Level switches with rotating blade for granular material

SL.-SL.ATEX

Level controls propeller for solids

The SL level controls are employed for the level control in tanks that contain powders or granulars. The indicator’s working is very simple: a synchronous motor that rotates at low speed activates a propeller placed inside the tank to be controlled. In lack of material the motor is under voltage and the propeller revolves. The presence of material round the propeller bridles the rotation provoking control contacts exchange. Electric circuit opening and closing causes the command of an acoustic or visual signal, or the silo’s load, the conveyors and worm conveyors stop etc.
Versions:
• SL- for the control of the level of powders or granulars, in general;
• SL-ATEX for the level control of materials in thanks which, inside (process zone 20) or outside (environment zone 21) a potentially explosive atmosphere, like dust cloud, can be present.
➤ SL - SL-ATEX 24VCC/S with inverter board, uses a synchronous AC motor (brushless) driven by an electronic board, integrated in the housing, which converts the tension from DC to AC. The use of a brushless motor solves the typical problem of DC motors which have a limited lifetime due to the wear on the brushes.
General features:
• Aluminium casting instrument.
• Protecion degree IP65.
• The steel shaft is mounted on hermetic seal ball bearings.
• Plastic propeller (standard), aluminium or steel.
• Threaded hub 1”1/2 inch gas.
• Shaft with propeller is 15, 30, 50 cm long: the part that works inside the tank.
• ATEX type, to use where an atmosphere potentially explosive can be present.

Photogallery

1. Earth outside terminal
2. Hub in stainless steel 1" 1/2" gas
3. Shaft
4. Propeller
5. Presscables

MOUNTING

The instrument is mounted on the external wall of the tank, on the side or on the top through the threaded hub 1”1/2 Gas. The material should be free to move round the propeller, that should be not fouled by the material direct jet: so arrange baffles on the indicator when weight on propeller is high (high specific weight material or subject to move in block ones).