Standard Air Control

Technical Specifications:

These are exhaust fans used to overcome air resistance up to 15 - 20 mm WG. Cast Aluminium alloy impellers with aerofoil section is mounted either directly on the motor shaft or through belt drive arrangement to isolate motor from air path.

These fans are generally available in standard series of 12",15",18",24",28",32",36",42" as fan diameter.

These are high efficiency blower ranging 0.25 HP up to 150 HP, capacity up to 1,50,000 M3/Hr. These equipments are manufactured from heavy M.S. or S.S. sheet. Impellers are fabricated following aerodynamic principals either directly mounted on motor shaft or through indirect drive by mounting on shaft.

All products are dynamically balanced as per grade 2.5 of ISO 1940/1-86. Testing of blowers shall be as per code IS-4894. For operating temp. above 150oC shaft shall be either air cooled or water cooled to protect bearings. Vibration transmitted shall be reduced by using suitable vibration isolators. Selection of same is based on total static load, lower vibrating frequency and isolation required.

In this type, Filter bags are mounted in a common housing. Dusty air enters in the unit from bottom inlet with velocity higher than convey velocity. As it enters in the unit, due to sudden reduction in velocity, most of the particles are being separated from air stream and collected in the bottom hopper. Air moves vertically upwards and passes across the filter bags from outside to inside. Air is being sucked by virtue of high pressure developed due to centrifugal blower located at the terminal end of the system. As filtration continues dust particles deposited over the surface of the filter bags. Over a period of time dust cake is formed over the surface. To remove the cake formation, a high pressure air pulse is being imposed on the filters from inside to outside. This separates dust cake from filter surface and continuing filtration.

Each row of filters are being pulsed in turn in a continues sequence. Pulsing time and ideal time between successive pulses are being controlled with a sequential timer.

Proper selection of air permeability, type and material of filters, porosity of filter, air velocity are the key factor for efficient performance of the unit. Efficiency of centrifugal blower is also plays vital role in overall performance of the system.

mproper design parameters may lead to:

• reduction is suction capacity
• clogging of filters
• detoriate filter life
• inferior dust collection efficiency
• increased cross contamination of pollutants
• Lesser lead time for dust removal from unit
• Increased maintenance of impeller, blower and filters
• Higher dust concentration of dust in outlet.

In a packed bed scrubber the liquid is broken up into thin films by distributing it over the top of deep beds of extended surface packing and allowing it to trickle downward while the gas passes up from the bottom, thereby producing counterflow of liquid and gas.

Venturi scrubber consists of a venturi shaped air passage with water entry in the high velocity throat. The water may be introduced either by overflow or through nozzles and is broken un into fine droplets by the action of the high velocity gas stream. Particle conditioning takes place in the throat and as the gas decelerates in the diffuser section. The dispersed material in the dirty gas is deposited on the droplets by impaction, diffusion and condensation.