Gas-Engines and Producer-Gas Plants

orces, suddenly and repeatedly exerted, producing violent reactions on the foundation. It follows that the foundation must be made

ould be laid on edge. It is advisable to increase the stability of the foundation by long

oarse sand, crushed slag, well-screened, may be employed. The mortar should consist of 2?3 slag and 1?3 cement. Oil shoul

oil and to line the bottom with concrete, in order to form a single mass of artificial sto

d not rest directly on the vault below or on the joists, but should be built upon the very fl

d of building

taging, the method of securing it in plac

inadequate for special cases in which trepidation is to be expected. Such is the case when engines are to be installed in places

Elevated

substances depends much on the manner in which they are applied. It is always advisable to interpose a layer of one of these substances, from one to four inches thick, between the foundation and the surrounding soil, the thickness varying with the nature of the material used and the effect to be obtained. Between the bed

k for the bottom of the foundation; for water may cause the cor

of such size the author recommends an arrangement as simple as it is efficient, which consists in placing the foundation of the engine in a veritable masonry basin, the bottom of which is a bed of concrete of suitable thickness. The foundation is so placed that the lateral surfaces are absolutely ind

nt, for which reason the base-area and weight should be increased by 30 to 40 per cent. The expense entailed will be largely offset by

hemselves give rise to vibrations, the dynamos are secured directly to the foundation of the engin

dispense with the services of experts, whose long experience has br

the bricks should be thoroughly moistened before t

the cast base, so as to form a small box or trough, in which cement is also poured for the purpose of firmly binding the engine frame and foundation together. When, as in the case of electric-light engines, single extra-heavy fly-wheels are employed, provided with bearings held in independent cast supports, the following rule should be observed to prevent the overheating due to unlevelness, which usually occurs at the bushings

r to attain this end the bricks are laid around the bolt-holes, alternately projected and retracted as shown

n of noises and the displacement of air by the piston should

e other is due to vibrations transmitted to the air. In both cases, in order to reduce the noise to a minimum, the moving parts should be kept nicely adjusted, and above all, shocks avoid

ment of air is thus produced. In the case of a forty horse-power engine having a cylinder diameter and piston-stroke respectively of 133?4 inches and 213?5 inches, it is evident that at each stroke the

ubic feet. From this it follows that the 2 cubic feet of air in the case supposed will be alternately displaced six times each second, which means the displacement of 12 cubic

suction, between the quantity of air expelled on the forward stroke of the piston and the quantity of air drawn into the cylinder. From

ement corresponding in period with half the number of revolutions of the engine. It follows from the preceding that, in order to do away with the air vibration occasioned by the piston in dr

ulated from the foundation and from the walls through which they pass as well as from the ground, as metal pipes

xhaust-pipe. The most commonly employed means for rendering the exhaust less perceptible consists in extending the pipe upward as far as possible, even to the height of the roof. This is an ea

ceptacles. But this remedy is attended with the same faults that mark the use of extremely long pipes. The best plan is to mount a single e

-Exhaust

ting. Into the lower part, which is empty, the exhaust-pipe discharges; in the upper part, paving-blocks or hard stones not likely to crumble with the heat, are placed. Between this layer of stones and the cover it is advisable to leave a space equal to the first. Here the gases may expand after having been divided into many parts in passing through the spaces left between adjacent stones. The trough should not be closed by a rigi

baffle-plates. This casing is preferably made of wood, lined with metal, so that it will not be resonant. The size of the casing, the number of partitions and

Among these systems may be mentioned those in which the pipe is forked at its end to form eith

g.

types of exha

ntly, in connecting the pipes, care should be taken that the joints or seams have no interior projections. Occasionally, water may be injected into the exhaust-muffler in order to condense the vapor