IMPROVEMENTS IN APPARATUS TO BE APPLIED TO THE HYDRAULIC MAINS OF GAS WORKS
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
We FRANCIS HARMER BACON and BRYAN DONKIN Junior a Member of the
firm of Bryan Donkin & Co both of Southwark Park Road Bermondsey in the
County of Surrey Engineers do hereby declare the nature of our invention for
IMPROVEMENTS IN APPARATUS TO BE APPLIED TO THE HYDRAULIC MAINS OF
GAS WORKS," to be as follows:-
"
This Invention has for its object improvements in apparatus for drawing off gas
from the hydraulic mains of gas works and also for continuously drawing off tar
and ammonical liquor therefrom and conducting them into separate receivers all in
such manner that the gas may at all times be brought effectually into contact with
the aqueous liquor in the main. Contact with the aqueous liquor improves the
quality of the gas and would not be effectually brought about if the tar in the main
were not always covered to a sufficient depth by the ammonical liquor.
By the same apparatus also a constant depth of "dip" or immersion of the
pipes by which the gas is led from the retorts into the hydraulic main is
maintained.
For these purposes we fix upon the hydraulic main a casting in which there are
two trough like passages both terminating at a face which is covered by a slide
valve. These troughs project into the hydraulic main and their upper edges are on
a higher level than is reached by the liquor in the main. One of the troughs serves
as the outlet for the ammonical liquor and the other as the tar outlet. The liquor
enters the first by an aperture in the bottom and the tar rises into the other by a
pipe which descends from the bottom of the trough to the lower part of the
hydraulic main and dips in to the tar which is there to be found. The pressure of
the liquid in the main causes the tar to ascend the pipe into the trough.
When the valve is raised it entirely closes the passages so that neither gas tar or
ammonical liquor may pass but when the valve is lowered it allows the gas to go
forward regulates the level of the ammonical liquor and draws off the tar.
The level of the aqueous liquor in the main is controlled in the usual way, the
liquor flowing over the top of the valve which serves as an adjustable dam to
maintain the liquor in the main on a level with its upper edge. The surplus liquor
flowing over is led away into a suitable receiver,

page_text: The same valve according to our Invention also serves to draw off the tar
automatically in a regular and continuous manner and to prevent it from
accumulating in the main.
The tar also overflows the upper edge of the valve at that part which abuts on
the end of the tar passage and the tar so over flowing is led by ribs on the back of
the valve into a receiver which is separate and distinct from that in which the
ammonical liquor is collected.
The part of the valve over which the tar passes is at a different level from that
part by which the aqueous liquor overflows and so a compensation is effected for
the different specific gravities of the two liquids.
The screw which actuates the valve is provided with a stop nut which can be set
to limit the opening of the valve or in other words the, amount of the dip. Thus
the valve may at any time when necessity arises be closed and when it is again
opened the same depth of dip as before will be established and this without any
special care on the part of the workmen.
By these means also the hardening of the tar within the main so as to obstruct
it is effectually prevented.
We FRANCIS HARMER BACON and BRYAN DONKIN Junior a member of the
firm of Bryan Donkin & Co both of Southwark Park Road Bermondsey in the
County of Surrey Engineers do hereby declare the nature of our invention for
"IMPROVEMENTS IN APPARATUS TO BE APPLIED TO THE HYDRAULIC MAINS OF
GAS WORKS" and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
This invention has for its object improvements in apparatus for drawing off gas
from the hydraulic mains of gas works and also for continuously drawing off tar
and ammoniacal liquor therefrom and conducting them into separate receivers all in
such manner that the gas may at all times be kept effectually from contact with
the tar in main. Such contact with tar deteriorates the quality of the gas and
would not be prevented if the tar in the main were not always covered to a
sufficient depth by the ammoniacal liquor.
By the same apparatus also a constant depth of "dip" or immersion of the
pipes by which the gas is led from the retorts into the hydraulic main is
maintained.
For these purposes we fix upon the hydraulic main a casting in which there are
two trough like passages both terminating at a face which is covered by a sliding
valve. These troughs project into the hydraulic main and their upper edges are on
a higher level than is reached by the liquor in the main. One of the trouglis
serves as the outlet for the ammoniacal liquor and the other as the tar outlet,

page_text: Figure 2 is a transverse section.
Figure 3 is a horizontal section of the same.
A¹ A are the two parts of a double trough which projects into the hydraulic
main and is secured upon the same by a flange A* bolted to the side of the main in
a manner to form a secure joint.
B is a pipe projecting downwards from the part A¹ of the trough sufficiently far
to reach nearly to the bottom of the hydraulic main and to dip into the tar which
is there.
C is an opening in the bottom of the part A2 of the trough by which the
ammoniacal liquor in the main rises into this portion of the trough. The position
in which the apparatus is fixed upon the main is such that the liquor does not
overflow the sides or walls of the trough.
D is a slide valve working against a face at the outer end of the double
trough A¹ A. This valve is attached to a rod D* passing through a stuffing
box E. When the valve D is raised it closes the aperture to which it is applied in
such manner that neither gas tar nor ammoniacal liquor can pass out.
There is a screw thread upon the stem D* of the valve and this part of the stem
passes through a hole in a bridge piece F and receives nuts G. G. G. upon it by
turning which the valve can be raised or lowered.
The uppermost pair of nuts are employed to limit the extent to which the valve
can be opened when lowered again after closing.

page_text: Notches are formed in the upper edge of the valve D at D¹ D₁. At the notch D¹
the tar overflows from the trough A' and from the notch D2 the ammoniacal liquor
overflows from the trough A².
D³ D³. are ribs upon the back of the valve which confine the tar and the
ammoniacal liquor each to its own side of the valve as it runs down from the notch
above.
H is a chamber at the lower part of the valve case into which the valve descends
when lowered to its greatest extent. This chamber receives the tar and the
ammoniacal liquor and there is a ridge at H¹ across the bottom of the chamber H
to keep the tar and the liquor separate.
The tar escapes by a pipe I and the ammoniacal liquor by another similar pipe K
and these pipes lead to suitable receivers.
L is the outlet for the gas, by this outlet it passes away for further treatment as
at present.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
First-The improved apparatus' substantially as described and represented by
the annexed drawings by which the gas the tar and the ammoniacal liquor are all
drawn off separately and the tar and liquor maintained at their own respective
levels.
こ
Second. The combination of parts consisting of the divided trough the valve face
and the slide valve with overflow notches at différent levels for the tar and
ammoniacal liquor substantially as described.
Dated this 10th
1