Bulk material handling
A conveyor train, a bin, a crusher and a belt weigher behave the same way whether they are feeding a boiler, an asphalt plant or a concrete batching plant. The material changes; the control problem does not.
We have worked on all of them.
Conveying
Sequenced start and stop against the direction of material flow, so a belt never runs into a stopped one. Interlocks, run-back protection, belt drift and pull-cord monitoring, blockage and choke detection.
Bins, silos and feeders
Level measurement and the problems it does not solve — bridging, rat-holing, aeration. Loss-in-weight and belt-weigher feeders, totalising, and reconciliation between what was weighed in and what was weighed out.
Crushing, screening and milling
Load control on crushers and mills against motor current, protection against choking and against running empty, and product size feedback where instrumentation allows it.
Weigh batching and recipe control
Dosing of aggregates, cement, water and additives to a recipe, with correction for material moisture. Batch records, and the accuracy the recipe depends on being an instrument specification rather than a hope.
Solid fuel handling on energy boilers
Fuel allocation across feeders by calorific value on a 260 t/h circulating fluidized bed boiler firing petroleum coke, coal, gas and fuel oil, with the coke calorific value calculated automatically from the combustion result. Combustion air and oxygen cascade control, SO2 and NOx control through furnace temperature and lime dosing.
See the CFB boiler advanced controllers project and Plant Performance for reference implementations.
Dust
Coal and coke dust are explosible atmospheres — ATEX zones 20, 21 and 22 — and crushing and milling generate them by design. Dust extraction and suppression, electrostatic precipitators and baghouse filters, and equipment selection and circuit design for classified dust areas.
Intrinsically safe circuit design for classified areas is covered under Oil and Gas.