Coal & Pet Coke Bunker Cleaning

A coal bunker rarely fails all at once. It loses capacity quietly — a layer on the wall, then a rat-hole, then a throat that hangs up every few shifts — until the feeder is starving and the mill is tripping, and nobody can say exactly when it started.

What goes wrong in a coal bunker

Symptom	What is happening
Feeder starves, mill trips	A hang-up in the bunker throat. Coal above it is not moving at all.
Bunker reads full but empties fast	Rat-holing. You are cycling a narrow channel while the bulk sits caked on the wall.
Bunker never runs down fully	Dead stock keyed to the wall. It has not moved in months and will not move on its own.
Wet coal, monsoon months	Moisture binds fines into a plastic mass that bridges across the outlet and sets hard.
Repeated poking from the access door	The manual fix — and the one that puts a person under a suspended mass of coal.

Wet coal, and why the monsoon decides your year

Coal arriving wet behaves nothing like coal arriving dry. Moisture binds the fines into a plastic mass that will not flow, bridges across the outlet, and then sets against the wall as it dries in place. What was a manageable layer in March becomes a structural problem by September.

This is why bunker cleaning is worth scheduling rather than reacting to. A bunker cleaned before the monsoon holds its capacity through it; a bunker left until it blocks costs an unplanned outage at the worst possible time.

What it costs while you wait

• Feeder starvation and mill trips — each one an unplanned interruption to generation or production.
• Lost live capacity — you are cycling a fraction of a bunker you already paid for and still insure and maintain in full.
• Degraded dead stock — coal that has not moved in months is not the coal you bought.
• Manual poking from the access door — the usual fix, and the one that puts a person beneath a suspended mass of coal.
• It gets harder — build-up compacts with age. The job only gets longer and more expensive.

How we clean it

1. Survey and isolate. We inspect through the top hatch, establish how far the build-up extends, and agree the isolation and lock-out plan with your maintenance team.
2. Whipsets matched to the vessel. Bronze chain heads on the boom, lowered through the top hatch, cleaning caked coal off the wall as the bunker empties beneath — without damaging the plate or its lining.
3. Cardox CO₂ for hang-ups. Where coal has set solid at the throat or outlet, a tube fired through a wall socket breaks it in milliseconds — no explosives and no blasting licence.
4. Discharge through your own feeders. The coal goes where it was always meant to go. Recovered fuel, not disposal cost.

Also handled

Pet coke bunkers and silos, lignite, biomass and coke. Pet coke behaves differently from thermal coal — stickier and far more prone to plating on the wall — and usually needs a heavier whipset and more Cardox work at the outlet.