[Ill.u.s.tration: FIG. 56.--"PHoS TYPE E" GENERATOR.]

_Maker:_ ROSCO ACETYLENE COMPANY, BELFAST.

_Type:_ Non-automatic; carbide-to-water

The "Rosco" generating plant made by this firm comprises a generating tank _A_ which is filled with water to a given level by means of the funnel-mouthed pipe _B_ and the overflow _O_. On the top of the water-sealed lid of the generating tank is mounted the carbide feed-valve _L_, which consists of a hollow plug-tap with handle _M_. When the handle _M_ is turned upwards the hollow of the tap can be filled from the top of the barrel with carbide. On giving the tap a third of a turn the hollow of the plug is cut off from the outer air and is opened to the generating tank so that the carbide contained in it is discharged over a distributor _E_ on to the tray _N_ in the water in the generating tank. The gas evolved pa.s.ses through the scrubber and seal-pot _J_ to the storage gasholder _Q_. From the latter the gas pa.s.ses through the dry purifier _T_ to the service-pipe. A sludge- c.o.c.k _P_ is provided at the bottom of the generating tank and is stated to be available for use while generation of gas is proceeding. The purifying material ordinarily supplied is "Roscoline."

[Ill.u.s.tration: FIG. 57.--"ROSCO" GENERATING PLANT.]

_Maker_: THE RURAL DISTRICTS GAS LIGHT CO., 28 VICTORIA STREET, S.W.

_Type_: Automatic; water-to-carbide; contact, superposed trays.

The "Signal-Arm" generating apparatus made by this firm comprises a bell gasholder _A_, from the tank _B_ of which water is supplied through a swivelled pipe _C_ to a generating chamber _D_. One end of the swivelled pipe is provided with a delivery nozzle, the other end is closed and counter-weighted, so that normally the open end of the pipe is raised above the level of the water in the tank. A tappet _E_ on the bell of the gasholder comes into contact with, and depresses, the open end of the swivelled pipe when the bell falls below a certain point. As soon as the open end of the swivelled pipe has thus been lowered below the level of the water in the tank, water flows through it into the funnel-shaped mouth _F_ of a pipe leading to the bottom of the generating chamber. The latter is filled with cages containing carbide, which is attacked by the water rising in the chamber.

The gas evolved pa.s.sing into and raising the bell of the gasholder causes the open end of the swivelled pipe to rise, through the weight of the counterpoise _G_, above the level of the water in the tank and so cuts off the supply of water to the generating chamber until the bell again descends and depresses the swivelled pipe. The tappet on the bell also displaces a cap _H_ which covers the funnel-shaped mouth of the pipe leading to the generating chamber, which cap, except when the swivelled supply-pipe is being brought into play, prevents any extraneous moisture or other matter entering the mouth of the funnel. Between the generating chamber and the gasholder is a three-way c.o.c.k _J_ in the gas connexion, which, when the gasholder is shut off from the generator, brings the latter into communication with a vent-pipe _K_ leading to the open. The gas pa.s.ses from the holder to a chamber _L_ under grids packed with purifying material, through which it pa.s.ses to the outlet of the purifier and thence to the service-pipe. Either heratol or chloride of lime is used in the purifier, the lid of which, like the cover of the generator, is water-sealed.

[Ill.u.s.tration: FIG. 58.--"SIGNAL-ARM" GENERATING PLANT.]

_Maker_: ST. JAMES' ILLUMINATING CO., LTD., 3 VICTORIA STREET, LONDON, S.W.

_Type_: (1) Automatic; water-to-carbide; contact, superposed trays.

This plant consists of the generators _A_, the washer _B_, the equalising gasholder _C_, the purifier _D_, and the water-tank _E_. The carbide is arranged in baskets in the generators to which water is supplied from the cistern _E_ through the pipe _F_.

The supply is controlled by means of the valve _H_, which is actuated through the rod _G_ by the rise and fall of the gasholder _C_. Gas travels from the gasholder through the purifier _D_ to the service-pipe. The purifier is packed with heratol resting on a layer of pumice. The washer _B_ contains a grid, the object of which is to distribute the stream of gas through the water. There is a syphon-pot _J_ for the reception of condensed moisture. Taps _K_ are provided for shutting off the supply of water from the generators during; recharging, and there is an overflow connexion _L_ for conveying the water to the second generator as soon as the first is exhausted. There is a sludge-c.o.c.k _M_ at the base of each generator.

(2) Non-automatic; water-to-carbide; contact, superposed trays.

This resembles the preceding plant except that the supply of water from the cistern to the generators takes place directly through the pipe _N_ (shown in dotted lines in the diagram) and is controlled by hand through the taps _K_. The automatic control-valve _H_ and the rod _G_ are omitted. The gasholder _C_ is increased in size so that it becomes a storage holder capable of containing the whole of the gas evolved from one charging.

[Ill.u.s.tration: FIG. 59.--GENERATING PLANT OF THE ST. JAMES' ILLUMINATING CO., LTD. (SECTIONAL ELEVATION AND PLAN.)]

_Maker_: THE STANDARD ACETYLENE CO., 123 VICTORIA STREET, LONDON, S.W.

_Type_: (1) Non-automatic; carbide-to-water.

This plant comprises the generator _A_, the washer _B_, the storage gasholder _C_, and the purifier _D_. The generator is first filled with water to the crown of the cover, and carbide is then thrown into the water by hand through the gas-tight lock, which is opened and closed as required by the horizontal handle _P_. A cast-iron grid prevents the lumps of carbide falling into the sludge in the conical base of the generator. At the base of the cone is a sludge-valve _G_. The gas pa.s.ses from the generator through the pipe _H_ into the washer _B_, and after bubbling through the water therein goes by way of the pipe _K_ into the gasholder _C_. The syphon- pot _E_ is provided for the reception of condensed moisture, which is removed from time to time by the pump _M_. From the gasholder the gas flows through the valve _R_ to the purifier _D_, whence it pa.s.ses to the service-pipes. The purifier is charged with material supplied under the proprietary name of "Standard."

[Ill.u.s.tration: FIG. 60.--CARBIDE-TO-WATER GENERATING PLANT OF THE STANDARD ACETYLENE CO.]

(2) Automatic; water-to-carbide; contact, superposed trays.

This plant comprises the generators _A_, the washer _B_, the equalising gasholder _C_, the purifier _D_, and the water-tank _E_. The carbide is arranged on a series of wire trays in each generator, to which water is supplied from the water-tank _E_ through the pipe _Y_ and the control-tap _U_. The gas pa.s.ses through the pipes _H_ to the washer _B_ and thence to the holder _C_. The supply of water to the generators is controlled by the tap _U_ which is actuated by the rise and fall of the gasholder bell through the rod _F_. The gas pa.s.ses, as in the non-automatic plant, through a purifier _D_ to the service-pipes. Taps _W_ are provided for cutting off the flow of water to either of the generators during recharging and an overflow pipe _h_ serves to convey the water to the second generator as soon as the carbide in the first is exhausted. A sludge-cook _G_ is put at the base of each generator.

[Ill.u.s.tration: FIG. 61.--AUTOMATIC, WATER-TO-CARBIDE GENERATING PLANT OF THE STANDARD ACETYLENE CO.]

(3) Non-automatic; water-to-carbide; contact, superposed-trays.

This apparatus resembles the preceding except that the supply of water to the generators is controlled by hand through the taps _W_, the control valve _U_ being omitted, and the gasholder _C_ being a storage holder of sufficient dimensions to contain the whole of the acetylene evolved from one charging.

_Maker_: THORN AND HODDLE ACETYLENE CO., 151 VICTORIA STREET, S.W.

_Type_: Automatic; water-to-carbide; "drawer."

The "Incanto" generating plant made by this firm consists of a rising bell gasholder which acts mainly on an equaliser. The fall of the bell depresses a ball valve immersed in the tank, and so allows water to flow from the tank past an outside tap, which is closed only during recharging, to a generating chamber. The generating chamber is horizontal and is fixed in the base of the tank, so that its outer case is surrounded by the water in the tank, with the object of keeping it cool.

The charge of carbide is placed in a part.i.tioned container, and is gradually attacked on the flooding principle by the water which enters from the gasholder tank when the ball valve is depressed. The gas evolved pa.s.ses from the generating chamber by a pipe which extends above the level of the water in the tank, and is then bent down so that its end dips several inches below the level of the water. The gas issuing from the end of the pipe is thus washed by the water in the gasholder tank.

From the gasholder the gas is taken off as required for use by a pipe, the mouth of which is just below the crown of the holder. There is a lip in the upper edge of the gasholder tank into which water is poured from time to time to replace that consumed in the generation of the gas. There are from one to three generating chambers in each apparatus according to its size. The purifier is independent, and a purifying mixture under the proprietary name of "Curazo" is supplied for use in it.

[Ill.u.s.tration: FIG. 62.--"INCANTO" GENERATOR.]

_Maker:_ WELDREN AND BLERIOT, 54 LONG ACRE, LONDON, W.C.

_Type:_ Automatic; contact.

This firm supplies the "Acetylithe" apparatus (_see_ Belgium).