At the recent Congress of the Societe Technique de l'Industrie du Gaz en France, M. Meizel, Chief Engineer of the St. Etienne Gas Works, described a new exhauster devised by him on the reciprocating principle, and for which he claims certain advantages over the appliances now in general use. Exhausters constructed on the above-named principle have hitherto, M. Meizel says, been costly to fit up, owing to the necessity for providing machinery and special mechanism for the transmission of motion. This has prevented the employment of cylinders of large dimensions; and, consequently, when the quantity of gas to be dealt with has been considerable, the number of exhausters has had to be increased. The result of this has been inconvenience, which has led to a preference being shown for other kinds of exhausters, notwithstanding the manifest advantages which, in M. Meizel's opinion, those of the reciprocating type possess. The improvement which he has effected in these appliances consists in the application to them of cylinders working automatically; and the general features of the arrangement are shown in the accompanying illustrations.
The principal advantages to be gained by the use of this exhauster are stated by M. Meizel to be the following: Considerably less motive force is necessary than is the case with other exhausters, which require steam engines and all the auxiliary mechanism for the transmission of power. By its quiet and regular action, it prevents oscillation and unsteadiness in the flow of gas in the hydraulic main, as well as in the pipes leading therefrom - a defect which has been found to exist with other exhausters. The bells, being of large area, serve the purpose of a condenser; and as, owing to its density, the tar falls to the bottom of the lower vessels, which are filled with water, contact between the gas and tar is avoided. Although the appliance is of substantial construction, its action is so sensitive that it readily adapts itself to the requirements of production. It may be placed in the open air; and therefore its establishment is attended with less outlay than is the case with other exhausters, which have to be placed under cover, and provided with driving machinery and, of course, a supply of steam.
The total superficial area of the exhauster above described, including the governor, is 150 square feet; and its capacity per 24 hours is 230,000 cubic feet. It works silently, with an almost entire absence of friction; and consequently there are few parts which require lubrication. Exhausters of this type (which, M. Meizel says, could be made available for ventilation purposes, in case of necessity) may be constructed of all sizes, from 500 cubic feet per hour upward.