Improvements in or relating to Desiccation.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or relating to Desiccation.
I, HUBERT HIGGINS, of 4, Trinity Street, Cambridge, in the County of Cam-
bridge, Demonstrator of Anatomy to the Cambridge University, do hereby
declare the nature of this invention to be as follows:-
The object of this invention is to provide economical and efficient apparatus
for the employment of steam for the desiccation of organic or inorganic sub-
stances, either by utilizing the steam to heat the chamber in which the substance
is placed or by passing a current of superheated steam over or through the
substance to be desiccated, or if desired by heating air which can be employed
for desiccating purposes.
In carrying out the invention two or more jacketted chambers are employed
arranged so that the steam utilized in one chamber passes consecutively into
the other chambers of the series or into their jackets, the steam, which may then
be in a more or less condensed state, being ultimately utilized for heating pur-
poses returned to the steam generator or allowed to blow to waste.
A convenient form of apparatus comprises three jacketted chamber. The
jacket of the first chamber contains water and is utilized as the steam generator.
No steam is passed into this chamber which is heated solely by the surrounding
water and steam. The jacket of the second chamber preferably forms a con-
fined air space to prevent loss of heat from the chamber or this jacket may be
dispensed with and the chamber thoroughly protected with any suitable lagging.
A coil or other arrangement of piping which will give prolonged travel to the
steam forms the superheater, one end being connected with the upper portion
or steam space of the steam generator the other end opening into a second
chamber of the series which is therefore directly heated by the current of super-
heated steam. This chamber is connected by a pipe with the jacket of the third
chamber which is heated thereby, no steam being admitted within the chamber.
The first and third chambers are each supplied with an air shaft for carrying
away the vapours given off from the substance desiccated, and means may be
employed for increasing the draft in these shafts; or a current of air previously
heated may he passed through the chambers. The jacket of the third chamber
is provided with one or more escape pipes for the steam, which will be partially
or completely condensed, according to the temperature of the steam employed,
and the rate at which it circulates. In order to regulate the temperature in the
second chamber two or more superheaters may be provided each controlled by
a suitable valve.
The chambers may be arranged in any convenient manner with reference to
each other, being placed either on the same horizontal plane or one above the
other. In the latter case the escape pipe for the waste steam from the last cham-
ber may be connected with the steam generator so as to return the same to it by
gravity. The chambers are provided with suitable openings or doors for obtain-
ing access to their interiors, and with all suitable fittings such as thermometers

page_text: safety valves and the like. Conveniently an opening is provided in the door
to allow of the passage of the neck of a retort placed within the chamber.
Instead of three chambers as herein before described only two may be em-
ployed. The superheater or superheaters being connected with the chamber
enclosed within the steam generator. In this case the inside walls of this chamber
are preferably lagged to prevent the superheated steam losing its heat to the
water in the jacket.
The apparatus can be constructed in a portable form, or on a large scale as a
fixed installation. When on a large scale the waste pipe from the jacket of the
last chamber say of a series of three may be formed as a superheater, and the
steam employed in one or more auxiliary chambers. Or the waste steam either
partially or completely condensed may be utilized to heat air for use in a drying
room by circulating it around tubes through which the air is drawn by a fan.
If desired the air may be desiccated by passing it over calcium chloride.
Dated this 1st day of January 1898.
BOULT & WADE,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Desiccation.
I, HUBERT HIGGINS, of 4, Trinity Street, Cambridge, in the County of Cam-
bridge, Demonstrator of Anatomy to the Cambridge University, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
The object of this invention is to provide economical and efficient apparatus
for the employment of steam for the desiccation of organic or inorganic sub-
stances, either by utilizing the steam to heat the chamber in which the substance
is placed or by passing a current of superheated steam or through the
substance to be desiccated, or, if desired by heating air which can be employed
for desiccating purposes.
over
In carrying out the invention two or more jacketted chambers are employed
arranged so that the steam utilized in one chamber passes consecutively into
the other chambers of the series or into their jackets, the steam, which may then
be in a more or less condensed state, that is to say in the "act of condensing
being ultimately utilized for heating purposes returned to the steam generator
or allowed to blow to waste.
A convenient form of apparatus comprises three jacketted chambers which
may be of any size or shape. The jacket of the first chamber contains water
and is utilised as the steam generator. No steam is passed into this chamber
which is heated solely by the surrounding water and steam. The jacket of the
second chamber preferably forms a confined air space to prevent loss of heat
from the chamber or this jacket may be dispensed with and the chamber
thoroughly protected with any suitable lagging. A coil or other arrangement
of piping which will give prolonged travel to the steam, forms the superheater,
one end being connected with the upper portion or steam space of the steam
generator the other end opening into the second chamber of the series which is
therefore directly heated by the current of superheated steam. This chamber
is connected by a pipe with the jacket of the third chamber which is heated
thereby, no steam being admitted within the chamber. The walls of the chamber
may be roughened or corrugated to increase condensation.
The first and third chambers are each supplied with an air shaft for carrying

page_text: away the vapours given off from the substance desiccated, and means may be
employed for increasing the draft in these shafts; or a current of air previously
heated may be passed through the chambers. The jacket of the third chamber
is provided with one or more escape pipes for the steam, which will be partially.
or completely condensed, according to the temperature of the steam employed,
and the rate at which it circulates. In order to regulate the temperature in the
second chamber two or more superheaters may be provided each controlled by
a suitable valve.
The chambers may be disposed in any convenient manner with reference to
each other, being placed either on the same horizontal plane or on different
planes or superimposed. In the latter case the escape pipe for the waste steam
from the last chamber may be connected with the steam generator and means
provided to complete the condensation of the steam so as to return it as water
by gravity; or the steam may be employed to heat the feed water. The cham-
bers are provided with suitable openings or doors for obtaining access to their
interiors, and with all suitable fittings such as thermometers, safety valves and
the like. Preferably the steam is employed at substantially atmospheric pres-
sure, and the safety valves may be set to prevent the use of pressures greater
than say 4 lbs above the atmosphere. Conveniently an opening is provided in
the door to allow of the passage of the neck of a retort placed within the chamber.
The chambers may be of any convenient shape, for instance, for certain large
installations, such as brick fields, they may be tunnels.
Instead of three chambers as herein before described only two may be em-
ployed. The superheater or superheaters being connected with the chamber
enclosed within the steam generator. In this case the inside walls of this cham-
ber are preferably lagged to prevent the superheated steam losing its heat to the
water in the jacket.
The apparatus can be constructed in a portable form, or on a large scale as a
fixed installation. When on a large scale the waste pipe from the jacket of the
last chamber say of a series of three may be formed as a superheater and the
steam employed in a second series of chambers. The waste steam from the last
chamber either partially or completely condensed, may in any case be utilized
to heat air for use in a drying room by circulating it around tubes through which
the air is drawn by a fan. If desired the air may be desiccated by passing it
over calcium chloride.
Preferably the condensed steam is finally returned to the feed tank or to the
steam generator itself.
The accompanying drawings show diagrammatically two typical forms of
apparatus constructed according to this invention.
Figure 1 being an apparatus with two drying chambers and,
Figure 2 an installation comprising two series of chambers, the waste steam
from one series being utilised to heat the second.
Like letters indicate like parts in both figures.
Referring first to Figure 1, A is a drying chamber contained within a jacket B
which forms the steam generator; C is a superheater, which may be a coil or
any convenient arrangement of pipe which will give prolonged travel to the
steam the superheater is connected with the upper portion or steam space of
the generator B by a pipe C¹ and valve C, and with the chamber A by a pipe C³.
Above the chamber A is placed a second drying chamber A', provided with a
jacket B. The chamber A¹ may be supplied with steam from the chamber A
through the pipe A2 and valve A³, an escape pipe and valve for the steam being
provided at A In this case the jacket B would contain air and act merely
as lagging. Or the chamber A¹ instead of receiving steam, may be heated by
conduction from the jacket B¹, into which steam is introduced from the chamber A
by a pipe and valve 132, and an escape provided for the steam at B³, as shown in
dotted lines in the figure. In this latter case pipes D, D', may be provided for
passing a current of air through the chamber."

page_text: The steam may be allowed to blow to waste through the escape pipes A B³
but it may be returned to the feed tank L or to the generator B as shown in the
figure in full and dotted lines respectively, being first preferably utilized to
heat air in an apparatus such as shown at H Figure 2, and hereinafter described.
The chambers A A¹, may be of any convenient shape, preferably rectangular
and are provided with suitable openings for introducing and removing the
materials to be dried. K is an outside casing desirably provided with lagging K
and furnished with suitable openings at bottom and top for the supply of air
to the source of heat and for the escape of the products of combustion respec-
tively. Suitable arrangements may be provided for regulating the supply of
air and conducting the combustion gases to a chimney. E is the source of heat
which may be of any suitable character, depending on the size and purpose of
the installation, say a gas burner as shown in the figure, or an oil stove, or in
large installations a coal furnace. A perforated plate or plates such as C may
be provided to distribute the steam throughout the chamber.
The installation shown in Figure 2 comprises two series of drying cham-
bers FG connected by a superheater J. The first series F comprises three dry-
ing chambers A. A¹ A5, arranged side by side, though they may be arranged as
desired on different planes, or superimposed as in Figure 1. The chamber A is
surrounded by the steam generator B, as in Figure 1, but is not supplied with
steam, the super-heaters C, of which two are shown in this instance, being con-
nected by the pipes C with the second chamber A¹, the chamber A deriving its
heat by conduction from the surrounding water and steam of the generator.
The two chambers are enclosed within a casing K covered with lagging K¹
similar to that described in Figure 1. A third chamber A5 surrounded by a
jacket 1 is preferably placed outside the casing, the jacket being suitably pro-
tected by lagging, or this chamber might also be placed within the casing K
and receive heat from the combustion gases. The chamber A is not supplied
with steam but heated by its jacket B which receives the steam escaping from
the chamber A', through the tube and valve A, the jacket being provided with
escape pipes B³ B6. The chambers A and A³ may be provided with tubes D D¹
for passing currents of air through them.
A feed tank L and sources of heat, E, are provided.
This series of chambers F constitutes a complete drying installation. The
steam through the escape pipe B5 may be connected with an air-heating apparatus
or otherwise disposed of as in Figure 1.
Or the steam from the jacket B may be utilized to heat the series of drying
chambers G, by connecting the waste pipe B6 with a superheater J connected
with the first chamber A7 of the series G which may consist of two or more
jacketted chambers, preferably three, A7 A8 A9, as shown in the figure. These
chambers may be arranged relatively to each other as most convenient for the
space they are to occupy, and the purpose for which they are employed, and are
suitably lagged to prevent loss of heat. The steam from the superheater J
passes by the pipe into the first chamber A, thence into the second cham-
ber A8 by the pipe and valve A¹º. From this chamber it is carried into the
jacket 137 of the chamber A by the pipe B, and leaves the jacket by the escape
pipe and valve B.
The chamber A may be provided with pipes D D for the passing through it
of currents of hot air.
The steam from the jacket B7 may be allowed to blow to waste or be utilized
in any desired manner. Preferably the escape pipe B is connected with an air-
heating apparatus H consisting of a receptacle H with tubes H², and with a
conical hood on one end, in the orifice of which is placed a fan M to draw or
drive air through the pipes H². The steam enters the body of the receptacle H¹
by the pipe B, and the pipe H3 is placed in its lowest part to carry off the water
as the steam is condensed, and this may be carried into the feed tank L of the
generator B, or disposed of in any convenient manner.

page_text: One or other end of the receptacle H according to whether the fan is arranged
to draw or blow may be connected in any convenient manner with the pipes D
of the chambers A, A5, Aº, to send a current of hot air through said chambers.
When the generator B is on a lower level than the waste pipe or its condensing
or air-warming apparatus the water may be returned thereto by gravity, but
when necessary any usual means may be provided for supplying water to the
generator.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
-
1. In a drying apparatus in which steam is employed the combination with
a steam generator and one or more superheaters of a drying chamber contained
within the generator and which may or may not be connected with the super-
heater or superheaters and one or more drying chambers each of said chambers
being connected either directly or by means of a jacket either with the afore-
said chamber or with a superheater or with each other substantially as described.
2. In a drying apparatus such as described passing the waste steam through
a superheater for use in a second series of drying chambers substantially as
described.
3. In a drying apparatus such as described utilizing the waste steam to heat
air and passing said heated air through one or more of the drying chambers
substantially as described.
4. In a drying apparatus such as described and in which steam is employed
at substantially atmospheric pressure completing the condensation of the steam
after its utilization in the apparatus and returning it as water by gravity into
the generator substantially as described.
•
5. The complete drying apparatus substantially as described or as illustrated
in Figure or in Figure of the accompanying drawings.
2000
HUBERT HIGGINS.
Boult & Wade,
Agents for the Applicant.