Pulse Bag Dust Remover

The sack cleaner equipment is an important complementing machine in the hydropower station, it is necessary to take certain protective measure to it. This kind of protection is simpler, can guarantee under the unusual operating mode condition the sack cleaner is not damaged the automatic protective measure taken.

1. The bypass is protected

The bypass is protected to set up the bypass valve on the exit flue of the sack cleaner. As the warm temperature range that exceeds the filter bag and bears of cigarette, or the filter bag presses difference greatly when establishing value and can't lower, the bypass valve is turned on automatically, the imported and exported valve of the sack cleaner is closed, the exhaust gas passes the air-introduced machine and arranges to the chimney directly. There are built-in and putting type two kinds outside of bypass valves. The built-in bypass valve is set up on the exit flue that is passing the of the sack cleaner, the structure is compact.

Though this kind of bypass valve protective measure can get up effective protection to the sack cleaner, however, the exhaust gas has not undergone dust removal and reached the air-introduced machine directly, the wearing and tearing to the air-introduced machine is very serious; And discharge directly allow either. So, this kind of protective measure can only play the protective action in the twinkling of an eye in the warm ultra limit of cigarette, then the boiler should stop transport as soon as possible. In America and Europe, the country with very tight requirement for environment protection of some of Australia does not allow to adopt. If take this kind of bypass protective measure, bypass valve very important. Because only there is revealed little by little in the bypass valve, how long does it need, bypass valve seal will is it decrease to blow seriously, is it increase obviously to reveal, discharge and exceed standard, suck the air blower to wear and tear seriously but damages. It is very difficult that the built-in bypass valve should reach for a long time too tightly to leak in the exhaust gas that temperature changes. In order to solve the problem of revealing abroad, have designed and made the guard door of one pair of shutter types. This kind of guard valve has two layers and one hundred leaves, fill low-voltage to compress air between two one hundred leaf, is it make pairs of guard valve of shutter type leak the exhaust gas to heat all the time.

2. The open cold wind lowers the temperature

There is an open low-temperature wind on the flue in front of the imported guard door in the sack cleaner in this kind of protection ( It is generally atmosphere)  Automatically controlled valve. This valve is closed under the normal situation, as presenting the unusual operating mode (cigarette exceeds the temperature that the filter bag can be born warmly) When door open automatically not entering it play a role in protecting the filter bag lowering the temperature cold wind.

Which adopts this kind of protective measure, should pay attention to:

--The choice of entering wind quantity wants rationally. Because too big words of the amount of cold wind entered, the capacity of the related air-introduced machine obviously increases, must set up the exit with enough capacity on the export flue of the dust remover. In addition, the amount of cold wind entered is big, it is of great impact that the defeat to the burner hearth is pigeonholed, unfavorable to the steady burning of the boiler and automatic control of the aircrew.

--Because after entering the cold air, the oxygen content in the exhaust gas obviously increases, some strain material very sensitive to the oxygen content in the exhaust gas, so unsuitable to adopt protective measure of this kind of drop in the temperature in using this kind of sack cleaner which strains the material.

--In unusual cases, after the protective measure of two kinds of above-mentioned drop in the temperature works, still can't make the dust warm and drop to of the normal working range because of a certain other special reasons, that can only emergency shut down avoid cause unnecessary accident.

No matter which kind of forms of clear gray devices is adopted, the purpose of the clear dust and principle needing following are the same. Namely accumulating the dust to increase constantly on the filter bag, press difference to increase until a certain value before and after the filter bag, carry on the clear dust to the filter bag soon, will make the filter bag resume more ideal clean state. Two o'clock needs to pay attention to:

1. The clear dust can't be too frequent and too violent, the filter bag surface must be kept one layer and strain layer ( Can't strain material one arrived to collect strain layer clear to shed already)  ,This will be in the clear gray intensity soon ( Including clear gray frequency)  Consider at the time of the design.

2. Need the filter bag of clear dust to press difference and establish and click establishing rationally according to the operating position of the filter bag. Keep difference is it can't make too high a bit to establish, otherwise running time long detailed gray particle can imbed filter bag to be too dark, influence filter bag service life. Later stage in filter bag service life, because the thin gray particle imbeds filter bags already more, the frequency of the clear dust should increase.

With the constant development of science and technology, the control of the clear dust adopts PLC procedure to control now. The most ideal clear gray procedure presses difference before and after every filter bag and begins the clear dust while reaching the establishing value in theory, get difference of pressing and stop the clear dust while dropping to some one piece of establishing value. But the difference of pressing of determining each filter bag in fact is impossible. So clear gray procedure to filter to keep difference and keep according to each time size two parameter these, difference of change is it design to come unit generally. In normal cases, the clear gray system will be according to working out various kinds of good clear gray procedures and carrying on automatic clear dust and (" clear dust of timing " in advance according to the parameters measured Or " press the clear dust definitely " ). (measure component trouble, operating mode unusual operation have under special circumstances   ,etc.) ,Can switch over and control clear dust manually. Natural PLC procedure control device has functions, presenting the unusual situation will report to the police at any time, remind and operate personnel and pay attention to or take the emergency measure.

Carry on the clear dust when press difference and reach the establishing value on both sides of filter bag. Clear dust hour, is it promote clear the export, dust removal of unit of dust valve shut off, open blowback promote valve to want (dry by one low-voltage to offer against the hair-dryer instead) ,A stream of low-voltage wind enters and cleans the exhaust gas room to blow to the filter bag backward together with clean exhaust gas, make filter bag shrivel out of shape, dust is it is it fall into achieve clear purpose of dust to fall to clear gray Entrance, dry and promote the valve to close ,this unit is put into operation. Then turn into the next unit of dust removal and carry on the clear dust. Clear gray movements are slower for this way, the mechanical tension of acting on filter bag is relatively small, relatively light too to the damage of the filter bag. But the clear gray result comparatively speaking wants difference a little, so sometimes need continuous blowback to turn into the next clear dust of unit several times.

In addition, it is very important that the export of each dust removal unit promotes the tightness of the valve, otherwise reveal against the briefing, influence the result of the clear dust.

1. The blowback type sack cleaner of exhaust gas: Clean exhaust gas low-speed blow the sack backward after it utilizes and filters, make the sack out of shape to achieve the purpose of the clear dust. The sealing in the end mechanical tension that the dust remover of this form acts on sack in the clear dust is small, suitable for the dust remover of the filter bag of the glass .

2. The shaking type of machinery (vibration type) Sack cleaner: Like blowback sack cleaner of exhaust gas, the dust is collected in bag too. Its mechanical intensity to filter bag is expected relatively much, not so suitable to the filter bag of the glass.

3. Clear dust type sack cleaner of pulse: Different from the bag dust removers of first two kinds of patterns, the dust is collected outside the filter bag, the filter bag is supported by one bag of inside metal cages. Its clear dust is gushed out periodically by the clean compressed air to enter it in the filter bag, deform filter bag, remove the dust stockpiled outside the filter bag. The pressure, intensity and duration of the pulse of compressing the air are with different using the occasion to regulate, can divide the pulse blowback type sack cleaner into again according to these parameters:

--High-pressure pulse type: The pressure is to compress the air: 0.60-0.80Mpa

--China presses the pulse type: The pressure is to compress the air: 0.20-0.40Mpa

--Low-voltage pulse type: The pressure is to compress the air: 0.06-0.10Mpa