Gas filtering system

Abstract

The utility model relates to the technical field of filters, in particular to a gas filtering system. The utility model provides a gas filtering system. The gas filtering system comprises a tank body, a filter element assembly and a pulse blowback assembly, a tube plate is installed in the tank body, a cavity in the tank body is divided into a process gas cavity and a clean gas cavity by the tube plate, the clean gas cavity is located above the process gas cavity, and the clean gas cavity is communicated with a gas outlet pipe used for discharging clean gas. The side wall and the bottom of the process gas chamber are respectively communicated with a gas inlet pipe and an ash discharge pipe; a plurality of mounting holes are formed in the tube plate, the filter element assembly comprises a plurality of filter elements, the filter elements are in one-to-one correspondence with the mounting holes, the filter elements are arranged in the process gas chamber, and the opening ends of the filter elements are mounted in the corresponding mounting holes. The gas filtering system can achieve a good blowback effect under the working condition of low blowback gas pressure, and energy consumption of equipment is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of filters, and particularly relates to a gas filtration system. Background Art

[0002] Gas online filter systems are widely used in gas-solid separation fields such as fly ash, tail gas dust removal, and polysilicon. The filter usually has a tube sheet, and the filter element is usually fixedly installed on the tube sheet by welding, threading or pressing plates. One end of the filter element is closed, and the other end of the filter element is sealed with the tube sheet to isolate the raw material gas and the filtered clean gas. During filtration, the process gas containing solid dust enters the filter through the filter inlet. The solid particles in the gas are intercepted on the outer surface of the filter element. The clean gas enters the internal space of the filter element through the pores of the filter material of the filter element, then enters the clean gas space above the filter tube sheet, and finally flows out from the outlet of the filter. Since the solid particles deposit on the outer surface of the filter element to form a filter cake, as the filter cake accumulates, the filtration pressure drop increases, and the filtration becomes more and more difficult. It is necessary to periodically blow back with high-pressure gas pulses to remove the filter cake on the outer surface of the filter element. During high-pressure gas pulse backwashing, the high-pressure gas is blown into the filter element through the backwashing pipeline above the filter element to blow off the filter cake deposited on the outer surface of the filter element.

[0003] The existing backwashing structure usually requires the backwashing gas pressure to be ≥2.0 times the process gas pressure and greater than 0.5 MpaG to achieve a better backwashing effect. However, this high backwashing pressure increases the energy consumption of the equipment. Moreover, when the existing backwashing structure deals with the working condition of low backwashing gas pressure (generally referring to <2 times the process gas pressure), the backwashing effect is not good and cannot meet the actual production requirements. Summary of the Utility Model

[0004] (1) The problems to be solved by the utility model are that when the existing backwashing structure achieves a better backwashing effect, the energy consumption is high, and the backwashing effect is not good when dealing with the working condition of low backwashing gas pressure.

[0005] (2) Technical Solution

[0006] A gas filtration system includes a tank body, a filter element assembly and a pulse backwashing assembly; a tube sheet is installed inside the tank body, and the tube sheet divides the chamber inside the tank body into a process gas chamber and a clean gas chamber. The clean gas chamber is located above the process gas chamber. A gas outlet pipe for discharging clean gas is communicated with the clean gas chamber. The side wall and the bottom of the process gas chamber are respectively communicated with a gas inlet pipe and an ash discharge pipe;

[0007] A plurality of installation holes are provided on the tube sheet. The filter element assembly includes a plurality of filter elements, and the filter elements correspond to the installation holes one by one. The filter elements are arranged in the process gas chamber, and their open ends are installed in the corresponding installation holes;

[0008] The pulse backwashing assembly is used to wash the filter element to blow off the filter cake formed on the filter element. The pulse backwashing assembly includes a backwashing gas buffer tank, a plurality of Venturi tubes, and a plurality of backwashing tubes. The Venturi tubes, the mounting holes on the tube sheet, and the backwashing tubes correspond to each other one by one;

[0009] The outlet end of the Venturi tube is aligned with the corresponding mounting hole, and one end of the backwashing tube is aligned with the inlet end of the corresponding Venturi tube, and the other end thereof is communicated with the backwashing gas buffer tank;

[0010] The Venturi tube is used to increase the gas flow rate of the gas passing through the Venturi tube.

[0011] As an embodiment of the present invention, the Venturi tube includes a contraction section, a straight tube section, a diffusion section, and a connection section that are connected in sequence. The connection section of the Venturi tube faces the tube sheet, and the outlet of the backwashing tube is aligned with the contraction section of the Venturi tube.

[0012] As an embodiment of the present invention, from the contraction section to the connection section, the diameter of the contraction section gradually decreases, and the diameter of the diffusion section gradually increases.

[0013] As an embodiment of the present invention, the bottom end of the backwashing tube extends into the contraction section so that the bottom of the backwashing tube is lower than the inlet of the contraction section.

[0014] As an embodiment of the present invention, the Venturi tube includes a guide cover. The open end of the guide cover is connected to the inlet of the contraction section. The side surface of the guide cover is in a hollow shape, and a hole for the backwashing tube to pass through is provided at the top thereof.

[0015] As an embodiment of the present invention, a backwashing quick-opening valve for controlling on-off is installed on the backwashing tube.

[0016] As an embodiment of the present invention, the connection section of the Venturi tube and the corresponding mounting hole are sealed and connected.

[0017] As an embodiment of the present invention, one end of the gas inlet pipe extends into the interior of the tank body, and the other end thereof is connected to a riser pipe. The riser pipe is perpendicular to the gas inlet pipe, and the top end surface of the riser pipe is higher than the lower surface of the filter element.

[0018] As an embodiment of the present invention, the gas filtration system includes a purging pipe. One end of the purging pipe extends into the process gas chamber and faces the ash discharge pipe, and the other end is used to connect to a gas supply device.

[0019] As an embodiment of the present utility model, the gas filtration system includes a differential pressure transmitter, which is used to measure the pressure difference between the process gas chamber and the clean gas chamber.

[0020] Advantages of the present utility model:

[0021] A gas filtration system provided by the present utility model includes a tank body, a filter element assembly, and a pulse backwashing assembly; a tube sheet is installed inside the tank body, and the tube sheet divides the chamber inside the tank body into a process gas chamber and a clean gas chamber. The clean gas chamber is located above the process gas chamber. A gas outlet pipe for discharging clean gas is connected to the clean gas chamber. A gas inlet pipe and an ash discharge pipe are respectively connected to the side wall and the bottom of the process gas chamber; a plurality of mounting holes are provided on the tube sheet. The filter element assembly includes a plurality of filter elements, and the filter elements correspond to the mounting holes one by one. The filter elements are arranged in the process gas chamber, and their open ends are installed in the corresponding mounting holes; the pulse backwashing assembly is used to blow and wash the filter elements to blow off the filter cakes formed on the filter elements. The pulse backwashing assembly includes a backwashing gas buffer tank, a plurality of Venturi tubes, and a plurality of backwashing pipes. The Venturi tubes, the mounting holes on the tube sheet, and the backwashing pipes correspond to each other one by one; the air outlet end of the Venturi tube is aligned with the corresponding mounting hole, one end of the backwashing pipe is aligned with the air inlet end of the corresponding Venturi tube, and the other end thereof is connected to the backwashing gas buffer tank; the Venturi tube is used to increase the gas flow rate of the gas passing through the Venturi tube.

[0022] When the gas filtration system is dealing with the working condition of low backwashing gas pressure, the high-pressure gas in the backwashing gas buffer tank is blown into the air inlet end of the Venturi tube through the backwashing pipe. The gas enters from the inlet of the Venturi tube, and then the cross-section gradually decreases. The pressure of the high-pressure air decreases and the flow rate increases. A vacuum is generated inside the inlet of the Venturi tube, causing the surrounding air to be sucked into the Venturi tube. Finally, the gas after acceleration is blown into the filter element to blow off the filter cake on the filter element.

[0023] Compared with the traditional gas filtration system, the present gas filtration system has at least the following advantages:

[0024] First, since the gas blown out from the backwashing pipe has an increased gas flow rate after passing through the Venturi tube, therefore, a too large backwashing gas pressure is not required. This enables the present pulse backwashing assembly to achieve a good backwashing effect under the working condition of low backwashing gas pressure (generally referring to < times the process gas pressure), reducing the energy consumption of the equipment.

[0025] Second, a high backwashing efficiency under a relatively low backwashing gas pressure is achieved. Since a vacuum is generated inside the inlet of the Venturi tube, the surrounding clean air is sucked into the Venturi tube, thereby making use of the clean air in the clean gas chamber and reducing the consumption of the backwashing gas.

[0026] In addition, this pulse backflush assembly is applicable not only to conventional backflush gas pressure conditions but also to special conditions with low backflush gas pressure, having strong adaptability and being able to meet various different production requirements. Brief Description of the Drawings

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0028] Figure 1 Schematic diagram provided for an embodiment of the present invention;

[0029] Figure 2 Structural diagram of the Venturi tube provided for an embodiment of the present invention.

[0030] Reference numerals: 1, tank body; 101, tube sheet; 102, gas inlet pipe; 103, gas outlet pipe; 104, ash discharge pipe; 2, filter element; 3, differential pressure transmitter; 4, backflush gas buffer tank; 401, backflush pipe; 402, backflush quick-opening valve; 5, Venturi tube; 501, contraction section; 502, straight pipe section; 503, diffusion section; 504, connection section; 505, guide hood; 6, purge pipe; 7, discharge valve; 8, riser pipe. Detailed Embodiments

[0031] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0032] As Figure 1 and Figure 2As shown in the figure, an embodiment of the present utility model provides a gas filtration system, which includes a tank body 1, a filter element assembly and a pulse backwashing assembly; a tube sheet 101 is installed inside the tank body 1, and the tube sheet 101 divides the chamber inside the tank body 1 into a process gas chamber and a clean gas chamber. The clean gas chamber is located above the process gas chamber. A gas outlet pipe 103 for discharging clean gas is connected to the clean gas chamber. A gas inlet pipe 102 and an ash discharge pipe 104 are respectively connected to the side wall and the bottom of the process gas chamber; a plurality of mounting holes are provided on the tube sheet 101. The filter element assembly includes a plurality of filter elements 2, and the filter elements 2 correspond to the mounting holes one by one. The filter elements 2 are arranged in the process gas chamber, and their open ends are installed in the corresponding mounting holes; the pulse backwashing assembly is used to blow and wash the filter elements 2 to blow off the filter cakes formed on the filter elements 2. The pulse backwashing assembly includes a backwashing gas buffer tank 4, a plurality of venturi tubes 5 and a plurality of backwashing pipes 401. The venturi tubes 5, the mounting holes on the tube sheet 101 and the backwashing pipes 401 correspond to each other one by one; the air outlet end of the venturi tube 5 is aligned with the corresponding mounting hole, and one end of the backwashing pipe 401 is aligned with the air inlet end of the corresponding venturi tube 5, and the other end thereof is connected to the backwashing gas buffer tank 4; the venturi tube 5 is used to increase the gas flow rate of the gas passing through the venturi tube 5.

[0033] When the gas filtration system in this embodiment is dealing with the working condition of low backwashing gas pressure, the high-pressure gas in the backwashing gas buffer tank 4 is blown into the air inlet end of the venturi tube 5 through the backwashing pipe 401. The gas enters from the inlet of the venturi tube 5, and then the cross-section gradually decreases. The pressure of the high-pressure air decreases and the flow rate increases. A vacuum is generated inside the inlet of the venturi tube 5, causing the surrounding air to be sucked into the venturi tube 5. Finally, the accelerated gas is blown into the filter element 2 to blow off the filter cake on the filter element 2.

[0034] Compared with the traditional gas filtration system, this gas filtration system has at least the following advantages:

[0035] First, since the gas blown out from the backwashing pipe 401 has an increased gas flow rate after passing through the venturi tube 5, therefore, a too large backwashing gas pressure is not required, enabling this pulse backwashing assembly to achieve a good backwashing effect under the working condition of low backwashing gas pressure (generally referring to <2 times the process gas pressure), and reducing the energy consumption of the equipment.

[0036] Second, a high backwashing efficiency under a low backwashing gas pressure is achieved. Since a vacuum is generated inside the inlet of the venturi tube 5, the surrounding clean air is sucked into the venturi tube 5, thereby utilizing the clean air in the clean gas chamber and reducing the consumption of the backwashing gas.

[0037] In addition, this pulse backwashing assembly is not only applicable to the conventional backwashing gas pressure working condition, but also applicable to the special working condition of low backwashing gas pressure, with strong adaptability and capable of meeting various different production requirements.

[0038] As a preferred embodiment, as Figure 2 shown, the Venturi tube 5 includes a contraction section 501, a straight tube section 502, a diffusion section 503, and a connection section 504 that are connected in sequence. The contraction section 501 is a conical tube, the small-diameter end of which is connected to one end of the straight tube section 502, and the large-diameter end of which is the air inlet of the Venturi tube 5. The diameter of the straight tube section 502 is the same as the diameter of the small-diameter end of the contraction section 501. The small-diameter end of the diffusion section 503 is connected to the end of the straight tube section 502 away from the contraction section 501, and the other end is connected to the connection section 504. That is, along the direction from the contraction section 501 to the connection section 504 of the Venturi tube 5, the diameter of the contraction section 501 gradually decreases, and the diameter of the diffusion section 503 gradually increases. It should be noted that the connection section 504 is a circular tube, the diameter of which is the same as the diameter of the large-diameter end of the diffusion section 503, and the diameter of the connection section 504 is much larger than that of the straight tube section 502.

[0039] As Figure 1 shown, the connection section 504 of the Venturi tube 5 is hermetically installed at the installation hole on the tube sheet 101, and the air outlet end of the backflush tube 401 is aligned with and close to the contraction section 501 of the corresponding Venturi tube 5.

[0040] In this way, the gas blown out from the backflush tube 401 enters the contraction section 501 of the Venturi tube 5. Since the caliber of the contraction section 501 gradually decreases, the pressure of the high-pressure air decreases and the flow rate increases, thereby playing a role in increasing the gas flow rate. It can achieve a good backflush effect under the condition of low backflush gas pressure, reduce the energy consumption of the equipment, and because a vacuum degree will be generated in the contraction section 501 and the straight tube section 502, the surrounding air is sucked into the Venturi tube 5, making use of the clean air in the clean gas chamber and reducing the amount of backflush gas used.

[0041] It can be seen that the Venturi tube 5 provided in this embodiment can reduce energy consumption on the premise of ensuring the backflush effect, improve the use efficiency of the equipment, improve the performance and stability of the gas filter system, further enhance the performance and stability of the system, and ensure the long-term stable operation of the gas filter system. In addition, the structural design of this pulse backflush assembly is simple, easy to manufacture and maintain, and is conducive to large-scale application.

[0042] As a preferred embodiment, as Figure 2As shown in the figure, the lower surface of the bottom end of the backflush pipe 401 extends into the inside of the contraction section 501, and the axis of the backflush pipe 201 is collinear with the axis of the contraction section 501. The lower surface of the bottom end of the backflush pipe 401 is lower than the inlet of the contraction section 501. Since the gas flow rate at the outlet end of the backflush pipe 401 is large, the pressure around its outlet end is small. As a result, the gas in the clean gas chamber will be entrained to the outlet end of the backflush pipe 401. By extending the lower surface of the bottom end of the backflush pipe 401 into the inside of the contraction section 501, the gas in the clean gas chamber can be gathered in the contraction section 501, increasing the total amount of gas entering the Venturi tube 5, thereby increasing the total amount of gas blown into the filter element 2 and improving the backflush efficiency. Specifically, the absolute value of the height difference between the lower surface of the bottom end of the backflush pipe 401 and the inlet of the contraction section 501 is 5 mm - 20 mm. Preferably, it is 10 mm.

[0043] Furthermore, the ratio of the cross-sectional area of the backflush pipe 401 to the cross-sectional area of the inlet of the contraction section 501 of the Venturi tube 5 is 3 / 20 - 6 / 20. Through experiments, the entrainment effect is better at this time.

[0044] As an optional embodiment, as Figure 2 shown in the figure, a guide cover 505 is installed at the inlet of the contraction section 501. The guide cover 505 is in a horn shape. Its large-diameter end is connected to the inlet of the contraction section 501. A hole for the backflush pipe 401 to pass through is formed at its small-diameter end. A hollow structure is formed on the side of the guide cover 505 so that gas can enter the Venturi tube 5 from this hollow structure and so that the clean gas in the Venturi tube 5 can enter the clean gas chamber from this place. It should be noted that the guide cover 505 can play a guiding role to guide the backflush pipe 401 to be successfully positioned and extend into the contraction section 501 of the Venturi tube 5, and can also help the backflush pipe 401 quickly maintain a coaxial state with the Venturi tube 5.

[0045] In addition, in this embodiment, as Figure 2 shown in the figure, the range of the angle a formed between the right side of the cross-section of the contraction section 501 and the right side of the cross-section of the straight pipe section 502 is 10° - 15°. The range of the angle b formed between the right side of the cross-section of the straight pipe section 502 and the right side of the cross-section of the diffuser section 503 is 10° - 15°. The length of the straight pipe section 502 is 1 - 1.5 times its diameter.

[0046] As Figure 1 shown in the figure, a backflush quick-opening valve 402 is installed on each backflush pipe 401. The preferred opening and closing time of the backflush quick-opening valve 402 is 0.1 - 0.5 S. Among them, the opening and closing time refers to the time required for the backflush quick-opening valve 402 to move from the fully closed position to the fully open position.

[0047] It should be noted that the backflush gas buffer tank 4 is connected to the backflush gas pipeline. The backflush gas pipeline transports the backflush gas into the backflush gas buffer tank 4, and then the backflush gas is blown into the backflush pipe 401 through the backflush gas buffer tank 4.

[0048] Preferably, as Figure 1 shown, a differential pressure transmitter 3 is installed on the tank body 1. The differential pressure transmitter 3 is connected to the clean gas chamber through a pipeline and is also connected to the process gas through a pipeline at the same time. The function of the differential pressure transmitter 3 is to measure the pressure difference between the process gas chamber and the clean gas chamber, so that the staff can decide whether to perform backflush according to the pressure difference between the process gas chamber and the clean gas chamber. The entire gas filtration system includes a control module, usually a PLC control module or a DSC control module, preferably a PLC control module. The differential pressure transmitter 3 and each backflush quick-opening valve 402 are controlled by the PLC control module.

[0049] When solid particles deposit on the outer surface of the filter element 2 to form a filter cake, as the filter cake accumulates, a large amount of process gas stays in the process gas chamber and is difficult to filter quickly, resulting in more and more difficult filtration. At the same time, the pressure in the process gas chamber becomes larger and larger, that is, the absolute value of the pressure difference between the process gas chamber and the clean gas chamber becomes larger and larger. When it reaches the set value, it means that backflush work must be carried out immediately. At this time, the staff controls the pulse backflush assembly to work through the PLC control module and opens the backflush quick-opening valve 402 on the backflush pipe 401 to backflush the filter element 2 to blow off the filter cake. In addition, the pulse backflush assembly includes a timing module. The staff obtains the time required for the differential pressure transmitter 3 to rise from the normal value to the set value through multiple experiments, and the staff enters the time required for the differential pressure transmitter 3 to rise from the normal value to the set value into the timing module. In this way, when the time entered by the timing module reaches, it means that the pressure value measured by the differential pressure transmitter 3 at this time basically reaches the set value. At this time, the PLC control module controls the pulse backflush assembly to work and opens the backflush quick-opening valve 402 on the backflush pipe 401 to backflush the filter element 2. In this way, even if the differential pressure transmitter 3 is damaged, the timing module can still work normally, playing a dual insurance role. And through the mutual comparison between the differential pressure transmitter 3 and the timing module, it can also help the staff judge whether the differential pressure transmitter 3 or the timing module is damaged.

[0050] As Figure 1As shown in the figure, an exhaust port is provided on the side wall of the tank body 1 near the top. The exhaust port is communicated with the clean gas chamber, and a gas outlet pipe 103 is hermetically installed at the exhaust port. An air inlet is provided on the side wall of the lower half of the tank body 1. The air inlet is lower than the bottom of the filter element 2. The gas inlet pipe 102 is installed at the air inlet. The left end of the gas inlet pipe 102 is located outside the tank body 1, and the other end extends into the tank body 1. The bottom of the tank body 1 is funnel-shaped, and a dust discharge pipe 104 is installed at the bottom opening. A discharge valve 7 for controlling its on-off is installed on the dust discharge pipe 104.

[0051] Preferably, a riser pipe 8 is communicated at the end of the gas inlet pipe 102 extending into the tank body 1. The riser pipe 8 is vertically arranged. Its bottom end is communicated with the gas inlet pipe 102, and its top end is close to the tube sheet 101, that is, the riser pipe 8 is located between the filter elements 2.

[0052] It should be noted that for process gases with a large specific gravity, after they are introduced into the process gas chamber along the gas outlet pipe 103, due to their large specific gravity, it is difficult for the process gas to rise to the position of the filter element 2, resulting in the filter element 2 being unable to fully filter the process gas. In this embodiment, the process gas is directly conveyed to the position near the top of the filter element 2 through the gas inlet pipe 102 and the riser pipe 8 in sequence, so that the filter element 2 can fully filter the process gas and improve the utilization rate and filtering effect of the filter element 2.

[0053] When the system is filtering in the forward direction, the process gas containing solid particles passes through the gas inlet pipe 102 and the riser pipe 8 in sequence and then enters the process gas chamber. The solid particles in the gas are intercepted on the outer surface of the filter element 2. The clean gas enters the internal space of the filter element 2 through the pores of the filter medium of the filter element 2, and then enters the connecting section 504 of the Venturi tube 5 from the top opening of the filter element 2, and then passes through the diffuser section 503, the straight pipe section 502 and the contraction section 501 in sequence to flow out of the Venturi tube 5, and then is discharged into the clean gas chamber through the hollow structure of the guide cover 505, and finally flows out through the gas outlet pipe 103.

[0054] As the forward filtering progresses, the filter cake accumulated on the surface of the filter element 2 continuously thickens, and the pressure difference between the two chambers also continuously increases. Until the pressure difference measured by the differential pressure transmitter 3 reaches the set value, it means that backwashing and cleaning are required. At this time, the PLC control module controls the backwashing quick-opening valve 402 to open. The gas in the backwashing pipe 401 enters the contraction section 501 of the Venturi tube 5 and passes through the straight pipe section 502, the diffuser section 503 and the connecting section 504 in sequence, and then the gas is ejected from the connecting section 504 into the filter element 2 to backwash the filter cake on the filter element 2. Due to the gradually decreasing diameter of the contraction section 501 in cooperation with the straight pipe section 502, the pressure of the high-pressure air decreases and the flow rate increases, thus playing a role in increasing the gas flow rate, and good backwashing effect can be achieved under the condition of low backwashing gas pressure, reducing the energy consumption of the equipment.

[0055] The filter element 2 of a general filter is divided into multiple zones, and the number of filter elements 2 in each zone is the same. For example, there are 8 zones, and each zone consists of four filter elements 2. All the filter elements 2 will participate in the filtration during filtration.

[0056] When the differential pressure or circulation time of the filter reaches a preset value, pulse backwashing cleaning starts. All the quick-opening backwashing valves 402 corresponding to the filter elements 2 in one of the zones are opened, and high-pressure gas is distributed through each backwashing pipe 401 into each filter element 2 in this zone for backwashing cleaning, so as to clean all the filter elements 2 corresponding to this zone once. When the filter elements 2 in one zone are being backwashed and cleaned, all the other zones jointly undertake the filtration of all the gas, so the gas filtration still proceeds normally during backwashing. After the backwashing and cleaning of one zone is completed, the other zones are sequentially backwashed and cleaned one by one in a set order until the backwashing and cleaning of the filter elements 2 in all zones are completed. When the backwashing and cleaning of all zones are completed, one backwashing cycle ends, and the system realizes the primary cleaning of all the filter elements. When the differential pressure or circulation time of the filter reaches the preset value again, a backwashing cycle is started again. Through such continuous filtration and backwashing cycles, the filtration and dust removal process can maintain continuous long-term operation.

[0057] Optionally, as Figure 1 shown, the gas filtration system includes a purging pipe 6. One end of the purging pipe 6 extends into the process gas chamber and faces the ash discharge pipe 104, and the other end is used to connect to a gas supply device. In this way, by supplying gas to the purging pipe 6 through the gas supply device, the purging pipe 6 blows out high-pressure gas so as to quickly discharge the filter ash accumulated at the bottom of the tank body 1.

[0058] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0059] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the connection inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0060] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A gas filtration system, characterized in that: The invention comprises a tank body (1), a filter element assembly and a pulse back-blowing assembly; a tube sheet (101) is installed inside the tank body (1); the tube sheet (101) divides the chamber inside the tank body (1) into a process gas chamber and a clean gas chamber; the clean gas chamber is located above the process gas chamber; the clean gas chamber is connected to a gas outlet pipe (103) for discharging clean gas; the side wall and the bottom of the process gas chamber are respectively connected to a gas inlet pipe (102) and an ash discharge pipe (104); The tube sheet (101) is provided with a plurality of mounting holes, the filter element assembly comprises a plurality of filter elements (2), the filter elements (2) correspond to the mounting holes one by one, the filter elements (2) are arranged in the process gas chamber, and the open ends thereof are mounted in the corresponding mounting holes; The pulse back-blowing assembly is used to purge the filter element (2) to blow off the filter cake formed on the filter element (2), and the pulse back-blowing assembly comprises a back-blowing gas buffer tank (4), a plurality of venturi tubes (5) and a plurality of back-blowing pipes (401), wherein the venturi tubes (5), the mounting holes on the tube sheet (101) and the back-blowing pipes (401) correspond to each other one by one; The air outlet end of the venturi tube (5) is aligned with the corresponding mounting hole, one end of the backflush tube (401) is aligned with the corresponding air inlet end of the venturi tube (5), and the other end is connected to the backflush gas buffer tank (4); The venturi tube (5) is used to increase the gas flow rate of the gas passing through the venturi tube (5); The venturi tube (5) comprises a contraction section (501), a straight tube section (502), a diffusion section (503) and a connection section (504) which are connected in sequence, the connection section (504) of the venturi tube (5) faces the tube sheet (101), and the air outlet of the backflush tube (401) is aligned with the contraction section (501) of the venturi tube (5); From the contraction section (501) to the connection section (504), the diameter of the contraction section (501) gradually decreases, and the diameter of the diffusion section (503) gradually increases; The bottom end of the backflush pipe (401) extends into the contraction section (501) so that the bottom of the backflush pipe (401) is lower than the inlet of the contraction section (501); The venturi tube (5) comprises a guide cover (505), the large diameter end of the guide cover (505) is connected to the inlet of the contraction section (501), the small diameter end is formed with a hole for the backflush pipe (401) to pass through, and the side surface of the guide cover (505) is hollow.

2. A gas filtration system according to claim 1, characterized in that: The back-blowing pipe (401) is provided with a back-blowing quick-opening valve (402) for controlling on-off.

3. A gas filtration system according to claim 1, characterized in that: The connecting section (504) of the Venturi tube (5) is sealedly connected to the corresponding mounting hole.

4. A gas filtration system according to claim 1, characterized in that: One end of the gas inlet pipe (102) extends into the interior of the tank body (1), and the other end is connected to a riser pipe (8). The riser pipe (8) is perpendicular to the gas inlet pipe (102), and the top end surface of the riser pipe (8) is higher than the lower surface of the filter element (2).

5. A gas filtration system according to claim 1, characterized in that: The gas filtration system comprises a purge pipe (6), one end of which extends into the process gas chamber and faces the ash discharge pipe (104), and the other end of which is used to connect to a gas supply device.

6. A gas filtration system according to any one of claims 1 to 5, characterized in that: The gas filtration system comprises a differential pressure transmitter (3), which is used to measure the pressure difference between the process gas chamber and the clean gas chamber.

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