DEMECH provides a complete range of Rotary Airlock Valves (RAV) suitable for air lock applications ranging from gravity discharge of filters, rotary valves, cyclone dust collectors, and rotary airlock storage devices to precision feeders for dilute phase and continuous dense phase pneumatic conveying systems
RAVs are used in Bulk Handling System for free flowing dry powder, granular, crystal or pellets form of material. It is usually fitted below Chain conveyor / Screw Conveyor / Hopper / Silos / Bag filter / ESP/ Bins etc.
The main function of a RAV is to provide a rated Drop-through discharge, which determines the size and capacity of a RAV Besides this, it also functions as a rotary airlock to seal and prevents possibility of back flow of material in a pressurized system.
The selection of a RAV depends on three main factors i.e. Material density, Capacity desired & flowability of material. Temperature of dust and dust characteristics decide the material of construction of RAV.
RAVs are used for handling various materials including cement, ore, sugar, minerals, grains, plastics, dust, fly ash, flour, gypsum, lime, coffee, cereals, pharmaceuticals etc.
- DEMECH can supply RAV feeders from 1 TPH to 300 TPH capacity and inlet sizes ranging from 200 mm to 800 mm in round or square shape.
- DEMECH specializes in fabricated Rotary Air Lock feeders but they can also be supplied in castings for the smaller sizes in some special cases.
- The body is generally of mild steel, lined with hard plate material such as Sailhard or Hardox to increase the life of feeder especially where the material handled is abrasive in nature. The rotor with vanes is again of mild steel material but can be manufactured in special steel of higher hardness depending on properties of material handled.
- The vane edges are provided with replaceable tips of flexible material like spring steel for achieving good sealing.
- The deep groove ball bearings are always outboard type with no possibility of handled material coming in their contact. The shaft is sealed gland packing
- The drive arrangement for RAV can be of two types – (i) Direct drive using geared motor directly coupled to the feeder shaft through flexible coupling or (ii) Chain driven with primary reduction by geared motor.
Demech RAVs provide the following benefits –
- Various combinations of rotor Vanes to suit application number of vanes and closed or open vanes.
- Precision engineered to provide minimum clearance between rotor and housing and thus minimum leakage.
- Good throat opening at valve entry allowing high pocket filling efficiency.
- Minimum clearance at rotor tips and sides with body.
- Heavy shaft diameters minimizing deflection.
- Outboard bearings for non-contamination.
- Air purging provision for better sealing.
- Robust & compact design.