White Fume Enclosure Exhausting & Filtering System

The bag filter is a dry dust filter device. It is suitable for capturing fine, dry, non-fibrous dust. The filter bag is made of textile filter cloth or non-woven felt, and uses the filter function of the fiber fabric to filter the dusty gas. When the dusty gas enters the bag filter, the dust with large particles and large specific gravity will When the air containing fine dust passes through the filter material, the dust will be blocked and the air will be purified.

Introduction to Dust Collector

The bag filter is a dry dust filter device. After the filter material is used for a period of time, a layer of dust accumulates on the surface of the filter bag due to effects such as screening, collision, retention, diffusion, and static electricity. This layer of dust is called the first layer. During the subsequent movement, the first layer becomes The main filter layer of the filter material depends on the effect of the first layer, and the filter material with a larger mesh can also obtain higher filtration efficiency. With the accumulation of dust on the surface of the filter material, the efficiency and resistance of the dust collector will increase accordingly. When the pressure difference on both sides of the filter material is very large, some fine dust particles that have attached to the filter material will be squeezed away. Decrease the efficiency of the dust collector. Besides, the high resistance power will dramatically lower air volume of the dust collecting system. Therefore, after the filter resistance reaching a certain volume, the dust should be cleaned in time. When cleaning the dust, please do not damage the first layer in case the efficiency decline.

Working principle

The high dust removal efficiency of the bag filter is inseparable from its dust removal mechanism. When the dust-laden gas enters the ash hopper from the air inlet pipe at the lower part of the dust collector through the deflector, the coarse dust will fall into the ash hopper due to the collision of the deflector and the reduction of the gas velocity, and the rest of the fine dust will fall into the ash hopper with the gas. Entering the filter bag room, due to the inertia, diffusion, barrier, hooking, static electricity and other effects of the filter fiber and fabric, the dust is blocked in the filter bag, and the purified gas escapes out of the bag and is discharged through the exhaust pipe. The dust accumulated on the filter bag is removed by gas backwashing, and the removed dust goes down to the ash hopper, and is discharged to the ash conveying device through the double-layer ash discharge valve. The dust accumulated on the filter bag can also be removed by blowing pulsed airflow, so as to achieve the purpose of dust removal, and the removed dust is discharged by the dust discharge device. The high dust removal efficiency of the bag filter is also inseparable from the filter material. The performance and quality of the filter material are directly related to the performance and service life of the bag filter. The filter material is the main material for making filter bags. Its performance and quality promote the progress of bag dust removal technology and affect its application range and service life. the

The filter dust removal device includes a bag filter and a granular layer dust collector. The former usually uses a filter bag made of organic fiber or inorganic fiber fabric as the filter layer, while the filter layer of the latter mostly uses particles of different particle sizes, such as quartz sand, Composed of river sand, ceramsite, slag, etc. As the powder repeatedly adheres to the outer surface of the filter bag, the powder layer is continuously thickened, and the resistance value of the bag filter also increases; the pulse valve diaphragm sends out instructions, and the pulse valve opens when the left and right submerge, and the compression in the high-pressure air bag The air is ventilated, if there is no dust or it is small to a certain extent, the mechanical cleaning work will stop working.

The gas purification method of the low-pressure pulse bag filter is the external filter type, and the dust-laden gas enters the filter chambers of each unit through the guide tube. Due to the vertical distance between the bottom of the filter bag and the upper port of the air inlet in the design, there is sufficient and reasonable air flow through the appropriate guide. The air flow and natural flow direction are distributed to achieve uniform air distribution in the entire filter room. The particles and dust in the dusty gas are separated by natural sedimentation and then directly fall into the ash hopper. Under the guidance of the diversion system, the remaining dust enters the filter area of the middle box with the airflow. , adsorbed on the outer surface of the filter bag. The filtered clean gas is discharged through the filter bag through the upper box and the exhaust pipe.

The filter bag uses compressed air to spray and clean the dust. The dust cleaning mechanism is composed of an air bag, a blowing pipe and an electromagnetic pulse control valve. An injection pipe is installed on the top of the outlet of each row of filter bags in the filter chamber. The lower side of the injection pipe is facing the center of the filter bag with an injection port. Each injection pipe is equipped with a pulse valve and communicated with the compressed air bag. When cleaning dust, the electromagnetic valve opens the pulse valve, and the compressed air is sprayed by the dust cleaning control device (differential pressure or timing, manual control) to open the electromagnetic pulse injection according to the set program, and the compressed gas passes through each pulse in order in a very short time. The valve induces air several times larger than the injected air volume into the filter bag through the nozzle on the blowing pipe, forming an air wave, causing the filter bag to undergo rapid expansion and shock vibration from the bag mouth to the bottom, resulting in a strong dust cleaning effect, shaking off the filter bag Dust on bags.

Advantage

(1) The dust removal efficiency is high, generally above 99%, the dust concentration of the gas at the outlet of the dust collector is within tens of mg/m3, and it has a high classification efficiency for fine dust with submicron particle size.

(2) The range of air volume is wide, the small one is only a few m3 per minute, and the large one can reach tens of thousands of m3 per minute. It can be used for the dust removal of flue gas in industrial furnaces and kilns to reduce the emission of air pollutants.

⑶ Simple structure, easy maintenance and operation.

⑷On the premise of ensuring the same high dust removal efficiency, the cost is lower than that of the electrostatic precipitator.

(5) When using glass fiber, polytetrafluoroethylene, P84 and other high temperature resistant filter materials, it can operate under high temperature conditions above 200 °C.

⑹ Not sensitive to the characteristics of dust, not affected by dust and resistance.

Our company mainly business scope is as follows:   

1) The design, manufacture, installation, commissioning and training of the hot dip galvanizing lines, redesign and improve of the old galvanizing plants.   

1. Jobbing galvanizing line for construction parts: such as steel tower , tube tower parts, high rails and lighting poles , etc. 

2. Galvanizing lines for steel tubes:suitable for 1/2"-8" steel tube.

3. Galvanizing lines for small parts:suitable for bolts, nuts and other small parts. 

2) The related chemical preprocessing of products and alloy   

Our main products are : chemical pretreatment tanks, galvanizing furnace, zinc kettle, utilisation of fuel gas from the fuel furnace, drying pit.   

If you have any questions, please contact our engineers for consultation, online.