Year: 1897

page_text: Date of Application, 25th Jan., 1897
Complete Specification Left, 21st Oct., 1897-Accepted, 27th Nov., 1897
Date of Application, 20t
Complete Specification Left, 21st Oct., 1897-Accepted, 27th Nov., 1897
I, JOHN CLAYTON MEWBURN of the Firm of J. C. Mewburn & Ellis, of 55 and
56 Chancery Lane, in the County of London, Chartered Patent Agents, do hereby
declare the nature of this invention to be as follows:
This invention relates to apparatus for generating acetylene gas by the contact
of water with calcium carbide or other gas producing metallic carbides. The
apparatus is also applicable with any other solid substance which generates gas
on reaction with water or other liquid.
The object of this invention is to provide an apparatus which shall be automatic
and self-governing, and free from danger. The apparatus is especially designed
and adapted for use in isolated lighting, but is also applicable to gas plants pro-
ducing acetylene gas on a larger scale for distribution.
Most of the acetylene gas apparatus heretofore devised have operated on the
principle of controlling the admission of water into contact with the carbide by
variations in the pressure of the generatiol acetylene. Thus the water being
admitted into contact with the carbide, usually by rising up from beneath, wets
the carbide and sets up an active gencration of gas, which soon accumulates a
pressure sufficient to force down the level of water, thereby expelling the water
from contact with the carbide, and holding it out of contact there-
with until sufficient gas has been used to permit the water to again
rise and repeat the generating operation. Such apparatus are theoretically
operative, but practically are found subject to the objection that after each
wetting of the carbide, the generation of gas goes on with considerable rapidity
even after the water is expelled out of contact with the carbide, this being due
to two causes, namely (1) that the carbide and the resulting lime retain a con-
siderable quantity of water by capillary adhesion: and (2) that the water constantly
gives off vapor, assisted by the heat disengaged by the reaction, and this vapor
constantly attacks the carbide and generates gas. It results that the generation
of gas continues uninterruptedly, although at a greatly reduced rate, during the
time of little or no consumption, an effect which is neither avoided nor provided
for in existing apparatus. To overcome this difficulty, the present invention
provides an apparatus which is free from this inconvenience.
Fig. 1 of the accompanying drawings is a sectional elevation of the new apparatus
in its preferred form;
fmomentary section of part thereof in a different position.
TA

page_text: Referring to the drawings, let A A designate carbide reaction chambers for
generating gas, and B a gas-holder or gasometer for storing it. I provide by
preference two carbide chambers in order that they may be operated in alternation,
so that a continuous supply of gas may be maintained, as with only a single
chamber the supply would be interrupted during the period of replenishing this
chamber. A single chamber, however, is sufficient to render the apparatus opera-
tive, and as ordinarily only one chamber is in use at a time, I will describe the
apparatus with reference only to the one chamber which is in active service.
The carbide chamber A. consists of any suitable chamber or receptacle capable
of being closed hermetically against a slight pressure, and of being opened to
charge it with carbide. and for removing the residual lime. In the construction
shown, the chamber is open on one side and closed by a door indicated at the right
in Fig. 1. Within the chamber is a tray a of perforated metal, in which is placed
the calcium carbide, ordinarily in the form of lumps. Above this tray is arranged
a sprinkler b, constructed in this instance of small tubes radiating from a common
hub, and of such lengths as to distribute the entering water with approximate
uniformity over the entire area of the carbide. Water is admitted to the
sprinkler b through a pipe c, which leads from any suitable source of water, con-
veying water under a definite head or pressure. The most convenient source of
water is a slightly elevated water supply reservoir C, from the bottom of which
the pipe leads, extending first downward and then upward, and terminating in
the sprinkler b. This pipe has a valve c by which the water may be shut off.
The bottom of the chamber A slopes toward an outlet, and to this is connected
a trapped pipe constituting a hydraulic seal. Hence any portion of the water
which is showered upon the carbide, and which is not immediately taken up
thereby, runs off and is discharged through the pipe d, so that no water is per-
mitted to accumulate in the carbide chamber. From the top of the carbide
chamber leads a gas delivery pipe e which extends to the gas-holder B. It is
carried first upward, then horizontally, and then downward, being formed into
a condensing coil f, which is conveniently located in the water reservoir C, from
which the pipe extends downward, and at its lowest point is provided with a
drainage trap for discharging any water of condensation from the pipe, this
trap having a valve g for closing it. The gas pipe extends from the trap g
horizontally and upwardly into the gas holder.
The gas-holder is constructed as usual with an outer vessel or tank h con-
taining water or other sealing liquid, and with a floating bell D movable up and
down, and having any suitable means for guiding it in its movement. In the
construction shown the bell is guided by rollers carried by it and rolling against
upright guides j. The weight of the bell must be such as to compress the gas
to less extent than the pressure upon the head of the water entering the carbide
chamber. For example, if the head of water be three inches, the pressure put upon
the gas by the weight of the bell must be somewhat less than corresponds to
three inches of water, say for example two inches. It results from this that the
gas generated in the carbide chamber can flow into the gas-holder and lift the
hell thereof, without thereby generating such back pressure as will stop the
How of water. If the weight of the bell exceeds that which corresponds to this
-pressure, it should be counterweighted sufficiently to bring it within the weight
stated:
The gas-holder is provided with some suitable means for resisting the rise of
the floating bell abbre a given level, the resistance being sufficient to increase
the pressure of the gas enough to equal or exceed that of the water entering the
carbide chamber, and thereby to shut off the inflow of water before the bell can
rise to a higher level. The preferred construction for introducing such resistance
to the continued rise of the bell, is that shown, wherein a weight E is so con-
nected as to be picked up by the bell in its ascent, whereby the bell has the
weight thereof added to its own weight. In the drawing, this weight is shown as

page_text: suspended centrally above the bell, so that as the latter rises it comes against the
weight, and its continued rise lifts the weight. The weight is suspended by a
cord or chain k, which passes over pulleys, and carries at its other end a small
counterweight m, sufficiently heavy to keep the cord or chain k stretched. The
counterweight m serves as a stop for limiting the downward movement of the
weight E by being arranged to strike a fixed cross head 7 when at the upper
limit of its travel, whereby the descent of the weight E is arrested and it is loft
suspended at this level. The weight E should be heavy enough in proportion to
the area of the bell, so that before the bell can lift the weight, the pressure of
gas must be increased sufficiently to equal or exceed the pressure at which the
water enters the carbide chamber, so that before the weight can be lifted the
water is shut off. Assuming that the water enters the chamber under a head
of three inches, and. that the weight of the bell alone corresponds to two inches
of water, the weight E must be heavy enough to correspond to a pressure of at
least one inch of water; but to ensure safe and correct operation, I make the
weight heavy enough to correspond to a pressure of about three inches of water,
so that before the weight can he lifted, the flow of water is not only interrupted,
but the water is forced back within the pipe to a level about two inches lower
than that of the outlet.
3
From the gas-holder, the gas passes out by a pipe which leads to a dehydra
tor F, which is adapted in any suitable way to dry the gas as the latter passes
through it. A suitable dehydrator contains alternated trays of calcium carbide
which takes up the moisture from the gas as the latter flows over it. From the
dehydrator the gas is conducted by a piper to a governor or pressure regulator G,
and from this the gas flows at a uniform and reduced pressure through a pipe
to supply the burners. The piper is provided with a hydraulic trap for draining
off any moisture that may descend in the pipes s and r, a cock being provided
for closing this trap. The drawing shows the apparatus in full lines in the
normal position, the floating bell D being in contact with the weight E, but not
having lifted it. At starting the operation, the carbide chamber A having been
supplied with carbide, the cocks end e adjacent to this chamber are opened,
and water flows from the reservoir C to the sprinkler band falls upon the carbide,
some of the water flowing into the trap d and sealing it. Acetylene gas is rapidly
generated and flows out by the pipe e, the steam which is carried over with it
being condensed in the coil f, and the water of condensation therefrom running
into the trap g. The gas passes by pipe e to the gas-holder D, and flows through
the outlet pipe q until the air in the pipes and holder has been displaced, where-
upon the outlet may be closed either at the burners or by a cock s¹, or other-
wise, and the accumulating gas lifts the bell from its lowermost position until
it reaches the position where it bears against the weight E, and is stopped thereby
The bell remains stationary until the accumulating gas reaches a pressure corre
sponding to the weight of the bell plus that of the weight (in the example given
it rises from two inches of water to five inches), and as the pressure rises suffi-
ciently to counterbalance that of the column of water, the entrance of water to
the carbide chamber ceases, and the active generation of gas is discontinued.
The generation of gas will, however, continue at a slower rate by reason of the
water held by capillarity in contact with the carbide and lime, and the gas thus
generated increases the pressure in the holder until it lifts the bell and weight,
The bell may rise to the extreme position indicated in dotted lines, but in practice
the capacity of the bell will be calculated in excess of the volume of gas that can
be generated from the mere residue of water in contact with the carbide. ' As
gas is consumed, the holder falls, the gas continuing under the greater pressuri
(five inches of water in the example given) until the weight reaches its' bottoni
limit and becomes suspended by its chain or cord, after which the pressure may
fall until only sufficient to uphold the bell (two inches in the example given),
whereupon with a continued consumption in excess of any new generation of gas,
the bell will further descend. The fall of pressure, however, before it will permit

page_text: ".
the further descent of the bell, admits water again into contact with the carbide,
and a new generation of gas commences which ordinarily will raise the pressure
and quickly check the inflow of water. Ordinarily during the period when gas
is being consumed, the bell occupies the position shown in full lines, and the
variations of pressure serve to control the admission of water, and to render
automatic the consequent generation of gas. Only in the case of unusually rapid
or sudden consumption will the bell fall below this position; and it will rise
above it and lift the weight only in case the generation of gas considerably exceeds
the rate of consumption. When the burners are shut off, so that consumption
ceases or is greatly reduced, the continued generation of gas due to the influence
of residual moisture upon the carbide gradually raises the bell, which thus provides
a storage capacity ample for receiving this additional volume of gas
frequent variations in. pressure of the gas contained in the holder are compen-
sated for by the action of the governor G, which is set to permit the gas to pass at a
reduced pressure somewhat beneath the minimum pressure in the holder."
The
In case the spontaneous generation of gas continues after the holder is full, the
gas will escape into the room by forcing its way out beneath the bottom of the
bell, and in such case is liable to form an explosive mixture with the air. To avoid
this source of danger provide a special outlet for any possible excess of gas
beyond the capacity of the holder. To this end a portion of the vessel his boxed
in to form a sealed chamber t, and in line with this bell is provided with an up-
turned tube u in its side wall near the bottom. When the upper position is
reached, this tube u projects up into the chamber t above the water level therein,
as shown in Fig. 2, and as the gas accumulates and forces down the water level
within the bell, it uncovers the mouth of the tube u and may escape by bubbling
into the chamber t through the tube u, from where it is freely led off outdoors
by a vent pipe v.
The water reservoir C may be any usual construction of service tank supplied
by a float valve w from a water pipe H, and having an overflow pipe I for carrying
off any excess of water in case of leakage or derangement of the float valve.
provide a valve J to close the outlet from the reservoir to the pipe c in case the
bell of the gas-holder falls nearly to its lowermost position. This valve J
is suspended by a chain or cord y from an arm y projecting from the
bell, and is guided by a long stem y² projecting down into a deep
tube, this stem and tube being long enough to accommodate the whole range of
vertical movement of the holder. The purpose of this valve is to prevent waste
of water by flooding the carbide chamber A when the carbide has been con-
sumed, and when consequently no more gas is generated and the pressure falls,
permitting the bell D to descend. The valve J is arranged to close before the
bell reaches its lowermost position, and consequently while a pressure correspond-
ing to the weight of the bell is still maintained.
If
When the holder falls to its lowest position, it is known that the carbide is
exhausted, and consequently that the chamber A needs replenishing. The valves e¹
and care then closed to disconnect this chamber from the gas-holder.
duplicate carbide chambers are provided as shown, the corresponding valves for the
other chamber are opened, so as to put that chamber into service The valve J
being closed, no water can flow into this chamber to start the generation of gas,
for which reason it is necessary to lift the valve J by hand for a moment.
chamber which has been disconnected may then be opened, the tray a of residual
lime is taken out and emptied, and a tray of fresh carbide is put in its place,
whereupon the chamber is again closed. The valve e¹ may be opened at any
time, but the water valve c¹ should not be opened until this chamber is again put
in service.
The
With the proportions shown, the gas-holder bell encounters the weight E when
lifted to about one-fifth its capacity, leaving the remaining four-fifths as storage
capacity for the spontaneously generated gas. These proportions, however, are
variable.

page_text: The cocks g', g₁ and r¹ can be closed when originally starting the apparatus,
and opened after sufficient water has accumulated to form a seal.
The invention further provides means for guarding against another source of
danger. In case of neglect to promptly replenish the supply of carbide after_it
becomes exhausted, the bell D after closing the water valve J, will descend to the
lower limit of its movement, where its weight is borne by stops a suitably
arranged, and if the consumption of gas continues its pressure falls and the lights
at the burners go out. There is liability, however, that some remnant of unde-
composed carbide may undergo decomposition by reason of residual moisture,
and thereby maintain a slow generation of gas which would pass out through
the pipes rs to the burners, and if these latter were not closed, this gas would
escape and mingle with the atmosphere, and might possibly form an explosive
mixture. To effectually prevent this, I provide means whereby at or before the
time the floating bell reaches its lowest position it operates a valve or scal, or
some equivalent device for cutting off the outflow of gas. One way of accom-
plishing this is by suspending a valve K within the bell D in such position that
when the bell lowers to or near its bottom position, this valve shall seat itself
upon the upper end of the gas outlet pipe q. Another way is to provide a stop-
cock K in the pipe g (or in any other part of the outlet pipes leading to the
burners), and provide mechanical means for closing this stop-cock at the last
portion of the downward movement of the bell, the means shown consisting of
rod b, its lower end being pivoted to the handle of the stop-cock while its
upper end is guided in a guide encountered by an arm 63 carried by the bell,
so that as the latter nears the bottom of its descending movement, this arm strikes
the rod and pushes the latter downward, thereby turning the stop-cock to its
closed position. Any other mechanical device by means of which the descent of
the bell to or nearly to its lowermost position stops the outflow of gas through the
tube I will answer the requirements of this feature of my invention. Its result
is that when the hell descends to or about the bottom of its movement, and pre-
ferably after the closing of the water valve J, the outflow of gas is cut off, so that
the pressure in the outlet pipe immediately falls, and the burners are of course
extinguished. Thereafter no gas can pass into the outlet pipe, so that even in
case of neglect to turn off the gas at the burners, no leakage of gas can occur
from the burners until the apparatus is again put in service by replenishing the
carbide chamber, and setting it again in operation to cause the ascent of the
gas-holder bell. The valve K will open automatically by reason of such ascent,
but the valve K¹ will remain closed until opened by hand.
1
C
1007
J. C. MEWBURN & ELLIS
55 and 56 Chancery Lane London, Chartered Patent Agents.
Improvements in Apparatus for Generating Gas by the Reaction of
Solid Substances with Water or other Liquid, especially applicable
to the Generation of Acetylene Gas by Contact of Water with
Metallic Carbides.
Oxford

page_text: declare the nature of this invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and. by the following
statement:
This invention relates to apparatus for generating acetylene gas by the contact
of water with calcium carbide or other gas producing metallic carbides. The
apparatus is also applicable with any other solid substance which generates gas
on reaction with water or other liquid.
The object of this invention is to provide an apparatus which shall be automatic
and self-governing, and free from danger. The apparatus is especially designed
and adapted for use in isolated ligating, but is also applicable to gas plants pro-
ducing acetylene gas on a larger scale for distribution.
Most of the acetylene gas apparatus heretofore devised have operated on the
principle of controlling the admission of water into contact with the carbide by
variations in the pressure of the generated acetylene. Thus the water being
admitted into contact with the carbide, usually by rising up from, beneath, wets
the carbide and sets up an active generation of gas, which soon accumulates a
pressure sufficient to force down the level of water, thereby expelling the water
from contact with the carbide, and holding it out of contact there-
with until sufficient gas
has been used to permit the water to again,
rise and repeat the generating operation. Such apparatus are theoretically
operative, but practically are found subject to the objection that after each
wetting of the carbide, the generation of gas goes on with considerable rapidity
even after the water is expelled out of contact with the carbide, this being due
to two causes, namely (1) that the carbide and the resulting lime retain a con-
siderable quantity of water by capillary adhesion; and (2) that the water constantly
gives off vapor, assisted by the heat disengaged by the reaction, and this vapor
constantly attacks the carbide and generates gas. It results that the generation
of gas continues uninterruptedly, although at a greatly reduced rate, during the
time of little or no consumption, an effect which is neither avoided nor provided
for in existing apparatus. To overcome this difficulty, my invention provides
an apparatus which is free from this inconvenience.
+
Fig. 1 of the drawings left with the Provisional Specification and to which
reference is now made is a sectional elevation of the new apparatus in its preferred
form;
Fig. 2 is a fragmentary section of part thereof in a different position.
Referring to the drawings, let A. A designate carbide reaction chambers for
generating gas, and B a gas-holder or gasometer for storing it. I provide by
preference two carbide chambers in order that they may be operated in alternation,
so that a continuous supply of gas may be maintained, as with only a single
chamber the supply would be interrupted during the period of replenishing this
chamber. A single chamber, however, is sufficient to render the apparatus opera-
tive, and as ordinarily only one chamber is in use at a time, I will describe the
apparatus with reference only to the one chamber which is in active service.
The carbide chamber A consists of any suitable chamber or receptacle capable
of being closed hermetically against a slight pressure, and of being opened to
charge it with carbide, and for removing the residual lime. In the construction
shown, the chamber is open on one side and closed by a door indicated at the right
in Fig. 1. Within the chamber is a tray a of perforated metal, in which is placed
the calcium carbide, ordinarily in the form of lumps. Above this tray is arranged
a sprinkler b, constructed in this instance of small tubes radiating from a common
hub, and of such lengths as to distribute the entering water with approximate
uniformity over the entire area of the carbide. Water is admitted to the
sprinkler through a pipe c, which leads from any suitable source of water, con-
veying water under a definite head or pressure. The most convenient source of
water is a slightly elevated water supply reservoir C, from the bottom of which
the pipe leads, extending first downward and then upward, and terminating in
"
4

page_text: the sprinkler b. This pipe has a valve by which the water may be shut off.
The bottom of the chamber A slopes toward an outlet, and to this is connected
a trapped pipe d constituting a hydraulic seal. Hence any portion of the water
which is showered upon the carbide, and which is not immediately taken up
thereby, runs off and is discharged through the pipe d, so that no water is per-
mitted to accumulate in the carbide chamber. From the top of the carbida
chamber leads a gas delivery pipe e which extends to the gas-holder B. It is
carried first upward, then horizontally, and then downward, being formed into
a condensing coil f, which is conveniently located in the water reservoir C, from
which the pipe extends downward, and at its lowest point is provided with a
drainage trap g for discharging any water of condensation from the pipe, this
trap having a valve g¹ for closing it. The gas pipe extends from the trap g
horizontally and upwardly into the gas holder.
The gas-holder is constructed as usual with an outer vessel or tank con-
taining water or other sealing liquid, and with a floating bell D movable up and
down, and having any suitable means for guiding it in its movement. In the
construction shown the bell is guided by rollers i carried by it and rolling against
upright guides j. The weight of the bell must be such as to compress the gas
to less extent than the pressure upon the head of the water entering the carbide
chamber. For example, if the head of water be three inches the pressure put upon
the gas by the weight of the bell must be somewhat less than corresponds to
three inches of water, say for example two inches. It results from this that the gas
generated in the carbide chamber can flow into the gas-holder and lift the
Bell thereof, without thereby generating such back pressure as will stop the
flow of water. If the weight of the bell exceeds that which corresponds to this
pressure, it should be counterweighted sufficiently to bring it within the weight
stated.
The gas-holder is provided with some suitable means for resisting the rise of
the floating bell above a given level, the resistance being sufficient to increase
the pressure of the gas enough to equal or exceed that of the water entering the
carbide chamber, and thereby to shut off the inflow of water before the bell can
rise to a higher level. The preferred construction for introducing such resistance
to the continued rise of the bell, is that shown, wherein a weight E is so con-
nected as to be picked up by the hell in its ascent, whereby, the bell has the
weight thereof added to its own weight. In the drawing, this weight is shown as
suspended centrally above the bell, so that as the latter rises it comes against the
weight, and its continued rise lifts the weight. The weight is suspended by a
cord or chain, which passes over pulleys 11, and carries at its other end a small
counterweight m, sufficiently heavy to keep the cord or chain stretched. The
counterweight m serves as a stop for limiting the downward movement of the
weight E by being arranged to strike a fixed cross head when at the upper
limit of its travel, whereby the descent of the weight E is arrested and it is left
suspended at this level. The weight E should be heavy enough in proportion to
the area of the bell, so that before the bell can lift the weight, the pressure of
gas must be increased sufficiently to equal or exceed the pressure at which the
water enters the carbide chamber, so that before the weight can be lifted the
water is shut off. Assuming that the water enters the chamber under a head
of three inches, and that the weight of the bell alone corresponds to two inches
of water, the weight E must be heavy enough to correspond to a pressure of at
least one inch of water; but to ensure safe and correct operation, I make the
weight heavy enough to correspond to a pressure of about three inches of water,
so that before the weight can be lifted, the flow of water is not only interrupted,
but the water is forced back within the pipe c to a level about two inches lower
than that of the outlet.
From the gas-holder, the gas passes out by a pipe 7 which leads to a dehydra-
tor F. which is adapted in any suitable way to dry the gas as the latter passes
through it. A suitable dehydrator contains alternated trays of calcium carbide

page_text: From the
which takes up the moisture from the gas as the latter flows over it.
dehydrator the gas is conducted by a pipe r to a governor, or pressure regulator G,
and from this the gas flows at a uniform and reduced pressure through a pipe s
to supply the burners. The pipe r is provided with a hydraulic trap r¹ for draining
off any moisture that may descend in the pipes s and r, a cock being provided
for closing this trap. The drawing shows the apparatus in full lines in the
normal position, the floating bell D being in contact with the weight E, but not
having lifted it. At starting the operation, the carbide chamber A having been
supplied with carbide, the cocks e¹ and c¹ adjacent to this chamber are opened,
and water flows from the reservoir C to the sprinkler 6 and falls upon the carbide,
some of the water flowing into the trap d and sealing it. Acetylene gas is rapidly
generated and flows out by the pipe e, the steam which is carried over with it
being condensed in the coil f, and the water of condensation therefrom running
into the trap g. The gas passes by pipe e to the gas-holder D, and flows through
the outlet pipe q until the air in the pipes and holder has been displaced, where-
upon the outlet may be closed either at the burners or by a cock s¹, or other-
wise, and the accumulating gas lifts the bell from its lowermost position until
it reaches the position where it bears against the weight E, and is stopped thereby.
The bell remains stationary until the accumulating gas reaches a pressure corre-
sponding to the weight of the bell plus that of the weight (in the example given
it rises from two inches of water to five inches), and as the pressure rises suffi-
ciently to counterbalance that of the column of water, the entrance of water to
the carbide chamber ceases, and the active generation of gas is discontinued.
The generation of gas will, however, continue at a slower rate by reason of the
water held by capillarity in contact with the carbide and lime, and the gas thus
generated increases the pressure in the holder until it lifts the bell and weight.
The bell may rise to the extreme position indicated in dotted lines, but in practice
the capacity of the bell will be calculated in excess of the volume of gas that can
be generated from the mere residue of water in contact with the carbide. As
gas is consumed, the holder falls, the gas continuing under the greater pressure
(five inches of water in the example given) until the weight reaches its bottom
limit and becomes suspended by its chain or cord, after which the pressure may
fall until only sufficient to uphold the bell (two inches in the example given),
whereupon with a continued consumption in excess of any new generation of gas,
the bell will further descend. The fall of pressure, however, before it will permit
the further descent of the bell, admits water again into contact with the carbide,
and a new generation of gas commences which ordinarily will raise the pressure
and quickly check the inflow of water. Ordinarily during the period when gas
is being consumed, the bell occupies the position shown in full lines, and the
variations of pressure serve to control the admission of water, and to render auto-
matic the consequent generation of gas. Only in the case of an unusually rapid
or sudden consumption will the bell fall below this position; and it will rise above
it and lift the weight only in case the generation of gas considerably exceeds the
rate of consumption. When the burners are shut off, so that consumption ceases
or is greatly reduced, the continued generation of gas due to the
influence of residual moisture upon the carbide gradually raises the bell, which
thus provides a storage capacity ample for receiving this additional volume of gas.
The frequent variations in pressure of the gas contained in the holder are com-
pensated for by the action of the governor G, which is set to permit the gas to pass
at a reduced pressure somewhat beneath the minimum pressure in the holder.
In case the spontaneous generation of gas continues after the holder is full,
the gas will escape into the room by forcing its way out beneath the bottom of
the bell, and in such case is liable to form an explosive mixture with the air. To
avoid this source of danger I provide a special outlet for any possible excess of gas
beyond the capacity of the holder. To this end a portion of the vessel h is boxed
in to form a sealed chamber t, and in line with this the bell is provided with an
upturned tube u in its side wall near the bottom. When the upper position is

page_text: reached, this tube u projects up into the chamber t above the water level therein,
as shown in Fig. 2, and as the gas accumulates and forces down the water level
within the bell, it uncovers the mouth of the tube u and may escape by bubbling
into the chamber through the tube u, from where it is freely led off outdoors by
a.vent pipe v.
The water reservoir C may be any usual construction of service tank supplied by
a. float valve w from a water pipe H, and having an overflow pipe I for carrying
off any excess of water in case of leakage or derangement of the float valve.
provide a valve J to close the outlet from the reservoir to the pipe c in case the bell
of the gas-holder falls nearly to its lowermost position. This valve J is suspended
by a chain or cord y from an arm y¹ projecting from the bell, and is guided by a
long stem projecting down into a deep tube, this stem and tube being long
enough to accommodate the whole range of vertical movement of the holder. The
purpose of this valve is to prevent waste of water by flooding the carbide chamber A
when the carbide has been consumed, and when consequently no more gas is
generated and the pressure falls, permitting the bell 1) to descend. The valve J.
is arranged to close before the bell reaches its lowermost position, and consequently
while a pressure corresponding to the weight of the bell is still maintained.
When the holder falls to its lowest position, it is known that the carbide is
exhausted, and consequently that the chamber A needs replenishing. The
valves e and c¹ are then closed to disconnect this chamber from the gas-holder.
If duplicate carbide chambers are provided as shown, the corresponding valves for
the other chamber are opened, so as to put that chamber into service. The valve J
being closed, no water can flow into this chamber to start the generation of gas,
The
for which reason it is necessary to lift the valve J by hand for a moment.
chamber which has been disconnected may then be opened, the tray a of residual
lime is taken out and emptied, and a tray of fresh carbide is put in in its place,
whereupon the chamber is again closed. The valve e¹ may be opened at any time,
but the water valve c¹ should not be opened until this chamber is again put in
service.
With the proportions shown, the gas-holder bell encounters the weight E when
lifted to about one-fifth its capacity, leaving the remaining four-fifths as storage
capacity for the spontaneously generated gas. These proportions, however, are
variable.
The cocks g, g¹ and 2 can be closed when originally starting the apparatus, and
opened after sufficient water has accumulated to form a seal.
The invention further provides means for guarding against another source of
danger. In case of neglect to promptly replenish the supply of carbide after it
becomes exhausted, the bell D after closing the water valve J, will descend to the
lower limit of its movement, where its weight is borne by stops a suitably
arranged, and if the consumption of gas continues its pressure falls and the lights
at the burners go out. There is liability, however, that some remnant of unde-
composed carbide may undergo decomposition by reason of residual moisture, and
thereby maintain a slow generation of gas which would pass out through the
pipes rs to the burners, and if these latter were not closed, this gas would escape
and mingle with the atmosphere, and might possibly form an explosive mixture.
To effectually prevent this, I provide means whereby at or before the time the
floating bell reaches its lowest position it operates a valve or seal, or some equiva-
lent device for cutting off the outflow of gas. One way of accomplishing this is
by suspending a valve K within the bell D in such position that when the beil
the upper end
lowers to or near its bottom position, this valve shall seat itself upon
of the gas outlet pipe q. Another way is to provide a stop-cock K in
the pipe (or in any other part of the outlet pipes leading to
burners), and provide mechanical means for closing this stop-cock at the last
portion of the downward movement of the bell, the means shown consisting of a
rod b', its lower end being pivoted to the handle of the stop-cock, while its upper
end is guided in a guide bencountered by an arm carried by the bell, so that
the
B

page_text: as the latter nears the bottom of its descending movement, this arm strikes the rod
and pushes the latter downward, thereby turning the stop-cock to its closed
position. Any other mechanical device by means of which the descent of the bell
to or nearly to its lowermost position stops the outflow of gas through the tube g,
will answer the requirements of this feature of the invention. Its result is that
when the bell descends to or about the bottom of its movement, and preferably
after the closing of the water valve J, the outflow of gas is cut off, so that the
pressure in the outlet pipe immediately falls, and the burners are of course
extinguished. Thereafter no gas can pass into the outlet pipe, so that even in
case of neglect to turn off the gas at the burners, no leakage of gas can occur from
the burners until the apparatus is again put in service by replenishing the cacbide
chamber, and setting it again in operation to cause the ascent of the gas-holder,
bell. The valve K will open automatically by reason of such ascent, but the
valve K¹ will remain closed until opened by hand.
The provision for draining surplus water from the carbide chamber constitutes
an important feature of this invention. Heretofore the water has been admitted
to this chamber either from below in order to submerge the carbide, or by sprink-
ling it from above; in the former case a large quantity of water remains absorbed
by the residual lime and, continues to act upon the carbide for a long period; in
the latter case no provision has heretofore been made for immediately discharging
all surplus water, so that, this water remains in the chamber and acts upon the
carbide, either by absorption or by evaporating, so that its vapors slowly react
with the carbide. By this invention the water is sprinkled upon the carbide,
and, any water not immediately taken up thereby drops to the bottom of the
chamber and is drained off, so that no water is left to evaporate.
The invention may be considerably modified in the details of construction with
out affecting its essential features. The weight. E may be variously arranged, it
being only essential that the bell shall move freely during the lower portion of its
movement, and as it ascends shall pick up the weight at given level, and there-
after in its ascent shall carry the weight with it. It is not necessary that the
weight be arranged above the bell, as it might be arranged elsewhere to equal
effect. The essential resistance to the rise of the floating bell may be effected
otherwise than through the agency of a weight, as for example by substituting
any equivalent of a weight.
I am aware that it has been proposed to provide a series of water inlets to the
carbide chamber at different levels, and to construct the bell of the gas-holder as
it rises to pick up successively small weights, each of which increases the back
pressure upon the gas sufficiently to depress the level from one of said inlets to
the next lower one, so that when the bell in rising has picked up all the weights,
the water level is carried below the lowermost inlet, and the admission of water
to the carbide ceases. Such water inlets discharge over different portions of the
mass of carbide. The first operation of such an apparatus is to discharge water
through all the inlets simultaneously, this discharge continuing until the pressure
of gas becomes sufficient to raise the bell, thereby successively stopping the
discharge through the inlets, but by the time the bell has risen high enough to
pick up the entire series of weights and wholly stop the inflow of water, so much
water will have entered as to flood the carbide, and no means being provided for
discharging the excess of water, the generation of gas will be continued until all
the water has been decomposed, thereby with the proportions of apparatus pro-
posed generating gas greatly in excess of the capacity of the gas holder, so that if
the gas is not being consumed, a considerable loss of gas results. The improved
apparatus herein described avoids these disadvantages by introducing the water
by an inlet at one level only, by sprinkling it over the entire quantity of carbide,
and by providing an outlet for immediately draining off any excess of water not
taken up by the carbide, so that a regulation is effected solely at the lowermost
part of the movement of the bell, and almost the entire range of ascent of the

page_text: bell is utilized for storing the gas generated by the water already absorbed by the
carbide after the inflow of water is cut off.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me and in what manner the same is to be performed, I
declare that what I claim is:-
1. The herein described apparatus comprising a water inlet adapted to sprinkle
water over the carbide, a source of water supply therefor under a given pressure,
an outlet for the excess of water not retained by the carbide, a gas outlet pipe
leading to a gasholder, and means for resisting the rise of the bell of said holder
above a given level with sufficient force to accumulate a gaseous pressure exceed-
ing the hydrostatic pressure at the water inlet whereby to stop the inflow of water,
substantially in the manner and to the effect set forth.
2. The herein described apparatus having as a means for resisting the rise of
the floating bell of the gasholder, a weight engaged by said bell when it rises to
a given level and lifted thereby during its continued rise, whereby to increase
the pressure of the gas, the bell moving free of said weight beneath said given
level, to substantially the effect set forth.
3. The described apparatus comprising a gasholder the bell of which moves
freely beneath a given level and above said level lifts a weight, whereby to vary
the pressure of the contained gas, combined with a pressure governor in the gas
outlet pipe adapted to discharge the gas at a uniform reduced pressure, sub-
stantially as specified.
4. In the apparatus described, the gas generating chamber characterized by an
inlet pipe for sprinkling the water over the carbide, and a permanently open out-
let at its bottom for draining off any water not retained by the carbide, constructed
to retain a depth, of seal sufficient to resist the normal gaseous pressure in said
chamber, to the effect specified.
5. In the described apparatus, the arrangement of the gas pipe leading from
the generating chamber to the gasholder to pass as a descending coil through the
water in the reservoir supplying the generating chamber, whereby said coil
constitutes a condenser cooled by the fresh water entering said reservoir, to the
effect specified.
6. The described apparatus characterized by the provision of a valve for con-
trolling the flow of water from the water reservoir to the generating chamber,
connected to the floating bell of the gasholder to close when said bell descends to
approximately its lowest. position, whereby when the carbide is exhausted the
water supply is shut off substantially as specified.
7. In an acetylene gas apparatus, the means described for discharging surplus
gas when the gasholder is full, comprising a sealed chamber t having a vent pipe
v leading from it, and a discharge pipe carried by the floating bell, operating
substantially as set forth.
8. In an acetylene gas apparatus, the provision of a valve for closing the gas
outlet pipe from the gas-holder upon the descent of the bell thereof to its lowest
position, said valve constructed to thereupon remain closed until opened manually,
substantially as specified.
J. C. MEWBURN & ELLIS
55 & 56 Chancery Lane London, Chartered Patent Agents.