What are the hazards of liquid entrainment in HC cyclic hydrogen, and what are the solutions?

Liquid entrainment in the circulating hydrogen can easily cause liquid slugging in the circulating hydrogen compressor, leading to damage to the compressor. Solutions: 1. Try to reduce the temperature of the high-pressure separator. 2. Keep the liquid level in the high-pressure separator from rising too high. 3. Remove liquid from the recycle hydrogen buffer tank in a timely manner. 4. Slightly reduce the processing capacity of the plant. 5. Calibrate the level measurement devices in the high-pressure separator and the recycle hydrogen buffer tank to ensure accurate readings

Harm: To put it simply, at such high speeds, a single drop of oil is like an airplane in flight that is afraid of birds. Additionally, the treatment methods mentioned above are already comprehensive; I would like to add a few points: 1. Regularly inspect the level gauge in the liquid separation tank at the compressor inlet to prevent false readings or malfunctions of the electronic instruments； 2. Add interlock safety instruments above the liquid separation tank at the compressor inlet; in case the liquid level is not properly controlled and liquid enters the system, it is necessary to protect our \"heart\" – the compressor ；

Liquid carried in the circulating hydrogen can damage the impeller of the circulating hydrogen compressor, causing serious damage to this compressor and affecting the normal operation of the facility. As for how to address this issue, the simplest method is to remove the liquid from it. In terms of process considerations, it is most important to lower the temperature of the cold high-boiling fraction; by doing so, the conversion rate of the reaction is reduced, and the liquid level in the cold high-boiling fraction is decreased

As a supplementary note, the amount of water added should be appropriate or slightly more, to prevent ammonia from liquefying after compression

Liquids cannot be compressed, so allowing liquid to enter the compressor with the circulating hydrogen can easily cause damage to the compressor. First, it is necessary to analyze where the liquid comes from. I. Measures for high-pressure sections: 1. Reduce the temperature at the inlet of high-pressure areas. 2. Maintain an appropriate level of liquid in these areas; it should not be too high, and it is essential to calibrate the gauges properly. II. Measures for the circulating hydrogen desulfurization tower: 1. Keep the operating conditions of the circulating hydrogen desulfurization tower stable, paying attention to temperature differences and pressure differences. 2. Remove oil from the mixture. 3. Replace the amine solution and add water to reduce its purity. 4. Reduce the flow rate of the amine solution. There are many measures to take in this regard, and it is very important to prevent foaming of the amine solution. III. False level indications. Measures: 1. Use additional gauges; 2. Install two more gauges in the recycle hydrogen suction tank to facilitate monitoring. Liquid presence in the recycle hydrogen is a problematic issue – it can be caused by an excessively high conversion rate in the plant, primarily due to an excess of light hydrocarbons, or it can also arise when the processing volume is too large. All these factors need to be taken into consideration.

One more point: maintain stable system pressure, stable raw material composition, and stable hydrogen-to-oil ratio

Liquid carried in the circulating hydrogen causes the circulating hydrogen compressor to smoke; in severe cases, this can lead to vibration of the compressor and forced shutdown, as well as an increase in system pressure. When circulating hydrogen contains liquid, the following phenomena occur: ① The liquid level in the liquid separation tank at the inlet of the circulating hydrogen compressor is too high; when circulating hydrogen contains liquid, the flow rate of the circulating hydrogen compressor fluctuates, and in severe cases this can lead to vibration of the compressor and its shutdown due to failure. ②System pressure fluctuates. Reason: The high liquid level is too high or the foam breaker is malfunctioning, causing the circulating hydrogen to contain oil ； In units equipped with a circulating hydrogen desulfurization system, liquid carryover is caused by either an excessively high liquid level in the desulfurization tower or amine solution foaming due to hydrocarbons in the circulating hydrogen. Treatment: ① Increase the pressure relief valve from the hydrogen circulation machine inlet buffer tank to the cold low-pressure separator, and quickly adjust the liquid level in the inlet liquid separation tank to normal. ②Suspend the amine solution circulation in the cyclic hydrogen desulfurization tower if necessary. Check whether the mixing steam at the inlet of the cyclohydrogen compressor is enabled. After excluding the above factors, if the circulating hydrogen still contains liquid, the possibility of a failed defoamer screen should be considered; in emergency situations, shutdown procedures should be followed.

Today, I found relevant information in the workshop documents; let’s learn together about the damage caused by liquid slugging to reciprocating compressors. Introduction: The phenomenon in which liquid enters the cylinders of a reciprocating compressor and damages the suction valves, as well as the situation where the liquid remains in the cylinders and is not quickly expelled during the exhaust process, resulting in high pressure when the piston approaches the top dead center, is commonly referred to as liquid slugging. Water hammer can cause damage to components subjected to compressive forces (such as valve plates, pistons, connecting rods, crankshafts, piston pins, etc.) in a very short time, and it is a deadly threat to reciprocating compressors. Reducing or preventing liquid from entering the cylinder can prevent liquid hammer, so liquid hammer can be completely avoided. I. Processes and Phenomena: (1) Breakage of the intake valve plate. A compressor is a machine used to compress gases. The size of the intake and exhaust holes on the valve plate, as well as the elasticity and strength of the intake and exhaust valve elements, are all designed in consideration of gas flow. From the perspective of the force acting on the valve disc, the impact force generated by gas flow is relatively uniform. The density of liquids is dozens or even hundreds of times that of gases; therefore, the momentum of liquids in motion is much greater than that of gases, resulting in a much greater impact force. The flow of air containing many liquid droplets entering the cylinder is a two-phase flow. The impact generated by two-phase flow on the suction valve plates is not only intense but also occurs at a high frequency; it’s like a typhoon carrying pebbles striking a window, and its destructive power is self-evident. The rupture of the suction valve disc is one of the typical characteristics and processes of water hammer. (2) Damage to the linkage mechanism and motor: If the liquid does not evaporate and drain from the cylinder in time, the piston will compress the liquid as it approaches the top dead center, resulting in liquid slugging. The high pressure generated during this phenomenon is highly destructive; it can cause the connecting rods to bend or even break, while the components subjected to compression forces (such as the crankshaft, piston, and piston pins) may also become deformed or damaged. The motor will operate under overload, generating excessive heat, which will trigger the thermal protector. (3) Severe damage accident: A large amount of liquid enters the compressor cylinder, causing it to crack instantly. II. Factors causing liquid to enter the compressor: (1) A high level of liquid in the high-pressure tank, or when the tank is full, leads to an excessive amount of liquid entering the compressor and causing liquid to be carried in with it. (2) The temperature in the high-pressure tank is high; the heavier components condense into a liquid as they enter the compressor inlet pipeline along with hydrogen, resulting in liquid entrainment in the compressor. (3) Operator factors: Inadequate or incomplete drainage from the liquid separation tank at the compressor inlet and from the inlet manifold, resulting in liquid accumulation that enters the compressor and causes liquid entrainment. III. Measures to prevent liquid carryover: (1) Control the liquid level in the high-pressure tank properly; check the liquid level on-site during inspections to avoid false signals from the instruments. (2) Control the temperature of the medium entering the high-pressure tank within the specified range. (3) Enhance responsibility at the work post, improve liquid removal from the compressor inlet separator tank and inlet manifold; team leaders and managers should strengthen supervision over the liquid removal process in compressors. (4) Inspections must be thorough; promptly respond to any abnormalities in the compressor current or unusual noises

1. Drain the liquid from the circulating hydrogen buffer tank in a timely manner! 2. Appropriately reduce the device’s processing capacity! 3. Adjust the level measurements in the high-pressure and circulating hydrogen buffer tanks to ensure accurate readings! :handshake

1. Keep the operating parameters stable, especially high pressure and liquid level. 2. Operate the cyclohydrogen desulfurization tower properly to prevent flooding of the tower. 3. Interlocks are generally provided on the liquid separation tank at the cyclohydrogen inlet to protect the compressor.