What is a Silo Truck Compressor?

What is a silo truck compressor and where is it used?

A silo truck compressor is the pressure‑air producer used to empty cement, lime, gypsum and similar pulverised materials from a silobas or tanker and convey them to a storage silo or directly to the point of use. Compressed air is supplied to an inlet at the back or bottom of the tank; the air fluidises the powder and moves it along the hose towards the receiving silo or bunker. In other words, the silo truck compressor is the heart of the pneumatic conveying system: an electric or diesel‑driven compressor compresses air and feeds it into the tank so that cement can be moved safely and quickly.

Typical applications include ready‑mix concrete plants, cement factories, construction sites, precast and concrete element plants and mineral or aggregate facilities. Where grid power is available, an electric silobas compressor is usually preferred; on sites without power a diesel silobas compressor is chosen.

Pneumatic conveying principle: how do air and powder move?

Pneumatic conveying relies on compressed air carrying a powder in suspension through a pipe or hose. The silo truck compressor feeds air into the air inlet under or beside the tank. Inside the tank, the powder mixes with this airflow, its bulk density drops and it starts to behave like a fluid. It then travels towards the receiving silo or bunker. In many discharge operations working pressure is around 1–3 bar; pressure that is too high increases wear and safety risk in the hose, while too low a pressure causes plugging or very slow discharge.

Main components of the system are: the compressor (electric or diesel), tank air inlet, discharge hose, valves (on/off and sometimes pressure control), filters (dry and clean air is especially important for cement conveying) and the destination silo/bunker. Hose diameter and length must be selected according to conveying distance and material density.

Cement conveying scope: what is required?

In cement conveying the silo truck compressor is expected to deliver sufficient flow rate (m³/min) and pressure (bar), dry air (moisture reacts with cement and can cause lumps) and consistent performance through regular maintenance (filter, oil and seals). For cement, moisture control and filter quality are critical for both conveying efficiency and material quality. Typical scenarios are: unloading from silo truck to storage silo, filling a temporary silo on site and feeding a bunker in a precast plant. For more detail, see the cement conveying compressor guide.

Hose, valves and filters: safe and efficient operation

The discharge hose must be pressure‑rated, abrasion‑resistant and correctly sized; avoid crushing and sharp bends. Valves allow the operator to control pressure and flow – use them gradually rather than opening and closing suddenly. On the compressor side, an air filter and, where necessary, a dryer significantly improve service life and conveying quality, especially with moisture‑sensitive materials such as cement. Periodic maintenance (filter cleaning/replacement, oil level checks, seal inspection) is essential both for equipment life and for occupational safety.