I. Air compressor installation system diagram is shown in the figure:
Air compressor installation system diagram
Specific components: 1. Screw air compressor 2. Pre-air tank 3. Pre-filter 4. Freeze dryer 5. Precision filter 6. Ultra-precision filter 7. Post-air tank.
II. Air compressor installation precautions
1. Selection of installation site
The selection of air compressor installation site is the most neglected by the staff. Often, after the air compressor is purchased, they just find a place at random, and use it immediately after piping, without any prior planning. Little do they know that such a hasty result will lead to future air compressor failures, maintenance difficulties and poor air quality. Therefore, an appropriate installation site is a prerequisite for the correct use of the air compressor system.
(1) Choose a wide place with good lighting to facilitate the space and lighting required for operation, maintenance and repair.
(2) Choose a place with low air humidity, less dust, fresh air and good ventilation, and avoid water mist, acid mist, oil mist, dusty and fiber-rich environment.
(3) According to the requirements of GB50029-2003 "Compressed Air Station Design Specification", the heating temperature of the machine room of the compressed air station should not be lower than 15℃, and the temperature of the machine room during non-working hours should not be lower than 5℃.
(4) When the air intake of the air compressor or the cooling air intake of the unit is located indoors, the indoor ambient temperature should not be greater than 40℃.
(5) If the factory environment is poor and dusty, pre-filter equipment must be installed to ensure the service life of the air compressor system parts.
(6) When the single exhaust volume of the compressed air station is equal to or greater than 20m3/min and the total installed capacity is equal to or greater than 60 m3/min, it is advisable to install lifting equipment for maintenance, and its lifting capacity should be determined according to the heaviest component of the air compressor unit.
(7) Reserve passages and maintenance space. According to the requirements of GB50029-2003 "Design Specifications for Compressed Air Stations", the width of the passage between the air compressor unit and the wall is 0.8 to 1.5 meters according to the exhaust volume.
2. Matters to be noted in the piping of compressed air pipelines
(1) When piping the main pipeline, the pipeline must have an inclination of 1° to 2° to facilitate the discharge of condensed water in the pipeline.
(2) The pressure drop of the piping pipeline shall not exceed 5% of the operating pressure of the air compressor. Therefore, it is best to use a pipeline larger than the design value when piping. The calculation formula is as follows:
Pipe diameter calculation d = mm = mm
Where Q pressure - compressed air flow in the pipeline m3/min
V - compressed air flow rate in the pipeline m/s
Q from - air compressor nameplate scalar m3/min
P exhaust absolute - air compressor exhaust absolute pressure bar (equal to air compressor exhaust pressure plus 1 atmosphere)
(3) The branch line must be connected from the top of the main line to prevent condensate in the main line from flowing down to the working machine or back to the air compressor.
(4) The pipeline should not be arbitrarily reduced or enlarged. The pipeline must use a reducer. If a reducer is not used, turbulence will occur at the joint, which will cause a large pressure drop and have an adverse effect on the life of the pipeline.
(5) If there are purification buffer equipment such as air tanks and dryers after the air compressor, the ideal piping sequence should be air compressor + air tank + dryer. The air tank can filter out some of the condensed water and also has the function of lowering the gas temperature. The load of the dryer can be reduced by introducing the compressed air with a lower temperature and less water content into the dryer.
(6) If the air usage is large and the time is short, it is best to install another air tank as a buffer. This can reduce the number of times the air compressor is loaded and unloaded, which is of great benefit to the service life of the air compressor.
(7) Try to minimize the use of elbows and various valves in the pipeline.
(8) The ideal piping is that the main line surrounds the entire factory, so that compressed air can be obtained in both directions at any position. For example, when the gas usage of a branch line suddenly increases, the pressure drop can be reduced. In addition, an appropriate valve group should be configured on the ring main line to facilitate cutting off during maintenance.
(9) When the air output pipes of multiple air compressors are connected in parallel, it is not necessary to install a check valve at the output end of the air compressor.
3. Air compressor foundation
The foundation of the air compressor should be built on hard soil, and the foundation surface should be smoothed before installation to avoid vibration. If it is installed on the upper floor, anti-vibration measures must be taken, otherwise the vibration will be transmitted to the lower floor or resonance will occur, which is very likely to cause damage to the air compressor and the building. Generally, the vibration speed value of the screw air compressor is below 11.2mm/s (belt drive) and 7.1 mm/s (coupling drive). It is not necessary to make special arrangements to build a platform foundation with a height of about 120mm and a length and width slightly larger than the bottom area of the air compressor to facilitate sewage discharge.
4. Cooling system
The water quality standard for cooling water of water-cooled air compressors should comply with the provisions of GB5005 "Design Specifications for Industrial Circulating Cooling Water Treatment". When softened water is available within the enterprise and the system is economical and reasonable, softened water can be used for circulating water in the system.
The main purpose is to prevent calcium and magnesium ions in the water from chemically reacting in the cooler due to high temperature, and finally forming scale in the cooler, thereby affecting the cooling efficiency of the cooler. The cooling water pressure is generally between 0.15 and 0.4 MPa, and the cooling water outlet temperature should be maintained at 6℃ to 10℃ higher than the inlet temperature. The cooling water inlet pipe should be equipped with a filter, and the inlet and outlet pipes should be equipped with a pressure gauge, thermometer and stop valve respectively.
The air-cooled air compressor must pay attention to its ventilation environment. The air compressor must not be placed near high-temperature machinery or in a closed space with poor ventilation to avoid high exhaust temperature and shutdown. If placed in a closed space for use, air intake and exhaust equipment must be installed. The air inlet is located at the lower part of the machine room, and the air outlet is located at the upper part of the machine room to facilitate cold air circulation. Generally speaking, the air intake and exhaust volume must be greater than the air compressor heat dissipation exhaust volume.
5. Power system When distributing power to the air compressor, the correctness of the power supply voltage must be ensured
Select the correct power line diameter according to the power size of the air compressor used. Do not use a small power line, otherwise the power line will burn out due to high temperature caused by excessive load. The power line must use a multi-strand copper core cable, and one phase of the three-phase four-wire system is the grounding wire. It is best to use a separate power system for the air compressor, especially to avoid parallel use with other large power consumption systems, otherwise the main motor of the air compressor may be overloaded and shut down due to excessive voltage drop or three-phase current imbalance. High-power air compressors should pay special attention.
And the power supply network load should be uniform, the voltage fluctuation is within ±5%, and the three-phase voltage imbalance is allowed to be within ±1%. There should be no connection point in the middle of the power supply cable from the distribution cabinet to the air compressor. Select an appropriate air switch according to the power size of the air compressor to maintain the safety of the power system and maintenance. The grounding wire of the power system should be ensured to be installed, and the grounding wire cannot be directly connected to the compressed air delivery pipe or cooling water pipe.
6. Appendix
1kW is equivalent to 2 amperes of rated current, and 1 square millimeter of copper wire can pass 4 to 6 amperes of current.
Commonly used wire (rubber copper wire) specifications (number of cores × cross-section mm2 + number of cores × cross-section mm2)
3×10＋1×6, 3×16＋1×10, 3×25＋1×10, 3×35＋1×10
3×50＋1×16, 3×70＋1×25, 3×95＋1×35
The supporting capacity of the low-voltage 380V transformer is 3 times the rated capacity of the motor, and the supporting capacity of the high-voltage 6000V transformer is 2 times the rated capacity of the motor.