IMPROVEMENTS IN CENTRE VALVES EMPLOYED IN CONNECTION WITH GAS PURIFIERS
Year: 1884

page_text: I, ROBERT DEMPSTER, Junior of the firm of Robert Dempster and Sons of Elland
in the County of York, Gas Engineers, do hereby declare the nature of my
Invention for "IMPROVEMENTS IN CENTRE VALVES EMPLOYED IN CONNECTION
WITH GAS PURIFIERS" to be as follows:-
My Invention has reference to the ordinary form of dry faced centre valves,-
viz. that class of valve which has the outlet in the centre; the inlet being formed
by an annular space immediately around the said outlet.
Usually these centre valves work in connection with four purifiers, but it has
hitherto been found impossible to use all the purifiers at one and the same time,
the arrangement of the valves being such that one purifier always remained idle.
The object of my Invention is to construct such valves so that all the purifiers
employed may be in operation at one time, and this I accomplish by a modified
form of valve, and in the arrangement of parts for operating the same.
My improvements therein consist in forming three additional openings in the
main moveable portion of said valve, all of which are covered by a moveable
slide valve, somewhat in the form and manner of a high pressure steam engine
valve.
I also make a fourth opening at the top of the said moveable valve, which is
employed for the purpose of allowing the gases to pass to the main outlet from
the valve.
By the modifications herein mentioned the rim employed for dividing the outlet
from the inlet is not now connected by a passage to the other parts of the valve,
but is separated therefrom.
The slide valve cover is made to move on its scating by means of a lever arm,
attached to a boss on a hollow shaft, working upon the central shaft of the valve.
When the said slide valve has been moved in either direction; it is kept in its
place by weighted catches falling into notches formed in the indicator wheel.
Instead of the slide valve being moved on its seating by a lever arm on the
hollow shaft, a boss may be formed on the slide valve itself, and attached to
the hollow shaft direct, whereby the slide valve can easily be moved backward
and forward.
The whole of the moveable portions of the valve are enclosed in a cover for the
purpose of directing the flow of gas from the openings which are alternately
covered by the additional slide valve to the outlet in the centre of valve.
Dated this 16th day of January 1884

page_text: I, ROBERT DEMPSTER, Junior, of the firm of Robert Dempster and Sons of
Elland, in the County of York, Gas Engineers do hereby declare the nature of my
Invention for "IMPROVEMENTS IN CENTRE VALVES EMPLOYED IN CONNECTION
WITH GAS PURIFIERS" and in what manner the same is to be performed, to bo
particularly described and ascertained in and by the following statement:―
My Invention has reference to the ordinary form of dry-faced centre valves—
viz. that class of valve which has the outlet in the centre, the inlet being formed
by an annular space immediately around the said outlet.
Usually these centre valves work in connection with four purifiers, but it has
hitherto been found impossible to use all the purifiers at one and the same time,
the arrangement of the valves being such that one purifier always remained idle.
The object of my Invention is to construct such valves so that all the purifiers
employed may be in operation at one time, and this I accomplish by a modified
form of valve, and in the arrangement of parts for operating the same.
My improvements therein consist in forming three additional openings in the
main moveable portion of said valve; all of which are covered by a moveable slide
valve somewhat in the form and manner of a high pressure steam engine valve.
I also make a fourth opening at the top, and in the centre of the said main
moveable valve, which is employed for the purpose of allowing the gases to pass to
the inain outlet from the valve.
In order that this Invention may be better understood I herein give reference to
the accompanying Sheet of Drawings illustrating in several sections the general
construction of a dry faced centre valve with my improvements applied thereto.
Fig. 1 is elevation, and Fig. 2 vertical section whilst the remaining Figures are
cross sections on the various lines shown on the Drawings. Number indicates
the usual syphon pan, the gas entering therein at 2 as shown by the arrow, the
said gas passing into the annular space 3 formed around the central outlet pipe 4
from which it passes at the part 5 into the moveable valve 6 and out at 7 to
the first purifier; all of which are of ordinary construction, and will be well
understood.
After the gas enters the first purifier it returns again to the valve, and after
passing through the ports thereof is conducted to the second purifier, and again to
the third when in an ordinary valve the gas would finally return and be conducted
down the outlet 4, leaving the fourth purifier idle, which however would be used
when one of the other purifiers became impure and were no longer able to remove
the sulphuretted hydrogen from the gas, but notwithstanding this one purifier
would be standing and out of use.
By constructing and arranging such valves according to my Invention, all the
purifiers are constantly in use except when changing the lime or oxide of iron.
To carry out my Invention the rin or pipe & employed for dividing the outlet
from the inlet is not now connected by a passage to the other parts of the valve,
but is separated therefrom, except by midfeathers 9 so that the gases can freely
pass all around the annular space 3. In order to use all the purifiers at one and the
same time I form three openings in the top of the moveable valve 6, such openings
being clearly seen in sectional plan Fig. 3 and marked 10. 11. 12.
Upon the top of this moveable valve 6 I place a moveable slide valve 13 (moved
independently of the part 6) which is employed for conveying the gases from the
pipes of the third purifier to the pipes of the fourth purifier in the following
manner
When the gases have passed through the third purifier they enter the opening 14
of the valve, and in the ordinary course of things would enter into the space or

page_text: chamber 15 and pass down the central outlet pipe 4, but by my Invention this is
prevented as the slide valve 18 is wide enough to cover two openings-viz.-10
and 11 and in so doing the gases coming up the opening 10 are conducted by the
covering 13 down the opening 11 from whence they pass into the fourth purifier
by outlet 16 and return by pipe into inlet 17 then through the opening 12 in the
top of the valve 6 and into the chamber 15 and finally escaping down the exit
pipe 4, consequently passing through four purifiers.
If only three purifiers are required to be in use or when it is necessary to change
the lime of the purifiers the valve 13 is moved in the direction of the arrow (see
Fig. 3) covering up the two openings 11 and 12 leaving opening 10 clear so that
three of the purifiers may be in use until the fourth is changed.
Instead of employing a slide valve large enough to cover two openings 10 and 11
as shown in Figs. 3 and 4 I may employ a cover such as is shown in plan Fig. 5
and section in Fig. 6 where it will be seen the upper valve only covers one
opening, but it also covers the central pipe 4, in which case the gases do not enter
the chamber 15 but they are conducted direct to the outlet.
The manner of operating the valve 6, and the upper valve 13 is as follows:-
On the top of the valve 6 is a bridge or cross bar 18 which receives the lower
end of the shaft 19, the upper end of said shaft carrying a spur wheel 20 gearing
with a pinion wheel 21 working upon a stud or pillar 22 which also carries hand
wheel 23 employed for operating the wheels as and when required for the purpose
of turning the valve on its facings, and when the said valve lias been moved on its
facings in either direction it is kept in its place by means of a catch 24 supported
by pillar 25.
This catch is weighted at one end 26 so that the opposite end of said lever is
raised and drops into suitable notchies formed in the underside of the wheel 20
whereby the valve is held in position until removed again.
The valve cover 13 is connected by arm 27 to the long boss or hollow shaft 28
which surrounds the vertical shaft 19, and works within a stuffing box 29.
On the top of the long boss 28 is a projecting arm 30 carrying another weighted
lever 31 similar to the one already described and which in like manner catches
into a groove cut in the underside of the same wheel 20 shown in dotted lines 32
in Fig. 7.
It will therefore be seen that when it is necessary to change the position of the
rotary valve G that the weighted catch 24 must be removed from the notch and
the hand wheel 23 turned; whereby the pinion 21 will operate the wheel 20 and
the valve moved thereby and in like manner when it is necessary to move the
slide valve 13, the weighted lever 31 is removed from the groove 32, and the
handle 30 turned by which means the upper valve is moved upon the valve 6
covering or exposing the openings 10, 11, and 12 allowing either three or four
purifiers to be in operation as often, and as long as desirable.
Instead of connecting the slide valve 13 to the long boss by means of the arm 27,
the valve cover may be extended as shown in Figs. 5 and 6, and the long boss
secured thereto by set screws as shown.
Although I have shown in the Drawings the application of my Invention to a
centre valve connected with four and three purifiers 1 would have it understood
that it can be adopted and arranged so that two or one purifier only may be in
action at once which is easily done by forming the notches in the wheel 20 at
suitable distances apart, also that the flow of gas may be reversed if required.
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,
Firstly. In connection with a dry faced centre valve of the additional openings
10, 11, and 12 formed in the moveable valve 6 for purposes substantially as set
forth.
Secondly. In connection with a dry faced centre valve the employment of the
moveable slide valve 13 operated in the manner and for the purposes set forth.

page_text: Thirdly. The employment of apparatus such as herein shown and described,
whereby a dry faced centre valve is rendered capable of working four purifiers at
one and the same time.