Rotary air lock feeders [rafs] are useful for feeding material at a controlled metering rate while maintaining an air lock between the up and down stream. Feeders that are useful to meter do not require an air lock, whereas the feeders operating under differential pressures have close tolerances between the rotor and stator and thus maintain air lock. The design, configurations and combinations of the rotary air lock feeders [raf] depend on characteristics of the material being handled and its application requirements. The various type of rotary air lock feeders design include open, closed, semi-closed rotor with deep pockets; scalloped, adjustable flex tips and other different styles depending upon application. The body of these rotary air lock feeders can be `drop through` [inlet and outlet openings inline], `blow through` [provided with pipe connections for pneumatic conveying application], `offset` or `side entry` [with offset inlet and outlet opening centres]. The air leakage rates of different models vary according to pressure differentials; temperature, flow resistance etc. Application and can be designed to cater to the flow leakage criteria of process requirements. The company supplies these rotary air lock feeders in mild steel, carbon steel, stainless steel in combination with various other ferrous/non-ferrous metals material construction. Some of the salient features of these rotary lock feeders body/rotor with hardchrome/tungsten carbide, etc special coatings/lining and internally fitted sleeves/liners of special materials for high abrasion, corrosion applications; various options like body vent, seal air-purging, material deflectors, special shaped flanges to match preceeding and succeeding equipments, direct drive, flame proof versions, sheared inlet, etc.; and apart from theoretical calculations raf design involves several permutations and combinations in every stage keeping into view application and process parameters.
