The tail chlorine pipeline of the liquefier in the liquid chlorine liquefaction unit contains liquid chlorine

Is the energy regulation faulty? With such low inhalation pressure, the energy level might be too high

Low suction pressure is causing this unit to not operate. This screw compressor head underwent a major overhaul in November this year.

This post was last edited by smartcatii on 2017-12-14 at 12:37. Reasons for low suction pressure: 1. Faulty make-up valve; the unit is operating at its minimum load, but the make-up flow is still insufficient； 2. Load-carrying failure (failure of the load-reducing mechanism or leakage in the mechanical components used for load adjustment inside the head); the process load is low, yet the system is operated at a high capacity ； 3. The pipe (valve) from the liquid chlorine evaporator to the inlet of the machine head is blocked, resulting in high pressure inside the evaporator and low pressure at the inlet ； 4. Issues with the inlet pressure sensor ； 5. The refrigerant leakage is almost gone ； It is not a mechanical failure in the compressor; for example, the pressure at the inlet in case of a fault will be very high. A low inlet pressure, on the other hand, indicates that there is no problem with the mechanical parts of the compressor. Could you take a picture of the PLC interface to show the various parameters? Also, is the refrigerant level in the evaporator within the normal range?

Reasons for low suction pressure: 1. Faulty make-up valve; the unit is operating at its minimum load, but the make-up volume is still insufficient； (If we open this liquid supply valve a little, liquid will enter the compressor head, which proves that liquid fluorine is flowing in.) I feel that the Freon goes to the liquefier, circulates there without vaporizing, and then returns. 2. There may be loading-related faults (faults with the load-reducing mechanism or leaks in the mechanical components used for adjusting the load inside the unit); the process load is low, yet the unit is operated at full capacity ； (There might be malfunctions related to the slide valve; I’ve already contacted the manufacturer’s maintenance personnel and asked him to come and inspect it.) 3. The pipe (valve) from the liquid chlorine evaporator to the compressor inlet is blocked; as a result, the pressure inside the evaporator is high while the pressure at the inlet is low ； (Considering the liquid present in the nose cone, it’s unlikely that the back-fluorine pipeline is blocked.) 4. Issue with the inlet pressure sensor ； (The on-site gauge shows) 5. The refrigerant leakage is almost gone ； (It still doesn’t work even with the fluoride level at its maximum.) It’s not a mechanical fault in the compressor section; if there were a fault, the inlet pressure would be high. A low inlet pressure indicates that there is no problem with the mechanical parts of the compressor. Is it possible to take a photo of the PLC interface so we can see all the parameters? Also, is the level of refrigerant in the evaporator within the normal range? (Ours is a unit from 2004; it’s operated manually on-site, without any PLC control interface.) The liquid level of the refrigerant in the evaporator is not visible on-site; the liquid level in the fluorine storage tank is normal

The last edit to this post was made by smartcatii on 2017-12-14 at 14:31. In short, the direct cause is that the amount of refrigerant evaporating is lower than what the unit is capable of handling. What could be causing the relatively low evaporation rate? The most likely reasons are: 1. The evaporator (how can control it when the liquid level in the evaporator isn’t visible?) Reasons such as tube blockage, faulty chlorine valves with a very small actual opening, or clogged exhaust valves in this unit that prevent liquefied impurities from being removed, result in a low actual chlorine flow rate. As a consequence, the amount of refrigerant that evaporates is also low; if too much liquid is added, it will fill the evaporator and end up in the compressor head. It would be advisable to disassemble it for inspection if possible. 2. Another possibility is that the slider remains in its maximum load capacity state, resulting in a low process load and thus less evaporation. This can be seen by comparing the motor current with the current when it was operating normally in the past.

The evaporator is filled with liquid chlorine, which prevents it from draining and thus occupies the space needed for evaporation and heat exchange. As a result, the Freon does not evaporate completely, leading to liquid in the intake air and icing of the compressor unit. The high level of liquid chlorine in the evaporator also causes liquid to be present in the exhaust gas. You can call me at 13465726973

It is mainly caused by a dirty or clogged chlorine condenser, which leads to insufficient heat load; stopping the machine for cleaning will resolve the issue.

After all this hassle, our refrigeration units are now working properly (although the capacity isn’t high, they are able to reduce the system pressure). Regrettably, the root cause responsible for the lack of output some time ago has not been identified. Based solely on observations, it can be inferred that: the feeding of liquid chlorine into the liquefier is sluggish; this obstruction results in the liquefier being filled with liquid chlorine; consequently, the evaporation pressure on the fluorine side remains low. During that period, we replaced the thermal expansion valve on the on-site liquefier with a new one, charged it with Freon, and repaired the insulation on half a meter of the liquid chlorine pipeline, but there was no significant improvement. Currently, the suction pressure of the unit can reach around 0.6 kilograms. Thank you for following!

Hello, OP! Based on the symptoms of the liquid chlorine system mentioned in your post, as a colleague in this field I am also quite concerned about them. To further analyze the causes, I have three questions: 1. Did these symptoms appear suddenly? Or does it develop gradually? If it was sudden, what operations were performed on the system before the incident? Or were there any abnormalities in the peripheral systems? Are the symptoms resulting from a major overhaul of the nose cone? If this indeed occurred after a major overhaul of the engine nacelle, how long after the unit was put into service did this symptom appear? 2. You described “low suction pressure”. May I ask: “When the suction pressure is low, what is the evaporation pressure?” What is the pressure difference between the two? ” 3. The symptoms have improved currently; is this the effect of a multi-pronged approach? What specific measures were taken to improve the symptoms?