Blowing pipe

Abstract

The utility model discloses a blowing pipe which is located above a plurality of cloth bags, and a plurality of blowing holes are formed in the blowing pipe. The position of the blowing hole corresponds to the position of the cloth bag; the sum of the sectional areas of all the injection holes is greater than 1.2 times of the inner diameter sectional area of the injection pipe; and the injection range of the injection holes is between 25 degrees and 35 degrees. According to the utility model, the service life of the bag in the bag-type dust collector can be prolonged, and the use cost is saved.

Description

Technical Field

[0001] The utility model relates to a blowpipe technology in the field of bag dust collectors, and more specifically, to a blowpipe. Background Technique

[0002] A dust collector or dust removal equipment is a device that separates dust from flue gas. A bag filter, also known as a filter dust collector, is a dry high-efficiency dust collector. It is a dust removal device that uses a bag-type filter element made of fiber fabric to capture solid particles in the dust-containing gas. Its working principle is that dust particles are intercepted by colliding with fibers due to inertial force when they bypass the filter cloth fibers.

[0003] A bag filter is a dry dust removal device, which is suitable for capturing fine, dry and non-fibrous dust. The filter bag is made of woven filter cloth or non-woven felt. The dust-containing gas is filtered by the filtering action of the fiber fabric. When the dust-containing gas enters the bag filter, dust with large particle size and high specific gravity settles down due to the action of gravity and falls into the ash hopper. When the gas containing finer dust passes through the filter material, the dust is retained, and the gas is purified.

[0004] There is less existing parameter support, mainly supported by actual experience and lacking data support. For example:

[0005] Industry insiders have proposed a calculation formula for the average diameter of blowholes, pointing out that in order to ensure the average distribution of the multi-hole blow air flow, the aperture diameters of each blowhole should not be the same, but rather the aperture diameter of the blowhole far from the pulse valve should be smaller than that of the one close to the pulse valve. In addition, the aperture diameter of the blowhole is affected by various factors. For example, in order to improve the problem of poor dust cleaning, a mathematical relationship between the aperture diameter of the blowhole and the blow distance has been established; by studying the relationship between the aperture diameter of the blowhole and the diameter of the blowpipe, it is concluded that the hole-to-pipe area ratio is proportional to the dust cleaning intensity; through the research on different specifications of dust removal filter cartridges, a theory of the blowhole area ratio is proposed, that is, the ratio of the blowhole to the cross-sectional area of the filter cartridge corresponds one-to-one with the optimal blow distance; through the blowpipe pulse jet cleaning experimental system, a calculation formula for the optimal jet distance of the blowhole is established, and on the premise of the optimal jet distance, the optimal ratio of the blowhole diameter to the inner diameter of the filter cartridge is calculated to be 0.6 - 0.8. The above research shows that there is indeed a problem of uneven distribution of the multi-hole pulse blow air flow. Existing research mainly focuses on the optimization research of parameters such as nozzle type, blow distance and blow pressure, but there is no in-depth research on the design of the multi-hole blowhole diameter in the blowpipe. The main reason is that it is difficult to measure the instantaneous pulse blow air flow rate.

[0006] Some industry professionals have also measured the peak pressure on the side walls of each part of the filter cartridge and used a self-made pulse jet gas flow measurement device to measure the multi-hole pulse jet gas flow of existing filter cartridge dust collectors to determine the unevenness of the dust cleaning effect before optimization. They studied the influence of the jet hole diameter on the jet gas flow, optimized the jet hole diameter of the jet pipe of the filter cartridge dust collector, and used the peak pressure on the side walls of each part of the filter cartridge as an index for evaluation to verify the uniformity of the jet gas flow after optimization and whether the purpose of uniform dust cleaning is achieved. This can only provide a reference basis for the design of filter cartridge dust collectors, and there is no convincing technical solution in the industry.

[0007] In addition to adjusting the diameter of the jet holes, there are several other methods to optimize the distribution of the pulse gas flow:

[0008] 1) Optimize the number and diameter of nozzles: Through numerical simulation analysis, the influence of the number and diameter of nozzles on the dust cleaning effect can be studied. For example, increasing the number of nozzles can increase the amount of gas entering the filter element, thereby increasing the peak pressure on the wall of the filter element. However, the gas consumption and investment cost need to be considered at the same time.

[0009] 2) Adjust the jet pressure and pulse time: The jet pressure and time are important factors affecting the pulse dust cleaning effect. By reasonably designing the jet pressure and pulse time, the dust cleaning effect can be significantly improved. For example, when the jet pressure increases from 0.4 MPa to 0.6 MPa, the gas consumption during the pulse process can be increased, and at the same time, the amount of gas induced into the sintered plate by the nozzle jet also increases, thereby increasing the peak pressure on the wall of the filter element.

[0010] 3) Optimize the structure of the jet pipe: The design of the jet pipe, including the diameter of the jet pipe, the number of nozzles, the structural form of the jet short pipe, and the height of the end face of the jet short pipe from the filter bag mouth, will affect the distribution of the gas flow. For example, the use of a jet short pipe (or a guide pipe) can guide the pulse gas flow to enter the filter bag more effectively and reduce the phenomenon of gas flow deviation.

[0011] 4) Use numerical simulation methods: Through numerical simulation methods, such as computational fluid dynamics (CFD), the flow situation of the pulse jet gas flow inside the dust collector can be simulated, and then the design of the jet system can be optimized.

[0012] 5) Optimize the air receiver capacity and structural strength: The capacity and structural strength of the air receiver have an important impact on the working stability of the jet system. During design, it should be ensured that the air receiver capacity is large enough to maintain a stable working pressure, and at the same time, the structural strength should meet the relevant standards.

[0013] 6) Consider the coherence between the pulse frequency and the natural frequency of the bed: It has been found that there is coherence between the pulse frequency and the natural frequency of the bed, and this coherence can generate waves and an orderly bubble distribution in the vertical direction on the bed surface, which helps to improve the stability of bubble formation.

[0014] The above method provides a design idea for optimizing the pulsed air flow distribution. However, various complex factors need to be comprehensively considered, which is a long-term research topic for the industry to optimize the pulsed air flow distribution, improve the dust cleaning efficiency of the dust collector, and extend the service life of the filter bags. Content of the Utility Model

[0015] Aiming at the defects existing in the prior art, the purpose of the present utility model is to provide a blowpipe, which can increase the service life of the filter bags in the bag filter and save the usage cost.

[0016] To achieve the above purpose, the present utility model adopts the following technical solutions:

[0017] A blowpipe is located above a plurality of filter bags;

[0018] A plurality of blowholes are formed in the blowpipe;

[0019] The positions of the blowholes correspond to the positions of the filter bags;

[0020] The total cross-sectional area of all the blowholes is greater than 1.2 times the inner diameter cross-sectional area of the blowpipe;

[0021] The spraying range of the blowholes is between 25° and 35°.

[0022] Preferably, the aperture diameter of the blowholes is set as follows:

[0023]

[0024] In the formula, d is the inner diameter of the blowpipe, and n is the number of blowholes.

[0025] Preferably, a pulse valve is further provided on the blowpipe.

[0026] Preferably, the aperture diameter of the blowhole farthest from the pulse valve is 1 mm to 2 mm smaller than the aperture diameter of the blowhole closest to the pulse valve.

[0027] Preferably, the spraying range of the blowholes is 30°.

[0028] The blowpipe provided by the present utility model, while ensuring the dust cleaning of the filter bags, has a lower blow pressure of the blowpipe than the existing blow pressure, thereby increasing the blow times of the filter bags, extending the service life of the filter bags, and saving the usage cost. Brief Description of the Drawings

[0029] Figure 1 It is a layout schematic diagram of the blowpipe of the present utility model;

[0030] Figure 2It is a schematic diagram of the injection holes in the embodiment of the injection pipe of the present utility model. Detailed implementation mode

[0031] In order to better understand the above technical solutions of the present utility model, the technical solutions of the present utility model will be further described below in conjunction with the drawings and embodiments.

[0032] Combined with Figure 1 As shown, a blowing tube 1 provided by the present utility model is located above a plurality of filter bags 2, and the filter bags 2 are fixedly connected to a flower plate 3.

[0033] A plurality of blowing holes 4 are formed in the blowing tube 1, and the number of the blowing holes 4 is the same as the number of the filter bags 2.

[0034] The positions of the blowing holes 4 need to correspond to the positions of the filter bags 2.

[0035] In the present utility model, the total cross-sectional area of all the blowing holes 4 needs to be greater than 1.2 times the inner diameter cross-sectional area of the blowing tube 1.

[0036] At the same time, the spraying range α of the blowing holes 4 is between 25° and 35° (i.e., the spraying height), which can ensure that it is sprayed into the interior of the filter bag 2.

[0037] The aperture of the blowing holes 4 is set as follows:

[0038]

[0039] In the formula, d is the inner diameter of the blowing tube 1, and n is the number of the blowing holes 4.

[0040] A pulse valve is also provided on the blowing tube 1.

[0041] According to the above formula, the aperture of the blowing holes 4 on the blowing tube 1 can be calculated. The pulse air flow ejected by the pulse valve is uneven in speed and pressure along the length direction of the blowing tube 1. In order to ensure that the air injection volume of each blowing hole 4 is equivalent, and the farther the blowing hole 4 is from the pulse valve, the smaller the aperture of the blowing hole 4. Generally speaking, the aperture of the blowing hole 4 farthest from the pulse valve is 1 mm to 2 mm smaller than the aperture of the blowing hole 4 closest to the pulse valve.

[0042] After the general pulsed air flow is blown by the pulse valve, along the length direction of the blowpipe 1, the distribution of its velocity and static pressure is uneven. To ensure that the air injection volume of each blowhole 4 is equivalent, when designing this utility model, the uneven distribution characteristics of the air flow are fully considered, breaking through the usual practice: the diameter of the blowhole 4 far from the pulse valve is 1 - 2 mm smaller than that of the blowhole 4 close to the pulse valve (or preferably 0.5 - 1 mm). Such a design can control the difference in compressed air volume and pressure within a smaller range, thereby ensuring that the air injection volume of each blowhole 4 is roughly equivalent, significantly improving the uniformity of the air flow rate, thus improving the uniformity of dust cleaning, and ultimately improving the dust cleaning efficiency.

[0043] Embodiment

[0044] Combined with Figure 2 As shown, in this embodiment, the blowpipe 1 is a 1-inch galvanized blowpipe, and 4 cloth bags 2 are arranged below.

[0045] The inner diameter of the blowpipe 1 is 26 mm, the outer diameter is 33 mm, the wall thickness is 3.5 mm, and the cross-sectional area is 530.66 mm 2 .

[0046] 4 blowholes 4 are correspondingly opened on the blowpipe 1, and the aperture diameter of the blowhole 4 is calculated as follows:

[0047]

[0048] Then, according to the distance relationship with the pulse valve, the aperture diameters of the 4 blowholes 4 are specifically set as follows:

[0049]

[0050] That is, the aperture diameters of the 4 blowholes 4 meet the requirements.

[0051] At the same time, the spraying range α of the 4 blowholes 4 is all set to 30°, which can ensure that it is sprayed into the interior of the cloth bag 2.

[0052] Those of ordinary skill in the art in this technical field should recognize that the above embodiments are only used to illustrate the present utility model, rather than to limit the present utility model. As long as within the scope of the substantial spirit of the present utility model, the changes and modifications to the above-described embodiments will fall within the scope of the claims of the present utility model.

Claims

1. A blowpipe, the blowpipe being located above a plurality of filter bags, characterized in that: A plurality of blowholes are formed in the blowpipe; The positions of the blowholes correspond to the positions of the filter bags; The total cross-sectional area of all the blowholes is greater than 1.2 times the inner diameter cross-sectional area of the blowpipe; The spraying range of the blowholes is between 25° and 35°; 2. The lance according to claim 1, wherein, The aperture diameter of the blowholes is set as: wherein, d is the inner diameter of the blowpipe and n is the number of blowholes; 3. The injection pipe according to claim 2, wherein: A pulse valve is further provided on the blowpipe; 4. The injection pipe according to claim 3, characterized in that: The aperture diameter of the blowhole farthest from the pulse valve is 1 mm to 2 mm smaller than the aperture diameter of the blowhole closest to the pulse valve; 5. The lance according to claim 1, wherein: The spraying range of the blowholes is 30°.

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