Pulse bag filter

Brief introduction of pulse bag filter:

The pulse bag filter is an improved new high-efficiency pulse bag filter based on the bag filter. In order to further improve the pulse bag filter, the modified pulse bag filter retains the advantages of high purification efficiency, large gas processing capacity, stable performance, convenient operation, long filter bag life, and small maintenance workload. Pulse bag filter

In addition, the reform in structure and pulse valve solves the problems of open air installation and low pressure of compressed air source.

Working principle of pulse bag filter:

The pulse bag filter is composed of an ash hopper, an upper box, a middle box, a lower box, etc. The upper, middle and lower boxes are of sub-chamber structure. When working, the dust-laden gas enters the ash hopper from the air inlet duct, and the coarse dust particles fall directly into the bottom of the ash hopper. The gas enters the upper box to the clean gas collection pipe-exhaust duct, and is exhausted to the atmosphere through the exhaust fan. The cleaning process is to cut off the clean air outlet air duct of the chamber first, so that the cloth bag of the chamber is in a state of no air flow (the chamber is stopped to clear the dust). Then open the pulse valve and use compressed air for pulse blowing to clean the dust. The shut-off valve is closed for a sufficient time to ensure that the dust peeled from the filter bag after the injection settles into the ash hopper, so as to avoid the dust from being separated from the surface of the filter bag and then attached to the air flow. The phenomenon of reaching the surface of the adjacent filter bag, so that the filter bag is completely cleaned, and the exhaust valve, pulse valve and ash discharge valve are fully automatically controlled by the programmable controller.

Pulse bag filter features:

1. The pulse bag filter [1] adopts the technology of sub-chamber air stop and pulse jet dust cleaning, which overcomes the shortcomings of conventional pulse dust collector and sub-chamber back-flushing dust collector. It has strong dust cleaning ability, high dust removal efficiency, low emission concentration, and air leakage rate. Small, less energy consumption, less steel consumption, less floor space, stable and reliable operation, and good economic benefits. It is suitable for the purification of dusty gas and the recovery of materials in metallurgy, building materials, cement, machinery, chemical industry, electric power and light industry.

2. Due to the use of sub-chamber air-stop pulse injection to clean the dust, the purpose of complete dust cleaning can be achieved by one injection, so the cleaning cycle is prolonged, the energy consumption of dust cleaning is reduced, and the consumption of compressed air can be greatly reduced. At the same time, the fatigue degree of the filter bag and the pulse valve is correspondingly reduced, thereby multiplying the life of the filter bag and the valve plate.

3. The maintenance and replacement of bags can be carried out in separate rooms under the normal operating conditions of the system without stopping the system fan. The mouth of the filter bag adopts an elastic expansion ring, which has good sealing performance and is firm and reliable. The filter bag keel adopts polygonal shape, which reduces the friction between the bag and the keel, prolongs the life of the bag, and facilitates the unloading of the bag.

4. The upper bag extraction method is adopted. After the skeleton is pulled out when changing the bag, the dirty bag is put into the ash hopper at the lower part of the box and taken out from the manhole, which improves the operating conditions of bag changing.

5. The box body is designed with air tightness, which has good sealing performance. The inspection door uses excellent sealing materials. During the production process, kerosene is used to detect leakage, and the air leakage rate is very low.

6. The inlet and outlet air ducts are compactly arranged, and the airflow resistance is small.

Pulse bag filter series design:

1. The pulse bag filter is divided into three different series according to the different diameters of the filter bags [2], the different arrangements of the filter bags in each chamber, and the different filter areas, which are combined into rows in units of chambers, and are divided into single arrays and double arrays:

a. It is divided into single row and double row. The pulse injection pressure can be low pressure (0.2-0.3Mpa) or high pressure (0.4-0.5Mpa), which is selected by the user.

b. There is only double row arrangement, and the pulse injection pressure is generally designed to be low pressure (0.2-0.3Mpa).

c. There is only double row arrangement, and the pulse injection pressure is high pressure (0.4-0.5Mpa). If users have special requirements, special models can also be designed according to user opinions.

2. The dust concentration at the outlet of the dust collector is generally allowed to be below 30g/Nm3. If there are special requirements, it can be designed according to user requirements.

Selection of pulse bag filter:

1. Selection of filtration speed: Filtration speed is a key factor in the selection of pulse bag filter, which should be determined according to the nature of soot or dust, application, dust particle size, viscosity, gas temperature, water content, dust concentration and different filter materials, etc. factors to determine. When the particle size of the dust is small, the temperature and humidity are high, the concentration is large, and the viscosity is large, the lower value should be selected. Such as ≤1m/min; otherwise, a higher value can be selected, generally not more than 1.5m/min. For dust with large particle size, normal temperature, dryness, no viscosity, and extremely low concentration, 1.5-2m/min can be selected. When selecting the filtration speed, it should be calculated that the net filtration wind speed should not exceed the above value when reducing the filtration area of one room (when cleaning dust).

2. Filter material [3]: It should be considered according to the temperature, moisture content, acid and alkali properties of the dust-containing gas, the viscosity, concentration and abrasiveness of the dust. Generally, when the water content is small and there is no acidity, it is selected according to the temperature of the dust-containing gas. When the temperature is normal or ≤130°C, the polyester needle-punched felt of 500-550g/m2 is commonly used. When <250°C, use aramid Nomex needled felt or 800g/m2 glass fiber needled felt or 800g/m2 weft double glass fiber fabric or FMS [FMS] high temperature filter material (fluorine-containing gas cannot be used fiberglass material). When the water content is large and the dust concentration is large, it is advisable to use waterproof, oil-proof filter material (or anti-condensation filter material) or film-coated filter material (the base cloth should be needle-punched felt with waterproof treatment). When the dusty gas contains acid and alkali and the gas temperature is less than or equal to 190°C, Ryton (polyphenylene sulfide) needle-punched felt is often used. When the gas temperature is less than or equal to 240°C, and the requirements for acid and alkali resistance are not too high, P84 (polyimide) needle felt is selected. When the dust-containing gas is flammable and explosive gas, choose anti-static nylon needle-punched felt; when the dust-containing gas has a certain amount of moisture and is flammable and explosive gas, choose waterproof, oil-proof, anti-static (three-proof) Talon needle-punched felt.

3. Controller: The ash cleaning control of the pulse bag filter adopts a PLC microcomputer program controller, which is divided into three control modes: constant pressure (automatic), timing (automatic) and manual. Constant pressure control: control according to the set pressure difference, if the pressure difference of the dust collector exceeds the set value, each chamber will automatically clean the dust one by one. Timing control: According to the set time, every cleaning cycle, each room is cleaned in turn. Manual control: The on-site operation cabinet can be manually controlled to automatically clean the ash in each room in turn, or each room can be cleaned individually. The control method is selected by the user. If the user does not require it, the supply will be controlled according to the timing.

Installation of pulse bag filter

1. Construct according to the equipment foundation drawing, and do a good job of the concrete foundation for equipment installation.

2. After the foundation concrete reaches the standard strength, install the dust collector according to the following steps.

Implementation of the standard "bag filter installation technical requirements and acceptance specifications"

①Dust collector foundation

②Lower box

③Upper box

④ Fan, motor

⑤Cleaning device

⑥Air bag solenoid valve

⑦ Filter cage, filter bag

⑧Connect the power

⑨ Seal inspection, installation quality inspection

Debugging of pulse bag filter

1. Do a good job in preparing the equipment before commissioning with no-load operation.

2. Debug according to the following steps:

⑴. Adjust the ash cleaning controller to ensure that the electromagnetic pulse valve action sequence is correct, and the sequence of the ash cleaning units is correct.

(2) Check the volts of the electromagnetic pulse valve and the electronic control part (24V or 220V),

(3) Check whether the seals on the equipment are loose or fall off.

⑷. The pressure of compressed air for blowing should be kept at 5～7㎏/cm.

⑸. Check whether the motor and mechanical transmission part of the equipment are running normally.

⑹. Check whether the bag cage and filter bag on the equipment are firmly installed.

⑺. Carry out no-load operation and debugging of equipment, and require all parts to operate normally.

⑻. Carry out the commissioning of the equipment under load. All parts are required to operate normally, and the cleaning cycle (resistance method or timing method) should be adjusted according to the change of equipment operating resistance.

Operating procedures for pulse bag filter

(1) Local operation

Turn on the power switch, the power indicator light is on, switch the local remote switch to the local position (that is, turn the switch to the left to the end), press the fan start button, the fan starts to run, and observe whether the fan rotates correctly, after the fan rotates normally, that is It can be put into normal dust removal work. After a period of time, if it is necessary to clean and discharge dust (for example, if the air compressor is equipped with an air compressor first, then clean the dust), press the "clean dust start" button, the pulse valve will be opened to remove dust, and the screw will be turned on. The machine and the ash discharge valve also work at the same time. If you need to end the ash cleaning work, press the "clean ash stop" button. If the dust removal work is finally stopped, press the "fan stop" button.

(2) Remote control

Switch the local remote switch to the program-controlled position (that is, turn the switch to the right to the end), the short dry contact HJ of the remote start unit will be delivered, and the fan will run (such as with an air compressor, and the air compressor will run at the same time), as long as the fan rotates correctly, It can be put into normal dust removal. At this time, the timed cleaning control is implemented, that is, the dust removal runs for a period of time (adjustable for about 1 to 2 hours), and the cleaning control is automatically put into operation. Adjustable), after working for a period of time, it will automatically stop cleaning, and then enter the next cycle of automatic dust removal, cleaning, and ash removal, until the remote stop unit short dry contact TJ is delivered, and the unit stops.

(3) Matters needing attention:

1. The dust collector unit realizes on-line cleaning control;

2. The interval time of timed cleaning of the unit and the time of online cleaning are automatically executed by the time relay (adjustable);

3. Before cleaning the dust, pay attention to opening the valve on the air compressor and the air bag of the equipment, and there must be an air source and pressure.

Maintenance and maintenance of pulse bag filter

1. According to

Pulse bag filter

Pulse bag filter (4 photos)

 The dust volume of the dust collector [4] determines the regular dust removal maintenance time.

2. According to the accumulation of water in the air bag, determine the regular discharge of accumulated water.

3. Always check whether the pulse cleaning system of the dust collector is working normally. If it is not normal, focus on checking the loss of the diaphragm of the pulse valve and whether the electromagnetic pulse valve is out of order, and replace it in time. Filter bags should be cleaned and replaced regularly.

4. Regularly check whether the equipment is running normally according to the fluctuation of the resistance of the equipment.

5. Always check the usage of wearing parts according to the list of wearing parts.

6. Regularly add grease to the lubricating parts of the equipment, change the lubricating oil for the reducer every six months, and replenish the bearing lubrication points once a week.

7. Pay attention to checking whether the sealing degree of the electric control box is in good condition, prevent water and dust from entering, and clean the dust in the electric control box frequently.