IMPROVEMENTS IN APPARATUS EMPLOYED IN THE PURIFICATION OF COAL GAS
Year: 1878

page_text: LETTERS PATENT to Peter Duckworth Bennett, of Birmingham, in the County
of Warwick, Manufacturer, for the Invention of "IMPROVEMENTS IN APPARATUS
EMPLOYED IN THE PURIFICATION OF COAL GAS."
Senled the 8th Novembor 1878, and dated the 21st May 1878.
PROVISIONAL SPECIFICATION left by the said Peter Duckworth Bennett
at the Office of the Commissioners of Patents on the 21st May 1878.
PETER DUCKWORTH BENNETT, of Birmingham, in the County of Warwick,
Manufacturer. "IMPROVEMENTS IN APPARATUS EMPLOYED IN THE PURIFICATION
OF COAL GAS."
•
My Invention has reference to the centre valves of gas purifying apparatus, and
consists of the improvements in the said centre valves herein-after described, by
which improvements the inconveniences attending the use of centre valves as
ordinarily constructed are obviated, and a centre valve produced, efficient in action,
and casily manipulated.
I construct a centre valve according to my Invention in the following manner :-
I will describe my improvements as applied to a centre valve for working three or
four purifiers, but my said improvements may be applied to centre valves for
working other numbers of purifiers.
The apparatus consists essentially of three cylindrical chambers or vessels. The
lower one constituting the base of the apparatus contains the inlet and outlet gas
mains, and also serves as a tar well for receiving the tar and ammoniacal liquor
condensed in the apparatus. The second chamber or vessel fixed upon the bottom
one contains annular troughs or lutes for forming a water valve, and the lower or
fixed part of a dry valve.
The third chamber or vessel, which is capable of a rotatory motion surmounts
the second one, and contains the parts necessary for forming with the second
chamber or vessel, both a water valve and a dry valve, as herein-after more fully
explained. The second vessel is divided by the water lutes, and bottom dry faces

page_text: into three concentric annular portions, the inner central one fitting with a socket
and spigot joint into the outlet main of the tar well. The second annular portion
is connected with the inlet gas main, and serves as a channel for the incoming gas.
The third concentric portion is divided radially into eight compartments corre-
sponding to the inlets and outlets of the four purifiers. In each of these compart-
ments is a tar pipe which carries off the tar and ammoniacal liquor into the tar
well below. The bottoms of the lutes are connected by passages in the radial
divisions, opposite which passages are plugs in the exterior to facilitate the cleaning
out of the lutes. By this means the water in all the lutes is preserved at the same
level.
In every case the impure gas is enclosed by the faces of the dry valve which are
surrounded by the water valve.
From the bottom of the third or uppermost and moveable chamber or vessel
depend three concentric lute plates and radial and concentric valve faces, corre-
sponding with the annular troughs or lutes, and valve faces of the chamber or vessel
below. The said lute plates dipping into water in the concentric troughs of the
second chamber or vessel constitute a water valve, and the valve faces of the third
or top chamber make with the valve faces of the second chamber a dry valve. The
top vessel is rotated on the lower one by incans of a pinion and rack fitted on the
top vessel. There are only five radial divisions in the top portion of the valve, and
the concentric plate between the first and fifth divisions is cut away to allow the
gas to enter the first purifier. Over the outlet of the third purifier is a valve for
.working three or four purifiers.
A centre valve for gas purifiers made according to my Invention, has the advan-
tages possessed both by the ordinary dry and hydraulic valves, without any of the
inconveniences attendant on the use of one or other of the said valves.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter Duckworth Bennett in the Great Seal Patent Office on the
16th November 1878.
PETER DUCKWORTH BENNETT, of Birmingham, in the County of Warwick,
Manufacturer. "IMPROVEMENTS IN APPARATUS EMPLOYED IN THE PURIFICATION
OF COAL GAS,"
My Invention has reference to the centre valves of gas purifying apparatus, and
consists of the improvements in the said centre valves herein-after described, by
which improvements the inconveniences attending the use of centre valves as
ordinarily constructed are obviated, and a centre valve produced, efficient in action
and easily manipulated.
I construct a contre valve according to my Invention in the following manner: —
I will describe my improvements as applied to a centre valve for working one,
two, three, or four purifiers, but my said improvements may be applied to centro
valves for working other numbers of purifiers.
The apparatus consists essentially of three cylindrical chambers or vessels. The
lower one, constituting the base of the apparatus, contains the inlet and outlet gas
mains, and also serves as a tar well for receiving the tar and ammoniacal liquor
condensed in the apparatus. The second chamber or vessel fixed upon the bottom
one contains annular troughs or lutes for forming a water valve, and the lower or
fixed part of a dry valve.
The third chamber or vessel, which is capable of a rotary motion, surmounts the
second onc,
and contains the parts necessary for forming with the second chamber
or vessel, both a water valve and a dry valve, as herein-after more fully explained.
The second vessel is divided by the water lutes and bottom dry faces into three
concentric annular portions, the inner central one fitting with a socket and spigot
joint into the outlet main of the tar well. The second annular portion is connected
with the inlet gas main, and serves as a channel for the incoming gas.
The third concentric portion is divided radially into cight compartiments corre-
sponding to the inlets and outlets of the four purifiers. In each of these compart-
ments is a tar pipe, which carries off the tar and ammoniacal liquor into the well
below. The bottoms of the lutes are connected by pipes or passages in the radial
divisions, opposite which pipes or passages are plugs in the exterior, to facilitate the
cleaning out of the lutes. By means of these pipes or passages, the water in all the
lutes is preserved at the same level.
In every case the impure gas is enclosed by the faces of the dry valvo which are
surrounded by the water valvo.
From the bottom of the third and moveable chamber or vessel depend three
concentric lute plates and radial and concentric valve faces, corresponding with the
annular troughs or lutes and valve faces of the chamber or vessel below. The said
lute plates dipping into water in the concentric troughs of the second chamber or
vessel constitute a water valve, and the valve faces of the third chamber make with
the valve faces of the second chamber a dry valve. The third vessel is rotated on
the lower or second one by means of a pinion and rack fitted on the said third
vessel. In the top of the valve which surmounts the third vessel, there are only
five radial divisions, and the concentric plate between the first and fifth divisions is
cut away to allow the gas to enter the first purifier.
A centre valve for gas purifiers made according to my Invention, has the advan-
tages possessed both by the ordinary dry and hydraulic valves, without any of the
inconveniences attendant on the use of one or other of the said valves.
I will now proceed to describe with reference to the accompanying Drawings the
manner in which my Iuvention may be performed.
Figure 1 represents in elevation, and Figure 2 in vertical section, an apparatus
or centre valve constructed according to Invention.
my

page_text: Figure 3 represents in plan the lower vessel of the apparatus or centre valve.
Figure 4 is a plan of the upper vessel.
Figure 5 is a plan of the top part of the valve.
And, Figure 6 is a plan of the base or tar tank of the apparatus or centre valve.
The samo letters of reference indicate the same parts in the several Figures of the
Drawings.
The apparatus or centre valve is constructed in four portions, the lowest of which,
marked a², serves as a tar tank, and contains the main inlet pipe at, and the main
outlot pipe a³.
The second vessel, marked a, fixed upon the tar tank a² (which second vessel I
will call the lower vessel), consists of a casting containing a main outlet passage a³
in the centre, surrounded by a water lute b, to prevent the foul gas in the main
inlet passage a, which is concentric with the water lute 6 from mixing with the
purified gas escaping by the main outlet a. Around the main inlet passage a³ of
the lower vessel a, is another concentric lute e, and around the lute e arc radial
divisions d, corresponding to the inlets and outlets of the purifiers. These radial
divisions & are surrounded by the external water lute e, which prevents the escape
of gas into the air.
The lutes are all joined near the bottom by radial pipes f, by which the same
water level is maintained in the three lutes, and the latter permitted to be cleaned
from the exterior of the apparatus.
In the bottom of each radial division of the lower vessel a is placed a tar pipe g
to convey the tar and ammoniacal liquor to the tar tank a² below, where the ends
of the said pipes g are sealed by the ammoniacal liquor.
The third portion of the apparatus or centre valve which I term the upper vessel
is marked h, and has concentric lute plates 1, 2, and 3, which engage in the water
lutes e, e, and b, of the lower vessel a. The said upper vessel h has also radial
divisions d², corresponding to the radial divisions d in the lower vessel a, and has
also inlet and outlet passages similar to those in the lower vessel a, excepting that
the main inlet passage is covered at the top h², and opens at h* into one of the radial
divisions, which also has a solid top ³ to prevent the escape of gas into the
vessel above it, which vessel I term the top valve, and is marked l. Thus, the gas
enters by the opening into one of the radial divisions h³, and descends into the
corresponding division in the lower vessel a, and thence to the first purifier to bo
treated in the ordinary way. On the top of the upper vessel 7, are two water lutes
,, one inside the main outlet, and the other around the outside of the top valve l,
which lotes i, k, are also joined by tubes.
The top valve has two concentric lute plates, working in the top lutes i, l,
of the upper vessel h. The top valvo Z is closed at top, and has four radial divisions
and an outlet passage in the centre (see the plan Figure 5).
One of the radial compartments into which the top valve is divided by the radial
divisions has a blank face z extending over one division of the upper vessel, and an
opening y corresponding to the next division, through which opening the gas passes
to the main outlet, which outlet forms the centre tube of the valve, and is connected
by a bend to the main outlet in the tar tank a³.
An indicator dial m is fixed over the top valve 1 to a rod n, which said rod is
cottered into a cross piece p in the lower vessel a The dial m (shown separately
in plan in Figure 7) is immoveable, and is marked with the names of the different
purifiers with which the apparatus is connected, and with divisions corresponding
to the centres of the inlets and outlets of the centre valve or apparatus. On the rod 5
n which carries the dial m, is a tube or hollow shaft q connected to the upper vessel
h. The tube or hollow shaft q carries a fingor or pointer 7, which points directly
over the centre of the division from which the gas first leaves the centre valve or
apparatus, and enters the first inlet of the purifiers. This finger or pointer is
distinguished by the words "first inlet," and shows on the dial m to which purifier 5
the gas passes first.
Another finger or pointer s is fixed to the top valve 2, and moves with it. This

page_text: finger always points over the centre of the division which leads to the main outlet
where the gas leaves the last purifier outlet. The finger 8 is distinguished by the
words "last outlet," and the puritier outlet on the dial to which it points is the last
one that is being worked.
The top valve and the upper vessel
pinions on their outsides, as represented in
The top valve and the upper vessel
which the fingers of a watch turn.
are moved as required by the racks and
Figure 1.
are always turned in the direction in
The apparatus or centre valve represented is suitable for working in conjunction
with four purifiers, and is capable of sixteen changes without the aid of the detached
valves sometimes used in the interior of the apparatus as ordinarily constructed.
The general method of working the apparatus or centre valve so nearly resembles
the method of working centre valves as ordinarily constructed, that I do not con-
sider it necessary to enter into further details relative to the working of a centre
valve constructed according to my Invention, as I believe any person conversant
with the working of centre valves of the ordinary construction, will be able to work
apparatus or centre valves constructed according to my Invention by the description
herein-before given, reference being had to the accompanying Drawings.
It will be seen by an examination of Figure 2 that the parts of the apparatus or
centre valve which are required to move upon one another, gas-tight, consist of
two plain dry faces, and for the most part annular, or nearly annular faces working
tightly upon one another, and constituting a dry valve, each of the said dry annular
faces being surrounded by water lutes and lute plates constituting with the water
contained in the said lutes water valves. By this arrangement, the separation of
the incoming gas from the outgoing gas is very efficiently accomplished.
Having now described the nature of my Invention, and the manner in which tho
same is to be performed, I wish it to be understood that I claim as iny Inven-
tion of improvements in apparatus employed in the purification of coal gas,
the general arrangement and combination of the parts of the said apparatus
herein-before described, and illustrated in the accompanying Drawings, constituting
a centre valve, and particularly the arrangement and combination of parts, whereby
the dry face portions of the valve are surrounded with, or supplemented by water
lutes, which combination or arrangement of dry and water valves prevents leakage
between the incoming and outgoing passages of the valve or apparatus, substantially
as described and illustrated.
In witness whereof, I, the said Peter Duckworth Bennett, have hereunto set
my hand and seal, this Thirteenth day of November, in the year of our Lord
One thousand eight hundred and seventy-eight.
PETER DUCKWORTH BENNETT, (Ls.)
Witness,
CHARLES SOMERVILLE BENNETT.