GB646148A - Improvements in or relating to dust arrestors - Google Patents

Abstract

646,148. Washing gases. AMERICAN AIR FILTER CO., Inc. July 11, 1947, No. 18461. Convention date, June 5, 1943. Addition to 646,147. [Class 55(ii)] To enable dust arrestor devices according to the parent Specification to operate efficiently when air flows are other than normal, they are provided with a liquid level control means for maintaining the liquid in the suction side of the bath at a predetermined high level during air flows varying within the operating range, while permitting the low liquid level to vary, the control means causing the volume of liquid swept through the baffle zone to increase and then decrease as the air flow increases through the said range. In the form shown, the control means consists of a box 10 divided into three vertical chambers, a low level chamber 11 communicating with bath 3 and open to atmosphere, a high level chamber 12 communicating with bath 3 through chamber 11 and closed at the top. the top air space being connected by a pipe 19 to the outlet air space 6 of the arrestor so that the liquid level in chamber 12 corresponds to the high level in bath 3. These levels are controlled by a weir 17 across which excess liquid can flow to the third chamber, which is divided into an overflow compartment 13 connected by a sealed standpipe 20 to a drainage chamber 14. When the plant is started up a solenoid valve opens to allow a small continuous flow of make up water to enter chamber 12 through pipe 27. With normal air flow, part of this water passes to tank 3 to make up evaporation loss and part escapes over weir 17. To compensate for air flows above or below normal, which would cause flooding or starving of the baffle zone of water, the low level of the tank is permitted to alter to render available less or more water for passage through the zone, whilst the high level is held constant.