Gas-Engines and Producer-Gas Plants / A Practice Treatise Setting Forth the Principles of Gas-Engines and Producer Design, the Selection and Installation of an Engine, Conditions of Perfect Operation, Producer-Gas Engines and Their Possibilities, the Care of Gas-Engines and Producer-Gas Plants, with a Chapter on Volatile Hydrocarbon and Oil Engines

by Rodolphe Edgard Mathot

equal to 86 degrees F., to the second reservoir, where a further cooling of 18 degrees F. takes place. In passing on to the following reservoirs the temperature is still further lowered, until the water finally reaches its minimum temperature, after which it flows back to the engine-cylinder.

Fig. 64.—Circulating pump with by-pass.

In order to effect this cooling, the reservoirs can be connected in several ways. The most common method, as shown in Fig. 63, consists in connecting the reservoirs by oblique pipes. This is open to criticism, however, since leakage occurs, caused by the employment of elbows which retard the circulation. A less cumbrous and more efficient method of connection consists in joining the reservoirs by a single pipe at the top, as shown in Fig. 61; but care must be taken to extend this pipe at the point of its entrance into the adjoining reservoir by means of a downwardly projecting extension, or to fit its discharge-end with a box, closed by a single partition, open at the bottom.

In order to prevent incrustation of the water-jacket surrounding the cylinder, a pound of soda per 17 cubic feet of the reservoir capacity is monthly introduced, and the jacket flushed weekly by a cock conveniently mounted near the cylinder (Fig. 59). The jacket is thus purged of calcareous sediments, which are prevented by the soda from adhering to the metal. The flushing-cock mentioned also serves to drain the water-jacket of the cylinder in case of intense or persistent cold, which would certainly freeze the water in the jacket, thereby cracking the cylinder or the exposed pipes.

In order to regulate the circulation of the water in accordance with the work performed by the engine, a cock should be fitted to the water supply pipe at a convenient place.

In engines of large size, driven at full load for long periods, cooling by natural circulation is often inadequate. In such cases, circulation is quickened by a small rotary or reciprocating pump, driven from the engine itself and fitted with a by-pass provided with a cock. This arrangement permits the renewal of the natural thermo-siphon circulation in case of accident to the pump (Fig. 64).

Fig. 65.—Water-cooler in which tree branches are employed.