Home → Services → Fly ash silo cleaning
Ash silos and hoppers cleared of ratholes, bridging and hardened wall build-up, with the crew outside the vessel throughout.
Fly ash is fine, abrasive and hygroscopic. It picks up moisture from humid air, sets against the silo wall, and quietly takes your storage capacity with it. By the time the ash handling system starts tripping, most plants are running a silo at a fraction of its rated volume.
We clean fly ash silos, ash hoppers and bunkers across Indian thermal power plants and cement plants — without a single person entering the vessel.
The reason nobody wants this job: a fly ash silo is a confined space, full of respirable dust, with an unstable material bridge overhead that can collapse without warning. Every fatality in this category happens the same way — someone went in to break the blockage manually.
| Symptom | What is actually happening |
|---|---|
| Silo fills faster than it should | Wall build-up has shrunk the effective diameter — you are filling a smaller vessel than you think |
| Erratic discharge, then nothing | Ratholing. Ash flows down a narrow central channel; the rest is set solid against the wall |
| Flow stops completely, vessel still heavy | Bridging — a self-supporting arch has formed across the outlet |
| Extraction port chokes repeatedly | Compacted ash at the outlet, usually with lumps from moisture ingress |
| Aeration pads no longer help | Build-up has covered the pads; fluidising air is going nowhere |
We inspect through the top hatch, establish where the build-up sits and how hard it is, and agree the isolation and lock-out plan with your maintenance team. No scaffolding goes inside the vessel.
The whip head enters through the top hatch on a mechanical boom assembly. Rotating chain and hammer whipsets run at 800–1,000 rpm and clean coating off the wall without gouging concrete, steel liners or welds. The operator controls speed and position from the silo roof, watching the vessel empty beneath.
Where ash has set beyond what mechanical whipping will shift — typically at extraction ports and in the cone — we use the Cardox System. A tube of liquid CO2 is energised electrically; the CO2 converts to gas, expands to 600 times its liquid volume and discharges at up to 40,000 psi. The blockage breaks. The vessel does not.
No explosives are involved, so there are no licensing requirements, no magazine storage and no statutory blasting notifications.
Dislodged ash leaves through your normal outlet and conveying system. There is no separate removal operation and no material handling contract to negotiate.
The same two systems work across effectively every bulk material we have encountered in 30+ years: coal and pet coke, cement, clinker and raw meal, gypsum, soda ash, slag, sinter, DRI, rock phosphate, lime, laterite and murram, and feed-grade powders.
Typical duration. Most vessels take from a few hours to a few days depending on size and how hard the build-up has set. As a reference point, we cleaned three 380-tonne coal bunkers in five days total, with zero confined-space entry.
Send us the vessel size, the material and how long it has been a problem. We will tell you what is involved, how long it takes and what it costs.
Plant already down? Say so — we mobilise for emergencies.