Selection basis
The air volume of the bag type dust collector refers to the volume of the gas that can be purified by the dust removal equipment per unit time. When designing or selecting the bag type dust collector according to the air volume, the dust collector cannot generally be operated in excess of the specified air volume. Otherwise, The filter bag is easy to block, the life is shortened, the pressure loss is greatly increased, and the dust removal efficiency is also reduced; but the air volume cannot be selected too much, otherwise the equipment investment and floor space are increased, and resources are wasted and energy saving is not performed.
Reasonable choices to handle air volume are often determined by process conditions and experience. The inlet dust concentration will directly affect the following factors:
1. Pressure loss and cleaning cycle
As the inlet concentration increases, the ash deposition rate on the same filtration area is fast, and the pressure loss increases, with the result that the number of cleaning operations has to be increased.
2, the way of operation
The bag type dust collector is divided into two types of operation modes: positive pressure and negative pressure. In order to reduce the wear of the fan, it is not suitable to use the positive pressure operation mode when the inlet concentration is large.
3. Pre-collection is necessary
Pre-collection dust is to add a first-stage dust removal equipment before the entrance of the dust collector, also known as pre-stage dust removal.
4. Wear of filter bags and cabinets
In the case where the dust is highly abrasive, the amount of wear can be considered to be proportional to the dust concentration.
5. Ash discharge capacity of the ash discharge device
The ash discharge capacity of the ash discharge device shall be based on the ability to discharge all the collected dust, and the dust amount is equal to the inlet dust concentration multiplied by the treated air volume.
Export dust concentration
The concentration of dust in the outlet refers to the concentration of the dust collector. The method is the same as the dust concentration of the inlet. The concentration of the dust in the outlet should be determined by local environmental protection requirements or the requirements of the user. The discharge concentration of the bag filter can generally reach 50mg/ Below Nm3.
Operating temperature
For bag filters, the temperature of use depends on two factors, the first is the maximum temperature of the filter material, and the second is that the gas temperature must be above the dew point temperature. At present, due to the large selection of glass fiber filter materials, the maximum use temperature can reach 280 ° C. For gases above this temperature, cooling measures must be taken. For gases below the dew point temperature, temperature adjustment measures must be taken.
Damaged bag
The bag samples were tested and the results showed that the air permeability, burst strength and breaking strength of the other parts except the damaged part were within the range of use. At the same time, it was found that the damaged part of the dust bag was almost 20 to 40 cm away from the bag mouth, and it was damaged from the internal wear. It is determined that the main reason should be related to the backflush system. First, the nozzle of the backflushing system is not correct, causing backflush deflection; on the other hand, the pressure of the backflushing compressed air is too large.
solution
1. Carry out the transformation of the injection system, which has high transformation cost and long cycle and cannot be completed within the normal maintenance period. After research, it was decided to add a sheath in the bag. This method is simple and easy to operate, and the cost is relatively low.
2. The anti-blowing compressed air pressure is controlled between 0.25 and 0.35 MPa, which can clear the ash on the bag. If the pressure is too high, the service life of the bag will be affected. It can be adjusted by observing the change of the pressure difference between the inlet and outlet of the precipitator, so that the pressure difference is within the control requirement range (design pressure difference <1700Pa).
3. Adjust the blowing program to adjust the pulse width from 150ms to 250ms to reduce the intensity of the spray and reduce the wear of the bag.
The poppet valve is stopped due to insufficient compressed air
1. The oil-water separator between the gas storage tank and the poppet valve is clogged with the filter element due to dirty air;
2. After the lifting valve is operated for a long time, the seal is worn, causing leakage of compressed air, resulting in insufficient air supply.
solution
1. Add a set of oil-water separators, one for each. When the filter element is found to be dirty, another set can be replaced to clean the dirty set;
2. In addition to timely replacement of the poppet valve seal, the following measures should be taken: the supply pressure of the poppet valve is adjusted between 0.25 and 0.5 MPa, ensuring that each poppet valve can operate within the specified time, and the pressure should not be too high. Otherwise, it is easy to age the cylinder seal. When the leak point increases, the supply pressure can be appropriately increased. Ensure that the oil-water separator supplies oil, and the oil supply speed should not be too small to avoid oil loss. In addition, add a certain amount of grease to the stem of the lift cylinder.
3. The dust collector can be operated under negative pressure or positive pressure. The body structure has no change, the dust collection efficiency is over 99.8%, the dust concentration of the purified gas is <100mg/m3, and the dust collector is used in cold regions or the smoke is lower than At zero point, an insulation heating device should be added, and the housing should be changed accordingly. The dust collector consists of a chain transmission device and a switching pulsation valve. The high-pressure fan is used for backflushing and cleaning. It is not restricted by the gas source conditions. The resistance is automatically controlled to reduce the dust and save energy to extend the use of the dust filter bag. Other areas in the cold area are installed indoors. It can be installed outdoors and can be widely used in many departments such as machinery, casting, mining, smelting, building materials, food and chemical industry.
Application scope:
Skin package for grouped food and drinks,bowl noodles,milk tea,mosquito coils,wallpaper,exercise books,filters,electrical switches,a variety of stationery,industry parts,commodities and cosmetics,etc.
Performance Characteristics:
1.Driven by three servo motors, the whole machine is easy to operate, the stability is high, the packaging efficiency is high
2.There are few mechanical components, which greatly reduce the failure rate, easy maintenance and less noise.
3.Adopt the design of reciprocating transversely sealed knife base, with beautiful appearance and good sealing performance.
4.High sensitivity photoelectric eye color standard tracking, mathematically input sealing position, so as to make the sealing position more accurate.
5.Side sealing can use electrostatic adsorption instead of heat sealing, so as to save the cost of packaging film, and the sealing line is smoother and beautiful.
6.Cantilever frame design body, robust and durable.
7.Temperature independent PID control, better suitable for various coating materials.
8.Positioning stop function, non-sticking knife, no waste of film.
9.The transmission system is simple, reliable and easy to maintain.
10.with automatic reversal of the cutter when cut to package, start up directly after restart for easy operation.
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Ruian Science Machinery And Technology Co., Ltd. , https://www.science-pack.com