Low-frequency and low-pressure control energy-saving method suitable for pulse valve of dust collector

Abstract

The present application relates to the technical field of valve control, and discloses a low-frequency and low-pressure control energy-saving method suitable for a pulse valve of a dust collector, which comprises the following steps: 1) changing the blowing frequency of the pulse valve to reduce the pulse frequency per unit time; 2) changing the opening time of the pulse valve to stabilize the pressure difference of the dust collector; 3) controlling the blowing pressure of the gas cylinder of the pulse valve to obtain stable blowing pressure; and 4) operating the dust collector under stable pressure difference and adjusting the blowing interval time of the pulse valve in seconds. The present application changes the previous operation mode of the pulse valve, controls the opening frequency, pressure and opening time of the pulse valve reasonably, improves the service life of the blowing component, reduces the operating pressure difference of the dust collector, reduces the consumption cost of the gas medium, guarantees the dust removal effect of the user and meets the requirements of the ultra-low emission standard.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valve control, in particular to a low-frequency and low-pressure control energy-saving method suitable for a pulse valve of a dust collector. BACKGROUND

[0002] A large amount of smoke dust is generated in the process of mixing molten iron and smelting in a converter, part of which is collected and filtered by a bag-type environmental dust collector. The smoke dust particles filtered by the bag-type dust collector are adsorbed onto the surface of the bag. This part of the smoke dust is rapidly sprayed into the bag by a pulse blowing valve opened at a fixed time, and the bag instantaneously expands to shake off the dust. The interval between two adjacent pulse valves is 6 seconds, and the opening time of the pulse valve is 0.2 seconds. The blowing mode between the valves is continuous and cyclic blowing. The running pressure difference of the dust collector is between 980 Pa and 1023 Pa, which is lower than the design rated pressure difference of 1700 Pa. This high-frequency blowing and low-pressure difference running mode causes frequent damage to the pulse blowing valve and the bag during operation, blowing pipe falling off, pressure difference fluctuation, particulate matter exceeding the emission index, and high cost of compressed air, etc. The specific circumstances are as follows:

[0003] a. The pulse valve with high-frequency blowing is prone to damage, has a short service life, and has high cost of spare parts replacement:

[0004] The interval time between two pulse blowing valves is 6 seconds. The dust collector has 48 groups of pulse blowing valves, each group having 6 pulse blowing valves. The interval time between two adjacent pulse blowing valve groups is 6 seconds. The daily blowing cycle is: (24 hours / day x 3600 seconds / hour) ÷ (48 groups x 6 pulse valves / group x 6 seconds interval time + 48 groups x 6 seconds / group interval time) = 42.857 times. That is, each blowing valve needs to be blown 43 times a day. When measured in months, the online continuous use cycle of the blowing valve is 8-12 months due to natural weathering, the service life is short, and the cost of spare parts replacement is high. The purchase price of each blowing valve is about 180 yuan.

[0005] b. High cost of compressed air medium energy:

[0006] The opening time of the blowing valve is 0.2 seconds, and the interval time is 6 seconds. The running pressure difference of the dust collector is between 980 Pa and 1023 Pa, which is far lower than the design rated pressure difference of 1700 Pa. The pulse interval time of 6 seconds causes the pulse valves to be in a continuous blowing state, causing the compressed air in the cylinder to be continuously output. The blowing flow rate is as high as 1250 m3 / hour. The bag surface is relatively clean after checking and cleaning the dust, and there is an excessive cleaning phenomenon. The processing cost of compressed air is 0.08 yuan / m3, increasing the cost of gas medium.

[0007] c. Easy to cause the blowing pipe to fall off and the dust collector to be in a high-pressure difference running state:

[0008] The blow pressure of the gas cylinder is 0.5 MP, and the blow time of the pulse blow valve is 0.2 seconds each time. When the general blow pressure is greater than 0.4 MPa, the diffusion angle of the air flow instantaneously sprayed along the axis of the blow pipe will be smaller, the air suction amount of the air around the blow pipe will be more, the blow pipe will be subjected to upward reaction force, and the blow pipe will be instantaneously bent upward. Under the action of repeated impact load, the blow pipe will be loosened and then fall off. The surface ash of the bag cannot be cleaned in time, the air permeability of the bag is reduced, the resistance is increased, and when the number of the blow pipe falling off exceeds 20% of the total number, the pressure difference of the dust collector will rapidly increase. If the blow pipe falling off cannot be recovered for a long time, a large amount of dust will enter the air holes of the bag, the bag cannot be completely cleaned, the bag will be permanently invalid, and the dust collector will run at high pressure difference.

[0009] d. The bag joint is easy to expand, which increases the risk of exceeding the emission standard:

[0010] When the working pressure is 0.5 MPa, the air volume of the pulse valve is about 500 liters per blow, and the air around the blow pipe is instantaneously introduced by the air flow, which will make the bag expand rapidly. Frequent large air expansion and contraction will cause the bag to be damaged at the joint, and the dust will be directly discharged into the atmosphere around the dust collector without filtration, which increases the risk of exceeding the emission standard.

[0011] e. High frequency and long time continuous blow mode is easy to cause the gas cylinder to be insufficient, which reduces the service life of the bag:

[0012] The pulse valve interval time of 6 seconds and the long time blow of 0.2 seconds cannot supply the pressure of the gas cylinder in time, which causes the gas cylinder to run at a low pressure below 0.3 MPa for a long time. The air blow volume of the pulse valve and the air intake around the blow pipe are reduced, the bag cannot expand rapidly, the shaking force of the bag is reduced, the surface ash cannot be completely cleaned, and the dust pressure difference of the dust collector will gradually increase with the increase of the running time. When the pressure difference exceeds the rated pressure difference of 1600 Pa, a large amount of dust will enter the air holes of the bag and cause serious blockage, the filtering effect will be obviously reduced, the bag will be in an invalid state and reach the scrap standard, and the service life of the bag is reduced.

[0013] Therefore, in order to solve the problems in the background art, eliminate the disadvantages in the high frequency pulse blow process of the dust collector, improve the cleaning effect of the bag of the dust collector, prolong the service life of the bag and the pulse valve, reduce the cost of compressed air medium, and provide a technical measure for achieving long service life of components and low control of medium cost by changing the blow frequency, valve opening time and blow pressure of the pulse valve. SUMMARY

[0014] Aiming at the problems in the prior art, the present application aims to provide a low-frequency and low-pressure control energy-saving method suitable for a pulse valve of a dust collector.

[0015] The technical scheme adopted by the present application to solve its technical problems is: a low-frequency and low-pressure control energy-saving method suitable for a pulse valve of a dust collector, comprising the following steps:

[0016] 1) changing the blowing frequency of the pulse valve to reduce the number of pulses per unit time;

[0017] 2) changing the opening time of the pulse valve to stabilize the pressure difference of the dust collector;

[0018] 3) controlling the blowing pressure of the pulse valve to obtain stable blowing pressure;

[0019] 4) running the dust collector under stable pressure difference and gradually adjusting the blowing interval time of the pulse valve in seconds.

[0020] Specifically, the blowing interval time of the pulse valve in step 1) is extended from 6 seconds to 30 seconds, and the number of pulses per day is reduced from 42 times to 8.6 times.

[0021] Specifically, in step 2), the pressure difference of the dust collector is stabilized to 950-1050 Pa, the opening time of the pulse valve is reduced from 0.2 seconds to 0.15 seconds, and the daily consumption of compressed air medium is reduced from 7.54 million m 3 to 6.48 million m 3 .

[0022] Specifically, in step 3), the blowing pressure of the cylinder is adjusted from 0.5 MPa to 0.32-0.37 MPa, the blowing pressure is reasonably controlled, the opening flow of the pulse valve is reduced from 500 liters / time to 300-350 liters / time, the air suction amount around the blowing pipe is also reduced, the reaction force of the blowing pipe is reduced, the blowing pipe shedding phenomenon is eliminated, the running pressure difference of the dust collector is stabilized to below 1000 Pa, and the normal operation of the dust collector pressure difference is restored.

[0023] Specifically, in step 4), when the dust collector runs under stable pressure difference, the blowing interval time is increased by 1 second every 3-5 days, and the blowing interval time is extended from 6 seconds to 30 seconds.

[0024] The present application has the following beneficial effects:

[0025] The low-frequency and low-pressure control energy-saving method suitable for the pulse valve of the dust remover changes the previous operation mode of the pulse valve, improves the service life of the blowing component, reduces the pressure difference of the dust remover, reduces the consumption cost of the gas medium, guarantees the dust removal effect of the user, and meets the requirements of the ultra-low emission standard.

[0026] a. The low-frequency control mode can prolong the service life of the pulse valve and the bag, and reduce the consumption cost of spare parts.

[0027] b. The long-time interval adjustment of the pulse valve can effectively reduce the cost of the gas medium.

[0028] c. The interval time of the pulse blowing is prolonged, the working pressure of the gas cylinder is reasonably controlled and stabilized, and the phenomenon of the spray pipe falling off is effectively controlled.

[0029] d. The reasonable blowing pressure and the air intake amount can improve the cleaning effect of the floating dust of the bag, reduce the air permeability of the bag, reasonably control the pressure difference of the dust remover, and improve the dust removal effect of the user. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application are further described in detail below. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0031] A blowing valve adjustment method for a bag-type dust collector mainly controls the dust collector pressure, frequency and blowing time reasonably to achieve the purposes of blowing pressure adjustment, low consumption of medium gas, short development time control and long service life of components, reduce the working pressure difference of the dust collector, improve the dust removal effect of the user, realize ultra-low dust emission, and the specific implementation measures are as follows:

[0032] a. Under the condition of ensuring that the pressure difference of the dust collector is below 1000 Pa and stable operation, the blowing interval time of the pulse valve is gradually adjusted in seconds. In principle, 1 second is added every 3-5 days. During the adjustment of the blowing interval time, the adjustment of the once-through dust removal system is used to stabilize the flue gas emitted from the converter mouth, stabilize the speed of the bag-type dust collector fan, eliminate external interference of the pressure difference fluctuation, gradually prolong the blowing interval time from 6 seconds to 30 seconds, and reduce the blowing period from 42 times per day to 8.6 times per day.

[0033] b. After the dust collector pressure difference is stabilized between 950-1050 Pa and the gas supply pressure of the gas cylinder is between 0.32-0.37 MPa, the opening time of the blowing valve is reduced from 0.2 seconds to 0.15 seconds. The pressure control consumption is judged by a compressed air flowmeter, and the daily consumption of compressed air medium is reduced from 75.4 thousand m3 to 6.48 million m 3 , the compressed air medium is reduced by 1.06 million m 3 .

[0034] c. After adjusting the air cylinder injection pressure to 0.32-0.37 MPa, the injection gas volume of the pulse injection valve is reduced from 500 liters / time to 300-350 liters / time through the cumulative measurement and consumption calculation of compressed air. According to the principle of fluid jet, reducing the gas flow rate of the injection port also reduces the suction amount of air around the injection pipe, reduces the reaction force of the injection pipe, and reduces the deformation amount of the injection pipe, avoiding the phenomenon of injection pipe falling off. The operating pressure difference of the dust collector is stabilized to below 1000 Pa, so that the dust collector can operate within the normal pressure difference control range.

[0035] d. The injection time is reduced from 0.2 seconds to 0.15 seconds, and the injection pressure of the air cylinder is reduced from 0.5 MPa to 0.32-0.37 MPa. Reasonable control of the injection pressure solves the problems of bag interface expansion and bag wear (the lower the compressed air pressure value, the smaller the degree of filter bag wear. If the cleaning effect is good, the cleaning air pressure value should be adjusted to a smaller range as much as possible), prevents smoke from being directly discharged into the atmosphere around the dust collector, and realizes ultra-low emission operation of the dust collector.

[0036] e. The injection interval time of the pulse injection valve is extended from 6 seconds to 30 seconds, and the pulse frequency is reduced from 42 times per day to 8.6 times per day. The pressure supplementing time of the air cylinder is increased to 30 seconds, the injection pressure is stabilized to 0.32-0.37 MPa, the injection time is reduced from 0.2 seconds to 0.15 seconds, and the filter bag reaches rapid expansion under appropriate injection pressure. The surface ash is thoroughly cleaned, the fine pores of the filter bag are prevented from being sucked into too much dust, and the service life of the filter bag is increased.

[0037] The present application is not limited to the above-mentioned embodiments, and any person should know that the structural changes made under the inspiration of the present application fall within the protection scope of the present application.

[0038] The technical, shape, and structure parts not described in detail in the present application are well-known technologies.

Claims

1. A low frequency, low pressure control energy saving method suitable for use in a pulse valve of a dust collector, characterized in that, The method comprises the following steps: 1) changing the blowing frequency of the pulse valve, reducing the number of pulses per unit time, and extending the blowing interval time of the pulse valve from 6 seconds to 30 seconds, and reducing the number of pulses per day from 42 times to 8.6 times; 2) change the opening time of pulse valve, the opening time of pulse valve is reduced from 0.2 seconds to 0.15 seconds, the daily consumption of compressed air medium is reduced from 75.4 thousand m 3 to 64.8 thousand m 3 , the pressure difference of dust collector is stabilized to 950-1050 Pa; 3) controlling the blowing pressure of the pulse valve gas cylinder to obtain stable blowing pressure, adjusting the blowing pressure of the pulse valve gas cylinder to 0.32-0.37 MPa, reasonably controlling the blowing pressure, reducing the opening flow of the pulse valve from 500 liters / time to 300-350 liters / time, correspondingly reducing the air suction amount around the blowing pipe, reducing the reaction force of the blowing pipe, eliminating the blowing pipe shedding phenomenon, stabilizing the operation pressure difference of the dust collector to below 1000 Pa, and restoring the normal operation of the dust collector pressure difference; 4) running the dust collector under stable pressure difference, adjusting the blowing interval time of the pulse valve in seconds, increasing the blowing interval time by 1 second every 3-5 days, and realizing the change of the blowing interval time from 6 seconds to 30 seconds.