Patent GB-1031522-A (GB)
Title: Rotating eliminator
IPC: F24F3/14
Filed: 1963-01-10
Abstract: 1,031,522. Air conditioning. BAHNSON CO. Jan. 10, 1963 [Jan. 29, 1962], No. 1153/63. Heading F4V. [Also in Divisions B1, B2, F1 and G3]. An eliminator 30, Figs. 1 and 2, for removing liquid droplets from an air stream flowing through a chamber 14 comprises a rotor structure 49, 51, 52, with its axis of rotation generally parallel to the direction of the air stream, blades 37 extending radially from the rotor structure and arranged in planes radial or oblique to the axis of rotation, and means for rotating the rotor-blade assembly to produce a centrifugally-induced helical outward flow path of the liquid droplets separated from the air stream. As shown, the eliminator is installed at the outlet end of an air-liquid contact apparatus for the conditioning of air in a textile mill. The apparatus comprises a casing 10, a motoroperated fan 12 for forcing dirt- and lint-laden air through the casing and nozzles 24, 25 fed through a header 21 connected to a pump 18 for spraying water into the air stream. Due to whirling of the air by the fan 12 most of the water, and solids are removed by centrifugal force in the chamber 13, excess moisture being removed in the eliminator. The rotor is secured to a shaft 31 supported in bearings 29, 32, fixed to struts 28, 35. The shaft 31 may be driven by an electric motor 46, the speed of which may be automatically controlled by conditions, such as humidity, prevailing in the room receiving air from the eliminator. Each rotor blade 37 is substantially planar throughout substantially its entire working area and may have oppositely twisted end portions at the air entrance and exit ends. The blade surfaces may be roughened throughout the area of the blade or near its tip by means of straight or curved ridges to facilitate coagulation of water droplets to increase separation. The inner edge portions of the blades are cut and bent to form on both sides of the blade a series of opposite loops 48 which are interlinked by rods 49, Fig. 2, held in plates 51 secured to the rotor hubs 52. The radially outer portions of the blades are held in spaced relationship by rubber spacers 55, Fig. 8. The water separated in the chambers 13, 14 is collected in a sump 15 and directed through a pipe 16 to a filter 17 for removing dirt and lint and the clean water is recirculated by the pump 18 to the header 21. Lint deposited at the entrance end of the blades is removed by water supplied through nozzles 20a. High velocity air is prevented from flowing from the chamber 13 directly between the casing wall and the blade tips by a baffle plate 36. The air exit end of the eliminator is surrounded by a seal assembly comprising rotary parts 39, 41, 42 secured to the blades and stationary parts 40, 43 secured to the casing. The pitch of the helical path taken by the air flowing through the eliminator depends on the speeds of the fan 12 and eliminator 30 and may be such that the air entering the rotor is rotated through 60 degrees before exiting. A number of eliminators are connected in series, Fig. 17, each being driven through sprockets 62, 63 and a chain 65 by an electric motor 61. The eliminators may be driven at the same or different speeds which may increase progressively from the air entrance to exit end, and in the same or opposite directions and may have different number of blades. One of the eliminators may be maintained stationary while those adjacent thereto are rotated so as to re-direct the air stream and improve the air entrance angle into the downstream eliminator. Cleaning of the blades is ensured by water sprayed from nozzles 101 which may be programmed to operate on a given cycle with the aid of a timer motor and switching devices which will switch the various operating components, i.e. pump 18, fan 12, nozzles 101, motor 46 or 61, on and off at the proper times and in the correct sequence. In Figs. 15 and 16 the eliminator shaft 31 is driven by a windmill-type air turbine which is located in the casing behind the eliminator and is rotated by the air leaving the eliminator. The turbine comprises a casing 66 secured to the shaft 31 and variable-pitch blades 68, 69 of airfoil section rotatably supported in the casing by shafts 71. Pinion gears 74 fast on the shafts 71 mesh with a face gear 75 rotatably mounted on the shaft 31 and carrying axles 77, 78 on which control gears 79, 80 are rotatably mounted. The gears 79, 80 mesh with a gear 81 rotatably supported on shaft 31 and having rigidly attached thereto a drive stud 82 which can be actuated by an air motor 85 flexibily secured to the casing 66. The gears 79, 80 are rigidly connected to a centrifugal governor having spring-biased control arms 87, 89 carrying flyballs 88, 90 and stops 93, 94. If the speed of the eliminator increases above a certain value, for example, due to an increase in air velocity through the washer, the governor operates to rotate the gears 79, 80 against the gear 81 which is maintained stationary by a given pressure on the piston 83 of the air motor 85. This causes the face gear 75 to rotate, thereby rotating the pinions 74 and varying the inclination of the blades 68, 69 so as to reduce the speed of the shaft 31 to its selected value. In like manner, upon decrease in eliminator speed, the governor will act to turn the blades in opposite direction to increase the torque on the shaft. The selected speed of the eliminator is determined by the value of the control air pressure on the motor piston 83. This value may be made to vary according to the humidity present in the room receiving air from the eliminator. This control air pressure acts on the piston 83 through tubes 95, 97 and a rotary union 96 so as to move the gear 81 and hence the gears 79, 80, to a given angular position, thereby fixing the mean position of the arms 87, 89 of the governor to correspond to the eliminator speed selected.