IMPROVE- MENTS IN OR CONNECTED WITH THE HYDRAULIC MAINS USED IN THE DISTILLATION OF COAL
Year: 1885

page_text: I, LEWIS THOMPSON WRIGHT of George Street, Nottingham, Nottinghamshire,
Civil Engineer, do hereby declare the nature of my said Invention for "IMPROVE-
MENTS IN OR CONNECTED WITH THE HYDRAULIC MAINS USED IN THE DISTILLATION
OF COAL " and in what, manner the same is to be performed to be particularly
described and ascertained in and by the following statement that is to say :-
My said Invention relates to the hydraulic mains connected with the apparatus
used in the distillation of coal and it has for its object the construction or arrange-
ment of such hydraulic-mains or of parts connected therewith in such an improved
manner that the action and efficiency of the apparatus is generally improved whilst
at the same time it is rendered more convenient for effecting any cleansing operations
that may be necessary.
In existing hydraulic mains as generally constructed the tar and ammoniacal
liquor entering through the dip-pipe collect in the hydraulic main until the liquid
reaches the level of the outlet for the gas, and thus the amount of sealing of the
dip-pipe is regulated by the position of the outlet which is usually put at the side
of the main. The liquid and gaseous products pass away through this outlet but
the tar being heavier than the amoniacal liquor falls to the bottom of the main
and for want of a proper circulation the lower layers of tar under the influence of
the high temperature and the washing action of the ammoniacal liquor gradually
thicken and become more or less converted into pitch. This action continually.
proceeding soon fills up the main with more or less thickened tar leaving only a
small space for the passage of the gas and fresh liquid products and it then
becomes necessary to open the main and remove the hardened mass by force.
By my Invention this liability of the tar to aggregate and form a hardened mass
and so obstruct the passage through the main is entirely obviated by maintaining
a continuous passage of the liquid products through the main by removing them
through the bottom of the main.
In carrying out my Invention the hydraulic main may be constructed of the
semicircular form in cross section commonly used or any other convenient form,
but in addition to the usual outlet for the gas and products formed at one side of
1

page_text: the main above the level of the lower end of the dip-pipe there is also formed an
opening at the bottom at the lowest point. To this opening there is fitted a
suitable pipe which curves upwards and communicates through a hollow casting
with the usual gas outlet. Instead of a curved pipe it is obvious that a hollow
casting may be arranged to be fitted to the outside of the main so as to form a
means of communication between the two openings. In the casting fitted to the
gas outlet there is formed an opening at the top closed by a suitable cover or lid
directly over the upper end of the curved pipe so that by removing the cover
access may be had to the curved pipe and gas outlet. This casting has an opening
at its side for the passage of the gas and liquids and there is fitted to this
opening an adjustable regulating stop valve which rises upwards when closing.
By means of this valve the level of the liquid in the main may be regulated and
the sealing of the dip-pipe may be conveniently adjusted without interfering with
the constant passage of the gas and liquid. The gas passing through the apparatus,
passes through the opening above the level of the liquid in the main, whilst the
liquid carrying with it the tar and other products in suspension passes down and
then up and through the curved pipe (or casting) and both the gas and liquid
products reunite and pass away through the opening having the regulating stop
valve fitted to it the gas being led to the condenser in an ordinary manner. By
this improved arrangement and by maintaining a continuous passage of the liquid
through the pipe the tar is less liable to thicken and cause obstructions. In
employing the Invention in the case of new mains it will be found preferable to
construct the main with its bottom sloping in all directions to one lowest point
whence the liquid products are drawn off.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append a sheet of explanatory drawings to
be hereinafter referred to and representing my improved arrangement or con-
struction of apparatus. In these drawings the same reference numerals are used
to mark the same or like parts wherever they are repeated.
The Figure on the accompanying sheet of drawings is a transverse vertical
section taken through a hydraulic-main and the parts immediately connected
therewith showing my improved arrangements. The drawing shows my Invention
as applied to a hydraulic-main 1, of well known form and having the ordinary
dip-pipe fitted into it and communicating through the usual ascension pipes with
the retorts. In the bottom of the main 1, there is formed a circular opening 2,
and to this opening 2, there is fitted one end of a flanged metal pipe 3. This
pipe 3, is curved and resembles somewhat in side view an inverted siphon one leg
however being longer than the other, the pipe 3, being fitted to the bottom of the
main 1, by its shorter leg whilst its longer leg projects upward by the side of
the main towards an opening 4, formed at one side near the upper part of the
main for the gas outlet. A tubular casting 5 is fitted by flanges to the upper end
of the pipe 3, and to the outside of the main round the opening 4, so as to form
a means of communication between the two openings 2, 4. In this casting 5,
there is also formed an opening 6, at the top directly over the pipe 3, and this
opening is provided with a removable cover 7, to permit of access to the pipe 3,
if required for any purpose. Opposite the gas outlet opening 4, there is formed
in the casting 5, an opening 8, which is at a lower level than the opening 4,
and with the lowest part of the opening on a level slightly above the lower end of
the dip pipe, so that when liquid is admitted into the main the dip-pipe is just
sealed. To the outside of the casting 5, round the opening 8, there is fitted an
adjustable regulating valve 9, which in closing rises upwards and also forms a
stop valve. By raising this valve it is obvious that the level of the liquid in the
hydraulic main may be regulated so as to effect the sealing of the dip pipe to any
convenient extent. By maintaining a constant passage of liquid through the main
and pipe 3, the liability of the formation of thickened tar is greatly lessened if not
entirely obviated and with the improved arrangements the parts liable to choke up

page_text: are rendered easy of access either for inspection or for the removal and replacement
of any part 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
(1.) The combination and arrangement of parts forming an hydraulic main
substantially as and for the purposes hereinbefore described with reference to the
drawings.
"
(2.) The method of obtaining a continual passage of liquid products through a
hydraulic main by means of an outer passage communicating from the bottom
or lowest part of the main to the gas outlet and having an adjustable regulating
stop valve whereby the sealing of the dip-pipe may be adjusted substantially as
hereinbefore described.