For several common types of compressors in the market, the following points need to be noted when selecting them:
1. It is necessary to "shape based on demand". Combining the needs of customers, finding the best operational economy will require a large number of decisions for future scale expansion. The basis of decision-making is the application or usage process of compressed air. The focus is on calculating the demand for air, the reserve volume and the potential for future expansion. Pressure is a decisive factor and has a significant impact on energy consumption. Using different compressors for different pressure ranges may sometimes be economically viable.
2. Attention should be paid to the calculation of working pressure. The equipment for compressed air determines that the necessary working pressure depends on the compressor, equipment and pipelines. The highest working pressure determines the necessary device pressure. At the gas-consuming locations, pressure reducing valves are used to meet the equipment requirements. In extreme cases, it is very uneconomical to install a separate air compressor. Working pressure: end user + final-stage filtration + pipeline system + dust particle filtration + dryer + compressor. The higher the pressure adjustment amplitude is, the greater the power consumption will be. The pressure drop caused by the size and length of the piping must be taken into consideration. List the operating pressures of various models. If the operating pressures vary greatly, it is necessary to purchase air compressors with different pressures. Do not use them at a lower pressure to increase the cost.
3. Calculation of air demand. Compressed air is a clean power source that converts electrical energy into potential energy of air and does work externally through the expansion of compressed air. However, its consumption of electrical energy is also very large. Generally speaking, the electricity consumed to compress 1 cubic meter of air to 0.7MPa is approximately 7 kilowatts. According to statistics, the electricity consumption of an air compressor station accounts for approximately 20% of the total electricity consumption of the entire enterprise. This means that saving compressed air and making rational use of it will bring you new profit margins! Air demand: The air consumption of all tools + machinery and equipment + related processes + leakage + wear + future air usage + usage factor (20% of the standard value).
4. Determination of the quantity and specifications of compressors. (1) Should one large machine or multiple small machines be chosen based on the required flexibility + control system + energy efficiency? The cost of downtime events during production, the utilization rate of electricity, changes in load, the cost of compressed air systems, and the space available on the floor. Due to cost reasons, if only one compressor is used to supply all the air in a device, then this system can prepare a quick interface for a mobile compressor for connection when in use, and an old air compressor can be used as an inexpensive backup power to provide a reserve air source. (2) Stability (a very important issue all along); (3) Energy consumption expenditure ① Pipeline leakage; ② The gas demand fluctuates constantly all the time (this is the most easily overlooked and the most serious aspect). ③ The output efficiency of a single machine (select the model with the best output efficiency range). (4) Generalization of spare parts: The optimized combination of multiple 110kW models may be 40-160m3/min, which is the best choice for the gas consumption range. (5) The operation analysis should be observed within one week, and more than 90% of the energy recovery should be measured. When the working pressure frequently drops over a certain period of time, the control system can be modified in accordance with the changes in production. Another factor to improve the use of the air compressor is to check for air leakage. Pay attention to the energy consumption ratio to save electricity: actual displacement/actual motor power consumption. The larger the value, the more electricity is consumed.
5. Selection of pipeline filters. Under normal circumstances, it is only necessary to select a filter with a processing capacity equal to or slightly greater than the flow rate of the air compressor based on its flow rate. Pipeline filters come in different precisions. The choice of precision depends on the enterprise's requirements for air quality. Of course, in special cases, activated carbon filters can also be added for handling.
6. Selection of gas storage tanks. A usually simple method is 15-30% of the air compressor's output volume (measured in m ³ /min). If one wants to make a calculation, it can be done through relevant formulas. In most formulas, V= the volume of the air bucket; Q= Air compressor air volume (m ³ /min) 8= constant (generally used at 7bar); △P= Pressure difference (bar, usually set at least at 0.6-1bar). Additionally, when selecting the model, the working pressure should also be determined based on the customer's needs, which can not only meet the customer's requirements but also save investment costs.
It is hoped that compressor users can be practical in their selection, combine the needs of their enterprises, and choose economical, reliable, efficient and environmentally friendly compressors to avoid problems such as machine maintenance and increased costs caused by incorrect selection.
