Compressed air with water can be caused by many reasons, including unreasonable process design and improper operation; there are structural problems of the equipment itself, and technical level problems of equipment and control components.
The screw air compressor itself has a water removal device, which is generally at the outlet of the machine, which can initially remove part of the water, and the water removal, oil removal and dust removal filters in the post-processing equipment can remove part of the water, but most of the water is mainly Rely on the drying equipment to remove it, make the compressed air passing through it dry and clean, and then send it to the gas pipeline. The following is an analysis of the various reasons and solutions for the incomplete dehydration of the compressed air after passing through the dryer in combination with some actual conditions.
1. The heat dissipation fins of the air compressor cooler are blocked by dust, etc., the cooling of the compressed air is not good, and the pressure dew point increases, which will increase the difficulty of water removal for the post-processing equipment. Especially in spring, the cooler of the air compressor is often covered with catkins clogged.
Solution: install a filter sponge on the window of the air compressor station, and blow the soot on the cooler frequently to ensure good cooling of the compressed air; ensure that the water removal is normal.
2. The water removal device of the screw air compressor – the steam-water separator is faulty. If the air compressors all use cyclone separators, add spiral baffles inside the cyclone separators to enhance the separation effect (and also increase the pressure drop). The disadvantage of this separator is that its separation efficiency is high at its rated capacity, and once it deviates from its separation efficiency, it will be relatively poor, resulting in a rise in dew point.
Solution: Check the gas-water separator regularly, and deal with faults such as blockage in time. If the gas-water separator is not drained in summer when the air humidity is high, check and deal with it immediately.
3. The amount of compressed air used in the process is large, exceeding the design range. The pressure difference between the compressed air at the air compressor station and the user end is large, resulting in high air velocity, short contact time between compressed air and adsorbent, and uneven distribution in the dryer. The concentration of flow in the middle part makes the adsorbent in the middle part saturated too quickly. The saturated adsorbent cannot effectively absorb the moisture in the compressed air. There is a lot of liquid water at the end. In addition, the compressed air expands to the low-pressure side during the transportation process, and the adsorption-type dry dispersion is too fast, and its pressure drops rapidly. At the same time, the temperature drops greatly, which is lower than its pressure dew point. Ice solidifies on the inner wall of the pipeline, and the ice becomes thicker and thicker, and may eventually block the pipeline completely.
Solution: increase the flow of compressed air. The excess instrument air can be supplemented into the process air, and the instrument air can be connected to the front end of the process air dryer, controlled by a valve, to solve the problem of insufficient compressed air supply for the process, and at the same time, it also solves the problem of compressed air in the adsorption tower of the dryer. The problem of “tunnel effect”.
4. The adsorption material used in the adsorption dryer is activated alumina. If it is not filled tightly, it will rub and collide with each other under the impact of strong compressed air, resulting in pulverization. The pulverization of the adsorption material will make the gaps of the adsorbent larger and larger. The compressed air passing through the gap has not been effectively treated, which eventually leads to the failure of the dryer. This problem is manifested in the field as a large amount of liquid water and slurry in the dust filter.
Solution: When filling activated alumina, fill it as tightly as possible, and check and replenish it after a period of use.
5. The oil in the compressed air causes the activated alumina oil to be poisoned and fails. The super coolant used in the screw air compressor has high thermal conductivity and is used to cool the compressed air, but it is not completely separated from the compressed air, which will cause the compressed air sent out of the air compressor to be oily, and the oil in the compressed air will be attached to the active oxidation The surface of the aluminum ceramic ball blocks the capillary pores of the activated alumina, causing the activated alumina to lose its adsorption capacity and cause oil poisoning and lose the function of absorbing water.
Solution: Regularly replace the oil separator core and post-oil removal filter to ensure complete oil-gas separation of the air compressor and good oil removal by the post-oil removal filter. In addition, the super coolant in the unit must not be excessive.
6. The air humidity changes greatly, and the drainage frequency and time of each timing drainage valve are not adjusted in time, so that the more water accumulates in each filter, and the accumulated water can be brought into the compressed air again.
Solution: The drainage frequency and time of the timing drainage valve can be set according to the air humidity and experience. The air humidity is high, the frequency of drainage should be increased, and the drainage time should be increased at the same time. The adjustment standard is to observe that the accumulated water can be drained without discharging compressed air every time. In addition, heat preservation and steam heat tracing are added to the conveying pipeline; a drain valve is added at the low point to check and drain water regularly. This measure can prevent the pipeline from freezing in winter, and can remove part of the moisture in the compressed air, reducing the impact of compressed air with water on the pipeline. user impact. Analyze the causes of compressed air with water, and take the above corresponding measures to solve it.
