Air-resistance-free type flow-dividing heat exchange pipeline and heat exchange equipment

Abstract

The invention discloses an air-resistance-free type flow-dividing heat exchange pipeline which comprises a flow-dividing type heat exchange unit arranged on a medium conveying pipeline, the flow-dividing type heat exchange unit comprises a plurality of heat exchange pipes arranged in parallel, and the heat exchange pipes are arranged from top to bottom. Inverted-U-shaped bends are arranged on the portions, on the water inlet side and the water outlet side of the heat exchange pipe, of the medium conveying pipeline, and the bent portions of the inverted-U-shaped bends are higher than the highest point of the heat exchange pipe. When the heat exchange pipeline is applied to the screen exchanger, the temperature difference between the upper portion and the lower portion of the screen inlet area and the upper portion and the lower portion of the screen outlet area can be eliminated, the temperatures of the upper portions and the lower portions of all the areas are consistent, and therefore the problem that a screen belt of the screen belt type screen exchanger inclines is effectively solved, the phenomena of screen clamping and screen belt breakage are avoided, the maintenance probability is reduced, the labor intensity of workers is lowered, and the production efficiency is improved. The product energy consumption and the production cost are reduced to the maximum extent, and the qualification rate of finished products is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat exchangers, in particular to a split-flow heat exchange pipeline without air resistance and a heat exchange device. BACKGROUND

[0002] A heat exchanger is a device for transferring heat between different media, and is widely used in heat management systems of industrial processes such as chemical industry, energy industry, and pharmaceutical industry. In the production of high polymer materials, a screen changer is usually equipped at the inlet end of an extruder to filter impurities in the melt and ensure continuous and stable production. The inlet and outlet areas of the screen changer are both provided with cooling pipelines, which function to solidify the melt by cooling, thereby forming a sealed environment in the filtration chamber.

[0003] Currently, such cooling pipelines usually adopt a one-in-one-out single waterway structure (see Figure 1 ) or a two-in-two-out double waterway structure (see Figure 2 ). However, regardless of the form, there is a problem of uneven cooling and inconsistent temperature distribution in the same area. Specifically, the upper part of the area has a higher temperature, and the lower part has a lower temperature, which leads to a relatively faster running speed of the passing screen belt in the upper part, and a slower running speed of the screen belt in the lower part due to the low temperature and obvious shrinkage. As shown in Figure 3 , the different speeds of the screen belt in the upper and lower parts easily cause the screen belt to run diagonally, which makes the edge of the screen belt deviate from the filtration area, and seriously affects the filtration efficiency. At the same time, the screen belt in the lower part with lower temperature is prone to form wrinkles due to shrinkage. With the continuous accumulation of wrinkles, the screen belt is difficult to smoothly enter the narrow screen groove, which may cause screen jamming (i.e., the screen belt stops) or even screen belt breakage.

[0004] In view of the above problems, ZL201621456757.2 discloses a heat exchange pipeline comprising a split-flow heat exchange unit, each of which comprises a longitudinal annular pipeline, and an inlet and an outlet are respectively arranged at the middle positions of the two longitudinal pipe sections of the longitudinal annular pipeline (see Figure 4 ). When the cooling water enters the longitudinal annular pipeline, it is divided into two streams for heat exchange, so that the temperatures of the upper and lower sections are kept consistent, and the screen belt is prevented from running diagonally. However, it is found in use that the water pressure and flow rate are required to be relatively high to automatically divide the water flow into two paths. When the water pressure is too low and / or the water flow is too small, the upper part of the cooling water path is prone to air resistance due to gravity, and the water flow will directly pass through the lower part without flowing through the upper part (see Figure 5 ), which further increases the temperature difference between the upper and lower parts of the inlet and outlet areas, and further aggravates the abnormal screen running. SUMMARY

[0005] In order to eliminate invalid heat exchange phenomenon caused by air blockage in upper section of shunt heat exchange unit, the application provides a shunt heat exchange pipeline without air blockage, provides a device containing the shunt heat exchange pipeline without air blockage, and also provides a screen changer containing the shunt heat exchange pipeline without air blockage, and the technical scheme can be specifically as follows. The shunt heat exchange pipeline without air blockage comprises a shunt heat exchange unit arranged on a medium conveying pipeline, the shunt heat exchange unit comprises a plurality of heat exchange pipes arranged in parallel, the heat exchange pipes are arranged from top to bottom, and a reverse U-shaped bend is arranged on the medium conveying pipeline on one side of the water inlet and one side of the water outlet of the heat exchange pipe, and the bending part of the reverse U-shaped bend is arranged higher than the highest point of the heat exchange pipe.

[0006] The heat exchange pipes arranged in parallel ensure sufficient heat exchange in upper and lower sections, meanwhile, the reverse U-shaped bend arranged on the medium conveying pipeline on one side of the water inlet and one side of the water outlet of the heat exchange pipe is higher than the heat exchange pipe, which avoids air blockage in the higher pipeline in the shunt heat exchange unit, and makes the water flow only in the lower pipeline in the shunt heat exchange unit, thereby solving the problem of uneven heat exchange in upper and lower sections of the heat exchange pipeline under the working condition of low flow and low water pressure.

[0007] Preferably, the heat exchange pipes are arranged in the same vertical plane, and at least one of the heat exchange pipes is arranged above the medium conveying pipeline, and at least one of the heat exchange pipes is arranged below the medium conveying pipeline. Further, the heat exchange pipes in each shunt heat exchange unit comprise two pipes arranged in parallel, and form a Chinese character-shaped structure distributed in the same vertical plane. The heat exchange pipes are arranged in the same plane to reduce the resistance of fluid medium conveying as much as possible, and the heat exchange pipes are arranged above and below the conveying pipeline to ensure the uniformity of fluid heat exchange in upper and lower sections.

[0008] Preferably, two or more shunt heat exchange units are arranged in series on the medium conveying pipeline, the planes where the heat exchange pipes of adjacent shunt heat exchange units are arranged are arranged in parallel, and the water inlets and outlets of the heat exchange pipes on the same side of adjacent shunt heat exchange units are arranged alternately. The water inlets and outlets of the heat exchange pipes on the same side of adjacent shunt heat exchange units are arranged alternately, so that the medium conveying pipeline section connecting the two can be arranged on one side of the shunt heat exchange unit, the length of the pipeline section is reduced, the fluid conveying efficiency is improved, and the standardization and aesthetic appearance of the pipeline section are improved.

[0009] Preferably, a reverse U-shaped bend is arranged on the medium conveying pipeline between the adjacent split-flow heat exchange units. Through experiments, it is found that the requirement that the heat exchange medium uniformly passes through all the heat exchange pipes in the split-flow heat exchange unit can be ensured by arranging a reverse U-shaped bend on the medium conveying pipeline between the adjacent split-flow heat exchange units, and arranging a reverse U-shaped bend at the inlet end and the outlet end of the medium conveying pipeline, respectively, which can simplify the pipeline design, save pipeline materials, and improve the installation effect.

[0010] Preferably, the bending parts of the reverse U-shaped bends are arranged at the same height. By arranging the bending parts of all the reverse U-shaped bends at the same height, the pipeline design is simplified, and the minimum pressure and the minimum flow of the heat exchange medium conveying are determined.

[0011] Preferably, an exhaust valve is arranged at the highest point of the heat exchange pipe at the top of each split-flow heat exchange unit. By arranging the exhaust valve at the highest point of the heat exchange pipe at the top of each split-flow heat exchange unit, it is beneficial to observe whether the split-flow heat exchange pipeline is in the full-pipe state, and when the air block phenomenon occurs accidentally, the exhaust can be conveniently performed to ensure the normal work of the heat exchange pipeline.

[0012] The application also provides a heat exchange equipment provided with a heat exchange pipeline, which adopts any one of the air-block-free split-flow heat exchange pipelines, and can meet the requirement of high uniform heat exchange of the equipment under the condition of small heat exchange medium flow and low pressure.

[0013] The application also provides a screen changer, which comprises a filter screen belt sequentially passing through an inlet screen area, a filtering area and an outlet screen area, and further comprises a heat exchange pipeline arranged in the inlet screen area and the outlet screen area, and the heat exchange pipeline adopts the air-block-free split-flow heat exchange pipeline. By adopting the air-block-free split-flow heat exchange pipeline, the temperature difference between the upper part and the lower part of the inlet screen area and the outlet screen area can be effectively avoided, and the air block phenomenon in the upper part of the split-flow heat exchange unit under the working condition of small water flow and low water pressure can be realized, the temperature of the upper part and the lower part of the cooling body is consistent, the problem that the screen belt is skewed under the working condition of small water flow and low water pressure in the initial water passing and long-term working process of the screen changer is effectively solved, and the failure rate of the screen belt type screen changer is reduced, so that the energy is saved and the production efficiency is improved.

[0014] Preferably, at least one split-flow heat exchange unit is arranged in each of the inlet screen area and the outlet screen area, and a reverse U-shaped bend connecting the split-flow heat exchange units in the inlet screen area and the outlet screen area is arranged in the filtering area. The air-block-free split-flow heat exchange pipeline with one inlet and one outlet is adopted, the pipeline design is simplified, and the on-site installation efficiency is improved.

[0015] Preferably, the heat exchange pipes of the split heat exchange unit are arranged in the shell of the inlet net area and the outlet net area, and the inverted U-shaped bends are arranged on the outer side of the shell of the inlet net area, the filter area and the outlet net area. Since the water inlets and outlets of the heat exchange pipes on the same side of adjacent split heat exchange units are arranged alternately, the medium conveying pipe sections connecting the two can be arranged on one side of the split heat exchange unit, even if the inverted U-shaped bends connecting adjacent split heat exchange units are arranged on one side of the shell, which helps to reduce the length of the pipe sections, improve the fluid conveying efficiency, and improve the standardization and aesthetics of the arrangement of the pipe sections.

[0016] The air resistance-free split heat exchange pipe provided by the application can be applied to a net changer and other working conditions with small heat exchange medium flow and unstable pressure but high requirement for the uniformity of the temperature of a cooling member. Since the inverted U-shaped bends are arranged before and after the split heat exchange unit on the medium conveying pipe, and the bending parts of the inverted U-shaped bends are higher than the highest point of the heat exchange pipe, the air resistance in the higher pipe in the split heat exchange unit can be effectively avoided under the condition of small heat exchange medium flow and unstable pressure, the phenomenon that the water flow only passes through the lower pipe in the split heat exchange unit is avoided, and the uniform heat exchange of the heat exchange pipe is ensured. For the net changer, the temperature difference between the upper part and the lower part of the inlet net area and the outlet net area can be eliminated, the temperature of each area is uniform, the problem of the net belt of the net belt type net changer being skewed is effectively solved, and the phenomenon of the net being stuck and the net belt being broken is avoided. Therefore, the probability of maintenance is reduced, the labor intensity of workers is reduced, the production efficiency is improved, the product energy consumption and production cost are maximally reduced, and the qualified rate of finished products is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structure schematic diagram of a prior one-in-one-out type cooling water pipe.

[0018] Figure 2 is a structure schematic diagram of a prior two-in-two-out type cooling water pipe.

[0019] Figure 3 is Figure 1 is a structure schematic diagram of the net belt of a net belt type net changer being skewed and wrinkled.

[0020] Figure 4 is a structure schematic diagram of a prior split heat exchange unit.

[0021] Figure 5 is a structure schematic diagram of the net belt of a net changer being skewed and wrinkled by using a split heat exchange unit.

[0022] Figure 6 is a structure schematic diagram of an air resistance-free split heat exchange pipe according to Embodiment 1.

[0023] Figure 7 is a structure schematic diagram of a heat exchange pipe of a net changer according to Embodiment 2.

[0024] Figure 8 is Figure 7 The developed structure schematic diagram of the heat exchange pipeline in the middle. Specific embodiments

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. These embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0026] Embodiment 1: The air-free resistance type shunt heat exchange pipeline described in the present invention includes a shunt heat exchange unit arranged on the medium conveying pipeline. The shunt heat exchange unit includes a plurality of heat exchange pipes arranged in parallel. The heat exchange pipes are arranged from top to bottom, and inverted U-shaped bends are arranged on both the water inlet side and the water outlet side of the medium conveying pipeline of the heat exchange pipes. The bending parts of the inverted U-shaped bends are all arranged higher than the highest point of the heat exchange pipes.

[0027] Specifically, as Figure 6 shown, a first inverted U-shaped bend 2, a shunt heat exchange unit, and a second inverted U-shaped bend 3 are sequentially arranged on the medium conveying pipeline 1. The above shunt heat exchange unit includes an upper section heat exchange pipe 4 and a lower section heat exchange pipe 5 located in the same plane. The upper section heat exchange pipe 4 and the lower section heat exchange pipe 5 are arranged in parallel. The water inlet 6 where they meet is connected to the outlet of the first inverted U-shaped bend 2, and the water outlet 7 where they meet is connected to the inlet of the second inverted U-shaped bend 3 (that is, a middle character structure is formed). And, the upper section heat exchange pipe 4 is located above the water inlet 6 and the water outlet 7, and is used for heat exchange in the upper area where it is located; the lower section heat exchange pipe 5 is located below the water inlet 6 and the water outlet 7, and is used for heat exchange in the lower area where it is located. The bending parts of the above first inverted U-shaped bend 2 and second inverted U-shaped bend 3 have the same height, and are both arranged higher than the highest point of the upper section heat exchange pipe 4.

[0028] Furthermore, according to the heat exchange requirements, the number of heat exchange pipes can be increased. Among them, at least one should be arranged above the medium conveying pipeline 1, and at least one should be arranged below the medium conveying pipeline 1, so that heat exchange can be realized in both the upper and lower sections. More, the same number of heat exchange pipes are symmetrically arranged above and below the medium conveying pipeline 1. The above-mentioned heat exchange pipes arranged in parallel in the same group are all located in the same vertical plane and are arranged from top to bottom, which can reduce the resistance of fluid medium transportation as much as possible, and enable the upper and lower fluids to fully exchange heat with the external environment.

[0029] Due to gravity, when the water pressure is too low and / or the water flow is too small, the heat exchange pipe located above the medium conveying pipeline 1 is prone to air blockage, causing the heat exchange medium to directly pass from the heat exchange pipe below the medium conveying pipeline 1 without flowing through the upper heat exchange pipe. Therefore, the present application is provided with a reverse U-shaped bend (i.e. first reverse U-shaped bend 2 and second reverse U-shaped bend 3) higher than the highest point of the heat exchange pipe on the medium conveying pipeline 1 at both ends of the heat exchange pipe in the same group (i.e. on the side of the water inlet and on the side of the water outlet), thereby ensuring that the heat exchange medium can fill the entire heat exchange pipeline, and even if the water pressure is too low and / or the water flow is too small, the phenomenon of not passing through the upper heat exchange pipe will not occur, allowing the upper and lower parts of the split-flow heat exchange unit to exchange heat, and achieving consistent temperature in the upper and lower parts of the cooling body.

[0030] Preferably, the reverse U-shaped bends at both ends of the heat exchange pipe are arranged at the same height, which can simplify the pipeline design and facilitate the determination of the minimum pressure and minimum flow rate of the heat exchange medium conveying. Further, an air vent valve is installed at the highest point of the upper heat exchange pipe 4 (i.e. the heat exchange pipe at the top of each split-flow heat exchange unit).

[0031] In use, first, the pipe is filled with water and the water flow is continuously maintained, then the air vent valve at the highest point of the heat exchange pipe is opened, and if water flows out, it indicates that the pipe filling is complete. At this time, the water pressure and water flow are adjusted according to the work requirements, and the heat exchange pipeline is in working condition.

[0032] Example 2: In actual application, more than one split-flow heat exchange unit is usually arranged on the medium conveying pipeline 1. In this case, the split-flow heat exchange units are arranged in series on the medium conveying pipeline 1, and only one reverse U-shaped bend is arranged between adjacent split-flow heat exchange units. Preferably, the planes on which the heat exchange pipes of all split-flow heat exchange units are arranged are parallel, and the water inlets and outlets of the heat exchange pipes located on the same side of adjacent split-flow heat exchange units are arranged alternately (see Figure 7 ). Thus, the medium conveying pipeline segment connecting the two can be arranged on one side of the split-flow heat exchange unit, facilitating the arrangement of the reverse U-shaped bend on the same side of the split-flow heat exchange unit, thereby reducing the length of the pipeline segment, improving the efficiency of fluid conveying, and improving the standardization and aesthetics of the arrangement of the pipeline segment.

[0033] The above-described air-free split-flow heat exchange pipeline comprising multiple split-flow heat exchange units and reverse U-shaped bends can be applied to the screen changer in the field of high polymer materials, and can also be applied to other devices with small heat exchange medium flow rate, low pressure, and high uniform heat exchange requirements. The screen changer is taken as an example for illustration.

[0034] As shown in Figure 7 , Figure 8The illustrated screen changer comprises a filter screen belt L that sequentially passes through a screen inlet area A, a filter area B and a screen outlet area C, and further comprises heat exchange pipelines arranged in the screen inlet area A and the screen outlet area C, wherein the heat exchange pipelines adopt the air resistance-free split heat exchange pipeline containing a split heat exchange unit and a reverse U-shaped bend according to the present application. The screen inlet area A is provided with a first split heat exchange unit 8, and the screen outlet area C is provided with a second split heat exchange unit 9 and a third split heat exchange unit 10. The first split heat exchange unit 8, the second split heat exchange unit 9 and the third split heat exchange unit 10 all adopt a parallel pipeline containing two heat exchange pipelines in a Chinese character shape, and the three parallel pipelines in the Chinese character shape are equal in size and correspondingly arranged in three vertical planes in the screen changer housing and are all perpendicular to the passing direction of the screen belt.

[0035] The inlet of the first split heat exchange unit 8 is located at the rear side of the screen changer housing, and the outlet is located at the front side of the screen changer housing. The inlet of the second split heat exchange unit 9 is located at the front side of the screen changer housing, and the outlet is located at the rear side of the screen changer housing. The inlet of the third split heat exchange unit 10 is located at the rear side of the screen changer housing, and the outlet is located at the front side of the screen changer housing. Therefore, a reverse U-shaped bend is arranged on the medium conveying pipeline 1 at the inlet end of the first split heat exchange unit 8 and located at the rear side of the screen changer housing, a reverse U-shaped bend is arranged on the medium conveying pipeline 1 between the first split heat exchange unit 8 and the second split heat exchange unit 9 and located at the front side of the screen changer housing and completely passes through the filter area B, a reverse U-shaped bend is arranged on the medium conveying pipeline 1 between the second split heat exchange unit 9 and the third split heat exchange unit 10 and located at the rear side of the screen changer housing, and a reverse U-shaped bend is arranged on the medium conveying pipeline 1 at the rear side of the third split heat exchange unit 10 and located at the front side of the screen changer housing. The reverse U-shaped bends are arranged at the same height, and the bending parts are all higher than the highest points of the heat exchange pipelines in the split heat exchange units.

[0036] The air resistance-free split heat exchange pipeline used in the screen changer can effectively avoid the air resistance in the higher pipelines in the split heat exchange units under the condition of small flow and unstable pressure of the heat exchange medium, and can avoid the phenomenon that the water flow only passes through the lower pipelines in the split heat exchange units, so as to ensure the uniform heat exchange of the heat exchange pipelines. Therefore, the temperature difference between the upper and lower parts of the screen inlet area and the screen outlet area of the screen changer can be eliminated, the temperature of each area is uniform, the problem of the screen belt passing obliquely in the screen belt type screen changer is effectively solved, and the phenomenon of screen jamming and screen belt breaking is avoided. Therefore, the maintenance probability is reduced, the labor intensity of workers is reduced, the production efficiency is improved, the product energy consumption and production cost are maximally reduced, and the qualified rate of finished products is ensured.

[0037] It should be noted that in the description of the present application, the terms indicating the orientation or positional relationship such as "front", "back", "left", "right", "vertical", "horizontal", "inner", "outer" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

Claims

1. A non-restrictive split-flow heat exchange pipeline, characterized in that: The device includes a split-flow heat exchange unit installed on a medium conveying pipeline. The split-flow heat exchange unit includes several heat exchange tubes arranged in parallel. The heat exchange tubes are arranged from top to bottom, and inverted U-shaped bends are provided on both the inlet and outlet sides of the medium conveying pipeline. The bends of the inverted U-shaped bends are all set higher than the highest point of the heat exchange tubes.

2. The air resistance-free split-flow heat exchange pipeline according to claim 1, characterized in that: The heat exchange tubes are arranged in the same vertical plane, with at least one heat exchange tube positioned above the medium conveying pipeline and at least one heat exchange tube positioned below the medium conveying pipeline.

3. The air resistance-free split-flow heat exchange pipeline according to claim 1, characterized in that: Two or more split-flow heat exchange units are connected in series on the medium conveying pipeline. The heat exchange tubes of adjacent split-flow heat exchange units are arranged in parallel, and the inlet and outlet of the heat exchange tubes on the same side of adjacent split-flow heat exchange units are alternately arranged.

4. The air resistance-free split-flow heat exchange pipeline according to claim 3, characterized in that: An inverted U-shaped bend is provided on the medium delivery pipeline between adjacent split-flow heat exchange units.

5. The air resistance-free split-flow heat exchange pipeline according to claim 1, characterized in that: The curved portions of the inverted U-shaped bend are all set at the same height.

6. The air resistance-free split-flow heat exchange pipeline according to claim 1, characterized in that: An exhaust valve is provided at the highest point of the heat exchange tube at the top of each of the aforementioned split-flow heat exchange units.

7. A heat exchange device, characterized in that: The system is equipped with heat exchange pipelines, wherein the heat exchange pipelines are the air resistance-free diversion heat exchange pipelines described in any one of claims 1-6.

8. A screen changer, comprising a filter belt that runs sequentially along an inlet zone, a filter zone, and an outlet zone, characterized in that: It also includes heat exchange pipelines installed in the inlet and outlet areas, wherein the heat exchange pipelines adopt the air resistance-free diversion heat exchange pipelines as described in any one of claims 1-6.

9. The screen changer according to claim 8, characterized in that: The inlet and outlet areas are each equipped with at least one diversion heat exchange unit, and the filter area is equipped with an inverted U-shaped bend connecting the inlet diversion heat exchange unit and the outlet diversion heat exchange unit.

10. The screen changer according to claim 9, characterized in that: The heat exchange tubes of the split-flow heat exchange unit are installed inside the shells of the inlet and outlet areas, and the inverted U-shaped bends are installed on the outer surfaces of the shells of the inlet, filtration, and outlet areas.

Images