Filter Cloth

Filter cloth, a filter medium woven from natural or synthetic fibers. Commonly used materials are cotton, hemp, wool, cocoon silk, asbestos fiber, glass fiber and some synthetic fibers. Such as cotton - woven canvas, twill and woollen cloth, etc. In a broad sense, press cloth also includes metal mesh or strainer.

The main synthetic fibers are polypropylene, polyester, nylon, Vinylon, etc. Polyester and polypropylene are the most commonly used, mainly solid-liquid separation, and nylon is widely used in coal washing plants, because of its excellent wear resistance.

Polyester, polypropylene, nylon, Vinylon, cotton and other materials of filter cloth, screen, are widely used in pharmaceutical, chemical, dye, steel, construction, iron metallurgy, chemical, ceramics, cement, geology, minerals and other industries.

Special filter cloth: aramid, PTFE, PVDF and so on, the use of high temperature.

Advantages of press cloth:

Close to zero emissions, can meet the most stringent environmental standards;

Good dust cleaning, can provide higher ventilation volume, or can reduce the pressure difference;

Prolonging the life of filter bag, reducing the cleaning times, so that equipment maintenance cost is reduced;

Higher gas cloth ratio, can be designed to use a smaller dust collector, the reduction of pressure difference when the energy consumption is reduced;

Dust bag from the temperature is roughly divided into 3 categories, normal temperature such as polyester needle felt bag anti-static dust bag, easy dust bag. Medium temperature like polyester film coated needle felt bag, three anti-dust cloth bag, water-repellent oil-repellent needle felt, high temperature like Metas, dust cloth bag, Flumis cloth bag, glass fiber needle felt filter bag, PPS acid and alkali resistant cloth bag, etc. The selection of dust bag should be based on the temperature, humidity and chemical characteristics of the gas, the size, weight, shape of the particulate matter, dust concentration filtering speed, cleaning mode, emission concentration and the working system of the bag dust collector and other factors.

In general, needle felt is selected for pulse jet bag dust generator, and woven fabric is selected for chamber reverse blowing bag dust collector or mechanical vibration bag dust collector. If the working condition is high temperature, acid and alkali resistance and humidity can be used in high temperature, such as coated flumez, etc., there are many factors to consider in choosing dust bag.

Classification of press cloth

1. According to the shape of cross section of dust removal filter bag, it is divided into flat bag (trapezoid and flat plate shape) and round bag (cylindrical shape).

2. According to the air inlet and outlet mode, it can be divided into: downward air inlet and upward air outlet and upward air outlet and straight flow (only limited to flat plate bag).

3. According to the filtration method of dust removal filter bag, it is divided into external filter type and internal filter type.

4, according to the temperature bearing capacity of dust filter bag is divided into: high temperature type, medium temperature type, normal temperature type 5, application field Application field: iron works, steel mills, ferroalloy factory, refractory factory, foundry, power plant, cement factory, chemical plant, grain processing plant, carbon black factory, aluminum factory, etc

5, according to the temperature:

(1) Low temperature class: suitable for raw material mill, cement mill, warehouse top, warehouse bottom and other local dust point bag dust collector use, but for high humidity content conditions also need to use oil-repellent waterproof treatment agent surface treatment;

(2) Normal and high temperature category: suitable for cement shaft kiln, rotary kiln tail, cooling machine, dryer and other high temperature waste gas treatment bag dust collector, and used for high temperature, high humidity content conditions also need to use oil-repellent waterproof treatment agent surface treatment;

Characteristics of press cloth

For press cloth, it is not only the wear of the material itself that affects its service life, but more importantly, the corrosion of the working material on the press cloth. Therefore, the requirements for industrial press cloth are very high, and the following characteristics are mainly required:

(1) Good trapping effect and long service life after solid material;

(2) Fast filtration speed, less plugging, stable filtration speed;

(3) The filter slag has good peeling property, no expansion and good dimensional stability.

Type selection

The selection of press cloth is very important, which plays a very important role in the process of filtration. Whether the selection of press cloth is reasonable directly affects the effect and speed of filtration. In the specific selection of press cloth, it should be based on the basic properties and filtration requirements of filter paste. The permeability (water permeability or air permeability), filtration level (maximum and minimum pore size and porosity of the filter cloth), service life (tensile strength and elongation), structure and weaving mode of the filter cloth, chemical properties and cost are considered.

1. The filter cloth that can effectively intercept the sludge particles during filtration should be selected according to the properties and particle size of the sludge, mainly based on the pore size of the filter cloth and its permeability (air permeability).

2. Different materials of filter cloth should be selected according to the PH value of sludge. Generally, in order to prolong the service life of the filter cloth, polypropylene series filter should be used in the environment of pH 4~8, and polyamide series filter cloth should be used in the environment of pH 5~8.5.

3, Filter cloth with different tensile strength and elongation is selected according to filtration pressure.

4. When the filtration performance of two kinds of filter cloth is similar, the cost of the filter cloth should be considered.