Bag filter and its device

The bag filter is a "dry" type dust collector. It is used for the purification of dust and gas-air compositions and is characterized by a high degree of efficiency. On the quality of processing, it is noticeably superior to wet cleaning equipment and electrostatic precipitators. The device is equipped with filter elements, operated at a high temperature regime and manufactured from materials such as polyamide and polytetrafluoroethylene.

Description

The bag filter is a universal equipment category, since it can be applied with equal efficiency in most of the technological processes characterized by a large amount of dust formed. It does not require constant monitoring and maintenance, but the operation is continuous.

Also worth noting the possibility of manufacturing a device with different sizes, design features and identical characteristics suitable for the conditions of use. Depending on the limitations and dimensions of the installation site, the design of the products can be selected or developed individually.

The characteristics of the dust-forming compositions determine the kind of material processing that can be, for example, oil-repellent or antistatic, as well as the structure itself. To make the right choice, dust analysis is often performed in special laboratories.

Application

The scope of the equipment is quite extensive, baghouse filter Provides cleaning of aspiration emissions and flue gases in various industries, such as:

• Manufacturing of building materials;
• Ferrous and non-ferrous metallurgy;
• Foundry;
• Automotive industry;
• Energy and mining industry ;
• Food production;
• Metal working;
• Furniture, glass and chemical industry.

Calculation of bag filter

The installation can have a different area of the filter material, the determining factor is the pressure drop occurring on the fabric. Other basic criteria should also be taken into account, among them are the following:

• Dew point temperature ;
• Moisture level;
• Pressure and temperature indicators;
• Properties of gases;
• Volume of medium to be cleaned;
• Explosion hazard of gases;
• Output dust concentration and its type;
• Technological parameters of the process;
• Presence of toxic substances in the formulation.

In order to calculate the bag filter, it is necessary to set the purge gas flow rate and the dusty compositions on the material. It is also necessary to take into account the filtration rate of the type of fabric used.

Sleeve

The filter element of the equipment is a sleeve made of needle-punched non-woven fabric. There are two basic constructions:

• Elliptic, placed both in vertical and horizontal position;
• Round, suitable for use only in a vertical arrangement.

The average period of operation of the hoses is about 3 years, in some cases they can be used for more than 7 years. Despite this, the effectiveness of the equipment directly depends on the regular replacement of sleeves. It is also recommended to use modern fabrics that reduce residual dustiness.

Regeneration system

Regeneration of bag filters ensures their functioning and autonomous operation. Several regeneration systems are used, the impulse variety is considered the most effective and reliable. It is carried out with the help of compressed air, which is previously cleaned of dust and oil contaminants, with a pressure of not more than 0.6 MPa. This process does not require a stop of the duty cycle and is performed in an automatic mode. Two basic regeneration modes are used for the production of filters, each of which is selected depending on the operating conditions:

• Standard , in which regeneration and gas purification occur simultaneously.
• Mode for complex conditions of use. It is carried out after disconnection of one of the sections of the functioning device. The sleeve bag filter in this embodiment may be able to completely disconnect each section from either side, which simplifies the replacement of the filter elements and performs preventive maintenance on the functioning equipment.

Inclusion of pulse regeneration is possible by timer and diaphanometer. Devices with this mode make up a large part of the market. There is also the possibility of manufacturing equipment in accordance with the features of production, for example, products with mechanical shaking and reverse blowing.

Kinds

There are many types of filters, it is worth noting the most common ones:

• Pressure;
• Products with horizontal placement of sleeves (maintenance is done from the side platform;
• Bag filter for cleaning gases with vertical sleeve placement;
• Cyclonic devices are equipped with a louvered separator for pre-cleaning and are manufactured in a round casing;
• Point equipment used for aspiration of supply bins and conveyors;
• Explosion proof bag filter;
• High-performance devices suitable for a large volume of gas and providing a low level of residual dustiness;
• Compact equipment equipped with corrugated sleeves.

Operation in difficult conditions

Bag filter, the characteristics of which are selected in accordance with the conditions of use, suitable for outdoor and indoor work. In the first variant, an addition is required in the form of the following constituent elements:

• Heat insulation of the body part, which is of particular importance in the condensation of vapors;
• Heating of equipment bins and regeneration systems;
• Special shelter, preventing the effects of atmospheric phenomena.

Among the main types of devices it is worth noting the two-row design, in the middle part of which there are pipes for the entry of contaminated and purified gas, as well as single-row, in which the branch pipes are located on the side of the structure.

Transportation of equipment is carried out by freight transport. To simplify this process, the bag filter, the drawing of which is presented above, is realized in partially disassembled form. The units are manufactured in various variations in accordance with the operating conditions. The welded method and bolted connections are used to assemble the structure . Most of the devices are designed for operation with excessive discharge or pressure.

Increased efficiency

In some cases, there is a lack of efficiency, despite compliance with the conditions of material selection and competent calculation. Improving the result is possible by intensifying the method of regeneration, but this contributes to higher costs due to a decrease in the period of operation of the matter, which is subject to strong mechanical stresses. It is also possible to reduce the filtration rate and increase the layer of accumulated dust, in this case the dimensions of the equipment increase. The device of the bag filter often assumes the presence of additional sections that ensure continuous operation and the possibility of carrying out repairs without stopping the apparatus.