Dust fan design features of this device

The development and design of aspiration systems at enterprises involves the correct selection of equipment. One of the representatives of such equipment is a dust fan, the choice of which is carried out according to strictly defined indicators. The apparatus itself must be specially designed to work effectively in heavily dusty environments and be able to move polluted air with a large amount of solid particles.

All dust fans are structurally produced of a radial type or, as they are also called, centrifugal. There is no generally accepted classification of such equipment, but they are usually divided according to certain criteria:

• By appointment.
• By the pressure generated.
• By the speed of the generated air flow.

Radial dust fans belong to the class of equipment for special purposes.

Special Purpose Fans

Dust fans for special purposes are devices designed for pumping and transporting non-aggressive air mixtures with a pollution density not higher than 1 kg / m3. These fans are not designed to work with sticky and fibrous materials. They can be used in the temperature range from -40 C to +80 C and are successfully used in aspiration and pneumatic conveying systems for grain crops.

There is also equipment that is designed for pumping explosive gases and high-temperature air-gas mixtures. It is produced in limited quantities to order a specific production, and has a significant cost.

Design features

The dusty centrifugal fan consists of a «spiral» or «volute» type housing, which can be made from several grades of steel, depending on the purpose and conditions of use: galvanized, carbon, or alloyed. Also in the design of the body there are intake pipes, an engine and an impeller made in accordance with the purpose of this device.

There are two mounting options:

• On the motor shaft.
• The electric motor drives the impeller through a belt drive.

In order to prevent solid particles from getting stuck between the body of the device and the impeller, a rather large gap is made between them, therefore, such devices have a lower efficiency than that of general-purpose fans.

Despite the fact that the equipment is used quite often in many industrial enterprises, only three types are mass-produced.

• TsP7-40 — has a diskless wheel with six blades. To reduce the level of noise generated by it, the wheel blades are bent forward. Some design features of this device allow you to assemble it for both right and left rotation.
• TsP6-46 — has an impeller, which consists of a disk with 6 blades attached to it. Due to some design features, this type of dust equipment cannot operate at high speeds, therefore it is considered a low pressure apparatus.
• TsP6-45 — structurally does not differ from the previous model, but has forward-curved blades. Thus, the possibility of a significant reduction in the cost of operating this equipment is achieved.

These devices have significant differences in the pressure generated. Many enterprises require the creation of high pressure, up to 12 kPa. Devices of such performance are called high-pressure dust fans. For certain operating conditions, impeller blades are produced from wear-resistant and anti-corrosion materials, among which the most commonly used are: titanium and its alloys, vinyl plastic, stainless steel.

The device with a plastic wheel has higher anti-corrosion rates, even than stainless steel, but is much inferior in strength. The main advantage of such devices is their speed. Some models are able to develop peripheral speeds up to 30 m/s.

Scope of application

Dust fans have found the widest application in agriculture, the agrarian sector and industry. Most often, devices are used in industry to remove dust pollution from the air, sawdust and metal chips directly from the working area. This equipment has found wide application in welding shops when removing smoke and slag. Such devices are used in pneumatic transport installations for moving grain products.

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Advice:
When removing abrasive particles, especially in aggressive environments, you should choose a fan with blades exclusively made of wear-resistant and hard alloys.