How to choose piston and screw compressors wisely.
Qualified approach to selecting piston and screw compressor units
There are many types of compressors. Their technology is based on compressing air. This is a great convenience in terms of sales. In the CIS countries, the most well-known compressors are those with a capacity of 100 m3/min and more. In the USSR, air compressor units were also manufactured, namely piston ones (not counting centrifugal models, whose capacity starts from one hundred cubic meters per minute). The counterpart to piston compressors was the production of screw compressors, but their design and manufacturing technologies were very complex and expensive. The economies of the USSR were in constant growth. They were known for their giant enterprises that consumed large amounts of compressed air — more than 100 m3/min. The value of the compressors lay in their low price and simple manufacturing technology.
Additionally, they could be used for a long time after repair. Most importantly, to extend their service life, timely maintenance must be performed. The interval between maintenance by air-treatment service technicians should be at least five hundred operating hours. If these conditions are met, the piston compressor will remain operational continuously. It follows that there should be at least two piston compressors at every large plant. This is because one can be used to the maximum while the other is undergoing maintenance or held in reserve.
Industrial piston compressors with a capacity of 5 m3/min or more should be installed in a dedicated, separately constructed room, since they produce strong noise and vibrations. Moreover, additional units required to cool and filter the air also take up a lot of space. Attempts to install a capacity-control system on piston compressors have not led to any results. It should also be noted that piston compressors are the main choice for operations where pressure exceeds 20–30 atmospheres. The only compressor that can compete with the piston type is a special turbo-compressor, which is also used for high compressed-air consumption. However, despite this, for production needs below 200 L/min, piston compressors are considered more efficient and cheaper.
Other types of compressors cannot compete with piston compressors because they are relatively inexpensive and have good technical characteristics; in addition:
1. Piston compressors are capable of operating in intermittent-repetitive mode, with large fluctuations in compressed-air demand. This is what makes their operation economical, unlike screw counterparts.
2. The operating performance of many types of compressor stations can be affected by the conditions in which they operate. The most unpretentious regarding operating conditions is the piston compressor, since it can work under large temperature variations and in workshops where coal is stored, as well as in cement-packaging installations.
3. The main difference between piston compressor stations and screw compressors has always been their comparatively low capacity. Piston compressors have the ability to continuously maintain a low level of output. The main thing when buying a compressor is that monetary costs do not end there. They will continue and increase throughout the life of the compressor. At present, a sufficient number of companies are engaged in the manufacture of compressor units, and each year one can see more and more compressor models. Compressor units are produced both by leading global companies and by small Chinese factories. The market features a wide variety of compressor types. This diversity is simply overwhelming. It is often difficult to decide on the type and purpose of a compressor, but it is necessary to know that they can be for household use as well as industrial. You can choose from a range of compressors from a single manufacturer or consider compressors from different companies. Our company sells piston compressor stations. Only with us can you see equipment from a manufacturer that guarantees quality and a long service life.
You should always immediately determine two things: what work the compressor station should perform and how it will operate. The main function of a compressor is always to compress air or gas. All compressors are classified according to which gas they compress. If it is necessary to compress air, an air compressor unit is used. If different gases need to be handled, gas compressors or other specialized compressor stations are required. Carbon dioxide compressors are used to produce solid or liquid carbon dioxide, while gases such as freon, ammonia, and other refrigerants are compressed by refrigeration compressors. These compressed gases are used in refrigeration equipment.
At present, piston compressors have begun to lose ground at the Russian enterprises where they were used. Screw compressors have been rapidly replacing them. Replacing compressor equipment is a very costly and labor-intensive process, but many plant and enterprise directors consciously take this step and, without doubt, successfully replace old equipment with new screw compressor stations.