The Feld washer, as shown in Fig. 200, consists of a series of superimposed sections, the bottom of each section being provided with ports for the passage of gas. The gas enters the bottom of the washer and passes from chamber to chamber to the top, whence it is led away. Each section or chamber is provided with a series of cones perforated at the top and mounted upon a cast-iron spider, which is carried on a vertical shaft. The shaft is suspended at the top in a specially designed anti-friction bearing, arranged so as to reduce the power required for operation to a minimum. The water is admitted into the top of the washer and overflows from section to section through the gas ports, the dirty water saturated with dust leaving the bottom of the washer.

"When the shaft revolves, the cones do likewise, and the water is raised by centrifugal force along the inner sides of the cones and is atomized at the upper edge. This upper edge of each cone is a little higher than the next outer one, thereby forming a certain number of horizontal sprays of water, depending on the number of cones. The upper portion of the outer cone, which is somewhat higher than the inner one, is perforated. The inner cones supply water to the perforated surface of the outer one. This results in the formation of a series of cascades composed of very small drops of water, through which the gas must pass en route through the apparatus.

"The washing is accomplished mostly in the lower sections, while the upper sections perform primarily the function of cooling the gas.

"For primary washing, the Feld washer is constructed with seven chambers or sections, the lower three being the washing chambers, the fourth one being a separating chamber and the upper three being the cooling chambers. For final washing, in the case of the gas being required for gas-engine purposes, the gas after being primarily cleaned is passed through an additional washer of the same general arrangement.

Reco Centrifugal Gas Washer

This gas washer is constructed by the Roessing-Ernest Company, of Pittsburgh, Pa., and is designed to cool, clean and, if necessary, dry the gas in one apparatus. This washer consists substantially of a vertical outer casing, a tube whose lower end is provided with serrations extending to within a few inches of a water seal, a revolving inverted cup, and a sleeve casing attached to the inverted cup. The outer casing, the cup, the tube, and the sleeve casing are provided with shelves and vanes. The apparatus is belt-driven. The spindle of the rotor on which the driving pulley is fastened is hollow, and the weight of the rotor is taken up by the shaft inside of this sleeve held by a ball bearing which is backed by a rubber buffer in order to equalize any irregularity during rotation.

"As shown in Fig. 201, the hot gas enters the apparatus at the point A, passes over the water, a certain amount of which the gas takes up by evaporation, and then passes into the tube B through the serrations at its base. During its passage through this tube the gas and water vapor are subjected to a thorough beating and mixing by the action of the vanes C of the revolving sleeve casing D, fastened to the top of the inverted cup E. The gas passes into this inverted cup, which is rotated by the driving sleeve F and the pulley G, and then flows downward, around and under the lower edge of the cup and then upward between the cup and the outer casing H. The outer surface of the revolving cup is provided with concentric shelves K and the outer casing H is provided with downwardly inclined shelves I, which receive the washing water from the water-sealed stuffing box J and through a series of water pipes L. The water, falling on the rapidly rotating shelves of the cup, is thrown by centrifugal force against the inner walls of the casing and thence flows downwardly along the inclined shelves, dripping on to the next rotating shelf, and so on. In this way the gas, while subjected to a thorough whirling and beating action, has to pass upward through several films of finely divided water or spray while the water passes downward, carrying with it the separated impurities.

"The apparatus operates on the counter-current principle, the cleanest gas passing from the apparatus meeting the cleanest water entering the apparatus.

Fig. 201. Reco centrifugal gas washer.

"The upper part of the casing is provided with a rack which, it is stated, can be packed with suitable drying material in case it is desired to dry the gas before leaving the apparatus.