【Mechanical Equipment Technology Edition】Daily Question 201802026: Common Faults in Refrigeration Systems (9.7)
Thread Content
This post was last edited by YORK Industrial Refrigeration on 2018-2-28 at 08:20. Starting from now, in order to enhance communication among users, a \"Question of the Day\" activity has been launched on the Mechanical Equipment Technology forum. We hope everyone will participate actively to progress and improve together! ! ! Rewards: 3 wealth points for active participation, 10-15 wealth points for correct answers. This question is valid for two days; no score will be assigned if more than two days pass. How can a screw compressor be checked using gas to determine whether it can be loaded or unloaded? Purge compressed gas or nitrogen into the loading port of the compressor, adjust the energy control knob, and conduct multiple tests in succession; each time, a \"ding\" sound should be heard at the end, indicating that the slide valve has reached its limit. When the gas is cut off, the slide valve can return to its original position automatically thanks to the spring. ============================== High-quality promotions: Mechanical equipment---Maintenance procedures for York screw compressors https://bbs.hcbbs.com/thread-1806833-1-1.html Mechanical equipment---Upgrading of York Quinton control centers https://bbs.hcbbs.com/thread-1804837-1-1.html Mechanical equipment---Major repairs for GEA Grasso screw compressors https://bbs.hcbbs.com/thread-1800467-1-1.html Mechanical equipment---Disassembly and maintenance of British HOWDEN screw compressors https://bbs.hcbbs.com/thread-1832529-1-1.html Mechanical equipment---Disassembly and maintenance of Japanese Maekawa MYCOM screw compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=
It’s a great topic; I had intended to work on it in my workshop some time ago, but unfortunately I didn’t do it. Instead, I carried out valve verification directly on the hydraulic system. I’m looking forward to hearing the experts’ answers.
Direct valve spool calibration on the oil circuit system
Gas is introduced at the solenoid valve; by adjusting the load amount, gas is used in place of hydraulic pressure, which transforms linear motion into rotational motion and thus drives the display pointer. Check whether the oil piston is stuck and whether the screw pair is stuck
Use gas testing to determine whether loading and unloading is possible: Facing the energy indicator, 1. First, introduce gas into the proximal oil port; the gas pushes the piston toward the distal end, causing the slide valve to move as well. Observe whether the energy indicator shows a decrease in load. 2. Then, introduce gas into the remote oil port; the gas pushes the piston toward the proximal end, causing the slide valve to move toward the proximal end as well. Check whether the energy indicator is activated.
Assuming it is exposed to a gas environment, the inlet and outlet pressures remain constant; the current increases under load and decreases when the load is reduced. If there is an outlet valve, keep its opening constant (i.e., maintain a constant back pressure); a pressure gauge should be installed in front of the valve, and the outlet pressure will increase after loading.
Compressed air is blown in separately to fill the two oil ports at the outlet of the load-switching valve; one port is pressurized while the other is released to the atmosphere. The same is true in reverse.
Use gas testing to determine whether loading and unloading is possible: Facing the energy indicator, 1. First, introduce gas into the proximal oil port; the gas pushes the piston toward the distal end, causing the slide valve to move as well. Observe whether the energy indicator shows a decrease in load. 2. Then, introduce gas into the remote oil port; the gas pushes the piston toward the proximal end, causing the slide valve to move toward the proximal end as well. Check whether the energy indicator is activated.
Gas is introduced at the solenoid valve; by adjusting the load amount, gas is used in place of hydraulic pressure, which transforms linear motion into rotational motion and thus drives the display pointer. Check whether the oil piston is stuck and whether the screw pair is stuck