What is the offline valve and bypass valve of boiler bag filter and its function

Bypass protection is to set a bypass valve on the inlet and outlet flue of the boiler bag filter. When the flue gas temperature exceeds the temperature range that the filter bag can bear, or the pressure difference of the filter bag is greater than the set value and cannot be lowered, the bypass valve is automatically opened, the inlet and outlet valves of the boiler bag filter are closed, and the flue gas is directly discharged to the chimney through the induced draft fan. There are two types of bypass valves: built-in and external.

The built-in bypass valve is set on the inlet and outlet flue through the bag filter body, and the structure is compact. Although this bypass valve protection measure can effectively protect the bag filter, the flue gas is directly to the induced draft fan without dust removal, and the wear and tear of the induced draft fan is very serious; And direct emissions are also not allowed. Therefore, this protective measure can only play a momentary protective role when the flue gas temperature exceeds the limit, and then the boiler should be shut down as soon as possible.

If this bypass protection is to be taken, it is very important that the bypass valve is tight. Because as long as there is a little leakage of the bypass valve, it will not take long for the sealing surface of the bypass valve to be seriously blown and damaged, the leakage will increase significantly, the discharge will exceed the standard, and the suction fan will be seriously worn and damaged. It is difficult to achieve long-term tightness in flue gases with variable temperatures with built-in bypass valves.

In order to solve the leakage problem, foreign countries have designed and manufactured double shutter baffle doors. This baffle valve has two layers of louvers, between which low-pressure compressed air is always filled and heated so that the double louvered baffle valve does not leak smoke.

The offline method of boiler bag filter is: It is convenient for dust collector cleaning. Dust bag to clean ash stone. The off-line valve works to cut off the inlet and outlet air. Cleaning is carried out in a confined space. The dust has sufficient time to settle. There will be no secondary adsorption.

A bypass valve refers to a bypass valve. That is, the flue gas is directly discharged to the chimney without passing through the dust collector, and it is not allowed to install a bypass valve at present.

Where is the boiler bag dust removal pulse valve used1. Connect the electric control valves and connect the control lines of the bag filter to the terminal seat of the electric control valve. In particular, it should be reminded that when we connect the control wires, the inlet port should prevent the inflow of rainwater in the later use process, and the inlet port is required to go downward, or use a joint and a section of nylon pipe to connect the air control valve and the electromagnetic assembly box.

2. The pulse valve is installed according to the actual design of the bag filter selection and design, with the appropriate blowing pipe and mounting parts, the pulse valve installation position should be correct, generally speaking, the pulse valve is installed on the flange seat on the outer wall of the air bag, and the injection passes through the air bag, and the valve cannot be installed upside down at the bottom of the air bag. What needs to be reminded here is that the valve of the bag filter is equipped with an air outlet pipe and a bulkhead connector, and the bulkhead connector cannot be used as a structural support component, and it cannot rely on the bulkhead connector alone to fix the air bag and blow pipe.

And the air bag and blow pipe are fixed. 3. Tighten the stuffy nut Tighten the stuffy nut with a torque of 20nm; Tighten the outlet pipe, the torque is 20N, test the working condition of the pulse valve of the bag filter, test the injection sequence of the pulse valve of the bag filter, test whether all the pilot valves are operating normally, and whether the pulse injection sound is crisp.

Generally, boiler bag filters have off-line valves and bypass valvesOff-line valvesIt is one for each silo chamber, and when the pulse valve is cleaned, it plays a role in closing a silo to achieve off-line cleaning. The bypass valve is the self-protection of the dust collector under the boiler ignition oil injection and flue gas temperature abnormalities and other boiler accident conditions, and can timely alarm and send a signal through the control system to open the bypass valve in time, so that the high temperature abnormal flue gas is directly discharged from the flue without passing through the filter bag, so as to avoid damage to the filter bag. The off-line valve is equipped with one in each chamber of the boiler dust collector, so that the boiler dust collector has the functions of offline cleaning and offline maintenance.

The poppet valve is a thin plate structure. Controlled by the cylinder, the valve cylinder seal is imported products, and the voltage level of the two-position five-way solenoid valve is 24V. The whole set of valves is simple and reliable, the opening and closing speed is fast, and one or more silos can be controlled to work at the same time through PLC, and one or more silos can be closed for off-line ash cleaning and off-line maintenance.

When the poppet valve and the manual switching valve are closed, it can ensure that the silo is completely offline, and realize the single-bin maintenance under the working condition of the dust collector (the manual switching valve can also be used to adjust the air intake), and the limiting device on the poppet valve can enable the operator to detect its operation status in time. The boiler dust collector off-line valve (or poppet valve) adopts the form of pneumatic quick-opening gland, which is a simple and reliable linear motion to avoid the trouble caused by the high rotation failure rate. The sealing ring is made of acid-alkali resistant and high-temperature resistant fluoroelastomer, and the general temperature resistance reaches 250 degrees.

Boiler bag filter bypass valve (or bypass valve).It adopts the form of pneumatic quick-opening gland, which is a simple and reliable linear motion and avoids the trouble caused by the high rotation failure rate. The cylinder controls the up and down movement of the valve plate, and the sealing ring is made of acid-alkali resistant and high-temperature resistant fluorine rubber, and the general temperature resistance reaches 250 degrees, which ensures zero leakage, ensures the self-protection of the dust collector under the boiler ignition oil injection and flue gas temperature abnormalities and other boiler accident conditions, and can alarm in time through the control system. The bypass valve is a thin plate structure.

Controlled by the cylinder, the valve cylinder seal is imported products, and the voltage level of the two-position five-way solenoid valve is 24V. The whole set of valves is simple and reliable, and the opening and closing speed is fast. The bypass flue of the boiler dust collector, when the boiler (or incinerator) is started, the bypass flue is opened to prevent the oil from burning badly during ignition, the oil sticks to the filter bag, and the filter bag is burned in case of open flame.

When the boiler has an accident, when the exhaust gas temperature exceeds the allowable temperature of the filter bag, the bypass is opened and discharged directly.

The offline valve of the bag filter should be the so-called dust removal cylinder.

By installing a PTFE support ring on the piston, the dust removal cylinder keeps the sealing performance uniform when the piston is moving, so as to reduce wear and prolong the service life. The buffer device adopts a new foreign structure, which can play the role of a check valve, making the cylinder structure more compact and reasonable.

The formation of negative pressure you said is generally that the design and selection of dust removal cylinders is small, and if the negative pressure is large, it will cause insufficient lifting capacity.

If you still have problems related to the dust removal cylinder, you can consult Hebei Jiuzheng Tongming.