| 摘要 |
A spray nozzle for a dual-purpose shower system for conditioning felt or wire fabric in a paper making process has two operative conditions depending on the selected function of the shower system. In one condition the nozzle provides a high pressure spray and in the other condition it provides a low pressure purging flow, the condition being determined by the relative location of an internal plunger (28) with respect to a surrounding tubular body (10) having a valve member (26) at one end thereof. The plunger (28) is slidable in the body (10) and has a through passage (40) for the flow of liquid through the nozzle, and the clearance between the plunger (28) and the valve member (26) determines whether or not a spray or a purging flow is discharged from the nozzle. The supply of liquid into the nozzle is controlled by co-operating openings (60, 20) and ports (62, 64) in the tubular body (10) and the plunger (28) respectively. These are arranged so that when the plunger (28) is in the spray position a greater area is open for the intake of liquid than when the plunger (28) is in the purging position. A spring (54) moves the plunger (28) into the purge position and liquid pressure acting on the plunger (2@) moves it to the spray position. |
