Patent ID: 7520137

Claim:
A method of controlling the injection of liquid into an inflow duct of a prime mover or driven machine, the method comprising: providing an injection device for a total nominal mass flow, the injection device having a number of pressure atomizer nozzles that are arranged in a distributed manner substantially uniformly over a cross section of the inflow duct to provide sufficient pumping distance, each nozzle being configured for throughput of a partial mass flow of the total nominal mass flow, the injection device having at least one symmetry line defining two sides; at a least three sequential injection mass flows which are below the total nominal mass flow, for each injection mass flow, admitting liquid to only some of the nozzles, wherein on each side of the symmetry line, liquid is admitted to the nozzles so that in sum the partial mass flows of the nozzles to which liquid is admitted is the same on each side of the symmetry line in order to avoid asymmetry of thermodynamic states that would be damaging to a compressor downstream of the injection device and would reduce the pumping distance; wherein at least two nozzles are combined to form a nozzle group, liquid being jointly admitted to the nozzle group having an associated group throughput of liquid, and control being provided for selective admission of liquid to the nozzle group, such that flow of liquid to different nozzles of the injection device may simultaneously be controlled; wherein at least two atomizer nozzles are arranged on at least one nozzle tube, with liquid being jointly admitted to the nozzles arranged on each of said at least one nozzle tube; and wherein nozzle tubes arranged essentially symmetrically to the symmetry line are combined to form a group to which liquid is to be jointly admitted.