Before describing the saturator we will explain the action of the double generators. Each generator having been filled up to the overflow b b with water and a given quantity of whiting, and the acid boxes D D filled with sulphuric acid, the pulley of one of the generators is set in motion. The first step is to get rid of the atmospheric air contained in the generator. To do this it is necessary to open the orifice B and also the tap Z. This will admit sulphuric acid into the generator, and cause a disengagement of carbonic acid gas which will drive the air out of the generator and will fill it with gas. As soon as the carbonic gas issues from the opening B close the acid tap, and a few moments after securely fasten down B. The generator is then full of carbonic acid gas, and is ready for work. Open the acid tap again and also the tap R, when the saturating pump may be set in motion. The effect of the pump on the generator is to draw the sulphuric acid on to the whiting. As soon as the materials come in contact, they produce carbonic acid gas, which, seeking to escape from the generator, presses on the rising column of sulphuric acid in the syphon tube, and stops its flow. This continues until the suction of the pump again diminishes the density of the gas in the generator, and causes a fresh flow of sulphuric acid, which is again checked by the slight pressure due to the generation of carbonic gas. The operator is warned that the materials are exhausted by the sulphuric acid descending to the level of a china knob fixed inside the acid box D. When the attendant sees this he puts the agitator of the other generator in motion (having expelled the air from it, as above described), and opening the acid tap and the tap R, puts it in communication with the pumps. For a moment both generators work together, and then the tap R and the acid tap of the exhausted generator are closed, and the materials renewed, so as to be ready to work again. The whole manufacture of the gas is being carried on automatically, and regulated by the pump or pumps themselves.

Fig. 139 represents the No. 3 saturator. The fast-and-loose pulleys B B are fitted to the axle or spindle of the fly-wheel A (in place of the handle E in Fig. 136), for driving the pump and the agitator in the condenser. The body of the machine is a strong cast-iron cylinder containing the solution pan. G is a smaller purifier made of glass, to enable the attendant to see if the circulation of the gas through the water is duly maintained. It also purifies the gas. S is the condenser fitted with pressure (m) and water (n) gauges and safety valve (s). e is the distributing tap, with graduated quadrant, for regulating the proportions of gas and water pumped into the condenser. The pump T is firmly fixed to strong brackets cast on the purifiers; and b b a similar tube for conveying the carbonated water to the filling or bottling machine.

The producing capacity of Machine 3 is said to be 2400 syphons or 600 dozen bottles daily. It is constructed for the use of whiting, or other similar substances, in the generation of the gas. The proportions of material used are about 5 1/2 lbs. of whiting, and 5 1/2 lbs. of sulphuric acid for each 300 bottles.

Machine No. 3 is constructed for working by steam, water, gas or other motive power. The power necessary is two-thirds of a horse power, but in all cases is strongly advised a higher power, so as to enable manufacturers to work any additional machines they may have, such as bottle-washing, or syphon-polishing apparatus, etc.

Fig. 140 is an apparatus which shall supply carbonic acid gas to any small saturating machine, instead of the ordinary generator and gasc meter. It consists of cylinder D (with stand) for containing sulphuric acid and water; generator C for containing bicarbonate of soda; glass purifier G with tube q for conveying the gas from the generator; screw-cap N and tap R and joint for connecting the purifier with the pump; screw-cap B and opening for charging cylinder C; water gauge n for showing the level of the acid solution; and india-rubber discharging tube t. The cylinders C and D are of lead and strongly made. The action is precisely similar to that of the other generators. This apparatus can be fitted to and worked with Bramah's or any other continuous process machine.

Fig. 139.   Mondollot Saturator

Fig. 139. - Mondollot Saturator.

Fig. 141 is a generator that has been specially designed for makers who are at present using the Bramah or other continuous system, and who, while wishing to alter the gas-generating portion of their plant, do not want to go to the expense of buying a new pump. The apparatus is constructed to generate carbonic acid gas and to purify it, automatically, so that it may be ready for the pump to use. It is made in two sizes: No. 1 to supply any sized pump up to 2 inches; and No. 2 to supply a 2 1/2 inch pump. This machine is almost identical to the No. 1 and 2 machines, but is without the saturator, pump, and fly-wheel. It consists of generating cylinder M, bolted on to a strong cast-iron frame; tubular opening B (top) and c (at foot); double purifier G G' with tubular opening F for filling and tap f for emptying the purifiers; gas tube q; gun metal screw-cap N; connecting pipe b leading to the pump; acid box D, with tap r, and siphon tube a a; safety vase V, with tube h leading from the safety valve to the generarator; and o pulley for driving the agitator in the generator.

Fig. 140.   Separate Mondollot Generator with Purifier

Fig. 140. - Separate Mondollot Generator with Purifier.

Fig. 141.   Separate Generator with Double Purifier

Fig. 141. - Separate Generator with Double Purifier.

Figs. 142 and 143 represent a double pump and an upright fountain, which require in addition a pair of double generators and a gas-washer to form a complete plant. This set of apparatus, in construction and workmanship similar to those already illustrated and described, is suitable for large establishments where a large production in a short time is required, and steam or other motive power is available. Economizing Gas in Continuous Apparatus. - In order to econo-mize the gas in large factories, the plan is frequently adopted of using enclosed safety valves in the condensers, and carrying back the escaped gas to the gas holder. It must be borne in mind that the water which passes through the condenser contains a large amount of atmospheric air, which is expelled by the gas, and rises to the top of the condenser (being lighter than the gas), and is therefore the first to pass off by the safety valve. This system, therefore, tends to introduce into the gas holder a large quantity of air, and unless proper means are taken to meet this difficulty, the quality of the waters will suffer very seriously, and much trouble will be caused.

Fig. 142.   Mondollot Double Pumps

Fig. 142. - Mondollot Double Pumps.

Fig. 143.   Mondollot Upright Cylinder

Fig. 143. - Mondollot Upright Cylinder.