Improvements in or relating to Drying and Sterilizing.
Year: 1897

page_text: Date of Application, 24th mar., 1897
Complete Specification Left 24th Dec 1897 Accented
10th Mar
1808
Date of Application, 24th Mar., 1897
Complete Specification Left 24th Dec 1897 Accented 10th Mar
1808
Improvements in or relating to Drying and Sterilizing.
I, HUBERT HIGGINS, of 4, Trinity Street, Cambridge, in the County of Cambridge,
Demonstrator of Anatomy to Cambridge University, do hereby declare the nature
of this invention to be as follows:-
This invention relates to the process of drying and sterilizing by the employment
of steam, and consists in apparatus for passing currents of superheated steam,
substantially at atmospheric pressure, through a chamber or series of chambers,
containing the material to be dried or sterilized.
Careful examination of the methods at present in use reveals either the necessity
of employing mechanical means for circulating the drying or sterilizing gases,
or the absence of any means of passing large volumes of gases rapidly and effectually
over the substances to be dried or sterilized.
The apparatus employed in carrying out this invention consists of a steam-
generator, one or more steam superheaters and a chamber, or chambers.
Any suitable steam generator may be employed, and is connected with the
chamber, through the superheater, which may be of any convenient kind and
heated in any suitable manner, but is so arranged that either the whole, or a part of
it may be used at will, for the purpose of regulating the temperature of the steam.
The chamber consists of an inner chamber, of suitable size and material, provided
with shelves or other means of holding the material to be operated upon, and is
completely surrounded by an outer chamber of somewhat larger size, forming what
is commonly known as a jacket. Proper provision is made for doors and all
necessary connections and fittings for supplying and circulating the steam, and
the jacket may be suitably lagged to economize heat.
In order to prevent condensation of steam in the chamber, the jacket is heated
either
(a) By passing through it the whole or a sufficient proportion of the combustion
gases from the heating apparatus of the boiler or superheater, or
(b) By the direct application of heat to the exterior of the jacket; the heat
supply being under control, and the necessary pipes, dampers etc. being provided,
in each case, for the circulation of the hot-air or gases.
It is more economical to employ a series of chambers, the steam passing from
one to the other through a super-heater, placed between each two chambers:
suitable cocks and pipes may be provided so that one or more of the chambers
can be cut out without interrupting the current of steam through the others.
On leaving the last chamber, a suitable proportion of the steam may be passed
again through the first chamber and so on in a continuous circuit or it may be
blown off to waste or employed for any suitable purpose.
All necessary valves, gauges and fittings are provided for properly working
and controlling the apparatus.
When in operation a continuous current of steam, substantially at atmospheric
pressure is maintained through the chamber, at the temperature best suited for the

page_text: material operated on: the jacket being meanwhile maintained at about the same
temperature. By making the chamber of a suitable shape and providing
hooks etc. for hanging the clothes or other material to be operated upon, the
apparatus can be used for a workhouse or hospital sterilizer.
D
.
1008
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to Drying and Sterilizing.
I, HUBERT HIGGINS, of 4, Trinity Street, Cambridge, in the County, of Cambridge,
Demonstrátor of Anatomy to the Cambridge University, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be partiou-
larly described and ascertained in and by the following statement:
-
This invention relates to the process of drying and sterilizing by the employment
of steam, and consists in apparatus for passing currents of superheated steam,
substantially at atmospheric pressure, through a chamber or series of chambers,
containing the material to be dried or sterilized.
The apparatus employed in carrying out this invention comprises a steam
generator, one or more steam superheaters and a chamber or chambers.
The accompanying drawing shows diagrammatically a series of two chambers
with their respective superheaters constructed according to this invention.
The steam is obtained from any convenient source of supply; the apparatus
may either be provided with its own boiler, of any ordinary construction, or may
draw its steam from a boiler primarily intended for other purposes. In either
case if the boiler be worked above atmospheric pressure the supply pipe to the
apparatus should be provided with a reducing valve placed between the source
of supply and the cock E so as to reduce the high pressure steam to atmospheric
pressure before its entry into the superheater.
The chamber consists of an inner chamber A preferably completely surrounded
by an outer chamber B of somewhat larger size forming what is commonly known
as a jacket.
The chamber A may be of any suitable size and material, and provided with
shelves or other fittings according to the purpose for which it is intended. Proper
provision is made for doors and it is connected by the pipe D with the super-heater C,
a pipe F being likewise furnished for carrying away the steam and provided with
a stop valve F
The superheater may be of any ordinary construction that gives a prolonged
travel to the steam and is provided with openings, controlled by valves, at various
portions of its length, so that the steam can be withdrawn at will after a greater
or less exposure to the heating medium. A convenient form consists of a coil,
as shown at C, receiving its steam through a pipe & controlled by a stop cock E
and having openings controlled by valves C2, C3, C4, C5, into the pipe D connected
with the chamber A., When the apparatus comprises only one chamber and
superheater the cock E is an ordinary stop valve but when more than one super-
heater and chamber are employed a three way cock is preferably provided as shown
in the drawing for the purpose hereinafter described.
The coil may be of any convenient form, either helical as shown or consisting or
zigzag or parallel tubes united by return bends, the essential point being the
faculty of controlling the length of travel of the steam when exposed to the heating
medium.

page_text: Four connections are shown as a convenient number, but more or less may be
used according to the range of temperature which may be desired to be employed
in the chamber.
The superheater may be heated in any convenient manner, either directly by
a gas or other furnace, or by the products of combustion from the generator furnace.
In order to prevent condensation of steam within the chamber A, it may be
provided with a jacket B, heated either (a) by passing through it the whole or a
sufficient proportion of the combustion gases from the heating apparatus of the
boiler or superheater, or (b) by the direct application of heat to the exterior of
the jacket, or (c) by passing a current of steam from the superheater through the
jacket. The necessary pipes, dampers, etc. are provided on each case so that the
temperature is under control and the jacket is preferably lagged.
It is more economical to employ a series of chambers, the heat passing from one
to the other through a superheater, placed between each two chambers, as shown in
the accompanying drawing, the pipe F being continued and connected with a
second coil C', identical in construction with the first described coil C and similarly
connected with a second chamber A¹
A
Any desired number of superheaters and chambers to operate in series may be
thus connected but it is necessary to provide suitable cocks and pipes so that one
or more of the chambers can be cut out of the circuit without interrupting the
current of steam through the others. Preferably this is done by employing a
three way cock E instead of an ordinary stop cock, and connecting its side branch
by the pipe H to the pipe F between the valve F¹ and the superheater C¹
second three way cock E is placed between the connecting point of the pipes H
and and the superheater C. By manipulating these cocks the current of steam
can be directed either through both the superheaters and chambers or through
either C and A or C and A' at will. If a third chamber and superheater be
employed the pipe H¹ on the side branch of the cock E¹ will be connected to the
escape pipe of the chamber A¹ in the manner in which the pipe H is connected
to the escape pipe F.
In this manner any number of chambers can be employed whilst any desired
chamber or chambers can be cut off from the cirouit for the purpose of emptying
and refilling whilst the other chambers remain in operation.
The escape pipe and the side branch of the three way cock of the last set of
the superheaters and chambers may conveniently be connected with the flue of
the steam generator or led to any convenient point where the steam can blow
to waste or be employed for any suitable purpose, so long as back pressure be
not put on the chambers.
All necessary gauges, pyrometers, and fittings are provided for properly working
and controlling the apparatus.
When in operation the jacket B is first heated so as to warm the chamber A
and prevent condensation on the initial admission of steam therein, and this
heating may be continued throughout the operation if desired. If all the chambers
of the series are to be employed the steam is admitted to the superheater C through
the valve E which is turned so that the passage is open between the pine G and
the superheater C and closed between G and H. One of the cocks C2 C3 C4 C5 is
then opened and a continuous current of steam passes into the chamber A through
the pipe D, escaping therefrom by the valve F and pipe F. According as the
temperature is required to be raised or lowered the steam is allowed to travel
through a greater or less length of superheater. If a temperature is required
only slightly in excess of 100° C. the cock C2 is opened and the steam passes
through only a short portion of the superheater before entering the chamber. A.
through the pipe 1). To raise the temperature the cock C is opened and C closed,
giving the steam a longer exposure to the heating medium, the highest temperature
being obtained by passing the steam through the whole length of the superheater

page_text: by opening the cock C, the others being closed. By this means a perfect control
of the temperature within the chamber is obtained.
The three way cock E is also opened so that the steam passes from the escape
pipe F of the first chamber into the superheater C and so into the chamber A
If it be desired to cut off the chamber A and work only the chamber A¹, the
cock F is closed and the three way cock E turned so as to open the passage
between G and H and close the passage into the coil C. The steam now passes
directly through the pipe H, into the superheater C¹.
By thus manipulating the cocks, a continuous current of steam substantially
at atmospheric pressure may be maintained in any one or more of a series of
chambers at the temperature best suited for the material operated on; the jacket
being meanwhile maintained at about the same temperature.
By making the chamber or chambers of a suitable shape and providing hooks etc.
for hanging the clothes or other material to be operated upon the apparatus can
be used for a workhouse or hospital sterilizer.
Having now particularly described and ascertained the nature of the said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. In drying and sterilizing apparatus in which steam is employed the use of a
superheater which enables the temperature of the steam to be varied without
thereby necessitating a change of pressure substantially as described.
2. In drying and sterilizing apparatus in which steam is employed the use of
steam at fixed (and preferably atmospheric) pressure but at varying temperature
such temperature being obtained by means of a superheater and regulated as herein
described.
3. In drying and sterilizing apparatus in which steam is employed the com-
bination of a jacketted chamber and superheater capable of regulation substantially
as described.
4. In drying and sterilizing apparatus in which steam is employed the com-
bination of a series of superheaters and chambers constructed and operating so
that a continuous current of superheated steam can pass through all the super-
heaters and chambers consecutively substantially as described.
5. In drying and sterilizing apparatus in which steam is employed the com-
bination of a series of superheaters and chambers constructed and operating so
that a continuous current of superheated steam can pass through only one or
successively through more than one or through all of said superheaters and
chambers substantially as described.
6. In drying and sterilizing apparatus in which steam is employed a superheater
such as C provided with branches controlled by valves substantially as and for
the purpose described.
7. The drying and sterilizing apparatus substantially as described and illustrated.
Dated this 24th day of December 1897
BOULT & WADE,
Agents for the Applicant.