What are the Different Types of Air Washers?

There are three different types of air washers.

They are:

1. Spray Type Air Washer:

There is no standardisation for air washers.

The essential requirements in the air washer operations are:

(a) Uniform distribution of the air across the spray chamber.

(b) An adequate amount of spray water broken up into fine droplets.

(c) Good spray distribution across the air stream.

(d) Sufficient length of travel through the spray and the wetted surfaces.

(e) The elimination of free moisture from the outlet air.

Refer Fig. 37.7 for the simple air-washer used in practice. A pumps recirculates water at a rate greater than the evaporation rate. Washers are commonly available from 0.8 to 118 m³\sec. capacity. This type of washer is used primarily as an evaporative cooler or humidifier.

2. High-Velocity Spray Type Air Washer:

Air velocity range is 6 to 9 m/s -12 m/s. Maximum capacity up to 70 m³/s.

These are generally rectangular in cross-section.

3. Cell-Type Air Washer:

These washers obtain intimate air-washer contact by passing the air through cells packed with glass, metal or fiber screens. Water passes over the cells arranged in tires. Behind the cells are blade- type or glass-mat eliminates. Most cell-type washers are arranged for concurrent air and water flow. They are also constructed for special duty with counter.

Current flow characteristics or in a combination of both arrangements, cell washers come to many sizes of insulated or un-insulated construction and standard washers are available up to 10 cells high by 12 cells wide with a capacity of up to 100 m³/s.

Atomisation of the spray water is not required in cell type washers, but good water distribution over the face of the cell essential. A saturation effectiveness of 90 to 97% is possible.