Pulverised fuel feeding for co-firing based on loss-in-weight flow metering

An experimental facility to investigate co-firing requires handling pulverised coal and biomass fuels, to deliver them to a well-instrumented experimental burner in a precise and flexible manner. A system based on loss-in-weight mass flow metering has been successfully used to deliver continuously a wide range of flows of diverse fuels with great accuracy, even in the presence of refill cycles. To achieve the required performance the system must be well-engineered, and in particular the implementation of an appropriate control strategy is essential.

► Innovative regulation of the fuel flow in a 500 kW (th) co-firing pilot plan.
► Dual feeding provides great flexibility and homogeneity in the mixture of both fuels.
► The loss-in-weight control requires combination of feedback and feedforward loops.
► A simple method is given to obtain a general feedforward function.
► Precise continuous discharge for diverse materials in the presence of refill cycles.