IMPROVEMENTS IN APPARATUS USED IN THE MANUFACTURE OF GAS
Year: 1879

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS
IN APPARATUS USED IN THE MANUFACTURE OF GAS." A communication
from abroad by Louis Dessirier, of Paris, France.
Sealed the 11th May 1880, and dated the 10th December 1879.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 10th December 1879.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. "IMPROVEMENTS IN APPARATUS USED IN THE MANU-
FACTURE OF GAS." [A communication from abroad by Louis Dessirier, of Paris,
France.]
The object of this Invention is to diminish or altogether remove the pressure in
gas retorts due to the height of the column of liquid in which the dip pipes are
immersed in the hydraulic main. This pressure, which the gas must overcome in
order to enter the hydraulic main, although lessened by the use of exhausters,
diminishes the production of gas and increases the incrustation of the retorts,
whereby their length of service is reduced and the transmission of heat to them
obstructed. As the chief object of the hydraulic main is to render the retorts
independent, and prevent the return of the gas on drawing and charging the retorts,
the above objections are entirely avoided by this Invention, which consists in the
employment of an apparatus by which the liquid is withdrawn from the hydraulic
main sufficiently to unseal the dip pipes during the distillation, and returned
thereto in order to seal the dip pipes again when drawing and charging the
retorts.
The Invention is illustrated in the annexed Drawings, in which Figures 1 and 2
show vertical sections of the apparatus on line A, B, Figure 4; Fig. 3 shows a plug
used in case of fracture of a retort; Figure 4 is a horizontal section on line
C, D, Figures 1 and 2; and Figure 5 is a vertical section on line E, F, Figure 4.
The apparatus consists of a cylinder or chamber R connected with the hydraulic
main b by a pipe c, and fitted with a piston p furnished with a rod a. t, t, are

page_text: the dip pipes. In order to prevent any pressure of the gas in the retorts during
the distillation the piston p is raised, as in Fig. 1, thereby drawing the liquid into the
chamber R, and lowering the level in the hydraulic main to a, B, thus unsealing
the dip pipes t. On lowering the piston as in Fig. 2, the liquid is returned to the
main b, the level raised to a', ẞ³, and the dip pipes sealed.
In the event of a retort cracking or otherwise becoming unserviceable its connec-
tion with the hydraulic main is cut off by a plug o, Figure 3, placed in the ascension
pipe. This plug consists of a small cylinder provided with a rod, and fitting the
ascension pipe. A tight joint is ensured by wrapping a cloth round the plug and
Iuting with fire clay.
In Figures 4 and 5 e is a tar collecting pipe, and d are pipes carrying the over-
flow from into e, the levels a, ẞ, and p, q, being at the same height.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the 9th
June 1880.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of
Middlesex, Patent Agent. " IMPROVEMENTS IN APPARATUS USED IN THE MANU-
FACTURE OF GAS." A communication from abroad by Louis Dessirier, of Paris,
Franco.
The object of this Invention is to diminish or altogether avoid the pressure in
gas retorts due to the immersion of the dip pipes in the liquid in the hydraulic
main. The column of liquid above the mouth of the dip pipes may be 3 to 6
inches in height, and the pressure of the gas must be great enough to overcome this
obstacle before it can enter the hydraulic main. Although the pressure required is
lessened by the use of exhausters, still it diminishes the yield of gas and increases
the incrustation of the retorts, whereby their length of service is reduced and tho
transmission of heat impeded.
The above objections are entirely avoided by this Invention, which consists in
the employment of an apparatus by which the liquid is withdrawn from the
hydraulic main sufficiently to unseal the dip pipes during the distillation, and
returned thereto in order to seal the dip pipes again and prevent the return of the
gas when drawing and charging the retorts. As the chief object of immersing the dip
pipes in the hydraulic main is to render the retorts independent and prevent the
return of the gas when drawing and charging, this function is in no way interfered
with by the above method of working.
The Invention is illustrated in the annexed Drawings, in which Figures 1 and 2
show vertical sections of the apparatus on line A, B, Figure 4; Figure 3 shews a
plug used in case of fracture of a retort; Figure 4 is a horizontal section on line
C, D, Figures 1 and 2; and Figure 5 is a vertical section on line E, F, Figure 4.
The apparatus consists of a cylinder or chamber R, connected with the hydraulic
main by a pipe c, and fitted with a piston p furnished with a rod a. t. t, are the
dip pipes. In order to prevent any pressure of the gas in the retorts during the
distillation the piston p is raised, as in Figure 1, thereby drawing the liquid into
the chamber R, and lowering the level in the hydraulic main to a, B, thus unsealing
the dip pipes t. On lowering the piston, as in Figure 2, the liquid is returned
to the main b, the level raised to a', B', and the dip pipes sealed.
In Figures 4 and 5 c is a tar collecting pipe, and d are pipes carrying the over-
flow from b into e, the levels a, B, and p, q, being at the same height.
According to another improvement of this Invention, in the event of a retort
cracking or otherwise becoming unserviceable, its connection with the hydraulic
main is cut off by a plug o, Figure 3, placed in the ascension pipe t. This plug
consists of a small cylinder provided with a rod and fitting the ascension pipe. A
tight joint is ensured by wrapping a cloth round the plug and luting with fire-
clay.
Having described the nature of the Invention, and the manner of performing the
same, I declare that what I claim as the Invention to be protected by the herein-
before in part recited Letters Patent is,-
1st. In the manufacture of gas the method of operating, which consists in
lowering the level of the water in the hydraulic main so as to unseal the dip pipes
during the distillation, and raising the level of the water so as to seal the dip pipes
again when charging and drawing the retorts, as hereinbefore described for the
purpose specified.
2nd. The combination with the hydraulic main of a cylinder r containing a

page_text: piston p, and connected by a pipe e with the hydraulic main, whereby the water
level in the latter is varied, as described and illustrated in Figures 1, 2, and 4, for
the purpose specified.
3rd. The employment in the ascension pipes t, t, of plugs o for cutting off com-
munication between the hydraulic main and any one or more of the retorts, as
hereinbefore described and illustrated in Figure 3 of the Drawings.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my band and seal, this Ninth day of June, in the year of our Lord
One thousand eight hundred and eighty.
A.
M. CLARK. (1.S.)