Baffle chambers

Baffle chamber A chamber consisting of baffles (slats) W hich present an obstruction to the flow of dust-laden air. 7 hese obstructions slow down the heavy particulate mattet, which then settles by gravity into an adjacent hopper... 

Methods of dust removal depend mainly on the particle size of the dust and the temperature and moisture content of the gas. The methods used are broadly divided into dry methods and wet methods. The dry methods involve the use of gravity and baffle chambers, cyclones, filters, and electrostatic precipitators, while the wet methods involve the use of spray towers and venturi scrubbers. In principle, wet cleaning is preferred to dry cleaning because of the excessive wear associated with and the difficulty in handling the fine dusty material removed in the dry methods. The wet methods, however, must be followed by such operations as filtration, drying of filter cakes, and recycling of water. 

As far as dry methods are concerned, gravity and baffle chambers and cyclones are suitable for separating larger particles, while filters and electrostatic separators are preferred for finer particles. 

The gravity and baffle chambers provide the simplest of gas collection techniques. The gas is allowed to travel through a large chamber or a long tunnel to reduce its velocity, causing the dust to drop out by the action of gravity. The gas flow is deflected by baffles, or the flow direction may be reversed in order to enhance the separation. 

Cyclones are more efficient than gravity and baffle chambers, and also occupy less space. The dust-laden gas makes a tangential entry into a cylindrical or conical chamber. The dust particles travel outwards to the outer wall due to centrifugal forces there they collide with the wall and fall downwards to the receiver chamber, whilst the gases escape from an opening provided at the top. 

Vertical blowdown drum/catch tank This type of drum, shown in Fig. 23-51, performs the same function and operates on similar princi-les as horizontal separators. These separators are usually used where orizontal space is limited. The two-phase mixture enters the vessel via a nozzle on the vertical shell and is distributed by an inlet baffle chamber. 

Settling chambers are probably the simplest forms of aerosol separation device, and they exist for both laboratory use and industrial-scale use. The aerosol flows or is pumped into a box or chamber of some kind, designed such that the aerosol particles or droplets settle out and are captured before the gas exits the chamber. A variation is the Baffle chamber, in which the aerosol is forced to abruptly change direction in order to flow around a baffle plate. This provides an opportunity for the particles or droplets to sediment out. 

Hu, Z. (2008). Electricity generation by a baffle-chamber membraneless microbial fuel cell. Journal of Power Sources, 179, 27-33. 

Naturally, in three-phase designs there are many possibilities for variations with the fitting of special baffles, chambers and channels into the front end of the bowl but the principle is the same. However the use of a skimmer (see Section 2.4.3) in three-phase designs is very useful in controlling the equilibrium line between the two liquid phases while the bow l is at speed. The casing design is, of course, different. 

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