The output was reduced successfully on 2 different hot gas generators with a maximum combustion capacity of approx. 20 MW.
For one HGG, the modification was necessary because the customer had oversized the burner. The pulverised lignite lance was modified for the new operating range. This will allow for a control range of 1.2 MW – 9 MW (instead of the previous 4 MW – 21 MW). No modifications to the burner were required.
On another HGG, the minimum load for pulverised lignite operation was reduced to 2.5 MW without any mechanical modifications whatsoever. As a result, the dust-fired HGG has a control range of 1 : 8.5! The customer required a lower output to dry new products, but other products still required the previous maximum output of 21 MW.