Dust Removal Equipment

Product Description

Selection criteria:
The operation of a dust collector not only directly affects the reliable operation of the dust removal system, but also relates to the normal operation of the production system, the environmental hygiene of the workshop and surrounding residents, the wear and service life of the fan blades, and also involves the recycling and utilization of economically valuable materials. Therefore, it is necessary to design, select, and use dust collectors correctly. When selecting a dust collector, it is necessary to fully consider the primary investment and operating costs, such as dust removal efficiency, pressure loss, reliability, primary investment, land occupation, maintenance management, and other factors. Based on the physical and chemical properties, characteristics, and production process requirements of smoke and dust, a targeted selection of dust collectors should be made.Different dust collectors have different dust removal efficiencies. For dust removal systems with unstable or fluctuating operating conditions, attention should be paid to the impact of changes in flue gas treatment capacity on dust removal efficiency. During normal operation, the efficiency of the dust collector is ranked as follows: bag filter, electrostatic precipitator and Venturi dust collector, water film cyclone dust collector, cyclone dust collector, etc.The working principle of bag type dust removal is the process of using filter cloth processed with cotton, wool, or artificial fibers to capture dust particles.

Bag filters have the following advantages:
① The dust removal efficiency is high, especially for fine powder, with a high replenishment efficiency of over 99%;
② Strong adaptability, it can handle different types of particulate pollutants (including high specific resistance dust that is difficult to handle by electrostatic precipitators). According to the processing capacity, it can be designed as a small bag filter or a large bag room;
③ When the operation flexibility is high and the dust concentration of the inlet gas changes significantly, it has little impact on the dust removal efficiency. In addition, the dust removal efficiency also has a certain degree of stability in relation to the variation of airflow velocity;
④ Simple structure, flexible use, easy to recycle dry materials, and no need for sludge treatment.The application of bag filters is mainly limited by the operational performance of filter fabrics, such as temperature resistance and corrosion resistance; The general usage temperature of filter cloth is less than 300 ℃; Bag filters are not suitable for removing dust particles with strong adhesion and moisture absorption, especially when the flue gas temperature cannot be lower than the dew point temperature, otherwise frost will form on the filter cloth, causing clogging of the bag and affecting the normal operation of the bag filter.

Technical Parameter：

Note: The above data is for reference only. Our company reserves the right to modify it and can support non-standard customization.

 Cleaning method:

The cleaning effect is an important indicator of the performance of dust collectors, and the cleaning methods are mainly divided into three categories: mechanical vibration, reverse airflow cleaning, and pulse cleaning. In recent years, there have been some new methods of cleaning dust, such as using elastic vibration mechanism to clean dust and using sound waves to assist in cleaning dust, and so on.Mechanical vibration cleaning is the use of a mechanical vibration mechanism to drag filter bags for horizontal vibration, or to use an eccentric wheel device to vibrate the filter bag frame or regularly lift the filter bag frame for cleaning, or to use a specialized mechanism to twist the filter bag at a certain angle to deform and clean the dust.Reverse airflow cleaning is the use of airflow opposite to the filtered airflow to deform the filter bag and cause the dust layer to fall off. This includes pulse injection, rotary blowback, and gas ring blowback using compressed air, clean gas, or other gases. Its cleaning effect is twofold: on the one hand, the reverse cleaning airflow directly impacts the dust block, and on the other hand, due to the change in airflow direction, the filter bag undergoes expansion and contraction vibration, causing the dust block to fall off. There are two forms of reverse airflow cleaning: reverse blowing cleaning and reverse suction cleaning. When dealing with large flow of dust and gas, reverse suction air is often used for dust removal. Air ring reverse blowing ash cleaning is a hollow circular ring placed on the outer side of an inner filtering cylindrical filter bag, close to the surface of the filter bag. The circular ring can move up and down and is connected to high-pressure gas or high-pressure fan through a hose. The air ring reverse blowing has a strong ability to clean dust and is suitable for filter bags made of felt. The rotary backwash bag filter adopts a downward inlet external filter type, and the clean air chamber is equipped with a rotatable cantilever tube. The backwash airflow is sent from the center tube to the rotary cantilever, and is blown vertically downwards into the filter bag through the spraying hole, causing the filter bag to swell and shake off the dust, achieving the purpose of cleaning.The bag filter for pulse jet cleaning relies on compressed gas to spray out a high-speed airflow (called primary gas) through the small hole of the blowing pipe through the pulse valve. The primary gas induces several times the surrounding gas (called secondary gas) into the filter bag through the inducer, forming a gas wave that causes the filter material to rapidly expand and vibrate, thereby achieving cleaning. According to different injection pressures, it can be divided into two types: high-pressure pulse and low-pressure pulse. The high-pressure pulse provides a gas source injection pressure of 0.4~0.7MPa. Due to the high injection pressure, high-pressure pulse spraying affects the service life of the bag, and there are many gas source configuration equipment, complex spraying systems, large one-time investment, and many vulnerable parts. Therefore, high-pressure pulse has a trend towards low-pressure pulse development. Low pressure pulse is an addition of a storage box on the basis of high pressure pulse, which outputs a low pressure gas source for gas supply. The blowing valve is fixed at the bottom of the air storage box. When the valve is closed, it presses the valve port. When it is opened, the low-pressure airflow from the air storage box enters the cloth bag, playing a role in cleaning the dust. This cleaning method has the characteristics of strong cleaning ability and good cleaning effect, and is currently widely used in many industries.

Filter cartridge dust collector:
The filter cartridge dust collector is composed of a filter cartridge as a filtering element or uses a pulse jet dust collector. The filter cartridge dust collector can be divided into oblique insertion type, side mounted type, lifting type, and top mounted type according to the installation method. Filter cartridge dust collectors can be divided into long fiber polyester filter cartridge dust collectors, composite fiber filter cartridge dust collectors, anti-static filter cartridge dust collectors, flame retardant filter cartridge dust collectors, membrane covered filter cartridge dust collectors, nano filter cartridge dust collectors, etc. according to the material of the filter cartridge.

The structure of a filter cartridge dust collector is composed of an inlet duct, an exhaust duct, a box body, an ash hopper, an ash cleaning device, a guide device, an airflow distribution plate, a filter cartridge, and an electrical control device, similar to the pulse bag dust removal structure of an air box.The arrangement of the filter cartridge in the dust collector is very important. It can be vertically arranged on the box flower board or obliquely arranged on the flower board. From the perspective of the cleaning effect, the vertical arrangement is more reasonable. The lower part of the flower board is a filtering chamber, and the upper part is an air box pulse chamber. An airflow distribution plate is installed at the inlet of the dust collector.After the dusty gas enters the ash hopper of the dust collector, due to the sudden expansion of the airflow cross-section and the action of the airflow distribution plate, some coarse particles in the airflow settle in the ash hopper under the action of dynamic and inertial forces; After the fine particle size and low density dust particles enter the dust filter room, they deposit on the surface of the filter material through combined effects such as Brownian diffusion and screening. The purified gas enters the clean air chamber and is discharged by the exhaust pipe and fan.The resistance of the filter cartridge dust collector increases with the increase of the thickness of the dust layer on the surface of the filter material. Clean the dust when the resistance reaches a certain specified value. At this time, the PLC program controls the opening and closing of the pulse valve. Firstly, the lifting valve of the first chamber is closed to cut off the filtered airflow. Then, the electromagnetic pulse valve is opened, and compressed air and a short period of time rapidly expand inside the upper chamber, flowing into the filter cartridge, causing the filter cartridge to expand and deform, resulting in vibration. Under the action of reverse airflow erosion, the dust attached to the outer surface of the filter bag is peeled off and falls into the ash hopper. After the ash cleaning is completed, the electromagnetic pulse valve is closed, the lifting valve is opened, and          the room returns to the filtering state. The cleaning process is carried out sequentially in each room, with one cleaning cycle from the first cleaning to the next cleaning. The detached dust falls into the ash hopper and is discharged through the ash discharge valve.During this process, it is necessary to regularly replace and clean the filter cartridge to ensure filtration efficiency and accuracy, because during the filtration process, in addition to being blocked, some dust will also deposit on the surface of the filter material, increasing resistance. Therefore, the correct replacement time is generally three to five months.

Dust cleaning device:
There are two ways to clean the dust in traditional filter cartridge dust collectors. One is high-pressure airflow reverse blowing, and the other is pulse airflow spraying. Practice has shown that the former has the advantage of uniform airflow, but the disadvantage is high air consumption; The advantage of the latter is low air consumption, but the disadvantage is weak airflow. There are two improvements that can be made for this: on the one hand, a guiding device can be added to the pulse blowing tube to strengthen the airflow induction effect, and on the other hand, the upper guiding air duct of the filter cartridge can be removed, allowing both the pulse airflow and the induced airflow to fully enter the filter cartridge at the same time. After this improvement, the air consumption is reduced, the air flow is uniform, and the cleaning effect is good. According to calculations, the flow rate of the cleaning air flow after the technical improvement is 3-5 times that of the pulse air flow.

Gas volume distribution board:
The airflow distribution of the filter cartridge dust collector is very important, and it is necessary to consider how to avoid the high wear area of the filter material caused by high wind speed at the equipment inlet. The airflow distribution plate has unique requirements for filter cartridge dust collectors, and the airflow distribution must be very stable and uniform. It is beneficial for the rise of airflow and the decrease of dust, and the opening rate of the airflow distribution plate is 35%. According to the calculation, the resistance coefficient is less than 2, indicating that the porous airflow distribution plate can meet the requirements of the filter cartridge dust collector when the airflow speed is less than 0.8m/s.