GB495038A - Improvements in or relating to pulverised fuel firing systems - Google Patents

Abstract

495,038. Pulverized - fuel mills. HOBBS, J. C. May 5, 1937, No. 12834. Convention date, May 14, 1936. [Class 59] [Also in Groups XII and XIII] In a pulverized-fuel furnace 10 secondary air is supplied to the burners 12 by a fan 38 and primary air is supplied by fans 46, 48 to pulverizers 100, 102, 104 and thence to the burners 12 through pipes 150, 152, 154. The primary and secondary air are separately heated by waste gases in heating apparatus divided by a partition 30. Secondary air supplied by the fan 38 passes over the heater to the left of the partition 30 and through the pipe 40 to the furnace. The fans 46, 48 draw air from the delivery of the fan 38 through a pipe 50 and discharge it at a higher pressure than the secondary air through a manifold 82 to the air heater to the right of the partition 30 and thence through a pipe 122 to the pulverizers. A byepass pipe 106 may supply cold air to the pulverizers by way of the manifold 108 and valve controlled conduits 110 112, 114 and the temperature of the air supplied to the pulverizers may thus be regulated. The fans 46, 48 may draw air direct from the atmosphere through valve controlled inlets 70, 72. Counterweighted valves are provided on the outlets of the fans 46, 48 and a valve 120 controlled by boiler pressure is arranged at the outlet of the manifold 82. The quantity of waste gases passing through the primary air heater may be controlled by a valve 36.