS IN APPARATUS FOR CONCENTRATING SYRUPS
OF SUGAR, APPLICABLE ALSO IN OTHER MANUFACTURES." A communication
from abroad by Jules Weibel, of Geneva, Switzerland, Engineer.
Sealed the 6th June 1879, and dated the 14th December 1878.
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office
of the Commissioners of Patents on the 14th December 1878.
SYDNEY PITT, of Sutton, in the County of Surrey. "IMPROVEMENTS IN APPA-
RATUS FOR CONCENTRATING SYRUPS OF SUGAR, APPLICABLE ALSO IN OTHER
MANUFACTURES." [A communication from abroad by Jules Weibel, of Geneva,
Switzerland, Engineer.]
In apparatus of double, treble, and in general multiple action employed in sugar
refineries for the concentration of syrups, steam is introduced into the condenser of
the first boiler, in which it condenses and causes the formation of an equivalent
quantity of vapour of water from the syrup to be concentrated. This vapour passes
into the condenser of a second boiler, where it similarly gives rise to another
quantity of vapour taken from the syrup, and so on.
These multiple evaporations can only take place when the liquors contained in
the successive boilers can enter into ebullition at lower and lower temperatures.
This result is obtained by producing a partial vacuum in the last boiler by means
of a surface or injection condenser supplied with cold water and provided with an
air pump.
The limits between which the multiple action process can be worked are the
absolute vacuum as the lower limit which in practice can only be approached, and
as the upper limit, the pressure which would render the apparatus too difficult to
Price G21

page_text: construct or too costly, and above all, the temperature to which the syrup to be
evaporated can be exposed without injury.
Within these limits it is possible in practice to obtain but a very restricted number
of successive evaporations.
I complete the multiple action apparatus by employing the high pressure steam
before it enters the multiple apparatus to produce the evaporation of a quantity of
syrup without exposing this to high pressures, and consequently to high tem-
peratures. I make use for this purpose of the process of increasing the temperature
of the vapour by compression by a mechanical force, and I combine this process
with that of multiple action in the following manner:-
I produce in one or in several generators vapour at high pressure and at tem-
perature T, and I employ this vapour to actuate a system composed of a steam
cylinder and of an exhausting and forcing vapour pump. In the steam cylinder
the steam from the generator acts in passing from the higher pressure at which it
has been produced to the lower pressure at which it can without inconvenience
be employed at a temperature T in the condenser of the first boiler of a multiple
action series. It produces its effect in this boiler, the vapour from which then acts
in the next boiler of the series, and so on up to the air pump.
Again, in addition to these boilers acting successively by the multiple action
process I have three or other number of other boilers, also furnished with internal
condensers, of any suitable construction, and which may exactly resemble those of
the boilers of the multiple action series.
These latter boilers are filled with syrup to be concentrated which has been
brought to a temperature t, at which the concentration should be carried on.
By means of the suction of the pump I produce in these boilers the degree of
pressure or of vacuum p which corresponds to the boiling of the syrup at a
temperature t.
The vapour of this syrup at a pressure p is itself at a temperature.6, which is
inferior to t by a quantity which depends upon the degree of concentration of the
syrup; it is drawn off by the pump and compressed by it to a pressure p¹ higher
than p. By this compression the vapour passes from the temperature to the
temperature 6. The compression is regulated in such manner that the temperature 4¹
is higher than t.
The vapour compressed at a pressure p¹, thus brought to a temperature corre-
sponding to 6', is conducted into the condensers of the boilers of the second series.
It comes against the walls of the condensers in contact with the syrup to be
evaporated which is at the temperature t. The vapours at a temperature 4¹ higher
than t condenses against the walls of the condensers, and thus restores to the liquid
all its latent heat. The ebullition of the syrup contained in the boilers of the second
series will thus be continuous as long as the pump remains in action.
With a given quantity of steam coming from the generator and passing in the
cylinder from the temperature T to the temperature T¹, I can raise by compression
from to 6¹ the temperature of a larger quantity of vapour taken from the syrup
to be concentrated according as the difference of T to T¹ is greater and that of 4 to g¹
smaller. It will be easy for a given weight of vapour passing into the cylinder to
determine T to T, 6 to 6', in such a manner that the quantity of vapours taken
from the syrup may be thrice that taken from the generator. In this case there
will be added to the triple effect produced by the vapour in the triple action
apparatus properly so called another similar effect, and consequently the action of
the vapour for evaporation of syrup is doubled without other expense than the small
consumption of fuel necessary for the increase of the pressure under which the
steam is produced in the steam generator.
The effect produced by the vapour in the boilers heated by the compression can
besides be varied at pleasure, as may be found practically convenient.
The process of compressing the vapour may also be applied to increase the yield
of multiple action apparatus by employing the elastic force of the steam passing in

page_text: the cylinder from the temperature T to the temperature T¹ to work an exhausting
and forcing pump, drawing the vapour from the last boiler of the triple action series
and compressing this vapour to raise its temperature so that it may enter into the
condenser of the first boiler of the new multiple action series.
The concentration of syrup may also be effected by employing only boilers
heated by the vapour which they produce after that this vapour has been
compressed.
In this case all the utilizable heat of the high pressure steam would be employed
in the cylinder to effect the compression of the vapour from all the evaporating
boilers.
The arrangement which I have described above in detail is in all respects
preferable to the two latter.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Sydney Pitt in the Great Seal Patent Office on the 13th June
1879.
SYDNEY PITT, of Sutton, in the County of Surrey. "IMPROVEMENTS IN APPA-
RATUS FOR CONCENTRATING SYRUPS OF SUGAR, APPLICABLE ALSO IN OTHER
MANUFACTURES." (A communication from abroad by Jules Weibel, of Geneva,
Switzerland, Engineer.)
In apparatus of double, treble, and in general multiple action employed in sugar
refineries for the concentration of syrups, steam is introduced into the condenser of
the first boiler, in which it condenses and causes the formation of an equivalent
quantity of vapour of water from the syrup to be concentrated. This vapour passes
into the condensor of a second boiler, where it similarly gives rise to another
quantity of vapour taken from the syrup, and so on.
These multiple evaporations can only take place when the liquors contained in
the successive boilers can enter into ebullition at lower and lower temperatures.
This result is obtained by producing a partial vacuum in the last boiler by means
of a surface or injection condensor supplied with cold water and provided with an
air pump.
The limits between which the multiple action process can be worked are the
absolute vacuum as the lower limit which in practice can only be approached, and
as the upper limit; the pressure which would render the apparatus too difficult to
construct or too costly, and above all, the temperature to which the syrup to be
evaporated can be exposed without injury.
Within these limits it is possible in practice to obtain but a very restricted
number of successive evaporations.
I complete the multiple action apparatus by employing the high pressure steam
before it enters the multiple apparatus, to produce the evaporation of a quantity of
syrup without exposing this to high pressures, and consequently to high tem-
peratures. I make use for this purpose of the process of increasing the temperature
of the vapour by compression by a mechanical force, and I combine this process
with that of multiple action in the following manner:-
As is represented by the Drawing annexed, I produce in one or in several gene-
rators G vapour at high pressure and at temperature T, and I employ this vapour
to actuate a system composed of a steam cylinder C and of an exhausting and
forcing vapour pump P. In the steam cylinder C the steam from the generator acts
in passing from the higher pressure at which it has been produced to the lower
pressure at which it can without inconvenience be employed at a temperature T in
the condenser of the first boiler of a multiple action series. It passes by the pipe a, b,
and produces its effect in the boiler A, the vapour from which then acts in A', and
so on up to the air pump p.
Again, in addition to the boilers A, A¹, A", acting successively by the multiple
action process, I have three or other number of other boilers B, B', BL, also furnished
with internal condensers of any suitable construction, and which may exactly
resemble those of the boilers of the multiple action series A, A¹, A¹¹.
These latter boilers are filled with syrup to be concentrated which has been
brought to a temperature t, at which the concentration should be carried on. By
means of the suction of the pump acting by the pipes c, c¹, c, d, I produce in the
boilers B, B1, B", the degree of pressure or of vacuum p, which corresponds to the
boiling of the syrup at a temperature t.
The vapour of this syrup at a pressure p is itself at a temperature 8, which is
inferior to t by a quantity which depends upon the degree of concentration of the
syrup. It is drawn off by the pump and compressed by it to a pressure p¹ higher
than p. By this compression the vapour passes from the temperature to the

page_text: temperature 6. The compression is regulated in such manner that the temperature 6¹
is higher than t.
The vapour compressed at the pressure p³, thus brought to a temperature corre-
sponding to 61, is conducted by the pipe e which ramifies in f¹, f¹, and f, into the
condensers of the boilers B1, B¹, and B. It comes against the walls of the condensers
in contact with the syrup to be evaporated, which is at the temperature t. The
vapour at a temperature 41 higher than t condenses against the walls of the con-
densers, and thus restores to the liquid all its latent heat. The ebullition of the
syrup contained in the boilers of the second series B, B', and B", will thus be
continuous as long as the pump P remains in action.
With a given quantity of steam coming from the generator G and passing in the
cylinder C from the temperature T to the temperature T¹, I can raise by compression
from 6 to ¹ the temperature of a larger quantity of vapour taken from the syrup
to be concentrated according as the difference of T to T' is greater and that of
to 'smaller. It will be easy for a given weight of vapour passing into the
cylinder C to determine T to T', to 6¹, in such a manner that the quantity of
vapours taken from the syrup may be thrice that taken from the generator. In
this case there will be added to the triple effect produced by the vapour in the triple
action apparatus, properly so called, another similar effect, and consequently the
action of the vapour for evaporation of syrup is doubled without other expense
than the small consumption of fuel necessary for the increase of the pressure under
which the steam is produced in the steam generator G.
The effect produced by the vapour in the boilers heated by the compression can
besides be varied at pleasure, as inay be found practically convenient.
The process of compressing the vapour may also be applied to increase the yield
of multiple action apparatus by employing the elastic force of the steam passing in
the cylinder C from the temperature T to the temperature T¹ to work exhausting
and forcing pump drawing the vapour from the last boiler of a multiple action series
and compressing this vapour to raise its temperature so that it may enter into the
condenser of the first boiler of a new multiple action series.
The concentration of syrup may also be effected by employing only boilers
heated by the vapour which they produce after that this vapour has been com-
pressed.
In this case all the utilizible heat of the high pressure steam would be employed
in the cylinder C to effect the compression of the vapour from all the evaporating
boilers.
The arrangement which I have described above in detail, and of which I give the
general design, is in all respects preferable to the two latter. I reserve to myself
however to vary the detail arrangement; thus in place of the three boilers B, B¹,
and B, heated by compressed vapour which I have shown in the Drawing, I may
have a greater number or a smaller number, or even only one, the arrangement of
condensing surfaces in condensers of greater or less extent having no influence upon
the increase of effect of the steam produced in the generator.
For the sake of clearness in the description and in the Drawing I have adopted
specially a group of boilers A, A¹, A", working by multiple action, and another
group B, B, B, working by compression. These boilers being exactly similar in
their construction, can be, both the one and the other, employed sometimes for the
one service, sometimes for the other. For this it is only necessary that the piping
should permit of their being put in connection with one another and with the
pump P in the desired conditions.
The details of construction of the boilers and of their indispensible accessories,
inlet pipes for the syrup to be concentrated, exit pipes for the concentrated syrup,
pipes for voiding the condensed water, safety vessels to prevent the passing over of
scums, manometers, &c., are not shown upon the Drawing, because although they
are necessary they are not peculiar to the arrangement above described, and do not
present any novelty. The same is the case as to the details of the steam cylinder

page_text: and of the exhausting and forcing pump, of which only the essential parts are
indicated without any accessory.
In conclusion, my process consists in the combination consisting of the apparatus
heated by the vapour which it itself disengages after that this has been compressed,
and the multiple action apparatus, with the object of employing the energy of the
same steam in two series of apparatus, so as to increase, for the purposes of evapo-
ration or concentration, the useful effect obtained up to the present time from a
given quantity of steam. This effect is obtained without exposing the syrup to too
high a temperature and without submitting the boilers to too high a pressure, but
on the contrary the power is retained to cause the concentration to take place in the
boilers heated by compressed vapour under the precise conditions of temperature
and pressure which the manufacture requires.
The combination above described, which is believed to be novel and generally
important in relation to the evaporation of liquids, is applicable not only in the
manufacture of sugar, but also in many other manufactures in which the concen-
tration is required of liquids containing salts, natural or chemical manures, viscus
or solid matters, &c., &c.
I claim the combination of apparatus berein described, such combined apparatus
being applicable for concentrating syrups in the manufacture of sugar, and also for
use in other manufactures.
In witness whereof, I, the said Sydney Pitt, have bereunto set my hand
and seal, this Eleventh day of June, in the year of our Lord One thousand
eight hundred and seventy nine.