An apparatus and method for reducing dry tail gas dust entrainment

Abstract

The application provides a device for reducing dust entrainment of drying tail gas, which comprises a dryer, a vertical tail gas pipeline and a tail gas outlet pipeline, the vertical tail gas pipeline is connected with the dryer vertically, the device for reducing dust entrainment of drying tail gas further comprises a reverse push shaftless screw, the reverse push shaftless screw is installed on the vertical tail gas pipeline, the tail gas outlet pipeline is connected with the reverse push shaftless screw, and the tail gas outlet pipeline and the vertical tail gas pipeline are at a certain angle; the reverse push shaftless screw comprises a conveying assembly and a transmission assembly, the conveying assembly comprises a screw shell and shaftless screw blades arranged in the screw shell, the transmission assembly drives the shaftless screw blades to rotate, the shaftless screw blades are used for intercepting dust in the drying tail gas and pushing the dust back to the dryer, and the device and the method can effectively reduce the dust amount entrained in the drying tail gas, meanwhile, the resistance drop of the system is not increased, and the risk of leakage of the dryer is not increased.

Description

Technical Field

[0001] This invention relates to the field of solid powder drying exhaust gas treatment technology, and in particular to a device and method for reducing dust entrainment in drying exhaust gas. Background Technology

[0002] In industries such as petrochemicals, chemicals, coal chemicals, metallurgy, and food, solid powders typically contain moisture, organic components, and other wetness, requiring dehydration and desolventization. Therefore, drying units are widely used in various industries. During the drying process, a certain amount of carrier gas is generally needed to carry the evaporated moisture and volatile organic compounds out of the drying system. In this process, some dust will be discharged with the carrier gas, and the discharged carrier gas, moisture or volatile organic compounds, and dust form the drying exhaust gas.

[0003] Currently, there are various methods for the subsequent treatment of dried exhaust gas in actual industrial production processes, including cyclone dust collectors, bag filters, scrubbing towers, heat exchangers, and combinations of various dust removal methods. For processes that require the recovery of moisture or volatile organic compounds, scrubbing towers are generally used for dust removal and cooling, or heat exchangers are used for spray cooling to recover the dust and the moisture or volatile organic compounds carried within.

[0004] During application, due to the differences in the properties of various materials, the drying exhaust gas often contains a large amount of dust, which can cause blockages in the scrubbing tower or heat exchanger. For example, polyphenylene ether (PPE) has a high content of small particles in its raw materials, resulting in a high dust content in the drying exhaust gas. Furthermore, PPE particles easily stick to the walls, which can easily cause blockages in the exhaust gas pipes and subsequent scrubbing towers. For ultra-high molecular weight polyethylene (UHMWPE), because its density is less than that of water, its dust easily floats on the water. As the operating time increases, the dust gradually accumulates, causing blockages in the subsequent scrubbing tower. Currently, the common way to deal with this phenomenon is to add a cyclone dust collector or bag filter before the scrubbing tower to remove most of the dust. This method can effectively reduce the blockage problem in the subsequent exhaust gas pipes and scrubbing tower. However, for drying materials containing organic solvents, a closed carrier gas circulation system is mainly used. The entire system is in a positive pressure operating state. Adding a cyclone dust collector or bag filter increases the pressure drop of the system, resulting in a higher operating pressure for the dryer, which increases the risk of dryer leakage and the hidden dangers in system operation. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a device and method for reducing dust entrainment in drying exhaust gas. The application of this device and method can effectively reduce the amount of dust entrained in the drying exhaust gas without increasing the system's resistance drop or the risk of dryer leakage.

[0006] To achieve the above objectives, the present invention provides a device for reducing dust entrainment in drying exhaust gas, comprising a dryer, a vertical exhaust gas duct, and an exhaust gas outlet duct. The vertical exhaust gas duct is vertically connected to the dryer. The device for reducing dust entrainment in drying exhaust gas further includes a reverse-push shaftless screw, which is installed on the vertical exhaust gas duct. The exhaust gas outlet duct is connected to the reverse-push shaftless screw, and there is a certain angle between the exhaust gas outlet duct and the vertical exhaust gas duct.

[0007] The reverse-push shaftless spiral includes a conveying component and a transmission component. The conveying component includes a spiral housing and shaftless spiral blades placed inside the spiral housing. The transmission component drives the shaftless spiral blades to rotate. The shaftless spiral blades are used to intercept dust in the drying exhaust gas and push the dust back into the dryer.

[0008] In some embodiments, the spiral casing is a variable diameter spiral casing, with the spiral casing gradually increasing in size from the dry exhaust gas inlet to the dry exhaust gas outlet.

[0009] In some embodiments, the shaftless helical blades are helical blades with varying diameters and thicknesses, with the diameter gradually increasing and the thickness increasing from the dry exhaust gas inlet to the dry exhaust gas outlet.

[0010] In some embodiments, the conveying assembly further includes a blade end flange and stiffeners, the shaftless helical blade is connected to the side of the blade end flange, and the stiffeners are staggered between the shaftless helical blade and the side of the blade end flange, and the number of stiffeners can be two.

[0011] In some embodiments, the transmission assembly includes a support frame, bearing housing, gasket, bearing, bearing cap, bearing retaining ring, shaft end, motor, coupling, lock nut, first oil seal, second oil seal, packing gland, packing, and shaft end flange, all configured together.

[0012] In some embodiments, the first oil seal and the second oil seal are located on both sides of the bearing, and the packing and packing gland are installed on the support frame.

[0013] In some embodiments, after the shaft head is welded to the shaft end flange, it is inserted into the support frame. One side of the support frame is connected to the bearing seat. The motor is connected to the shaft head through the coupling. The spiral housing with shaftless helical blades is connected to the support frame with the shaft head.

[0014] In some embodiments, the reverse thrust shaftless spiral further includes a heat tracing assembly, specifically a heat tracing pipe disposed on the reverse thrust shaftless spiral housing.

[0015] The present invention also provides a method for reducing dust entrainment in drying exhaust gas, comprising the following steps:

[0016] The dry exhaust gas from the dryer is discharged from the dryer exhaust gas outlet into the vertical exhaust gas pipe. The reverse shaftless screw is installed on the vertical exhaust gas pipe, and the dry exhaust gas enters the reverse shaftless screw.

[0017] The dust in the drying exhaust gas is intercepted by the blocking action of the shaftless spiral blades inside the reverse shaftless spiral, and as the reverse shaftless spiral rotates, the intercepted dust is pushed back into the dryer.

[0018] The dried exhaust gas after passing through the reverse-propulsion shaftless spiral dust collector is discharged to the subsequent system through the exhaust gas outlet pipe.

[0019] In some embodiments, a heat tracing pipe is provided on the reverse-propeller shaftless spiral shell, and steam or hot water is used for heat tracing to prevent the condensation of moisture in the drying exhaust gas.

[0020] Compared with the prior art, the advantages of the technical solution of the present invention are as follows:

[0021] This invention provides a device and method for reducing dust entrainment in drying exhaust gas. The application of this device and method provides a reliable solution for the treatment of drying exhaust gas in solid powder drying units, reduces the dust content in drying exhaust gas, effectively solves the problem of easy clogging in drying exhaust gas treatment systems, and provides a reliable solution for the stable operation of drying exhaust gas after-treatment systems.

[0022] The present invention provides a device and method for reducing dust entrainment in drying exhaust gas. The method adopts the method of adding a reverse-push shaftless screw to the outlet pipe of the drying exhaust gas to intercept most of the dust carried in the drying exhaust gas and push the intercepted dust back into the dryer. This can effectively solve the problem of pipe and subsequent equipment blockage during the drying exhaust gas treatment process and improve the stability of the device operation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of the device for reducing dust entrainment in drying exhaust gas, as shown in an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the reverse-engineered shaftless spiral structure shown in an embodiment of the present invention;

[0026] in:

[0027] 1-Dryer;

[0028] 2- Vertical exhaust pipe;

[0029] 3-Exhaust gas outlet pipe;

[0030] 4- Reverse-push shaftless spiral;

[0031] 41-Conveying assembly; 411-Spiral housing; 412-Shaftless spiral blade; 413-Blade end flange; 414-Firming plate;

[0032] 42-Transmission assembly; 4201-Support frame; 4202-Bearing housing; 4203-Sealing gasket; 4204-Bearing; 4205-Bearing gland; 4206-Bearing retaining ring; 4207-Shaft end; 4208-Motor; 4209-Coupling; 4210-Locking nut; 4211-First oil seal; 4212-Second oil seal; 4213-Stuffing gland; 4214-Stuffing; 4215-Shaft end flange;

[0033] 43-Heat tracing components. Detailed Implementation

[0034] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of protection of the appended claims.

[0035] Certain terms are used in this specification and the following claims to refer to specific components or parts. Those skilled in the art will understand that users or manufacturers may use different names or terms to refer to the same component or part. This specification and the following claims do not distinguish components or parts by differences in name, but rather by differences in function. The terms "comprising" and "including" used throughout this specification and the following claims are open-ended and should be interpreted as "including but not limited to". Furthermore, the term "connection" here includes any direct and indirect electrical connection means. Indirect electrical connection means include connections made through other means.

[0036] It should be noted that in the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and "about", or "approximately", "substantially", "left and right", etc., indicating the orientation or positional relationship or parameters, are all based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, a specific size, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] like Figure 1 According to one embodiment of the present invention, a device for reducing dust entrainment in drying exhaust gas is provided, including a dryer 1, a vertical exhaust gas pipe 2, and an exhaust gas outlet pipe 3. The vertical exhaust gas pipe 2 is vertically connected to the dryer 1. The device for reducing dust entrainment in drying exhaust gas also includes a reverse-push shaftless screw 4, which is installed on the vertical exhaust gas pipe 2. The exhaust gas outlet pipe 3 is connected to the reverse-push shaftless screw 4, and there is a certain angle between the exhaust gas outlet pipe 3 and the vertical exhaust gas pipe 2.

[0038] Among them, such as Figure 2 As shown, the reverse-push shaftless spiral 4 includes a conveying assembly 41 and a transmission assembly 42. The conveying assembly 41 includes a spiral housing 411 and shaftless spiral blades 412 placed inside the spiral housing 411. The transmission assembly 42 drives the shaftless spiral blades 412 to rotate. The shaftless spiral blades 412 are used to intercept dust in the drying exhaust gas and push the dust back into the dryer 1.

[0039] In this embodiment, the spiral shell 411 is a variable diameter spiral shell. The spiral shell 411 gradually increases in size from the dry exhaust gas inlet to the dry exhaust gas outlet. In this embodiment, the spiral shell adopts a variable diameter method, and the spiral shell gradually increases in size from the dry exhaust gas inlet to the dry exhaust gas outlet, which has a certain effect on the settling of dust in the dry exhaust gas.

[0040] In this embodiment, the shaftless spiral blade 412 employs a variable diameter, unequal thickness spiral blade, with the diameter gradually increasing and the thickness increasing from the inlet to the outlet of the drying exhaust gas. This variable diameter, unequal thickness spiral blade effectively traps dust in the drying exhaust gas and simultaneously pushes the trapped dust back into the dryer. The application of this variable diameter, unequal thickness spiral blade results in less deflection and a longer service life.

[0041] The conveying assembly 41 further includes a blade end flange 413 and stiffeners 414. The shaftless helical blade 412 is connected to the side of the blade end flange 413. The stiffeners 414 are staggered between the shaftless helical blade 412 and the side of the blade end flange 413, and the number of stiffeners 414 can be two. In this embodiment, the root of the shaftless helical blade is welded to the side of the blade end flange, and there are four stiffeners. The four stiffeners are welded at a 90° angle between the blade and the blade end flange. The stiffeners strengthen the blade. The assembled blade is inserted into the helical housing, thus completing the assembly of the conveying assembly.

[0042] In this embodiment, the transmission assembly 42 includes a support frame 4201, a bearing seat 4202, a sealing gasket 4203, a bearing 4204, a bearing cap 4205, a bearing retaining ring 4206, a shaft head 4207, a motor 4208, a coupling 4209, a lock nut 4210, a first oil seal 4211, a second oil seal 4212, a packing cap 4213, a packing 4214, and a shaft end flange 4215, all of which are installed together.

[0043] The first oil seal 4211 and the second oil seal 4212 are located on both sides of the bearing 4204. The packing 4214 and the packing gland 4213 are installed on the support frame 4201. The shaft head 4207 is inserted into the support frame 4201 after being welded to the shaft end flange 4215. One side of the support frame 4201 is connected to the bearing seat 4202. The motor 4208 is connected to the shaft head 4207 through the coupling 4209. The spiral housing 411 with shaftless spiral blades 412 is connected to the support frame 4201 with the shaft head 4207.

[0044] In this embodiment, after the shaft head 4207 is welded to the shaft end flange 4215, it is inserted into the support frame 4201. The other side of the support frame 4201 is connected to the bearing seat 4202. Then, the first oil seal 4211, bearing 4204, bearing retaining ring 4206, second oil seal 4212, bearing cover 4205, and lock nut 4210 are installed in sequence. The packing 4214 and packing cover 4213 are installed at the support frame 4201. The spiral housing 411 with spiral blades is connected to the support frame 4201 with shaft head 4207 by bolts. Finally, the motor 4208 is connected to the shaft head 4207 by coupling 4209.

[0045] To prevent the condensation of the drying exhaust gas and the material from sticking to the wall, the reverse thrust shaftless spiral 4 in this embodiment also includes a heat tracing component 43. The heat tracing component 43 is specifically a heat tracing pipe, which is installed on the reverse thrust shaftless spiral shell 411 and uses hot water or steam for heat tracing.

[0046] Another embodiment of the present invention provides a method for reducing dust entrainment in drying exhaust gas. The method uses the above-mentioned equipment and includes the following steps:

[0047] The drying exhaust gas from dryer 1 is discharged from the dryer exhaust gas outlet into the vertical exhaust gas pipe 2. The reverse shaftless screw 4 is installed on the vertical exhaust gas pipe 2, and the drying exhaust gas enters the reverse shaftless screw 4.

[0048] The dust in the drying exhaust gas is intercepted by the blocking action of the shaftless spiral blades 412 inside the reverse shaftless spiral 4, and as the reverse shaftless spiral 4 rotates, the intercepted dust is pushed back into the dryer 1.

[0049] The dried exhaust gas after being removed by the reverse-propulsion shaftless screw 4 is discharged to the subsequent system through the exhaust gas outlet pipe 3. The exhaust gas outlet has a certain angle with the vertical direction, and the angle varies depending on the characteristics of different materials.

[0050] The reverse-propulsion shaftless spiral shell 411 is equipped with a heat tracing pipe, which uses steam or hot water for heat tracing to prevent the condensation of moisture in the drying exhaust gas.

[0051] This invention provides an apparatus and method for reducing dust entrainment in drying exhaust gas. The application of this apparatus and method provides a reliable solution for the treatment of drying exhaust gas in solid powder drying units, reduces the dust content in the drying exhaust gas, effectively solves the problem of easy clogging in the drying exhaust gas treatment system, and provides a reliable solution for the stable operation of the drying exhaust gas after-treatment system.

[0052] The device and method for reducing dust entrainment in drying exhaust gas provided in this invention embodiment adopts the method of adding a reverse-push shaftless spiral to the outlet pipe of the drying exhaust gas to intercept most of the dust carried in the drying exhaust gas and push the intercepted dust back into the dryer. This can effectively solve the problem of pipe and subsequent equipment blockage during the drying exhaust gas treatment process and improve the stability of device operation.

[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A device for reducing dust entrainment in drying exhaust gas, comprising a dryer, a vertical exhaust gas duct, and an exhaust gas outlet duct, wherein the vertical exhaust gas duct is vertically connected to the dryer, characterized in that: The device for reducing dust entrainment in the dry exhaust gas also includes a reverse thrust shaftless screw, which is installed on the vertical exhaust gas pipe. The exhaust gas outlet pipe is connected to the reverse thrust shaftless screw, and there is a certain angle between the exhaust gas outlet pipe and the vertical exhaust gas pipe. The reverse-push shaftless spiral includes a conveying component and a transmission component. The conveying component includes a spiral housing and shaftless spiral blades placed inside the spiral housing. The transmission component drives the shaftless spiral blades to rotate. The shaftless spiral blades are used to intercept dust in the drying exhaust gas and push the dust back into the dryer.

2. The device for reducing dust entrainment in drying exhaust gas according to claim 1, characterized in that: The spiral casing is a variable diameter spiral casing, which gradually increases in size from the dry exhaust gas inlet to the dry exhaust gas outlet.

3. The equipment for reducing dust entrainment in drying exhaust gas according to claim 1 or 2, characterized in that: The shaftless helical blades are helical blades with varying diameters and thicknesses, with the diameter and thickness gradually increasing from the dry exhaust gas inlet to the dry exhaust gas outlet.

4. The device for reducing dust entrainment in drying exhaust gas according to claim 1, characterized in that: The conveying assembly also includes blade end flanges and stiffeners. The shaftless helical blade is connected to the side of the blade end flange, and the stiffeners are staggered between the shaftless helical blade and the side of the blade end flange. There are two stiffeners.

5. The device for reducing dust entrainment in drying exhaust gas according to claim 1, characterized in that: The transmission assembly includes a support frame, bearing housing, sealing gasket, bearing, bearing cover, bearing retaining ring, shaft head, motor, coupling, lock nut, first oil seal, second oil seal, packing cover, packing, and shaft end flange, all installed together.

6. The device for reducing dust entrainment in drying exhaust gas according to claim 5, characterized in that: The first oil seal and the second oil seal are located on both sides of the bearing, and the packing and packing gland are installed on the support frame.

7. The device for reducing dust entrainment in drying exhaust gas according to claim 5, characterized in that: After the shaft head is welded to the shaft end flange, it is inserted into the support frame. One side of the support frame is connected to the bearing seat. The motor is connected to the shaft head through the coupling. The spiral housing with shaftless helical blades is connected to the support frame with the shaft head.

8. The device for reducing dust entrainment in drying exhaust gas according to claim 1, characterized in that: The reverse thrust shaftless spiral also includes a heat tracing assembly, which is specifically a heat tracing pipe disposed on the shell of the reverse thrust shaftless spiral.

9. A method for reducing dust entrainment in dry exhaust gas using the apparatus as described in claim 8, characterized in that: Includes the following steps: The dry exhaust gas from the dryer is discharged from the dryer exhaust gas outlet into the vertical exhaust gas pipe. The reverse shaftless screw is installed on the vertical exhaust gas pipe, and the dry exhaust gas enters the reverse shaftless screw. The dust in the drying exhaust gas is intercepted by the blocking action of the shaftless spiral blades inside the reverse shaftless spiral, and as the reverse shaftless spiral rotates, the intercepted dust is pushed back into the dryer. The dried exhaust gas after passing through the reverse-propulsion shaftless spiral dust collector is discharged to the subsequent system through the exhaust gas outlet pipe.

10. The method for reducing dust entrainment in drying exhaust gas according to claim 9, characterized in that: The reverse-propulsion shaftless spiral shell is equipped with a heat tracing pipe, which uses steam or hot water for heat tracing to prevent the condensation of moisture in the drying exhaust gas.

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