Improvements in and connected with Apparatus for Disinfecting by Steam.
Year: 1892

page_text: Date of Application, 18th May, 1892-Accepted, 24th Sept., 1892
Improvements in and connected with Apparatus for Disinfecting
by Steam.
I, CHARLES HERSCHER of 42 Rue du Chemin Vert, Paris in the Republic of
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:-
The improved arrangements in the construction of stoves, digesters, and the like
apparatus for disinfecting by means of steam, have for their object to obtain :
1. A sure and rapid disinfection of contaminated articles by the combined action
of steam under pressure and steam in motion.
2. Improvements in the working of the apparatus by the preservation of heat
in the casing, thus diminishing the condensation caused by external cooling.
3. The means of easily ascertaining the complete discharge of the air contained
in the apparatus at the commencement of the operation without it being necessary
to allow this air to escape into the work room.
4. The certainty of not placing in open communication the two chambers, one of
which contains the contaminated articles and the other the disinfected ones, by the
simultaneous opening of the inlet and outlet doors of the stove.
5. A vigorous suction of the vapours released during the drying, and a rapid
circulation of air through the stove or digester to accelerate the drying of the
articles previously disinfected.
6. A method of closing the apparatus which contributes to increase the safety of
the work people attending the same.
The improvements forming the object of this invention are shown on the annexed
drawings.
In order to obtain a reliable and methodical penetration of the articles submitted
to the action of the steam in motion under pressure, this steam reaches the stove by
means of a distribution pipe A, Figures 1 and 2, placed interiorly at the side &
little above the centre and perforated with holes running throughout the length of
the stove.
A screen B facilitates the immediate ascension of this steam to the top
of the stove. The discharge is effected by means of a tube C lying horizontally
along the bottom of the apparatus and also perforated with holes throughout its
length. The steam thus passes from top to bottom and reaches every part of the
stove at the same time, effectively acting on all the articles submitted for the opera-
tion of disinfection.
Without the screen, the steam would have the tendency to go directly from the
pipe A to the pipe C, in place of first ascending to the top of the stove and then
descending whilst traversing the materials to be disinfected. The screen B is a
kind of longitudinal gutter, placed in front of the tube A throughout its entire
length, it is fixed below to the cylinder and there is left an opening O at top for
the exit of the steam, which after having struck the wall of B will be directed to
the upper part of the stove.
In order that the steam may pass away in a continuous flow without the pressure
in the interior of the stove decreasing, I employ one or other of the two following
processes:
1. The steam is introduced by a tap or valve D of any suitable form whilst it is
discharged from the stove by means of an adjustably weighted tap E. The degree
of opening of the tap E is regulated, by the weight, to such an extent that the
quantity of steam which can continually escape will be always in proportion to the
power of the boiler. By this means, the
maintained by opening the admission tap Due in the stove may therefore be
tions of the manometer G.
more or less according to the indica-

page_text: 2. In the second process, it is the orifice of the admission tap D which can be
regulated, so that, as in the previous case but inversely, the amount of incoming
steam shall be proportionate to the 'power of the boiler.
The discharge in this process is effected by a valve E of any suitable kind but so
weighted or controlled that it will only open and act when the pressure in the stove
is sufficiently great to discharge all the steam arriving by the inlet tap. In this
arrangement, the person in charge has no longer need to constantly observe the
manometer G, the pressure being maintained in the stove automatically.
In both the processes, the steam, on its exit either from the tap or the valve, is
conveyed by a tube H into the main discharge passage J; for this purpose, the
valve is cased in such a way as to prevent the steam from escaping into the
work room.
In order to avoid as far as possible any loss of heat through the walls of the stove,
this latter is cased on all its cylindrical surface with a covering of wood having
sheets of cork or other insulating material inside.
In the use of a steam pressure stove, when, at the commencement of the opera-
tion, the steam admission tap is opened, it is indispensable to allow the air previously
contained in the stove to escape freely until it is entirely replaced by the steam.
The usual method of attaining this result consists in placing, on the side of the
stove, an air-escape tap with an open nozzle. On the steam being seen to issue
from this tap, it at once shows the moment that the air has been expelled and when,
consequently, the tap should be closed.
But it may be useful or desirable that this escape shall not take place in the
work room; the following is the arrangement I accordingly employ for this
object:
"
The air tap K is finished off with a link (or plate) on which I fix a piece called
a thermometer support tube;" this piece itself, which forms part of the tube
prolonging the tap, is continued by a tube N N which may be made to open under
the ash pan of the boiler, or into the chimney, or in the discharge flue J, or simply
straight outside. The tube carrying the thermometer is shown in detail in
Figures 6 and 7, but I can employ instead of this device other arrangements to
that shown in the drawings, but the characteristic point of my process consists
essentially in the employment of a thermometer in the air discharge tube; a
reading of this thermometer will show if the air has completely cleared out of the
apparatus; as soon as the steam commences to escape, the temperature shown by
the thermometer rapidly rises up to about 100 degrees.
It may happen when a stove has two doors opening into two separate rooms that,
by the negligence of the persons in charge, these two doors may be left open
simultaneously. A risk is then incurred of a current of air being established across
the stove, and of microbes and other germs, arising from the adjacent chamber,
being carried into the chamber where the disinfected articles are.
To prevent such negligence taking place, I employ the following arrangement
shown in Figures 3, 4 and 5 of the drawing :-
Two
An axis XY runs parallel on the side of the stove. It is held up by two
supports (or brackets) T and U fixed on the cylindrical wall of the stove.
levers X and Y F are keyed at right angles on the shaft X Y in such a way that
they can only pass before the doors of the stove if these latter are entirely closed;
and, finally, the rotation of the shaft X Y is limited by pins L L' acting as stop
catches after a quarter revolution.
It may thus be seen that, in order to open the door O, it is necessary to turn the
lever YF upwards; the lever X I is turned thereby in tront of the door V and
prevents it being opened. If it be desired to open the door V, the lever Y F must
be lowered, which can only be done if the door O be closed. Thus only one door
can ever be open at the same time.
In order to expel, at the end of an operation, the vapour contained in the stove,
and, at the same time, to dry the articles by means of a strong current of air,
arrange, in the upper part of the stove, a discharge pipe J, Figures 1 and 2, of large

page_text: dimensions closed at the bottom by means of a valve P of any suitable kind. Above
the valve a curved tube R is placed, which brings steam from the boiler, and which
is arranged for acting as an aspirator. I can also replace this aspirator by an
ejector of suitable kind placed between the valve P and the discharge pipe or
between the valve P and the stove. Finally, at the bottom of the stove and on
the side opposite to the discharge pipe, a valve Q is arranged for allowing air to
re-enter. This valve Q may be placed directly in the chamber containing the
purified articles which have been passed through the store.
If, however, it be necessary, as in certain cases, that the drying of the articles
shall be performed in an absolutely sterile atmosphere, I arrange, in front of the
valve, a tube containing a plug of cotton serving as a filter, or I cause the air to
pass through a tube which traverses the furnace of the boiler, before reaching the
valve Q.
When a disinfecting operation is completed, the valve P is first opened, which
allows the steam to escape to the outside of the building. The steam tap S of the
aspirator or of the ejector is then opened, and the lower valve Q is also opened. All
the moist air in the stove is carried off and replaced by external air, which
comes directly in contact with the lower heating apparatus. This air is heated as
it penetrates into the stove, and is thus much more likely to absorb moisture from
the articles placed in the latter. By this process, the drying is effected very
rapidly.
The discharge tube and the two valves are of large dimensions in order that
considerable circulation of air in the stove may be produced merely by the action
the draught without setting the aspirator.
The hinged bolts usually employed for securing the doors of stoves, do not afford
all the requisite security unless the fastening pieces are of the best make. If a
slight slipping of these bolts should possibly take place, the door might burst
suddenly open under the effect of the internal pressure and cause accidents.
In order to entirely prevent such accidents arising, I have invented a modification
of the system usually employed, by which modification the displacement of the bolts
under the effect of the internal pressure is rendered impossible, and which, conse-
quently, imparts to this kind of fastening all the necessary security.
Figures 8 and 9 show this improved arrangement :-
a is the axis on which the bolt c d turns. The wing nut fg, which presses on
the circumference h h of the door, has a cylindrical facing k engaging in a
made in this circumference. This seating is formed either by boring out the metal
seating
of the door, or by introducing a recessed washer 1, and having pins m. n. p. q as
shown in the drawing which are inserted after the winged nut has been screwed
home. It will thus be seen that, when once the wing nut is screwed down, it could
only be undone after the pins m n and p q of the inserted washer have been
removed.
It will be seen from the foregoing description of the accompanying sheet of
drawings, that the figures represent the following views :-
-
Figures 1 and 2 side view and cross section respectively of the entire disinfecting
apparatus.
Figures 3, 4 and 5 give a side view, plan view and end elevation of the safety
door device applied to the apparatus.
Figures 6 and 7 show a sectional elevation and cross section of the thermo-
meter M; and
Figures 8 and 9, a face view and cross section respectively of the means for
securing the bolts from slipping.
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 :-
1. The arrangements hereinbefore set forth for allowing the steam to pass away
in a continuous manner without causing a fall of pressure in the interior of the

page_text: apparatus, and which consist either in the use of a discharge tap with a regulatable
orifice or else in the use of a similar method applied to the admission tap, substan-
tially as described with reference to Figures 1 and 2 of the accompanying drawing.
2. The adaptation, to the discharge pipe, of a tube holding a thermometer (M) for
indicating, at the commencement of each operation, the precise moment when the
air contained in the apparatus has been expelled, substantially as hereinbefore
described, with reference to Figures 1, 6 and 7 of the accompanying sheet of
drawings.
3. The improved means for preventing the two doors of a stove of the kind
described being open simultaneously, substantially as described with reference to
Figures 3, 4 and 5 of the accompanying drawing, or any other mere mechanical
equivalent of such arrangement.
4. The improved means for rapidly drying the disinfected articles by means of
circulating air, which consists in employing an aspirator or ejector, drawing in the
air and expelling it from the orifice by means of a discharge tube, substantially as
described with reference to Figures 1 and 2 of the accompanying drawing.
5. The improved means or method for fixing the hinge bolts, in connection with
the doors of disinfecting stoves, for the purpose of preventing the displacement of
such bolts under the effect of internal pressure, substantially as described with
reference to Figures 8 and 9 of the accompanying drawings.
Dated this 17th day of May 1892.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.