A baghouse also known as a fabric filter dust collector is an air pollution control device that removes particulates rom a gas stream. Baghouses are often employed in large industrial applications such as power generation, steel mills, chemical production and manufacturing plants to capture air pollutants generated during normal operation. In many countries environmental regulation essentially mandates the installation and operation of a baghouse system achieve a reduction of hazardous air emissions from industrial sources. Additionally, in some instances the baghouse functions to recover product as part of the industrial process such as by collecting precious metals or pharmaceutical dusts created during manufacturing. Baghouses are also used for workplace safety purposes such as the prevention of combustible dust explosions and reducing worker exposure to harmful compounds.
A baghouse uses a series of fabric filters (often called bags) to remove particulate matter (i.e. dust) from the air. The dirty air is brought to the collector by means of a ductwork system that uses a motor-driven fan to create a vacuum that pulls in the dirty air and then pushes it through the system. Once it enters the baghouse, the dirty air is forced through the fabric filter causing the particulate to be caught by the fabric and then allowing the now clean air to pass through. This dust build up is referred to as a dust cake. The dust cake serves as a layer of protection over the filters. Filtering the air stream is the function of the dust cake while the filter supports it.
Over time most systems will use a self-cleaning mechanism to remove the excess from the surface of the filters. Three most common cleaning systems are Pulse-Jet, Reverse Air, and Shaker. Pulse-Jet dust collectors are the most common of the three. These collectors utilized high pressure compressed air that projects down into the filters to remove excess dust. The benefit of utilizing a Pulse-Jet cleaning method is that the baghouse can still be functioning while cleaning occurs. Reverse Air collectors are cleaned by first shutting off the system and then using a downward flow of clean low pressure air. Shaker style baghouses also need to be shut off in order for their cleaning cycle to begin. Shaker collectors are cleaned by using an electric motor driven system to shake the structure of the equipment, causing the dust to release from the bags.
Despite the passing of numerous environmental and safety regulations that essentially require the use of a baghouse, many facilities still operate without one. Installing, maintaining and operating a baghouse that is sufficient to capture and control the facility's hazardous particulate pollution.
With a history going back to the early 1900s, baghouses now play a vital role in control emissions of harmful air pollutants. Without baghouse most industrial processes would not be possible or would release massive amounts of devastating pollution.
Applications[edit | edit source]
- Thermal-Spray Coatings
- Carbon Black
- Industrial Boilers
References[edit | edit source]