This cut represents an apparatus of combined construction, viz., used with or without gasometer.

A is the generator with acid chamber, pressure gauge and safety valve. B B B are purifiers. C cylinder with blow-off cock, pressure gauge and mixer for salt solutions. D pipe that leads the gas either from the last purifier or from the pump into the cylinder. A gasometer is usually connected with this apparatus, from where the pump draws the gas, or the pump is so constructed as to inject water into the cylinder to prevent waste of gas. The apparatus is made entirely of copper and tin-lined with generator lead-lined.

Fig. 199.   German Intermittent Apparatus   I

Fig. 199. - German Intermittent Apparatus - I.

The principle of the construction of this apparatus, Fig. 200, is to raise the necessary pressure of the carbonic acid gas in a gas reservoir that is directly connected with the cylinder. E is the generator, S the acid chamber, W the purifiers, of which one communicates with the generator; the other is connected by pipe c with the gas purifier G. The latter is secured in a large box R, that is lined inside with tinned copper sheets and partially filled with water. Pump N N forces water from the box into the gas reservoir, thus compressing the gas contained in it. The gas reservoir being connected with cylinder M by pipe d and with the pressure gauge by pipe c, the pressure is also transferred to the others. By means of the pump the gas reservoir can be entirely filled with water and emptied by the aid of cock X X. Tube g is the equalizing pipe for the bottling arrangement, tube f the same for the little mixer i. This mixer is also intended for salt solutions, and fed at the opening cock K. V is the inlet to the cylinder through which the carbonate is getting introduced. To estimate the contents of the gas reservoir the water gauge l is attached, which communicates at both ends with the gas reservoir. The material is copper, respectively lead and tin lined. This kind of apparatus is not much in use, as it has the grave disadvantage that the atmospheric air which the water holds in absorption and is constantly connected with, will mix with the carbonic acid gas and contaminate it.

Fig. 300.   German (Hamburg) Apparatus   II

Fig. 300. - German (Hamburg) Apparatus - II.

Fig. 201 is another German apparatus. A is the generator, a globular copper cylinder, lead lined, b charging bung, c discharge valve, D acid chamber, e flow-regulating valve, f inlet for acid, g safety valve, h gas tube, i stop valve, k agitator, m m m gas washers made of copper, n n n water inlet, o water outlet, p connecting tubes reaching down to bottom of washer, r connecting tubes from the top of washer, s stop valve, T mixing cylinder made of copper and sheet tin lined, u inlet, v mixer for salt solutions, w safety valve, z pressure gauge, a tube and cock connecting pressure gauge with generator, x agitator, v discharge tube connected with filling apparatus.

Fig. 301.   German Intermittent Apparatus   III

Fig. 301. - German Intermittent Apparatus - III.

The following illustrations represent some other styles of apparatus, each one different from the other in construction.

They are put up in different forms, but are alike in principle and similar in appearance to that represented by Fig. 201 and described thereafter. Fig. 204 represents the smallest apparatus even without gas-washers, and is intended for the decomposition of but the purest carbonate, such as bicarbonate of soda, with pure diluted sulphuric acid.

A new German apparatus,Fig. 206, as manufactured by N. Gressler in Halle a S., is next illustrated. This style differs from all hitherto described. A, the generator, is divided in three chambers, the upper (to the right) contains water for washing the gas, the middle chamber contains the acid, and the lower chamber the carbonate. To generate the carbonic acid gas the indicator on the index plate is moved from 0 to 1, and so on until the desired pressure on the pressure gauge is indicated, then leave the indicator on this point; if more gas is necessary, move it to a higher number on the index plate. On large generators the movement is regulated by a mechanical arrangement. The safety valve, the agitator crank, the outlet for residue, the inlet for the carbonate, one for the acid and one for the water, also the outlet tor the discharge of water from gaswasher are seen in illustration. A connection with a flexible rubber hose leads the generated gas over to the cylinders or fountains.

Fig. 202.    German Intermittent Apparatus   IV

Fig. 202. - -German Intermittent Apparatus - IV.

Fig. 203.   German Intermittent Apparatus   V

Fig. 203. - German Intermittent Apparatus - V.

Fig. 204.   German Intermittent Apparatus   VI

Fig. 204. - German Intermittent Apparatus - VI.

Fig. 205.   German Intermittent Apparatus   VII

Fig. 205. - German Intermittent Apparatus - VII.

Fig. 206.   German Intermittent Apparatus   VIII

Fig. 206. - German Intermittent Apparatus - VIII.

Fig .207.   German Detached Swinging Generator

Fig. 207. - German Detached Swinging Generator.