CS

Scrubbers – different designs for washing contaminated gases with liquids in order to extract one or more components from them. Centrifugal scrubbers of CS class are dust-collecting units designed to clean the air from dust clogs generated during transportation and processing of coke, quartz sand, coal, abrasives, limestone, ores of various kinds, etc.

Structural advantages

The CS class centrifugal scrubber is a hollow, vertically mounted cylinder. The contaminated gas inlet connection is located at the bottom of the cylinder. In the upper area around the circumference of the cylinder, there are nozzles through which the liquid enters the inner surface of the cylinder to create a thin water film. Capacity of CS scrubber models varies from 1000 to 10000 m3/h, diameter of the cylinder – 300 ÷ 800 mm, height – 2355 ÷ 5715 mm, weight – 80 ÷ 407 kg, hydraulic resistance – 400 ÷ 850 Pa. The recommended entry speed of the polluted flow into these scrubbers is 15-23 m/s. For optimal operation of the scrubber the water head in front of the nozzles must be constant and equal to 0.2 atm, which is ensured by installing an intermediate water tank (ball valve).

Depending on the density, dispersity of contaminants, the flow rate of contaminated air and the diameter of the cylindrical section of the scrubber, the purification efficiency of the dusty air reaches 86% – 90%. It becomes higher with the increase of dust density, feed rate, with the decrease of the diameter of the cylindrical section. The cleaning level for particles larger than 30 microns is 90%, decreasing to 80% for particles closer to 5 microns, and 40% for particles smaller than 5 microns.

Principle of Operation

The CS Centrifugal Scrubber is a cylindrical body, in the lower zone of which the polluted air enters through an inlet pipe. In the upper zone of the casing, nozzles are installed to supply water which creates a thin film of water flowing down the walls of the casing. The flow of contaminated air in the scrubber cavity makes helical movements, rising to the upper zone. The dust particles are pressed against the walls of the unit due to the centrifugal force. The displaced wet dust rolls by gravity together with water to the lower zone of the structure, forming pulp. It is removed from the unit by means of a discharge pipe which, at the right moment, is closed by a special gate. The cooled humidified purified air medium leaves the scrubber structure unhindered.

Application

Centrifugal scrubbers of the CS class are widely used for capturing coking products, cleaning dust from industrial gas mixtures, for cooling and moistening gas media in chemical and technological processes of various kinds. Centrifugal scrubbers of the CS class are in demand in exhaust ventilation systems for the purification of clogged air from dust generated during transportation, as well as processing of limestone, quartz sand, abrasive materials, coal, various ores, coke, etc..

Scrubbers of the CS class are used:

1. the first stage of purification:
   • exhaust ventilation systems from crushing and screening equipment – elevators, crushers, transfer units, etc. ;
   • exhaust ventilation systems from knockout grilles at foundries, earth preparation equipment;
2. second treatment step:
   • exhaust systems with large values of the initial concentration of contaminants – suction from sandblasting booths and chambers.

Features of installation and operation

It is recommended to install the CS class scrubber upstream of the fan (at the suction), in order to protect it from wear and tear, with the water drained from the lower zone of the fan casing.

The air is exhausted from this unit:

• upwards, bypassing the sump or sideways through the volute – installation of the scrubber after the fan;
• through the volute – installation of the scrubber up to the fan.