Solids Level Switches
Solid level switches are point devices that detect when powder, granules or bulk material in silos, bunkers and hoppers reaches a set level. They prevent overfilling during loading and complete emptying during discharge.
The two most common types are motorised rotary paddle switches and capacitive switches. In the rotary type a small motor turns a paddle that stops when buried in material, operating a microswitch; the capacitive type detects material presence with no moving parts.
Main Applications
- Cement, sand and aggregate silos
- Flour, sugar and feed silos
- Plastic granule and raw material hoppers
- Sawdust and biomass bunkers
- Conveyor transfer points
Technical Data
| Types | Motorised rotary paddle; capacitive (by model) |
|---|---|
| Rotary housing | Cast aluminium; plastic or stainless by model |
| Rotary shaft and paddle | Stainless steel; optional PTFE coating |
| Paddle type | Standard, large surface, folding (by model) |
| Mounting | Side horizontal; top vertical (with extension shaft or cable) |
| Connection | Threaded or flanged |
| Contact | NO / NC microswitch |
| Capacitive type | For solids, min. dielectric constant 1.6 |
| Temperature and density | By model and paddle size |
Material Options
| Part | Rotary paddle | Capacitive |
|---|---|---|
| Housing | Cast aluminium (optional plastic, stainless) | PBT, aluminium or stainless |
| Sensing element | Stainless paddle | Probe (AISI 304 / 316) |
| Moving parts | Yes (motor and paddle) | None |
| Use | Dense and coarse material | Light and fine powder |
Which material? As solid level switches are not listed separately in the store, selection is made per project by material density, particle size and temperature. Large-surface paddles suit light materials and folding paddles suit narrow nozzles.
Advantages
Overfill Prevention
- Filling stopped when the silo is full
Empty Silo Warning
- Prevents running dry on discharge
Two Technologies
- Rotary and capacitive
Flexible Mounting
- Side or top
Construction and Design Features
- Housing fitted to the silo wall
- Paddle or probe reaching into the material
- Motor and torque mechanism (rotary type)
- Microswitch or relay output
Write the material, density, temperature and mounting location; we will define a suitable rotary or capacitive switch together.
How to Choose?
- Define the materialWrite density, particle size and temperature.
- Choose the typeUse rotary for dense material and capacitive for light powder.
- Select the locationMount from the side or top for high level and from the side for low level.
- Choose the paddlePick a paddle suited to the material and nozzle size.
Complementary Products
Why ORFA?
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Details →Get a quote for your project
Our sales team will prepare the best solution for your needs.