Roots blowers
Roots blower is a positive displacement blower, which is a type of rotary blower. It uses two or three leaf-shaped rotors to move relative to each other in the cylinder to transport gas. Due to the continuous rotation of the rotor, the pumped gas is sucked into the air between the rotor and the pump shell from the air inlet, and then discharged through the exhaust port. The gas passes through the Roots blower without internal compression.
Roots blower is a commonly used blower in small and medium-sized sulfuric acid plants. When the required air volume is small, centrifugal blowers are often not suitable because the diameter of the impeller is small and it is generally difficult to reach the pressure head required for sulfuric acid production at a speed of 2950 rpm. Roots blowers have the advantages of both reciprocating compressors and centrifugal blowers. The reciprocating compressor has the characteristic that when the speed is constant, the air pressure changes slightly and the air supply volume remains unchanged, that is, the proportional relationship between the speed and the air volume is maintained. , also has the advantages of high centrifugal blower speed, no need for air valves and crankshafts, light weight, and easy application. The disadvantage is that when the outlet is blocked, it is easy to increase the pressure and even cause damage to the machine itself. After long use, the air supply volume decreases due to the expansion of the gap between the two rotors and the gap between the rotor and the casing.
Blast furnace blower
Current blast furnace blowers all use blade fans, which mainly fall into two categories: centrifugal and axial flow. The centrifugal blower has the advantages of simple structure, reliable operation, high efficiency at the design point, and low noise. Centrifugal blast furnace blowers have relatively mature manufacturing and use experience in China, and blast furnaces below 400m3 are widely used in regions and countries with backward industries. However, as the blast furnace increases, the centrifugal blower's adjustment loss, overall dimensions, and fan weight increase significantly, which brings great difficulties to manufacturing, transportation, installation, and maintenance. At the same time, it is also subject to The limitations of the material strength of the rotating parts-impeller, the stiffness of the main shaft, the starting of the motor and other factors have reduced the reliability and economy of the fan operation. The axial flow blower has the characteristics of compact structure, small size, light weight, good load adjustment, wide range of use, small fan inertia, and easy starting of the motor, so it is widely used in large-scale and modern blast furnaces. China has widely used axial flow blowers in blast furnaces above 500m3, and has accumulated certain experience in manufacturing and operation.
