(1) gas collecting hood: gas collecting hood is used to collect polluted air, and its performance has direct influence on the technical and economic indexes of the purification system. As the pollution source, equipment structure and production operation process are different, the form of gas collecting hood is varied.

(2) air duct: in the purification system, the pipe used to transport the air flow is called the air pipe, and the equipment and components of the system are connected into a whole through the wind pipe.

(3) purification equipment: in order to prevent air pollution, when the content of pollutants in exhaust exceeds the emission standard, the purification equipment must be adopted to deal with the pollution. When the discharge standard is reached, the atmosphere can be discharged.

(4) fan: fan is the motive force of the gas flow in the system. In order to prevent ventilator wear and corrosion, usually in the wind behind machine purification equipment.

(5) chimney: the chimney is the exhaust device of the purification system. The purified flue gas still contains a certain amount of pollutants. These pollutants diffuse and dilute in the atmosphere and eventually sink to the ground.

The basic type of gas collection hood

The gas collecting hood is a collecting device for the pollution source of the flue gas purification system, and the dust and gas pollution source can be introduced into the purification system, and meanwhile, the dust can be prevented from spreading to the production workshop and the atmosphere, thereby causing pollution.

Form:

(1) according to the air flow pattern of the hood, it is divided into: suction type and blow type;

(2) according to the relative position and applicable range of gas collector and pollution source, the air suction hood can be divided into airtight hood, exhaust hood, external gas collecting hood, and accepted gas collecting hood, etc..

Definition: the local or whole part of the pollution source is sealed up, and a certain negative pressure is kept in the cover, so as to prevent any diffusion of pollutants. Features: the minimum exhaust air demand, the best control effect, and free from indoor air flow interference, the design should be preferred.

Structure: local whole sealed cover, airtight cover, large volume sealed cover

1. part airtight cover

Features: small size, less material consumption, convenient operation and maintenance;

Application: it is a place where dust spots are fixed, dust production, airflow speed is small and continuous dust production.

2. integral airtight cover

Features: large volume, good tightness.

Suitable for dust producing equipment with multi point dust source, carrying gas, large flow rate or vibration.

3. large volume sealed cover

Features: large capacity, can cushion dust airflow, reduce local positive pressure, equipment maintenance can be carried out in the hood.

Application: multi point source, paroxysmal and air current equipment and pollution source.

4. layout requirements

A. sets the necessary observation windows, doors and doors;

B. hood should maintain a certain balance of negative pressure, to avoid dust escape;

C. as far as possible to avoid dust centers, to prevent a large number of materials with the airflow to the mouth to be sucked;

D. heat treatment material, should consider the effect of hot pressing on air flow, usually increase the airtight cover volume, suction point is arranged on the top of the highest point.