What Is a Rotary Blower?

Rotary blowers (ary blowers) are also called rotary blowers, and the most common type is called roots blowers. Working principle is similar to rotary pump and gear pump. It is mainly composed of a body and two rotors with special shapes and opposite rotation directions. During operation, one end of the rotating part is in close contact with each other, and the other end is in contact with the body wall. The body is divided into two chambers: one chamber draws in gas and one chamber exhausts gas. No valve device is required. Simple structure and uniform conveying. .

Rotary blowers come in many forms, the most commonly used are Roots blowers. The working principle of the roots blower is similar to that of a gear pump. As shown in the figure below, there are two special-shaped rotors in the casing, which are usually waist-shaped or triangular. The gap between the two rotors and the casing is small, allowing the rotor to be free. Less leakage due to rotation. The two rotors rotate in opposite directions, so that gas can be sucked in from one side of the casing and discharged from the other side. If the rotation direction of the rotor is changed, the suction port and the discharge port are interchangeable.

The structure of Roots blower is compact, the whole machine has small vibration, can run for a long time, the gas sent out does not contain oil, and the maintenance is quick and easy. These advantages are more prominent in the newer L48X66WD-1 machine (suitable for large and medium-sized seedling rooms of about 1500m ³ water). This model belongs to a volume rotary blower. The rotor's dynamic balance accuracy is very high, and the whole machine has less vibration. The biggest feature is that in use, when the pressure is adjusted within the allowable range, the flow change is small and the pressure selection range is wide. The working medium is air and works in a standard state. When the working pressure of the blower air inlet is 101325Pa, the temperature is 20 ° C, the density is 12kg / m ³ , and the relative humidity is 50%, the relationship between the important data is shown in the figure below. ^[2]

Roots blowers, the air supply valves of each air supply branch must be fully opened during use. If there are more hatching, he does not have eggs or larvae. Stopping the supply of air to these hatching tanks by mistake will cause the blower exhaust to be greatly reduced. , The air pressure inside the machine increased sharply, the blower rotor operation was blocked, the motor load increased rapidly, which caused the motor speed to decrease. The Roots blower is a three-phase asynchronous squirrel-cage motor. After the three-phase AC power is connected to the phase stator windings, a rotating magnetic field is generated in the internal space of the motor.

Under the action of the rotating magnetic field, the rotor will rotate in the same direction. The speed of the rotor is represented by n _2. Under light load, n _{1 is} slightly greater than n _2. For a motor, the speed of the rotating magnetic field is fixed. If the rotor is blocked as described above, the rotor speed will be significantly reduced, the difference between n ₁ and n ₂ will increase, and the rotating magnetic field will cut the rotor conductor at a speed of n ₁ -n ₂ , which will produce a larger Induced current. This current is transmitted by the power supply through the electromagnetic winding through the stator winding, so the stator winding current will also increase sharply, which is about the starting current value, that is, 4 to 6 times the rated current, causing the motor to overheat. If the time is long, the stator winding will be burned. Therefore, in actual production, it should be noted that no matter how many incubation tanks are in use, all valves in the air supply pipeline must be fully opened to prevent the blower rotor from being blocked and causing the motor to overload. ^[2]