The two blade Roots blower is a type of volumetric rotary blower, and the following is a detailed introduction to it:
1、 Working principle
The working principle of a two blade Roots fan mainly relies on the relative motion of two blade rotors inside the cylinder, which compresses and delivers gas through this motion. During the operation of the Roots blower, the two rotors are kept in mesh through the synchronous gear at the shaft end. The concave surface on the rotor and the inner wall of the cylinder together form the working volume. During the rotation of the rotor, gas is introduced from the intake port. When the rotor moves near the exhaust port, the pressure inside the working volume suddenly increases due to the reflux of high-pressure gas, which is then transported to the exhaust channel. It is worth noting that there is no contact between the two rotors, but rather a tightly controlled gap for sealing, ensuring that the discharged gas is not contaminated by lubricating oil.
2、 Characteristics
1. Simple structure: The two blade Roots blower has a compact structure and is easy to manufacture, making it very suitable for gas transportation and pressurization tasks under low pressure conditions. It can also be used as a vacuum pump.
2. Energy saving: The two blade Roots fan adopts advanced blade design and high-speed rotating impeller structure, which can effectively improve the pressure and flow rate of gas, ensuring the stability and performance of equipment operation.
3. Widely used: Two blade Roots fans mainly transport clean air, clean coal gas, sulfur dioxide, and other inert gases. Excellent performance in the transportation and high-pressure conditions of special gas industries such as coal gas, natural gas, biogas, carbon dioxide, sulfur dioxide, etc., making it a product. Therefore, this blower is widely used in multiple industries such as metallurgy, chemical industry, fertilizer, petrochemicals, instruments, and building materials.
3、 Model and Parameters
The model and parameters of the two blade Roots fan may vary depending on different manufacturers and application scenarios. Taking the L103b two blade Roots fan as an example, its boost range can reach 9.8kpa49kpa, air volume range can reach 421.5m3/min557.1m3/min, shaft power range can reach 87.6kw518.2kw, and supporting motor power range can reach 132kw560kw. In addition, the pressure and flow rate of the fan will also vary at different speeds.
4、 Comparison with Three Leaf Roots blower
Compared with the three blade Roots blower, the two blade Roots blower may be slightly inferior in terms of vibration and noise. The Roots blower with a three bladed rotor has been improved in terms of vibration and noise. Its vibration and noise are smaller than those of a two bladed blower, and the lifespan of the bearings used on the three bladed blower is about 15% longer than that of a two bladed blower. At the same time, the three blade Roots blower has also been improved in terms of internal leakage flow, so that under the same working conditions, the internal leakage flow of the three blade blower is often smaller than that of the two blade blower.
5、 Usage and maintenance
1. Preparation before starting: Before starting the two blade Roots blower, it is necessary to ensure that the inlet control valve, outlet control valve, and bypass pipe are all open, and carefully check whether the air filter, pipeline, valve, muffler, and support structure of the air filter at the inlet are stable and reliable. At the same time, it is necessary to check the condition and depth of the lubricating oil, as well as whether the cooling water system is unobstructed. In addition, the coupling should be turned to observe whether the impeller rotates flexibly, and the connection of each component should be checked for tightness and no looseness. All debris around the fan to ensure its normal operation.
2. Operation monitoring: After the two blade Roots blower is running normally, the operator should closely monitor the status of various components, including machine temperature, vibration, and muffler noise. Once any abnormalities are detected, the machine should be stopped immediately for inspection.
3. Shutdown operation: When shutting down, the bypass pipe should be opened first for "venting". When the air pressure drops to near zero, the power should be cut off and the intake valve and cooling water system should be closed in sequence.
4. Regular maintenance: To ensure the stable operation of the two blade Roots blower and reduce noise, it is necessary to regularly check the temperature of bearings, lubricating oil in the oil tank, and motors to ensure that they do not exceed the specified values. Simultaneously taking measures to reduce noise, such as using mufflers or digging underground tunnels. In addition, it is necessary to regularly replace lubricating oil and inspect components such as mufflers.
In summary, the two blade Roots blower has the characteristics of simple structure, energy saving, and wide application, but may not be as good as the three blade Roots blower in terms of vibration, noise, and internal leakage flow. During use and maintenance, it is necessary to strictly follow the regulations for operation and maintenance to ensure its normal operation and extend its service life.
