What is a filter bag?
Definition Edit This paragraph's durable filter bags are made of pure, high-quality melt-blown microfiber filter cloth that is finely hot-melted or machined.
The filtration precision of the filter bag is usually the nominal filtration precision.
Filter bags are a key part of the operation of bag dust collectors. Usually cylindrical filter bags are hung vertically in the dust collector. The fabric and design of the filter bag should strive for high-efficiency filtration, easy dust removal, and durability.
Features Edit this paragraph In pulse and air box pulse dust collectors, dust adheres to the outer surface of the filter bag. When dusty gas passes through the dust collector, the dust is collected on the outer surface of the filter bag, and the clean gas enters the inside of the filter bag through the filter material. The cage inside the filter bag is used to support the filter bag and prevent it from collapsing. At the same time, it helps to remove and redistribute the dust cake.
From loose to dense
forming gradient filtration
* High dirt holding capacity, long filter life, low pressure difference
Material: PP (polypropylene), PE (polyester), PTFE (polytetrafluoroethylene)
Collar ring: stainless steel ring, plastic ring.
2. Capillary fiber oil-absorbing filter bag
It consists of three parts: pre-filter layer, main filter layer and wire mesh cover. It is specially designed to effectively absorb grease in liquids.
The void ratio in the filter material is as high as 80, which greatly improves the service life of the product. The oil absorption capacity is up to 12 to 20 times the weight of the filter bag itself (specifically varies depending on fluid and grease characteristics and flow rate)
3. Absolute precision seamless filter bag
Made of pure polypropylene Capillary fiber hot melt blown molding. The outer layer is made of thickened depth filter material to provide layered filtration;
The inner large-diameter filter element is used to further enhance the overall depth filtration effect and improve the ability to hold impurities. The service life is on average more than five times that of ordinary polypropylene filter bags. The highest filtering precision is 3um. The collar ring is a plastic ring.
4. Wire mesh filter bag
The available materials include nylon monofilament mesh, polyester monofilament mesh, and polypropylene multi-strand mesh. The highest filtration precision is 20um
Features: absolute filtration precision, high toughness, damage resistance, no free fibers, and can be used repeatedly.
Performance editing The filter material in this section is temperature-resistant, strong acid, weak acid, strong alkali, weak alkali, oils, aromatics, alcohol ethers, organic solutions, and microorganisms.
Filter precision: PE/PP/PTFE
0.5, 1, 3, 5, 10, 25, 50, 80, 100, 125, 150, 200, 300, 400, The impurity capture capacity of 600, 800 and 1000 multi-layer high-efficiency filter bags is 2-3 times that of ordinary needle felt filter bags, and the removal efficiency is higher than 90
Filter bag industry standard
GB 12625-1990 Technical conditions for filter materials and filter bags used in bag dust collectors
HCRJ 015-1998 Technical conditions for certification of bag dust collectors
HCRJ 016-1998 Bag dust collector filters Technical requirements for bag frame certification
HJ/T 327-2006 Technical requirements for environmental protection products Bag dust collector filter bags
JC/T 584-1995 Glass fiber filter bags
Category Edit this paragraph 1. According to the shape of filter bags, they are divided into: flat bags (trapezoid and flat) and round bags (cylindrical).
2. According to the air inlet and outlet methods, it is divided into: bottom air inlet and top air outlet, top air inlet and bottom air outlet and direct flow type (only limited to plate-shaped flat bags).
3. Bag filtration methods are divided into: external filter type and internal filter type.
Fibres used for filter materials include cotton fiber, wool fiber, synthetic fiber, glass fiber, etc. Filter materials woven from different fibers have different properties.
Commonly used filter materials include 208 or 901 polyester velvet cloth. The use temperature generally does not exceed 120°C. The use temperature of glass fiber filter bags treated with silicone resin generally does not exceed 250°C. Cotton wool fabrics are generally suitable for non-corrosive applications; the temperature is Dusty gas below 80-90℃.
Usage Edit this section Filter sealed filtration: The filter bag is used together with the matching filter. The system fluid pressure is used to squeeze the liquid through the filter bag to achieve the purpose of filtration. It has the advantages of fast flow rate, large processing capacity and long service life of the filter bag. It is especially suitable for occasions where large flow rates require closed filtration.
Self-flow open filtration: The filter bag is directly connected to the pipeline through a suitable joint, and the fluid gravity pressure difference must be used for filtration. Its distinguishing feature is that it requires no equipment investment and the filtration is simple and feasible. It is especially suitable for small-sized, multi-variety, and intermittent economical liquid filtration.
Bag dust collector is a dry dust filtering device. It is suitable for capturing fine, dry, non-fibrous dust. The filter bag is made of textile filter cloth or non-textile felt. The filtering effect of fiber fabric is used to filter dust-containing gas. When the dust-containing gas enters the bag dust collector, dust with large particles and heavy specific gravity will be removed due to gravity. It will settle down and fall into the ash hopper. When the gas containing fine dust passes through the filter material, the dust is blocked, thus the gas can be purified. Generally, the dust removal efficiency of new filter materials is not high enough. After the filter material is used for a period of time, due to effects such as sieving, collision, retention, diffusion, and static electricity, a layer of dust accumulates on the surface of the filter bag. This layer of dust is called the primary layer. During the subsequent movement, the primary layer becomes The main filter layer of the filter material relies on the function of the primary layer. Filter materials with larger meshes can also achieve higher filtration efficiency. As dust accumulates on the surface of the filter material, the efficiency and resistance of the dust collector increase accordingly. When the pressure difference on both sides of the filter material is large, some small dust particles that have been attached to the filter material will be squeezed out. Reduce dust collector efficiency. Besides, high resistance power will significantly lower air volume of the dust collecting system. Therefore, after the dust collector resistance reaching a certain volume, the dust should be cleaned in time. When cleaning, do not damage the first layer to avoid a decrease in efficiency.
The structure of the bag dust collector is mainly composed of an upper box, a middle box, a lower box (ash hopper), a dust cleaning system and an ash discharge mechanism.
In addition to the correct selection of filter bag materials, the dust cleaning system plays a decisive role in the performance of the bag dust collector. For this reason, the dust cleaning method is one of the characteristics that distinguishes the bag dust collector, and it is also an important part of the operation of the bag dust collector.