The difference between micro-oil screw compressor and oil-injected screw compressor

Micro-oil screw compressor and oil-injected screw compressor are two common types of screw air compressors, which are significantly different in lubrication mode, working principle, application scenario and maintenance requirements. Here are the specific differences between the two:

1. Lubrication mode and working principle

• micro-oil screw compressor:

• lubrication method: Only use trace amounts of lubricating oil in key parts such as bearings and gears, and the compression chamber does not directly contact the oil.

• Working principle: Compress the gas by rotating two intermeshing screws. Trace lubricating oil mainly plays a role in reducing friction and cooling, and does not enter the compression chamber.

• Features: The output gas has extremely low oil content (usually ≤ 1-3 mg/m & sup3;), and no oil and gas separator is required.

• oil-injected screw compressor:

• lubrication method: The lubricating oil is directly injected during the compression process to form an oil film to lubricate the screw and cool the gas.

• Working principle: The gas is mixed with a large amount of lubricating oil to achieve efficient sealing and cooling, but the output gas contains trace oil (to be processed by an oil and gas separator).

• Features: High single-stage pressure ratio (up to 8-13), high efficiency and low noise.

2. Comparison of advantages and disadvantages

3. Application Scenarios

• micro-oil screw compressor:

• applicable Scenarios industries with high requirements for gas cleanliness, such as food processing, medicine, electronics (oil-free compressed air), precision instrument manufacturing, etc.

• Case medical oxygen supply, food packaging pneumatic conveying, semiconductor production clean workshop.

• oil-injected screw compressor:

• applicable Scenarios: General industrial scenarios, not sensitive to gas oil content, such as machinery manufacturing, mining, construction, textiles, etc.

• Case: Pneumatic tool drive, concrete mixing, tire manufacturing compressed air supply.

4. Maintenance Requirements

• micro-oil screw compressor:

• maintenance Focus: Bearing and sealing system, no need to change lubricating oil frequently.

• Cost maintenance costs are low, but the initial investment may be high (due to precision machining needs).

• oil-injected screw compressor:

• maintenance Focus regularly replace the lubricating oil and oil-gas separation filter element, and clean the oil system.

• Cost: Maintenance costs are higher, but equipment prices are usually lower than micro-oil screw compressors.

5. Comparison of technical parameters

summary

• select Recommendations:
• preferred micro-oil screw compressor: If oil-free or low oil content compressed air is required (e. g. food, medicine, electronics industry).
• Preferred oil-injected screw compressor: If the pursuit of high efficiency, low cost, and the gas oil content is not sensitive (such as machinery manufacturing, construction, mining).
• Trend: With the advancement of material technology (such as ceramic bearings) and oil and gas separation technology, the performance gap between the two compressors is narrowing, and users can choose flexibly according to actual working conditions.