To permit partial load operation, a control arrangement is provided to effect, in dependence upon an operating load of the boiler, control of at least one of the flow rate of the combustion air into {HEAD ~ the boiler}, and the operating pressure in {TAIL ~ the combustion chamber} of the boiler 
To permit partial load operation , a control arrangement is provided to effect , in dependence upon an operating load of the boiler , control of at least one of the flow rate of the combustion air into { HEAD ~ the boiler } , and the operating pressure in { TAIL ~ the combustion chamber } of the boiler
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH