Chemical Process Equipment Area: [Weekly Topic] Issues with the Ingersoll Rand M350KWHV? (2011.8.15-8.21)

Without inlet guide vanes, there must be disc valves; it’s impossible to start the system at full load. There’s no need to unload it when shutting down – it’s certainly possible to do that, but it’s better not to.

There should be a butterfly valve at the inlet. Also, it’s possible not to unload the machine when it’s shut down, but that’s not good for the machine

This post was last edited by yeying34 on 2011-8-23 at 10:47. 1. The inlet guide vane mentioned by the original poster refers to the inlet valve, which is electrically operated. At full load, fully open ； When reducing the load, close the inlet valve appropriately; at this time, the negative pressure of the incoming air is high. When 4APT (exhaust pressure) reaches the Offline Pressure (trigger pressure), unloading operation begins: the inlet valve is fully opened, and the 3SV (vent valve) is also fully opened. 2. When shutting down, we smoothly switch the outlet valve to the vent valve, and then press the shutdown button; the system will automatically shut down. Our company offers models of 160KW, 200KW, and 350KW. The emergency stop button for the 160KW model is located on the right side of the control panel, quite close by; it’s easy to accidentally press it while using the up/down page navigation buttons, so one needs to be careful with their finger movements when pressing these buttons. The 160KW issue occurs when using the up/down page navigation keys; the machine owner ends up with no recorded parking data. The reason for this is unknown – could it be due to equipment aging (it has been in use for over 6 years)? The emergency stop buttons for 200 and 350 are on the left. 3. The equipment does not have a current display; therefore, maintenance personnel must pay close attention to whether the equipment is operating under overload conditions, in order to prevent the motor from being damaged. It is best to contact the electrical staff daily and keep track of the current levels and motor temperature. 4. It is recommended to check the oil level of the equipment at least once per shift, especially for standby equipment. It is advisable to keep the oil level at around 1/2. When refueling the equipment, the power should be turned off or the emergency stop button pressed. 5. During inspections, attention should be paid to the drainage of solenoid valves, and equipment maintenance should be strengthened. This activity is quite good; there are still many moving devices involved in air separation. Here are two more issues I’ve just encountered: 1. Our company’s 350KW screw compressor, during normal operation, starts to unload when the pressure reaches the unloading pressure; once the pressure drops, it resumes loading. At this time, the unloading solenoid valve isn’t fully closed, resulting in a lower exhaust pressure (1 bar lower than normal), which prevents the pressure from rising. How to determine: (1) Abnormal sound, louder than normal ； (2) Touch the discharge pipeline; if it is hot, it proves that it has not been fully closed. Solution: First press the uninstall button, then press the load button; this should basically resolve the issue. If that still doesn’t work, it proves that the unloading solenoid valve is stuck, and the only solution is to shut down the machine. 2. There is one unit with a capacity of 160 KW; due to electrical work involving the replacement of relays and other components, sparks are generated when the unit starts up. It might be caused by foreign objects on the contactor. It is also this device that experiences a shutdown due to \"main motor overload\" when started, accompanied by abnormal noises inside the control box. We had never encountered this issue with any of the previous models.

Bingbinggo, the unload and shutdown buttons are rarely used when shutting down the machine – so how do you bring it to a stop? I have previously worked with two sets of Ingersoll Rand centrifugal compressors, but I can’t recall their exact models; both of them used imported vanes for control. My current equipment is from Atlas, and I feel that the control panel of the Ingersoll Rand units isn’t as user-friendly as that of the Atlas units. (I’ve seen few devices, so it’s hard for me to participate in this discussion.)

Reply to 5# you*n*nyou: Since the unit rarely stops, usually after switching the outlet to vent mode, the emergency stop button is pressed directly. The load/unload buttons are rarely used. Additionally, our unit has a shutdown knob located below the page-up and page-down buttons, which I think also poses a potential hazard. It shuts down if touched accidentally.

Ingersoll Rand screw compressors. Under normal conditions, it will not stop operating; it loads when the pressure is low and unloads when the pressure is high. It has no inlet guide vanes; it is a piston driven by gas. The inlet piston opens during loading and closes during unloading. However, this piston is not 100% closed during unloading; a 5% clearance is left for operation, otherwise the oil cut-off valve cannot supply oil to the unit.

Ingersoll Rand, Atlas, and Fusheng screw compressors are basically the same. Units that are slightly larger are of the water-cooled type, while those that are smaller are of the air-cooled type. Additionally, the units are divided into oil-injected series and oil-free series units. Oil-free units are expensive. The gas used for general instruments generally meets the requirements. Each system is equipped with a buffer tank and a water removal system. The unit itself has its own automatic drainage system. This unit requires a high level of environment.

Reply to 2# zhouhuihubei: I intend for the machine to operate at no load initially when it is turned on; once the machine reaches its rated speed without any load and operates smoothly, and the oil pressure builds up, all components are properly lubricated. Only after these conditions are met does loading begin, with the load being increased gradually until the machine is in a proper working condition. It’s fine not to unload during an emergency stop, but it’s best to follow the steps for planned stops. That’s what I think; it’s not necessarily correct.