Negative pressure central feeding suction belt drive Roots blower south air supply

The Roots blower is composed of five main parts: casing, wall panel, impeller, oil tank, and muffler.

Shell: mainly serves as a support (wall panel, impeller, muffler) and fixation.

Wall panel: mainly used to connect the casing and impeller, support the rotation of the impeller, and achieve the effect of end face sealing.

Impeller: It is the rotating part of a Roots blower, divided into two blades and three blades. However, due to the advantages of three blades, such as smaller outlet pulsation, lower noise, and smoother operation, it has gradually replaced the two blade Roots blower.

Oil tank: mainly used to store lubricating oil for lubricating gears and bearings.

Silencer: used to reduce the noise generated by airflow pulsation during the inlet and outlet of Roots blower.

Roots blower is a type of volumetric fan. There are two three blade impellers that rotate relatively in the space sealed by the casing and wallboard. Since each impeller is involute, or the envelope of Epicycloid, the three blades of each impeller are identical, and the two impellers are identical, which greatly reduces the processing difficulty. Numerical control equipment is used for impeller processing, which ensures that under the condition that the Centre-to-centre distance between the two impellers is constant, no matter where the two impellers rotate, a certain minimum clearance can be maintained, so as to ensure that the gas leakage is within the allowable range.

The two impellers rotate in opposite directions. Due to the extremely small gap between the impeller and the impeller, between the impeller and the casing, and between the impeller and the wall panel, a vacuum is formed at the intake port. Air enters the intake chamber under the action of atmospheric pressure, and then two blades of each impeller form a sealing chamber with the wall panel and the casing. During the rotation of the impeller, the air in the intake chamber is continuously carried to the exhaust chamber by the sealing chamber formed by the two blades, Because the impellers in the exhaust chamber mesh with each other, the air between the two blades is squeezed out. This continuous operation continuously transports air from the inlet to the outlet, which is the entire working process of the Roots blower.

Due to the use of a three blade rotor structure and a reasonable structure at the inlet and outlet of the casing, the fan has low vibration and low noise.

The impeller and shaft are of an integral structure and have no wear on the impeller. The performance of the fan remains unchanged and can operate continuously for a long time.

The fan has large volume utilization rate, high Volumetric efficiency, compact structure and flexible installation mode.

The models are complete and can meet the needs of different users for different purposes.

1. The inlet temperature of the conveying medium should usually not exceed 40 ℃.

2. The content of particles in the medium shall not exceed 100mg/m3, and the maximum size of particles shall not exceed half of the minimum working gap.

3. The bearing temperature during operation shall not exceed 95 ℃, and the lubricating oil temperature shall not exceed 65 ℃.

4. The operating pressure should not exceed the pressure range specified on the nameplate.

5. The clearance between the impeller and the casing, between the impeller and the side plate, and between the impeller and the impeller of the Roots blower has been adjusted before leaving the factory. When reassembling, it is necessary to ensure this clearance.

6. When roots blower is running, the oil level of main oil tank and Drop tank must be between the two red lines of oil level gauge.

7. Check if there are any forgotten fastening parts at the inlet and outlet connections, and if the supporting parts of the piping are complete. For blowers and vacuum pumps that require cooling water, it is necessary to check whether the installation of cooling water meets the requirements.

classification

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Roots blowers can be roughly divided into single stage and double stage according to their different working methods. A blower with only one compression stage is called a single stage blower, while a blower with two single stage blowers connected in series to continuously compress the gas twice is called a double stage series blower.

Divided by the number of impeller heads: two blade Roots blower and three blade Roots blower;

Classified by purpose: vertical kiln blower, gasification blower, aeration blower, etc;

According to the type of medium: air blower, gas blower, hydrogen blower, sulfur dioxide blower, etc;

Classified by transmission mode: direct connected blower and belt connected blower, etc;

Classified by cooling method: air-cooled blower, water-cooled blower, and countercurrent cooling blower, etc;

Classified by structural type: vertical blower, horizontal blower, vertical axis blower, dense group blower, etc;

According to sealing types, there are various types of blowers, including labyrinth seals, expansion ring seals, packing seals, and mechanical seals.

Installation and debugging

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Due to the high-speed operation of the Roots blower, it generates vibration, and the pulsation of the internal air also increases the vibration of the Roots blower. Therefore, the installation of the Roots blower needs to be fixed on the ground. [3] According to the different fan models, a 150 * 150mm square pit with a depth of 300mm is excavated at the corresponding position on the ground according to the fan size, and the foundation bolts are buried. Then, the fan is connected with bolts and nuts, and finally, the pit is filled with cement concrete. After the concrete is fixed, the nuts are tightened with force to firmly connect the fan base and concrete, This can reduce the vibration displacement of the Roots blower during operation, improve the operational safety of the equipment, and greatly extend the service life of the blower by reducing vibration.

Precautions:

1. The fan should not be installed in places where people frequently enter and exit to prevent injury and scalding.

2. Fans should not be installed in places prone to producing flammable, explosive, and corrosive gases to prevent accidents such as fire and poisoning.

3. According to the direction of the intake and exhaust ports and maintenance needs, there should be appropriate and ample space left around the foundation surface.

4. When installing the fan, it is necessary to check whether the foundation is firm, whether the surface is flat, and whether the foundation is above the ground.

5. When configuring the fan outdoors, a rain shelter should be installed.

6. The fan can be used for a long time under the ambient temperature of no more than 40 ℃. When the temperature exceeds 40 ℃, Whole-house fan and other cooling measures should be installed to improve the service life of the fan.

7. When transporting air, biogas, natural gas, and other media, the dust content should generally not exceed 100mg/m3.

1. Check the fastening of each part and whether the positioning pins are loose. 2. There is no oil leakage inside the blower body.

3. There should be no scaling, rusting, or peeling inside the blower body.

4. Pay attention to whether the lubrication and heat dissipation are normal, pay attention to the quality of lubricating oil, often listen to whether the blower runs noisily, pay attention to whether the unit operates under the condition that does not meet the requirements, and pay attention to adding grease regularly.

5. The overload of the blower is sometimes not immediately displayed, so it is necessary to pay attention to the increasing trend of inlet and outlet pressure, bearing temperature, and motor current to determine whether the machine is operating normally.

6. Before disassembling the machine, each fitting size of the machine should be measured, recorded, and marked on the components to ensure that the original fitting requirements are maintained after assembly.

7. The oil tank of the new machine or overhauled blower should be cleaned and put into operation according to the usage steps. It is recommended to replace all lubricating oil after 8 hours of operation.

8. Maintenance and repair should develop a reasonable maintenance system based on specific usage conditions, carry out on schedule, and keep records. It is recommended to conduct an annual overhaul and replace bearings and related vulnerable parts.

9. It is recommended that the blower be overhauled by professional maintenance personnel [3].

Operational inspection

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1. Pre startup inspection:

(1) Check the connection tightness of bolts and nuts.

(2) Check the lubrication condition to ensure that the oil level is at the center of the oil gauge.

(3) Check the belt tension and pulley alignment.

(4) Check the voltage and frequency of the power supply;

(5) Check whether all instruments are normal, and inform the maintenance personnel to replace them in case of any abnormality.

(6) Open the main valve on the pipeline and the outlet valve of the fan that needs to be operated, while keeping the outlet valves of other fans that are not running in the "closed" state to avoid overloading the fan and damaging the machine.

2. Check during startup:

(1) If the fan needs to run at "power frequency", simply turn the corresponding blower switch on the electric control box to the "power frequency" position, and then press the "start" button. Turn the switches of other fans and frequency converters to "stop". Be sure to check whether the outlet valve of the running fan is open before pressing the "start" button, Is the fan pressed with the 'start' button consistent with the actual running fan.

(2) If the fan needs to run "variable frequency", turn the switch of the frequency converter to the "start" button, and then turn the corresponding blower switch on the electric control box to the "variable frequency" position. Note that the switches of other fans are in the "stop" position. Before turning the switch to the "variable frequency" position, be sure to check whether the outlet valve of the running fan is open, Is the fan pressed with the 'variable frequency' button consistent with the actual running fan.

(3) After the fan operates normally (usually taking 1 minute), slowly close the exhaust valve to avoid burning the motor due to excessive instantaneous current caused by the fan closing too quickly.

3. During operation inspection:

(1) Adjust the air inlet valve of the contact oxidation tank to ensure uniform aeration;

(2) Dissolved oxygen should be controlled between 2-4mg/L (read by a dissolved oxygen analyzer).

(3) In the initial stage of operation, there may be noise and excessive current due to the viscosity of the lubricating oil. It can disappear automatically after running for 10-20 minutes.

(4) The flow rate cannot be adjusted by opening or closing the valve. The fan is a volumetric compressor that changes the flow rate and shaft power by adjusting the speed;

(5) The pressure gauge switch is in the normally closed state. If you need to measure the pressure, you can turn on the pressure gauge switch.

(6) The same model also has differences in noise, as the location and piping of the fan in the mechanical room can cause differences in noise.

4. Shutdown check:

(1) Slowly open the "exhaust valve" until it is fully open.

(2) Press the "Stop" button on the electronic control box.