GB536753A - Improvements in or relating to the electrical precipitation of suspended particles from a stream of gas - Google Patents

Abstract

536,753. Electrostatic precipitation apparatus. LODGE-COTTRELL, Ltd. (Research Corporation of New York). April 30, 1940, No. 7776. [Class 39 (i)] In the electrostatic precipitation of particles suspended in gases of the type in which the gas under treatment is passed first through an ionizing field and subsequently through a spatially separated precipitating field between non-discharging electrodes, a film of liquid is formed on the non- discharging electrodes of the ionizing field only and the particles are collected in a substantially dry condition on the collecting electrodes of the precipitating field. Preferably means are provided for preventing direct impingement of the gas stream on the liquid film and directing it into proximity with the discharging electrodes. As applied to a precipitator of the kind described in Specification 512,313, comprising precipitating electrodes 43, 44 composed of gas pervious material disposed transversely across the gas stream, and an ionizing field consisting of high potential discharge electrodes 15 alternating with extended non-discharge electrodes 16 in a plane transverse of the gas stream, the electrodes 16 are tubular and are filled from a pipe 19 with liquid which overflows at the upper end of the electrode and runs in a film down the outside. Preferably baffle plates 40 are provided in advance of the ionizing field to direct the flow of gas towards the discharging electrodes 15 and prevent the direct impingement of the gas on the wet surface of the electrodes 16. Baffles 47, 48, 70, 72 are provided between the edges of the earthed precipitating electrodes 43 and the sides of the casing 11 to prevent the gas stream from byepassing any of these electrodes. The alternate precipitating electrodes 44 are supported on insulated bus-bars 56, 60, and are connected to a source of high potential. Rapping mechanism consists of weights 83 hanging from a shaft 81 which is turned to bring the weights between the electrodes and reciprocated to strike them. The deposited material falls into a hopper 14 and is removed by a conveyer 75 acting against a spring-pressed door 78 closing the conveyer channel. The liquid film may be produced by spraying or by providing holes in the wall of the electrodes. The electrodes 15 are mounted between arms 28a, 28b projecting from a frame 28 which is suspended by hooks 31 from a busbar 30, and is prevented from tilting by the engagement of a cross-bar 28c and an arm 30a depending from the bus-bar. The earthed electrodes 43 in the precipitating zone are located by pairs of pins 51 projecting from the sides of the casing 11 and are suspended from the upper pairs of pins by cross-pins 52. The high tension electrodes 44 are connected by extensions of their frame members to bars 55 which pass through clearance openings formed by cutting away the corners of the baffle members 47 at the upper edges of the earthed electrodes. The upper bars are carried by bus-bars 56 and the lower engage bus-bars 60. The invention may be applied to other types of precipitator as for example the tubular or parallel plate type in which the gas flows parallel with the electrodes.