IMPROVEMENTS IN THE METHOD OF WORKING GAS PROTRIES
Year: 1874

page_text: LETTERS PATENT to William Thomas Walker, of Highgate, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN THE
METHOD OF WORKING GAS PROTRIES"
PROVISIONAL SPECIFICATION left by the said, William Thomas
Walker at the Office of the Commissioners of Patents, with his
Petition, on the 8th June 1874.
I, WILLIAM THOMAS WALKER, of Highgate, in the County of
Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE METHOD OF WORKING GAS PURIFIERS," to be as follows,
that is to say:-
This Invention relates to an improved arrangement and method of
working purifiers for purifying coal gas from carbonic acid, sulphuretted
hydrogen, sulphur compounds, bi-sulphide of carbon, and other
impurities.

page_text: To carry out my Invention I use by preference a series of cight
purifiers, although this principle of working may be applied or partially
applied to a lesser number, videlicet, to seven, six, five, or four purifiers,
especially if the purifiers are made of large capacity for the work they
have to perform, so as to enable them to continue working a long time
without being changed.
One of the chief objects of this Invention is to have the facility of
completely reversing the direction of the flow of gas during the process.
of purification. This facility in some processes of purification is of great
importance. I will instance by way of example that what is called
"foul lime" in gas works or sulphide of calcium is known to be one of
the most effective agents for purifying, gas from sulphur compounds,
other than sulphuretted hydrogen; but the odours given off by it are so
offensive that it cannot be used in towns or even in their immediate
vicinity. This renders another system of purifiers necessary to meet
such cases, both for this purpose and also for giving additional facilities
in the working of the purifiers for the application of chemical processes.
which require the changing or the bringing back of the flow of gas in
the direction or to the point from whence it commenced its flow.
My improved system or arrangement of purifiers consists in furnishing
each purifier with a double inlet and two outlets; in placing two centre
valves one on either side of each purifier, and attaching to each centre
valve a gas valve to prevent foul gas finding a passage from the inlet to
the outlet, and to obtain the means of reversing the flow of gas as
described, and of working the purifiers in the way found desirable for
using the different chemical processes referred to.
I sometimes use a return main placed at the lower part and connected
to the inlet main on the left hand side; and by this main I return. the
gas from the left hand side to the right hand side, which gives me the
means of passing the gas through one or all of the purifiers in a similar
manner to that herein-before described, and brings the outlet to the
opposite end, to the inlet end.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Thomas Walker in the Great Scal Patent
Office on the 8th December 1874.
'
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
THOMAS WALKER, of Highgate, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of June, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Thomas Walker, Her
special licence that I, the said William Thomas Walker, my executors,
administrators, and assigns, or such others as I, the said William Thomas
Walker, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an In-
vention for "IMPROVEMENTS IN THE METHOD OF WORKING GAS PURIFIERS," upon
the condition (amongst others) that I, the, said William Thomas Walker,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe
and ascertain the nature, of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Thomas Walker, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed to be particularly described and ascertained in and by
the following statement, reference being had to the Drawing hereto
annexed and to the figures and letters marked thereon, that is to
say:
This Invention relates to an improved arrangement and method of
working purifiers for purifying coal gas from carbonic acid, sulphuretted
hydrogen, sulphur compounds, bi-sulphide of carbon, and other

page_text: To carry out my Invention I use by preference a series of eight
purifiers, although my improved method of working may be applied or
partially applied to a lesser number, videlicet, to seven, six, five, four,
three, or two purifiers, especially if the purifiers are made of large
capacity for the work they have to perform, so as to enable them to
continue working a long time without being changed.
One of the chief objects of this Invention is to obtain the means of
completely reversing the direction of the flow of gas during the process
of purification. This means in some processes of purification is of great
importance. I will instance by way of illustration that what is called
"foul lime" or sulphide of calcium is known to be one of the most
effective agents for purifying gas from sulphur compounds other than
sulphuretted hydrogen; but the odours given off by it are so offensive
that it cannot be used in gas works in towns or in their immediate
vicinity. This defect renders another method than that ordinarily in
use of working purifiers necessary, both for avoiding this objection and
also for giving additional facilities in the working of the purifiers for
the application of chemical processes which require the changing or the
bringing back of the flow of gas in the direction or to the point from
which it commenced its flow.
In carrying out my improved method of working gas purifiers each
purifier is furnished with a double inlet and two outlets, and with two
centre valves (preferably Walker's), one placed on either side of each
purifier, and to each centre valve is attached a slide or other suitable
gas valve to prevent foul gas from finding a passage from the inlet to
the outlet, and to furnish the means of reversing the flow of gas and of
working the purifiers in the way found desirable for using the various
chemical processes employed in the purification of gas.
I sometimes use a return main placed at the lower part and connected
to the inlet main on the left hand side, and by means of this main I am
enabled to return the gas from the left hand side to the right hand side,
and am enabled also to pass the gas through one or all of the purifiers,
and bring the outlet end to the end opposite to the inlet end.
To make my Invention better understood I will proceed to describe
the same by reference to the accompanying Drawing, in which Figure 1
is a plan shewing a series of eight purifiers A, B, C, D, E, F, G, and H;
I, the inlet, and I¹ the outlet for the gas, shewn for the sake of illustra-.

page_text: tion on the right hand side; J, J, J, J, are the centre valves, one on
each side of the purifier; K, K, the double inlets (or the inlets may be
separate); and L, L, the two outlets of each purifier; M, M, the gas
valves; N, bye pass. By this arrangement it will be seen that the gas
passes into the purifier A, as shewn by the arrows, and proceeds conse-
cutively through the whole of the purifiers B, C, D, E, F, G, and H, to
the end of the main on the left hand side, where the arrows indicating
the flow of the gas turn at right angles.
It will be understood also that any separate number of purifiers can
be similarly worked. Thus the purifier A or the purifier H can be
worked alone, and all or any of the others may be bye-passed by giving
the centre valves a quarter turn; or the gas can be made to enter the end
purifier H first, and the flow or dircction herein-before described may bc
reversed, that is to say, proceed from H to G, F, E, D, C, B, and A, thus
working through the whole of the purifiers in the reverse way conse-
cutively. Or any separate number of purifiers can be separately worked,
the gas flowing inversely from the left hand to the right hand, instead
of from the right hand to the left hand whenever required.
-
I will give some illustrations of the importance and necessity of this
mode of working. The first two purifiers A and B can be worked for
purifying gas from carbonic acid, the purifiers C, D, E, and F, for
sulphur, and the last two G and H as catch or finishing purifiers; or
the first four purifiers A, B, C, D, may be used for the ordinary mode of
purification, and the purifiers E and F may be used to receive the gas
thus purified, and being charged with the necessary chemical agents,
such for instance as the sulphide of calcium, will act entirely on the
sulphur compounds other than sulphuretted hydrogen, while the last
two purifiers G and H will act as catch or finishing purifiers, and take
up any sulphuretted hydrogen or other impurity that the gas may have
absorbed in passing through the purifier or purifiers containing sulphide.
of calcium. This mode of working may also be reversed, and the gas
may be purified in the ordinary way, videlicet, by passing through
E, F, G, and H. The purifiers C, D, having been first charged with
sulphide of calcium, or with other chemical agents, the gas could be
brought back from H to D, C, to be purified from the sulphur com-
pounds other than sulphuretted hydrogen, and the operation of finishing
the purification be completed in the purifiers A, B, or either one of
them.

page_text: To give a further example of the operation of this Invention with
regard especially to the offensive odour of "foul lime," I would stato
that by this arrangement and method of working, the purifiers containing
this offensive smelling agent may be rendered free from smell; thus,
supposing any two purifiers to be full of "foul lime," or sulphide of
calcium, or other like chemical agent, the reversing action enables the
coal gas containing carbonic acid to be admitted so as to displace the
sulphur, which will then pass on to the next purifier or purifiers charged
with oxide of iron or other chemical, absorbing the sulphur without
giving off offensive odours, and so preventing the nuisance.
In the plan in Figure 2 of the Drawing I shew the same principle
carried out in a more perfect manner by the employment of the return
main O, which return main enables me to obtain a more complete'
command, and also to work all the purifiers consecutively in rotation, or
to throw any of the number in or out of action.
It will be seen that the purifiers are marked with letters from A to H,
as in Figure 1, and I will now describe how the whole number, by the
use of the return maiu O, may be worked consecutively, and the whole.
of the purifiers be bye-passed by means of the bye-pass P in connection
with the return main O.
The gas enters at the inlet I at the right hand side, and on arriving at
the end on the left hand side it turns into the return main O, as shewn
by the arrows.
The purifiers can therefore be worked in the following order,
videlicet :-

page_text: purifiers may be also so worked, or any or either may be bye passed out
of action. To enable this mode of working to be more fully understood
I will describe my improvements applied to a set of four purifiers (this
being the number usually employed in gas works), and compare its
action with that of the centre valve, as heretofore used, when working
three purifiers on and one off. With the centre valve as heretofore used
in gas works the set of four purifiers can only be worked as follows,
videlicat
thereby giving about twenty-five per cent. additional purifying power,
which becomes of great importance where large purifiers are used. - Not
only is this large addition of purifying power rendered available, but any
or cither of the purifiers may be thrown in or out of action, emptied,
replenished, charged with different purifying materials, or any change
that may be required effected at once, thus giving command and control
over each and all of the purifiers, and enabling them to be worked in
any way suitable for the various chemical processes used for purifying
gas.
Having now described my Invention, and the manner in which the
same is to be performed, what I claim as new and intended to be
protected by the herein-before in part recited Letters Patent is,-
Firstly. The arrangement of purifiers with centre valves and slide
valves on each side thereof, and with a double inlet and outlet, and
system of connections to enable them to be worked, substantially in the
manner and for the purposes herein-before described and represented in
the accompanying Drawing.

page_text: Secondly. The arrangement of purifiers, with the addition of a return
main and valves, and an additional bye-pass to enable the purifiers to be
worked in a more perfect manner, substantially as herein-before described
and represented in the accompanying Drawing.
In witness whereof, I, the said William Thomas Walker, have
hereto set my hand and seal, this Eighth day of December,
in the year of our Lord One thousand eight hundred and seventy-
four.
WILLIAM THOMAS WALKER. (L.S.)
Witness,
W. A. GILBEE,
4, South St.,
Finsbury.