Roots Blower Wastewater Treatment

Three-Lobe Roots Blower, Wastewater Treatment Blower, Power Plant Return Air Blower

The Roots blower, also known as a Roots-type blower, falls under the category of positive displacement rotary blowers. Its working principle is based on the relative motion of two lobe-shaped rotors within a cylinder to achieve gas compression and transportation. This type of blower has a compact structure and is simple to manufacture, making it highly suitable for gas transportation and pressurization tasks under low-pressure conditions. It can also be used as a vacuum pump.

Basic Principle

The Roots blower, a positive displacement rotary blower, operates on the principle of the synchronous meshing motion of two lobe-shaped rotors within a cylinder. Precise meshing of the two rotors is maintained by timing gears located on the rotor shafts. Gas is drawn into the working volume formed by the concave curved surfaces of the rotors and the inner wall of the cylinder during the rotor's rotation. As this volume moves near the exhaust port, high-pressure gas backflows into it, causing a sudden pressure increase, and the gas is ultimately delivered to the exhaust passage. It is worth noting that the two rotors do not make direct contact with each other; sealing is achieved through strictly controlled clearances, ensuring that the discharged gas is not contaminated by lubricating oil.

Main Features

The Roots blower exhibits minimal flow variation when adjusted within its permissible pressure range, demonstrating a wide pressure selection range and forced gas delivery characteristics. The conveyed medium is pure and oil-free. Furthermore, this blower features a simple structure, convenient maintenance, long service life, and low overall machine vibration.

However, due to the periodic suction and exhaust processes and instantaneous constant volume compression, the Roots blower generates airflow velocity and pressure pulsations, leading to certain aerodynamic noise. Additionally, the clearance between the rotors and the cylinder can cause gas leakage, potentially affecting efficiency. Its displacement range is 0.15 to 150 cubic meters per minute, and the rotational speed ranges from 150 to 3000 revolutions per minute. The single-stage pressure ratio is typically less than 1.7, with a maximum of 2.1, and performance can be further enhanced through multi-stage series connection.

Main Media

The Roots blower is primarily used for conveying clean air, clean coal gas, sulfur dioxide, and other inert gases. In specialized gas industries such as the transportation of coal gas, natural gas, biogas, carbon dioxide, sulfur dioxide, and under high-pressure conditions, it performs exceptionally well and becomes the preferred product. Therefore, this blower is widely applicable in numerous industries including metallurgy, chemicals, fertilizer production, petrochemicals, instrumentation, and building materials.

Structure

The structure of the Roots blower can be classified into two-lobe type and three-lobe type based on the rotor shape. The three-lobe type rotor completes three suction and exhaust processes collaboratively by the two rotors per revolution. Compared to the two-lobe type, it exhibits smaller gas pulsation, with correspondingly reduced vibration and noise.

Parameters

The rotational speed range of the Roots blower is 150 to 3000 revolutions per minute, the flow range is 0.15 to 1200 cubic meters per minute, and the pressure range is 9.8 to 196 kilopascals. The power and single-unit weight can reach up to 0.75 to 1000 kilowatts and 100 to 9000 kilograms, respectively.