The screw compressor component in screw air compressors is internally manufactured using a new CNC grinding machine, paired with online laser technology to ensure unparalleled manufacturing tolerances. Its reliability and performance guarantee that the operating costs of the compressor remain low throughout its usage period. The new products in the L/LS series compressors include the adjustable compressor, integrated compressor, and desiccant series.

Screw air compressors provide compressed air for various industries with their advantages such as high performance, efficiency, low maintenance, and high reliability.

Advantages of Screw Air Compressors:

The screw-type air compressor equipment utilizes high-capacity compression components with a low peripheral speed of the rotor and oil injection, achieving efficiency and reliability. The new design ensures reduced system and compressed air temperatures. It guarantees cooling effects and extended service life for all components.

1. The screw air compressor boasts high stability, efficiency, low vibration, and low noise.

2. The Yin-Yang rotor and its fit with the housing are pre-set, resulting in minimal gas backflow and leakage, and no excess clearance volume, thus ensuring high efficiency.

3. The lubricating oil sprayed in has the functions of sealing, cooling, noise reduction, and lubrication.

4. Compared to piston engines, there are fewer wear parts and a lower failure rate.

5. The screw compressor's working curve is smooth, with less vibration and lower noise compared to reciprocating compressors.

6. Cooling methods generally include: water cooling and air cooling.

7. Heat Dissipation System: Utilizes a fin-and-tube structure and materials to ensure the cooler is pressure-resistant, has high heat dissipation efficiency, and excellent corrosion resistance.

8. Air Filters: Heavy-duty, multi-stage air inlet filters with dust removal precision of 1um (98% removal rate), large working surface, and relatively long service life.

9. Oil/Gas Separator: The new-generation separator features innovative filter materials for enhanced efficiency, with oil content in air below 2ppm.

10. Smart Controller: All operations and related data of the air compressor are displayed on the control panel, fully at your fingertips for easy, convenient, and accurate control.

Air Compressor Equipment - Screw air compressors are driven at speeds suitable for their intended use by a transmission system. They require no maintenance during normal operation.

Air Compressor Equipment - The innovative compressor design of our screw air compressors saves unnecessary maintenance costs. All components are designed for long life, with large inlet filters, oil filters, and fine separators ensuring the quality of compressed air. All oil filters and separator components for models up to 22kW (30hp) are centrifugal shut-off, further reducing maintenance time. The "Quick Repair Points" enable repairs to be completed in minutes, minimizing downtime and maintenance costs.

Screw air compressor principle:

(1) Suction Process: The motor drives the rotor. As the main and slave rotors turn to the intake end wall opening, the space between their teeth is large, allowing external air to fill it. When the intake side face of the rotor moves away from the housing intake port, the air between the teeth is sealed between the main and slave rotors and the housing, completing the suction process.

(2) Compression Process: At the end of the intake stroke, the enclosed volume formed by the main and auxiliary rotor tooth peaks and the housing decreases as the rotor angle changes and moves in a helical pattern, which is referred to as the "compression process."

(3) Compression Gas and Injection Process: During transportation, the volume continuously decreases, causing the gas to be compressed and the pressure to rise, while the temperature also increases. At the same time, due to pressure differences, the lubricant in a mist form is injected into the compression chamber, thereby achieving compression, temperature reduction, sealing, and lubrication.

(4) Exhaust Process: As the enclosed tooth crest of the rotor rotates to meet the casing exhaust port, the compressed air begins to be expelled until the mating surface of the tooth crest and the groove reaches the exhaust face. At this point, the groove space is zero, indicating the completion of the exhaust process. Simultaneously, another pair of grooves on the main and slave rotors have rotated to the intake end, creating a large space and initiating the intake process, thus beginning a new compression cycle.

Screw air compressor principle

Screw air compressor displacement:

Definition

Air volume discharged by the air compressor within a unit of time, converted to the suction state.

Factors affecting the actual exhaust volume of screw air compressors

1. Equipment Speed:

The exhaust volume of a screw air compressor is proportional to its speed, which often varies with the voltage and frequency of the power grid. When the voltage or frequency decreases, the speed will drop, reducing the exhaust volume of the screw air compressor.

2. Suction State:

Screw air compressors are volumetric compressors with a constant intake volume. When the intake temperature rises or the intake pipe has excessive resistance, causing a drop in intake pressure, the gas density decreases, which consequently reduces the screw air compressor's exhaust volume.

3. Gas Leak

The rotors do not touch each other or the casing during operation, maintaining a certain gap, which leads to gas leakage. When the pressure increases, the gas leaks through the gaps into the suction pipe and the suction grooves, reducing the exhaust volume. To minimize leakage, sealing teeth are added to the top of the driven rotor's teeth, sealing slots are cut into the root of the driving rotor's teeth, and annular or strip-shaped sealing teeth are machined on the end face. If these sealing lines wear down, the leakage amount will increase, so these factors should be considered during routine maintenance.

4. Cooling Effect:

Gases heat up during the compression process, and the temperature of the rotor and housing also increases accordingly. Therefore, during the intake process, the gas expands due to being heated by the rotor and housing, which consequently reduces the intake volume. Some screw air compressors use oil cooling in the rotor and water cooling in the housing, one of the purposes being to lower their temperatures. If the cooling is ineffective, the temperature rises, leading to a decrease in the discharge volume of the screw air compressor.

Screw air compressor operation and maintenance:

Safety Precautions

Operation, maintenance, and service of compressors must be performed by qualified personnel.

2. The compressor cannot be reversed. Before starting the compressor, it must be confirmed first that the motor's rotation direction is consistent with the specified direction, especially after the initial start-up or electrical control system maintenance.

3. High-temperature components must cool down to ambient temperature before disassembly.

4. Recommend using screw compressor oil. Mixing oils of different brands is not permitted.

5. Do not make any modifications or additions to the compressor that affect its safety or reliability without the manufacturer's permission.

6. Original equipment manufacturer (OEM) compressor parts are specifically designed and manufactured. It is recommended to use genuine parts to ensure the reliability and safety of the compressor operation.

7. Compressor intake ports must not be blocked during operation.

8. Compressed air is not to be used for breathing unless it is specifically marked as suitable for that purpose.

9. Compressors must not be operated beyond the specified pressure and temperature limits.

10. Upon detecting any abnormal operation of the compressor, it should be immediately shut down and the anomaly should be addressed promptly.

11. Maintain and repair compressors with the proper tools.

12. Ensure all safety devices are re-installed and tools are removed from the compressor before powering on after maintenance.

Maintenance and care

Check oil levels, exhaust temperatures, and pressures daily, and listen for any abnormal sounds.

2. Before each week's startup, open the separator drain valve to discharge condensate, check for any leaks, inspect the safety valve, and examine the belt wear (visual inspection).

3. Regularly inspect the intake control valve, low-pressure valve, electrical control box terminal connections, safety valve, and cooling fan.

4. Regularly clean and sweep the cooler, test the reliability of the safety valve.

5. Regularly replace the oil filter element, oil separator filter element, intake filter element, and lubricating oil.

Common Fault Exclusion

Machine does not start: Check the main switch and power cord, inspect the motor.

2. Machine fails to load after power-on: Adjust the pressure switch setpoint or replace the pressure switch, inspect or replace the solenoid valve.

3. Compressor does not unload, safety valve discharge: Adjust the pressure switch setpoint or replace the pressure switch; inspect or replace the solenoid valve.

4. Excessive Fuel Consumption: Follow recommended oil usage, lower oil level to normal position, remove and clean the return oil line, and replace the fuel-air separator filter element.

5. Exhaust Pressure Below Specified Value: Reduce gas consumption, increase compressor capacity, check for system leaks, clean or replace intake air filter element, replace oil-gas separator filter element, inspect or replace solenoid valve, repair intake control valve, replace belts, adjust pressure switch setpoint.

6. Compressor High Temperature Protection Shutdown: Improve environmental ventilation conditions, clean or wash the cooler, add oil to the specified position, replace the engine oil filter.

7. Compressor unload operation, exhaust pressure still slowly rising, safety valve release: inspect or replace solenoid valve, overhaul intake control valve, overhaul unload pipeline.

8. Safety Valve Release: Inspection or replacement of safety valves, maintenance of low-pressure valves, replacement of oil-gas separator filter elements, inspection or replacement of pressure switches, check of intake control valve or solenoid valve.

Air Intake Filter Core Maintenance

The air filter is a component that filters out dust and impurities from the air. The clean air is then compressed in the screw rotor compression chamber. Since the internal clearance of the screw machine only allows particles of 15u or less to pass through, if the air filter element is clogged or damaged, a large number of particles larger than 15u will enter the screw machine's circulating system. This not only significantly reduces the lifespan of the oil filter element and the oil fine separation element but also leads to a large number of particles entering the bearing chamber directly, accelerating bearing wear, increasing the clearance of the rotor, reducing compression efficiency, and even causing the rotor to seize.

After 500 hours of operation, replace the oil filter element. Use a wrench to reverse-thread the oil filter element to remove it, then install a new filter element. Apply oil with a screwdriver before screwing the filter element into place, and tighten it with both hands, ensuring a tight seal. It is recommended to replace the filter element every 1500 to 2000 hours, and to change the oil filter element at the same time as the oil change. Reduce the replacement cycle in harsh environments. Never exceed the service life of the oil filter element; otherwise, due to severe clogging, the pressure differential will exceed the bypass valve's tolerance, causing the bypass valve to open automatically, allowing large amounts of dirt and particles to enter the screw main unit with the oil, resulting in severe consequences. The replacement of the diesel screw machine diesel engine oil filter element and diesel filter element should follow the diesel engine maintenance requirements and the replacement method is similar to that of the screw oil filter element.

Oil and gas separator maintenance and replacement

The oil-gas separator is a component that separates screw oil lubricant from compressed air. Under normal operation, the lifespan of an oil-gas separator is approximately 3,000 hours; however, the quality of the lubricant and the air filtration accuracy have a significant impact on its lifespan. It is evident that under harsh operating conditions, the maintenance and replacement cycle of the air filter core must be shortened, and even consider adding a pre-filter air cleaner. The oil-gas separator must be replaced upon expiration or when the pressure difference between the inlet and outlet exceeds 0.12 Mpa. Otherwise, it may cause motor overload and the oil-gas separator may leak due to damage. Replacement method: Remove the control tube fittings installed on the oil-gas drum cover. Take out the return oil tube that extends into the oil-gas drum from the cover, and remove the bolts securing the oil-gas drum cover. Remove the drum cover and take out the oil filter. Remove the asbestos gasket and debris stuck to the cover plate. Install the new oil-gas separator, ensuring that the upper and lower asbestos gaskets are stapled and aligned properly; otherwise, it may cause a blowout. Reinstall the cover plate, return oil tube, and control tubes in the original order, and check for leaks.

Maintenance and Replacement

The quality of screw oil significantly affects the performance of screw injection compressors. Good oil has excellent antioxidant stability, quick separation, good degassing properties, high viscosity, and good anti-corrosion performance, thus, users must use genuine screw oil. The first oil change should be done after 500 hours of initial operation, followed by a new oil change every 2,000 hours. Replace the oil filter at the same time as the oil change. Reduce the replacement cycle in harsh environments. Replacement method: Start the air compressor and run for 5 minutes to raise the oil temperature above 50°C, allowing the oil viscosity to decrease. Stop the operation and, when the oil and gas tank has a pressure of 0.1 Mpa, open the bottom drain valve of the oil and gas tank and connect it to the storage tank. Gradually open the drain valve to prevent hot, pressurized lubricant from splashing and causing injury or contamination. Close the drain valve once the lubricant becomes drip-like. Unscrew the oil filter core, drain the lubricant from all pipelines simultaneously, and replace the oil filter core with a new one. Open the oil filling port bolt, add new oil to maintain the oil level within the marking line, tighten the oil filling port bolt, and check for any leaks. Regularly inspect the lubricant during use; replenish with new oil if the oil level is too low. Also, frequently drain condensate water from the lubricant; generally, once a week, or every 2-3 days in hot weather. After stopping the machine for over 4 hours, open the drain valve while the oil and gas tank is pressure-free, drain the condensate water, and quickly close the valve once oil starts to flow. Never mix lubricants of different brands and avoid using lubricant past its expiration date. Failure to do so can degrade the lubricant quality, impair its lubricating properties, lower its flash point, leading to high-temperature shutdown and potential spontaneous combustion of the oil.