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

grate through a pipe leading from the heater or the vaporizer. This arrangement seems best adapted to prevent the leakage of gas which tends to take place by reaction after each suction stroke of the engine.

Ash-pits formed as water-cups, such as the Deutz (Fig. 106), the Wiedenfeld (Fig. 95), and the Bollinckx (Fig. 98), are fed by the overflow from the vaporizer. These ash-pits are themselves provided with an overflow consisting of a siphon-tube forming a water-seal.

Besides providing protection to the grate and other parts by this sheet of water, a larger proportion of the heat radiated from the furnace is utilized for the production of steam which contributes to enrich the gas. The doors of the ash-pits and their fittings are likewise exposed to a rapid deterioration.

For this reason these parts should be very strongly made, either of cast-iron or cast-steel. Furthermore, they should, at joint surfaces, be connected in an air-tight manner, which may be attained by carefully finishing the engaging surfaces of the frame and the door proper, or by cutting a dovetail groove in one of the sides of the frame which is packed with asbestos and adapted to receive a sharp edged rib on the other part.

The pintles of the hinges should also be carefully adjusted so that the joint members of the door shall remain true. Hinges with horizontal axes seem to be preferable in this respect to those having vertical axes. As a means of closing the door, the arrangement here shown (Fig. 107) seems to assure a proper engagement

of the joint surfaces. It consists of a yoke which straddles the door, and which, on the one hand, swings about the hinge, and on the other hand engages a movable hoop. A screw, fastened to the yoke, serves to tighten the door by pressure on its center. This screw can also be fastened to the end of the yoke (Fig. 108).

Figs. 107-108.—Fire-box doors.

It is very advantageous to provide in each door a hole closed by an air-tight plug, so that in case of need a tool may be introduced for cleaning the grate. In this manner the grate may be cleaned without opening doors and without causing a harmful entrance of air.

The door of the furnace, particularly, should be provided with an iron counter-plate held by hinged bolts (Fig. 109); or, better still, this door should be so constructed that it can be lined with refractory material to protect it against the radiated heat of the fire.