A3.10.1.1 Bag House


A bag house is an assembly of fabric filter bags. It is extremely efficient at removing suspended particulates.

A typical bag house comprises an array of long, narrow bags (each about 25 cm in diameter) that are suspended upside down in a large enclosure. Dust-laden air is blown upward through the bottom of the enclosure by fans. Particulates are trapped inside the filter bags, while the clean air passes through the fabric and exits at the top of the bag house. The bags are cleaned by mechanical shakers or by reversing the flow of air and the loosened particulates are collected and removed for disposal.

Source: Green Force Engineers

A fabric-filter dust collector is very efficient at removing small particles. However, they offer relatively high resistance to airflow, and are expensive to operate and maintain. To prolong the useful life of the filter fabric, the air to be cleaned must be cooled before it is passed through the unit; and therefore cooling coils are needed for this purpose, adding to the expense.

Low-Excess-Air Firing (LEA)

LEA is a method of reducing NOx in combustion processes. Quite simply it consists of operating the combustor with a decreased amount of combustion air. It is possible to reduce NOx emissions by 10-15%.