Due to the motor power and the length of the main shaft, the air compressor will have a small amount of exhaust. The following is a simple analysis of the phenomenon that the air compressor has insufficient air volume.
Selection is too small
Many users just started to know the specific gas consumption situation they produced, and blindly selected according to their own estimates, causing the exhaust pressure not to come up, lower than the rated exhaust pressure, and unable to meet the normal gas consumption of the factory.
You can check the pipeline for leaks first, close the valve behind the gas tank, if the unit can quickly raise the pressure, open the valve, the pressure will drop quickly, and finally at a pressure point, then you can confirm The selection of the air compressor unit is too small, and the displacement of the unit is less than the actual gas consumption of the production.
The solution is to add a new unit, so that the air compressor is more scientific than the gas consumption of 10-20%.
Selection of working pressure (exhaust pressure):
When the user is ready to purchase the air compressor, first determine the working pressure required by the gas end, plus the 1-2 bar margin, and then select the pressure of the air compressor (the margin is considered to be installed from the air compressor) The pressure loss from the location to the actual end of the pipeline, depending on the length of the distance between 1-2 bar, consider the pressure margin). Of course, the size of the pipe diameter and the number of turning points are also factors that affect the pressure loss. The larger the pipe diameter and the smaller the turning point, the smaller the pressure loss; otherwise, the pressure loss is greater.
Therefore, when the distance between the air compressor and each of the air end pipes is too far, the diameter of the main pipe should be appropriately enlarged. If the environmental conditions meet the installation requirements of the air compressor and the working conditions permit, it can be installed near the air end.
Volume flow selection:
1 When selecting the volume flow of the air compressor, first understand the volume flow of all the gas equipment, multiply the total flow rate by 1.2 (that is, enlarge the 20% margin); 2 the new project can be based on the flow value provided by the design institute. Select the type; 3 to the gas equipment supplier to understand the volume flow parameters of the gas equipment for selection; 4 air compressor station transformation can refer to the original parameter value combined with the actual gas situation for selection.
Proper selection is beneficial to both the user and the air compressor equipment. The selection is too large and wasteful. If the selection is too small, the air compressor may be in a state of being loaded for a long time or the gas may not be used up or the pressure may not be able to be used.
The relationship between power and working pressure and volume flow:
When the power is constant, the volume flow rate and the working pressure also change correspondingly when the rotational speed changes. For example: a 22kW air compressor, the working pressure is determined to be 7bar at the time of manufacture, the speed is calculated according to the technical curve of the compressor main engine, the displacement is 3.8m3/min; when the working pressure is determined to be 8bar, the speed must be reduced (otherwise The drive motor will be overloaded. At this time, the displacement is 3.6m3/min. Because the speed is reduced, the exhaust is reduced accordingly, and so on.
The power selection is to satisfy the working pressure and volume flow, and the power supply capacity can meet the power of the matched drive motor.
Therefore, the steps of selecting an air compressor are: first determine the working pressure, then determine the corresponding volume flow, and finally the power supply capacity.
Air compressor unit failure
If there is no leak point in the compressed air line, it is a problem with the air compressor unit itself. There are several problems in the air intake caused by the air compressor unit:
1. Is the maintenance timely? The air compressor exhaust volume is reduced. After removing the above possibilities, first check whether the compressor has been maintained. How long has the maintenance been? If the environment is not ideal, the air compressor should be checked for 2,000 hours after the air compressor is running for 2000 hours. Lighter can use dust to remove dust; blockage is serious, replace with new air filter.
In many cases, the air compressor exhaust volume drops, there is no big problem, that is, the customer is neglected to maintain, the air compressor is blocked by air filter, and after replacing the new air filter, it can be used normally.
In addition, in addition to air filtration, lubricating fluids and other filter elements are also critical. Check if the lubricating fluid is within the standard range. If it is missing, please add it as appropriate.
2. Is the intake valve fully open? Compressor exhaust volume drops, check the unit, if just maintenance, eliminate the three filter and oil problems, then first check the compressor intake valve, remove the intake hose, open the compressor, and watch the opening of the intake valve Is it normal? The theoretical design life of the intake valve is 100,000 times. Because each manufacturer uses different brand batches, the quality is also different. Therefore, the failure of the intake valve may cause the unit to reduce the exhaust volume.
If the intake valve cannot be fully opened when the air compressor is loaded, it can be concluded that the exhaust gas volume is a failure of the intake valve and should be removed for repair or replacement.
3. Motor failure. After the above intake valve failure is eliminated, the unit exhaust volume has not changed, and the motor should be considered to be faulty. Due to local short circuit in the motor coil, or bearing wear, the motor shaft wears, causing the motor speed to be lower than the rated speed, so that the air compressor exhaust volume is reduced. The motor coil, bearing, etc. should be repaired, and the air compressor row should be tested after repair. Gas volume.
4. The pressure switch sets the working pressure too low, and the upper pressure limit should be adjusted upwards.
When commissioning in the air compressor factory, adjust to the specified pressure according to customer needs, and then set a pressure difference. For example, the air compressor starts to start, and the air tank is pumped. When the pressure is 10kg, the compressor stops or unloads. When the pressure reaches 7kg, the air compressor starts to start again. There is a pressure difference between the two. This process can make The air compressor takes a break to protect the air compressor.
Different air compressor switches have different adjustment methods. One is that the differential pressure is fixed by the switch itself, and only the automatic stop pressure and the highest pressure are adjusted. This kind of rotary knob with two flat-blade screwdrivers on the switch, the two knobs must be adjusted consistently, otherwise they will stop together, stop and start, and burn out the electrical appliances.
The other is a starting pressure (low pressure), a shutdown pressure, (high pressure).
Air compressor pressure adjustment:
a. Turn the pressure adjustment screw clockwise to increase the closing and opening pressure synchronization.
b. Turn the pressure adjustment screw counterclockwise to decrease the closing and opening pressure synchronization.
Air compressor differential pressure adjustment:
a. Rotate the differential pressure adjustment screw clockwise to maintain the closing pressure and increase the opening pressure.
b. Rotate the differential pressure adjustment screw counterclockwise. The closing pressure is constant and the disconnection pressure is reduced.
If the pressure switch of the air compressor fails, the working pressure error will occur. It is necessary to overhaul the pressure switch, and if it cannot be repaired, replace it with a new one.
5. The environment changes, causing the exhaust volume to drop. Previously used in inland areas, because the factory was built in the northwest region, the air compressors were used together with other equipment to the new plant. The altitude increased and the environment became humid, which may cause the unit's exhaust volume to drop.
The higher the altitude, the thinner the air, the smaller the gas production per unit time; the excess moisture in the air, the compressed air contains a lot of water, and in the latter treatment, the water vapor is precipitated, resulting in a decrease in the exhaust gas volume.
6. The belt driven by the air compressor is too loose, resulting in a decrease in transmission efficiency. The drive belt needs to be adjusted, and if it is damaged, replace it with a new one.
According to the cooperation of the pulley and the shaft, the appropriate positioning method is selected, and the pulley is mounted on the air compressor head shaft and the compressor motor, and the air compressor head wheel is first fixedly locked.
For loose transitions, tap the softer copper, aluminum or rubber hoe. For the tight fitting with the press plate pressing or heating red assembly method for assembly, the heating temperature is controlled at 120 ~ 150 °C. If the tolerance of the taper sleeve pulley is slightly tight, the inner hole of the taper sleeve can be slightly supported on the shaft. Use a level ruler (accuracy ≤ 0.5mm) to measure the perpendicularity of the two pulleys to the same reference plane, with an allowable error ≤ 0.5mm. The verticality error is greater than 0.5mm. The gasket head can be used to adjust the compressor head or the compressor oil and gas barrel mounting feet to ensure that the vertical error on the same reference plane does not exceed 0.5mm.
Tighten the air compressor head or the air compressor barrel mounting bolts. Install the belt on the pulley according to the principle that the belt is in the same position. Taking the small pulley as the reference, the straightness of the two pulleys is measured with a ruler or a laser measuring instrument, and the tolerance is ≤0.5 mm. Use the air compressor motor adjustment screw to tension the belt. In turn, based on the large pulley, the plane straightness of the two pulleys is re-examined, the tolerance is ≤0.5mm, and finally the adjustment screw and nut are locked.
The replacement of the belt and the adjustment of the belt are the same, but it is necessary to pay attention to the replacement of the belt. It is not possible to replace only one belt. Otherwise, the new belt will be damaged due to different belt tension; do not splash the oil on the belt or pulley to prevent it. The belt slips. Check the belt after the new machine is running for 30h for the first time. If the compressor belt is slack, it should be adjusted immediately.
