往复式压缩机反向角课件.ppt

If the inner end suction valve was failed or the inner end of the cylinder was unloaded, inlet pressure would be exposed to both sides of the piston. As we mentioned earlier, with equal pressure acting on unequal surface areas, there are unequal forces. The outer end of the piston has greater surface area so the net force would try to keep the rod in compression longer than desired. If the leak is bad enough, we may never achieve 40 degrees of reversal. Again, you can see why monitoring valve condition and proper compressor configuration are important. It is always recommended to unload the outer end when single acting a cylinder. As the ratio of rod size to piston size gets smaller, a non-reversing condition could occur even with good valves. The next few slides will explain how a non-reversing condition could occur. Once again, let’s recap the normal compression cycle. While the gas is being compressed to discharge pressure and delivered on the outer end of the cylinder, gas, at inlet pressure, is entering the inner end of the cylinder. Reciprocating Compressor ROD REVERSAL往复式压缩机活塞杆反向角 Animated cross-section of compressor压缩机剖面动态图 连杆通过大头瓦与曲轴相连 刮油盘根 活塞杆盘根 曲轴箱 连杆通过小头瓦与十字头相连 活塞杆 PISTON ROD IN COMPRESSION 活塞杆在受压状态 CONN ROD BUSHING 连杆衬套（小头铜套） X－HEAD BUSHING 十字头衬套（十字头销孔） PISTON ROD IN TENSION 活塞杆在拉伸状态 FAILURE OF OUTER END DISCHARGE VALVE 缸头端排气阀损坏 FAILURE OF OUTER END DISCHARGE VALVE 缸头端排气阀损坏 FAILURE OF OUTER END DISCHARGE VALVE 缸头端排气阀损坏 FAILURE OF FRAME END SUCTION VALVE OR UNLOADING FRAME END 机身端进气阀损坏或机身端卸荷 FAILURE OF FRAME END SUCTION VALVE OR UNLOADING FRAME END 机身端进气阀损坏或机身端卸荷 FAILURE OF FRAME END SUCTION VALVE OR UNLOADING FRAME END 机身端进气阀损坏或机身端卸荷 FAILURE OF FRAME END SUCTION VALVE OR UNLOADING FRAME END 机身端进气阀损坏或机身端卸荷 ALWAYS SINGLE ACT ON FRAME END ONLY 只能采用机身端（曲柄端）单作用 HIGH PRESSURE CYLINDERS ARE IN DANGER OF NON-REVERSING LOADS EVEN WITH GOOD VALVES 高压气缸有无反向负载的潜在危险 即使所有气阀都完好 HIGH PRESSURE CYLINDERS ARE IN DANGER OF NON-REVERSING LOADS