Heat exchanger

Abstract

To provide a heat exchanger in which a flow passage where gas flows can be efficiently cleaned.SOLUTION: There is provided a multiple pipe type heat exchanger 1 that serves to exchange heat between first gas and second gas through a plurality of heat transfer pipes 12 arranged in parallel to extent vertically, the first gas flowing outside the heat transfer pipes 12 and the second gas flowing inside the heat transfer pipes 12. The first gas includes solid foreign matter, and the heat exchanger comprises a baffle plate 13 which changes the flow direction of the first gas, an air pipe 11 which are arranged in parallel with the heat transfer pipes 12 and in which compressed air flows, and a blowout part 11a which blows the compressed air out to the air pipe 11, the blown-out compressed air being blown to the baffle plate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] A heat exchanger is a device that transfers heat (exchanges heat) from a warm fluid to a cold fluid, and the fluid used can be liquid or gas. If solid foreign matter is mixed in the fluid, the solid matter may remain and accumulate in the flow path. The accumulation of solid foreign matter has adverse effects on the heat exchanger, such as clogging the flow path and reducing the heat exchange efficiency.

[0002] Known methods for removing accumulated solid foreign matter include circulating a chemical solution such as an acid or alkali inside the heat exchanger, or filling the inside of the heat exchanger with the chemical solution and inserting a nozzle into the flow path to inject high-pressure air through the bubbling action to clean and remove the foreign matter. However, these methods have drawbacks, such as requiring a temporary shutdown of the heat exchanger and the bubbling action only having a localized effect.

[0003] To address this drawback, Patent Document 1 discloses a technology relating to a heat exchanger having a structure in which air ejection holes are drilled in a tubular baffle plate retaining rod fixedly installed inside the can shell, and an air inlet pipe is arranged to connect to the baffle plate retaining rod from the outside of the can shell. This technology is said to have the effect of effectively bubbling and cleaning the entire inside of the can shell, sufficiently preventing adhesion of solid foreign matter to the tube walls or completely cleaning and removing them, thereby ensuring normal and safe operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Jpn. Jpn. Published No. 57-41593 [Patent Document 2] Japanese Patent Application Publication No. 9-61072 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology of Patent Document 1 involves bubbling cleaning by ejecting high-pressure gas into a liquid, and assumes that the fluid flowing through the heat exchanger is a liquid, and it is unclear whether bubbling cleaning will occur when the fluid is a gas. Therefore, the problem that the present invention aims to solve is to provide a heat exchanger that can efficiently clean the flow path through which the gas flows. [Means for solving the problem]

[0006] The aspects of the invention for solving the above problems are as follows. (First aspect) A heat exchanger that performs heat exchange between a first gas flowing outside a plurality of heat transfer tubes arranged in parallel and extending in a vertical direction and a second gas flowing inside the heat transfer tubes, the first gas is a gas containing solid foreign matter, A baffle plate that changes the flow direction of the first gas; An air pipe through which compressed air flows, which is arranged in parallel with the heat transfer pipe; The air pipe is provided with a blowing section from which compressed air is blown out, The compressed air blows against the baffle plate. A multi-tube heat exchanger characterized by:

[0007] When a heat exchanger in which the flowing fluid is gas is continuously used, the gas supplied contains solid foreign matter such as dirt, dust, and other solid foreign matter, and these solid foreign matter also flow into the flow path. Since the flow path is composed of, for example, a heat transfer tube, the inner wall of the tube body, a baffle plate, and the like, the solid foreign matter adheres to the heat transfer tube, the inner wall of the tube body, and the baffle plate as the gas flows, and gradually accumulates. For this reason, in the past, the use of the heat exchanger was restricted by providing a cleaning means as described in Patent Document 1, or by handling the gas containing solid foreign matter not to flow into the shell side flow path in the first place.

[0008] In this embodiment, the blown compressed air is configured to blow against the baffle plate, so that the solid foreign matter accumulated on the baffle plate is blown off and removed by the blowing of compressed air. In addition, when the compressed air is blown into the flow path, the internal pressure of the flow path is instantaneously increased, and the impact of the pressurization also reaches the components of the flow path, such as the heat transfer tube, the inner wall of the copper tube, and the baffle plate. As a result, the solid foreign matter attached to and accumulated on these components is blown up or moved by the impact. The impacted solid foreign matter flows together with the gas flowing through the flow path and is discharged from the heat exchanger. Note that Patent Document 2 is a heat exchanger having a porous heat transfer material, and the mechanism of blowing out the compressed air is different from that of this embodiment. Effect of the Invention

[0009] According to the present invention, a heat exchanger capable of efficiently cleaning a flow passage through which gas flows is provided. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 illustrates an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of the cross section AA of FIG. [Diagram 3] FIG. 2 is a cross-sectional view of FIG. [Figure 4] FIG. 2 is a cross-sectional view of the cross section AA of FIG. [Diagram 5] FIG. 4 is a diagram showing an example of the arrangement of heat transfer tubes. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] First Embodiment Next, an embodiment of the present invention will be described. Note that the embodiment is an example of the present invention. The scope of the present invention is not limited to the scope of the embodiment.

[0012] The multitubular heat exchanger 1 of this embodiment is a heat exchanger 1 that exchanges heat between a first gas flowing outside the heat transfer tubes 12 and a second gas flowing inside the heat transfer tubes 12 through a plurality of heat transfer tubes 12 arranged in parallel extending in the vertical direction, the first gas is a gas containing solid foreign matter, the multitubular heat exchanger 1 is characterized in that it is provided with baffle plates 13 (13a, 13b, 13c, 13d, ...) that change the flow direction of the first gas, air tubes 11 through which compressed air flows that are arranged in parallel to the heat transfer tubes 12, and a blowing section 11a from which the compressed air is blown out to the air tube 11, and the blown out compressed air blows against the baffle plates 13. Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1.

[0013] (Flow path) The multi-tubular heat exchanger 1 of this embodiment has two types of flow paths that do not intersect with each other, a tube-side flow path and a shell-side flow path. The second gas 32 flows inside the heat transfer tube 12, i.e., in the tube-side flow path, flows in from the second inlet portion 51 provided in the upper part of the tube body 2, passes inside the heat transfer tube 12, and flows out as the second gas 33 after heat exchange from the second outlet portion 6a provided in the lower part of the tube body 2. The first gas 30 flows outside the heat transfer tube 12 in the tube body 2, i.e., in the shell-side flow path, flows in from the first inlet portion 3 provided below the second inlet portion 51 in the tube body 2, passes outside the heat transfer tube 12, and flows out as the first gas 31 after heat exchange from the first outlet portion 4 provided above the second outlet portion 6a in the tube body 2. The second inlet section 51 and the first inlet section 3 are separated by a partition wall 5a, so that the second gas 32 flowing in from the second inlet section 51 and the first gas flowing in from the first inlet section 3 do not mix. In addition, the second outlet section 6a and the first outlet section 4 are separated by a partition wall 5b, so that the second gas passing through the inside of the heat transfer tube 12 and the first gas passing through the outside of the heat transfer tube 12 do not mix. The heat exchanger 1 of this embodiment can be installed so that the axial direction of the tube body 2 is aligned along the vertical direction, and of the vertical direction, the upward direction represents the direction of symbol U in FIG. 1, and the downward direction represents the direction of symbol D in FIG. 1.

[0014] (upper chamber, middle chamber, lower chamber) The tube body 2 is divided into an upper chamber 52, a middle chamber 53, and a lower chamber 54 from the top. The upper chamber 52 and the middle chamber 53 are separated by a partition wall 5a, and no fluid flows between the two chambers. The middle chamber 53 and the lower chamber 54 are separated by a partition wall 5b, and no fluid flows between the two chambers. The base end of the heat transfer tube 12 is located in the upper chamber 52, and the tip end is located in the lower chamber 54. The second gas that flows into the upper chamber 52 from the second inflow portion 51 flows into the inside of the heat transfer tube 12 from the base end of the heat transfer tube 12, is released from the tip of the heat transfer tube 12 into the lower chamber 54, and flows out of the heat exchanger 1 from the second outflow portion 6a. The lower chamber 54 is preferably formed into a hopper shape 6 so that the second gas can easily flow out.

[0015] A baffle plate 13 is provided in the middle chamber 53 so as to block the flow direction of the first gas. If there was no baffle plate 13, the first gas would flow into the middle chamber 53 from the first inlet portion 3 provided on the upper side of the middle chamber 53 and flow toward the first outlet portion 4 provided on the lower side of the middle chamber 53. However, due to the presence of the baffle plate 13 in this embodiment, the flow direction is changed and the first gas proceeds to the first outlet portion 4 while meandering.

[0016] The baffle plate 13 has a planar shape extending horizontally with respect to the tube shell 2 extending vertically, and has an opening with a diameter of the heat transfer tube 12 and an opening with a diameter of the air tube 11, through which the heat transfer tube 12 and the air tube 11 are inserted. The baffle plate 13 also has a cutout 14, and the first gas approaches the first outflow portion 4 through the cutout 14.

[0017] At least one baffle plate 13 can be provided in the middle chamber 53. For convenience, the baffle plates are distinguished as baffle plate 13a, baffle plate 13b, baffle plate 13c, ... from the top (a total of five baffle plates 13 are shown in FIG. 1, from baffle plate 13a to baffle plate 13e). Also, the notch of baffle plate 13a is given the reference symbol 14a, and the notches are distinguished as notch 14a of baffle plate 13a, notch 14b of baffle plate 13b, notch 14c of baffle plate 13c, ... from the top.

[0018] A preferred embodiment has a plurality of baffle plates 13 spaced apart in the vertical direction. If there are a plurality of baffle plates 13, the first gas flows in a meandering manner and is less likely to flow linearly toward the first outlet portion 4. A preferred embodiment also has the notches 14 of adjacent baffle plates 13 positioned differently in the circumferential direction of the heat exchanger 1. In this embodiment, the adjacent notches 14 do not overlap when the middle chamber 53 is viewed in the vertical direction, and the first gas flows in a large meandering manner in the middle chamber 53 and remains in the middle chamber 53 for a relatively long time, thereby improving the efficiency of heat exchange. The circumferential direction of the heat exchanger 1 refers to the direction in which the heat transfer tubes 12 of the heat exchanger 1 draw an arc around the axis when the axis is assumed to be along the vertical direction.

[0019] In addition, in a configuration in which the positions of the notches 14 in adjacent baffle plates 13 are different from each other in the circumferential direction of the heat exchanger 1, for example, it is preferable that the notches 14a and 14b differ by an angle of 150° to 180° in the circumferential direction of the heat exchanger 1, because the first gas advances in a large meandering manner. The shape of the notches 14 can be, for example, a line segment having any two points on the circumference of the baffle plate 13 as end points, but the line segment may be straight or curved, and if the heat transfer tube 12 or air tube 11 is located on the line segment, it is preferable to cut out the notch so as not to come into contact with (hit) the heat transfer tube 12 or air tube 11.

[0020] The flow direction of the first gas may be from the first inlet 3 to the first outlet 4, or conversely, from the first outlet 4 to the first inlet 3. The flow direction of the second gas may be from the second inlet 51 to the second outlet 6a, or conversely, from the second outlet 6a to the second inlet 51.

[0021] (bulkhead) The partitions 5a, 5b have a planar shape extending horizontally with respect to the tube shell 2 extending vertically, and an opening with a diameter of the heat transfer tube 12 and an opening with a diameter of the air tube 11 are formed, and the heat transfer tube 12 and the air tube 11 can be inserted into these openings. The heat transfer tube 12 and the air tube 11 can be arranged such that their leading ends are fixed by the partition 5a and their lower ends are fixed by the partition 5b. At least one heat transfer tube 12 and one air tube 11 can be provided.

[0022] (Heat transfer tube) A plurality of heat transfer tubes 12 are arranged in parallel and extend in the vertical direction.

[0023] (Air pipe) The air pipe 11 is arranged in parallel with the heat transfer pipe 12, and compressed air flows through it. The base end 11b of the air pipe 11 is connected to the air pipe 20, and the air pipe 20 is supplied with compressed air from the air header 9. When a plurality of air pipes 11 are provided, the air pipes 20 are also composed of a group of air pipes 20 consisting of the number of air pipes 11, and the base end 11b side of each air pipe 11 is connected to each air pipe. The air header 9 may be, for example, a form in which compressed air generated by a blower or compressor is sent to the air pipe 11, or a form in which pulse air is used for backwashing a bag filter provided in an incineration facility having a heat exchanger. The air pipe 20 may be provided with a valve 7 (for example, a pulse jet valve, etc.) for adjusting the amount of compressed air sent, and an opening adjustment means 8 for adjusting the opening of the valve 7. The tip of the air pipe 11 has a bottom, and is preferably located at the bottom of the middle chamber 53. It is preferable to provide at least one air pipe 11, and by providing, for example, 1 to 6 air pipes, compressed air can be blown evenly to the baffle plate 13, and accumulated solid foreign matter can be effectively suspended.

[0024] The blowing out of compressed air can be controlled so that the compressed air is blown out intermittently for 100 to 2000 milliseconds. Examples of the intermittent blowing out of compressed air include a method of controlling the blowing interval with a timer, a method of controlling based on a temperature difference, and the like.

[0025] Regarding the method of timer control, compressed air may be blown out of the heat exchanger 1 that operates continuously, for example, once every 30 minutes to 48 hours, more preferably once every 8 hours to 24 hours. If the interval is shorter than 8 hours, the amount of solid foreign matter accumulated on the plate is small, resulting in little effect. If the interval is shorter than 48 hours, the accumulated solid foreign matter is not sufficiently removed, resulting in little cleaning effect. However, this interval can be longer or shorter depending on the concentration of solid foreign matter contained in the gas, and is not generally determined.

[0026] Regarding the method of controlling based on the temperature difference, first, if the temperature difference between the inflow temperature and outflow temperature of the first gas in the heat exchanger 1 in a state where no solid foreign matter is accumulated on the baffle plate 13 (this temperature difference is also called the "optimum value during normal operation") is ΔT0, the temperature difference ΔT will decrease as the operation continues. Therefore, it is preferable to configure the compressed air to be blown out when the temperature difference ΔT becomes equal to or less than a predetermined value. Although the temperature difference ΔT cannot be determined in general, as an example of operation using the embodied product, the compressed air can be blown out when the temperature difference ΔT becomes equal to or less than 90% of ΔT0. The inflow temperature of the first gas in the heat exchanger 1 refers to the temperature of the first gas flowing through the first inflow section 3, and can be measured, for example, by a temperature sensor installed in the first inflow section 3. The outflow temperature of the first gas in the heat exchanger 1 refers to the temperature of the first gas flowing through the first outflow section 4, and can be measured, for example, by a temperature sensor installed in the first outflow section 4. For example, if the appropriate value ΔT0 during normal operation is 200°C, compressed air can be blown out when ΔT becomes 180°C or less. When solid foreign matter accumulates in the flow path, the flow path narrows, and the first gas that has flowed in flows out from the first outlet 4 faster than it initially did. This reduces the heat exchange efficiency, and the temperature difference between the first gas at the first inlet 3 and the first outlet 4 becomes smaller. Therefore, the amount of solid foreign matter accumulated in the flow path can be estimated from the temperature difference ΔT, and the timing of blowing out the compressed air can be controlled using the temperature difference ΔT. Immediately after the compressed air is blown out, the solid foreign matter is removed and the temperature difference becomes larger.

[0027] In addition, a method of combining a timer control method and a method of control based on a temperature difference is also effective. In the case of using the combined method, effective cleaning can be expected if the compressed air is controlled to be blown out when (1) 30 to 1500 minutes have elapsed since the heat exchanger 1 was operated or the compressed air was last blown out, or (2) the difference ΔT between the inlet temperature and the outlet temperature of the first gas becomes 90% or less, whichever occurs first.

[0028] When compressed air is blown onto the baffle plate 13, the solid foreign objects fly up even if they are not blown directly onto the solid foreign objects. This is due to the following action. When compressed air is blown into the shell-side passage, the gas in the shell-side passage is pressurized instantaneously, and the impact also reaches the solid foreign objects. The solid foreign objects accumulated on the baffle plate 13 gain momentum due to the impact, and as a result, they fly up or slide.

[0029] Air pipe 11 is provided with blowing section 11a from which compressed air is blown out into the shell-side flow path. If each air pipe 11 is provided with a plurality of blowing sections 11a spaced apart in the vertical direction, compressed air is blown out in the vertical direction within middle chamber 53, and solid foreign matter accumulated in various places is blown up by the wind pressure, which is preferable.

[0030] Moreover, it is preferable that at least one blowing section 11a is located near and above each baffle plate 13, so that the compressed air directly hits the baffle plate 13. Here, "near the baffle plate 13" cannot be generally defined as it depends on the flow speed of the blown compressed air, but it means that the distance between the baffle plate 13 and the blowing section 11a closest to the baffle plate 13 (for example, the distance of a perpendicular line from the blowing section 11a closest to the baffle plate 13 to the baffle plate 13) is 50 mm or less, more preferably 10 mm or less.

[0031] The shape of the blowing section 11a in the air pipe 11 is shown in Fig. 3. In Fig. 3, a plurality of blowing sections 11a are provided at intervals in the circumferential direction of the air pipe 11, and one is also provided at the bottom of the air pipe 11. In Fig. 3, six blowing sections 11a are provided in the circumferential direction of the air pipe 11, but the number is not limited, and 6 to 12 blowing sections 11a can be provided. The blowing section 11a provided at the bottom of the air pipe 11 is provided to blow away solid foreign matter accumulated on the partition wall 5b.

[0032] When the blowing section 11a is located near and above the baffle plate 13, it is preferable that the compressed air be blown downward from the blowing section 11a. Most of the solid foreign matter accumulates on the upper surface of the baffle plate 13, and so it is easy for the solid foreign matter to fly up when blown from above.

[0033] The blowing section 11a is not particularly limited as long as it can blow out compressed air, but for example, a nozzle with a diameter of 1 to 10 mm can be used. It is preferable that the compressed air is blown out from the nozzle at a flow rate of 20 to 100 Nm / sec. If the flow rate of the compressed air is too low, it will not be able to blow away solid foreign matter with sufficient force, and if the flow rate is too high, it may produce a large amount of noise.

[0034] An example of a specific form of the air pipe 11 is as follows: 37 blowing sections 11a are provided, the nozzle diameter of the blowing section 11a is 5 mm, and the air volume per air pipe is 0.65 Nm 3 / sec, compressed air blow time per blow is 200 ms, compressed air blow volume per air pipe is 0.13 Nm3 / time, blow interval is 30 minutes, compressed air required volume is 5 NL / min, volume of air header 9 is 0.15 m 3 It can be said that:

[0035] FIG. 2 is a cross section taken along the line AA in FIG. 1. A large number of heat transfer tubes 12 and air tubes 11 are arranged in the tube body 2. The air tubes 11 are arranged at intervals in the circumferential direction of the tube body 2. Also shown is a baffle plate 13b (a hatched area consisting of multiple straight lines drawn from the upper left to the lower right of the page) and an adjacent baffle plate 13c below it. Since the baffle plate 13c is below the baffle plate 13b, in reality, the part of the baffle plate 13c that faces the cutout portion 14b of the baffle plate 13b (a part excluding the hatched part) is visible. The cutout portion 14c of the baffle plate 13c is not actually visible, so it is shown by a broken line. FIG. 2 shows a configuration in which the positions of the cutout portions of the adjacent baffle plates 13b and 13c are mutually different (shifted) by 180° in the circumferential direction of the heat exchanger. In FIG. 2, a perpendicular line (dotted line) is hung from the axis of the tube body 2 to the cutout portion 14b, and a perpendicular line (dotted line) is hung from the axis of the tube body 2 to the cutout portion 14c, and the angle between the two perpendicular lines is 180°. Although not shown, the positions of the cutouts in the baffle plates 13a and 13b, the positions of the cutouts in the baffle plates 13c and 13d, and the positions of the cutouts in the baffle plates 13d and 13e may be different from each other by 180° in the circumferential direction of the heat exchanger. In addition, the positions of the cutouts in adjacent baffle plates may be different (shifted) from each other by 150° to 180° in the circumferential direction of the heat exchanger. FIG. 4 shows a form in which the positions of the cutouts in adjacent baffle plates are different (shifted) from each other by 150° in the circumferential direction of the heat exchanger. In Figure 4, a perpendicular line (dotted dashed line) is hung from the axis of the tube body 2 to the cutout portion 14b, and similarly a perpendicular line (dotted dashed line) is hung from the axis of the tube body 2 to the cutout portion 14c, and the angle formed by the two perpendicular lines is 150°.

[0036] The arrangement of the heat transfer tubes 12 is not particularly limited as long as the heat exchange efficiency is good. For example, as shown in FIG. 5, examples include (a) a square serial arrangement, (b) a staggered square arrangement, (c) a staggered triangular arrangement, and (d) a series triangular arrangement.

[0037] If the positions of the notches in the adjacent baffle plates are different from each other in the circumferential direction of the heat exchanger, the first gas meanders to pass through the different notches in the circumferential direction of the heat exchanger. Specifically, the flow direction of the first gas that has flowed into the shell-side flow passage is changed by the baffle plate 13a, flows along the surface of the baffle plate 13a, and passes through the notch 14a of the baffle plate 13a toward the adjacent baffle plate 13b. Thereafter, the first gas flows along the surface of the baffle plate 13b, passes through the notch 14b of the baffle plate 13b toward the adjacent baffle plate 13c. Furthermore, the first gas flows along the surface of the baffle plate 13c, passes through the notch 14c of the baffle plate 13c toward the adjacent baffle plate 13d. After that, if there are further adjacent baffle plates 13, the first gas flows in the above manner and finally reaches the first outlet 4. At this time, some of the solid foreign matter already adhering to the baffle plate 13 starts to flow due to the wind pressure of the flowing first gas, while other solid foreign matter remains attached thereto.

[0038] In addition, when the first gas flows into the tube body 2 from the first inlet portion 3 and flows out from the first outlet portion 4, solid foreign matter accumulated on the baffle plate 13a is blown away by the blowing of compressed air and falls from the notch portion 14a onto the baffle plate 13b provided below. The fallen solid foreign matter is blown away by further blowing of compressed air and falls from the notch portion 14b onto the baffle plate 13c provided below. This blowing away by compressed air is repeated, and the solid foreign matter falls successively onto the baffle plate 13 in the lower stage, and finally flows out from the first outlet portion 4 together with the first gas.

[0039] (others) The first gas flowing through the heat exchanger 1 contains solid foreign matter and is not particularly limited, and examples thereof include exhaust gas and dry exhaust gas generated in automobiles, gas turbines, incinerators, thermal power plants, and factories. The second gas may or may not contain solid foreign matter and is not particularly limited, and examples thereof include exhaust gas and dry exhaust gas generated in automobiles, gas turbines, incinerators, thermal power plants, and factories, and outside air. When the concentration of solid foreign matter contained in the first gas is 0.001 to 0.1 g / m 3 If this is the case, even if solid foreign matter accumulates in the flow path, it can be easily removed, which is preferable.

[0040] <Another aspect> The first aspect of the present invention has been explained above. In addition to this aspect, the following aspects are also desirable. (Second aspect) The blowing portion is located near and above the baffle plate. 1 is a cross-sectional view of a first embodiment of a shell-and-tube heat exchanger.

[0041] Since the baffle plate is plate-shaped, solid foreign matter tends to accumulate on it. In this embodiment, the blowing portion is located near and above the baffle plate, so that the blown compressed air tends to hit the solid foreign matter accumulated on the baffle plate. This provides the effect of efficiently cleaning the flow path.

[0042] (Third aspect) The baffle plate is provided in a plurality of spaces in the vertical direction. 1 is a cross-sectional view of a first embodiment of a shell-and-tube heat exchanger.

[0043] According to this embodiment, the first gas changes its flow direction due to the baffle plates and does not flow linearly, so that the first gas is retained in the flow passage for a longer period of time, thereby improving the efficiency of heat exchange.

[0044] (Fourth aspect) The air pipes are arranged in parallel at intervals, Each of the air pipes is provided with a plurality of blowing portions spaced apart in the vertical direction, The baffle plate is provided in a plurality of spaces in the vertical direction, At least one of the blowing sections is located near and above each of the baffle plates. 1 is a cross-sectional view of a first embodiment of a shell-and-tube heat exchanger.

[0045] Since the blowing portions are located near and above each of the baffle plates, solid foreign matter accumulated on each of the baffle plates is effectively removed by compressed air.

[0046] (Fifth aspect) The baffle plate has a notch, The positions of the notches in the adjacent baffle plates are different from each other in the circumferential direction of the heat exchanger. A shell-and-tube heat exchanger according to a fourth embodiment.

[0047] Since the positions of the adjacent notches are different from each other, the first gas flows in a serpentine manner, and the efficiency of heat exchange is improved.

[0048] (Sixth aspect) Compressed air is blown downward from the blowing portion. A shell-and-tube heat exchanger according to a second embodiment.

[0049] Compressed air is blown toward the baffle plate from a blowing portion provided above the baffle plate, so that solid foreign matter accumulated on the baffle plate is effectively removed.

[0050] (Seventh aspect) The blowing portion is provided in plurality at intervals in the circumferential direction of the air pipe. 1 is a cross-sectional view of a first embodiment of a shell-and-tube heat exchanger.

[0051] If the blowing direction is only one direction, solid foreign objects in directions other than the blowing direction are difficult to remove and may become stuck even if compressed air is blown. In this embodiment, compressed air is blown in multiple directions, so accumulations are less likely to occur and solid foreign objects are suppressed from sticking.

[0052] (Eighth aspect) Compressed air is blown intermittently for 100 to 2000 milliseconds. 1 is a cross-sectional view of a first embodiment of a shell-and-tube heat exchanger.

[0053] If the compressed air is blown out continuously, the flow of the first gas may be interfered with, and the efficiency of heat exchange may decrease. In this embodiment, the compressed air is blown out intermittently, so there is little interference with the flow of the first gas, and the efficiency of heat exchange is maintained.

[0054] (Ninth aspect) The compressed air is blown out when the temperature difference ΔT between the inlet temperature and the outlet temperature of the first gas in the heat exchanger becomes 90% or less. 1 is a cross-sectional view of a first embodiment of a shell-and-tube heat exchanger.

[0055] As the accumulation of solid foreign matter in the flow path increases, the difference decreases. If the compressed air is blown out when the difference falls within the above range, the accumulated solid foreign matter is removed by the compressed air when it reaches a predetermined amount, making cleaning effective. [Industrial Applicability]

[0056] The present invention can be used as a multi-tube heat exchanger. [Explanation of symbols]

[0057] 1 heat exchanger 11 Air pipe 11a Air outlet 12 Heat transfer tube 13a, 13b, 13c, 13d, 13e Baffle plates 14a, 14b, 14c, 14d, 14e Notch 30 First gas (inlet gas) 31 First gas (outflow gas) 32 Second gas (inlet gas) 33 Second gas (outflow gas)

Claims

1. A heat exchanger that performs heat exchange between a first gas flowing outside a plurality of heat transfer tubes arranged in parallel and extending in a vertical direction and a second gas flowing inside the heat transfer tubes, the first gas is a gas containing solid foreign matter, A baffle plate for changing the flow direction of the first gas; An air pipe through which compressed air flows, which is arranged in parallel with the heat transfer pipe; The air pipe is provided with a blowing section from which compressed air is blown out, The compressed air blows against the baffle plate. A multi-tube heat exchanger characterized by:

2. The blowing portion is located near and above the baffle plate. The multi-tube heat exchanger according to claim 1 .

3. The baffle plate is provided in a plurality of spaces in the vertical direction. The multi-tube heat exchanger according to claim 1 .

4. The air pipes are arranged in parallel at intervals, Each of the air pipes is provided with a plurality of blowing portions spaced apart in the vertical direction, The baffle plate is provided in a plurality of spaces in the vertical direction, At least one of the blowing sections is located near and above each of the baffle plates. The multi-tube heat exchanger according to claim 1 .

5. The baffle plate has a notch, The positions of the notches in the adjacent baffle plates are different from each other in the circumferential direction of the heat exchanger. The multi-tube heat exchanger according to claim 4.

6. Compressed air is blown downward from the blowing portion. The multi-tube heat exchanger according to claim 2.

7. The blowing portion is provided in plurality at intervals in the circumferential direction of the air pipe. The multi-tube heat exchanger according to claim 1 .

8. Compressed air is blown intermittently for 100 to 2000 milliseconds. The multi-tube heat exchanger according to claim 1 .

9. When no solid foreign matter is deposited on the baffle plate, the temperature difference between the inlet temperature and the outlet temperature of the first gas in the heat exchanger is ΔT 0 , The compressed air is blown out when a temperature difference ΔT between an inflow temperature and an outflow temperature of the first gas in the heat exchanger becomes 90% or less of ΔT 0 . The multi-tube heat exchanger according to claim 1 .

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