Heat exchanger and method for cleaning external surface of heat transfer pipe

Abstract

To provide a heat exchanger and a method for cleaning an external surface of a heat transfer pipe, capable of scraping off dirt adhering to an external surface of a heat transfer pipe and reliably discharging the scraped dirt to the outside of the system.SOLUTION: A heat exchanger 1 comprises: a trunk pipe 2; a plurality of heat transfer pipes 3 arranged in parallel within the trunk pipe 2; scraper plates 10A, 10B, 10C having through holes 14 through which the heat transfer pipes 3 are inserted, and capable of moving back and forth in a direction in which the heat transfer pipes 3 extend; driving means for moving the scraper plates 10A to 10C back and forth; first fluid circulation means for circulating first fluid within the heat transfer pipes 3; and second fluid circulation means for circulating second fluid within a chamber 20 between the inner surface of the trunk pipe 2 and the heat transfer pipes, where the inner peripheral surface of the through holes 14 slides against the outer peripheral surfaces of the heat transfer pipes 3 as the scraper plates 10A to 10C move, thereby scraping off deposits on the outer peripheral surfaces of the heat transfer pipes. The scraped material is blown out through the supply and discharge ports (8a, 8b, 9a, 9b) of the trunk pipe 2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heat exchanger, and more particularly to a heat exchanger equipped with a mechanism for scraping off dirt adhering to the outer surfaces of heat transfer tubes and discharging them outside the system, and also to a method for cleaning the outer surfaces of the heat transfer tubes of the heat exchanger. [Background technology]

[0002] Known examples of cleaning mechanisms for heat exchangers that have a physical cleaning mechanism that scrapes off dirt adhering to the outer surface of the heat transfer tube and expels it outside the system include a scraping lever type (Patent Document 1) and a moving cleaning plate type (Patent Document 2).

[0003] Patent Document 1 discloses a configuration in which, in a resin shell-and-tube heat exchanger, multiple baffles are reciprocally slid along the tubes to scrape off dirt adhering to the tube surfaces. However, if the dirt adhering to the tube surfaces is highly sticky dirt such as slime, there is a risk that the scraped off slime or the like will adhere to the baffles and remain.

[0004] Patent Document 2 discloses a configuration in which a cleaning plate (heat transfer tube cleaning device) made of hard rubber or plastic is reciprocally slid using an air cylinder to scrape off dirt from the outer surface of the heat transfer tube. However, the heat exchanger of Patent Document 2 has a structure in which the heat transfer tube is immersed in an open-type hot water tank, and therefore the flow rate near the outer surface of the heat transfer tube cannot be increased, resulting in poor heat transfer efficiency. In addition, the scraped off dirt falls to the bottom of the hot water tank and is supposed to be drained from the outlet at the bottom, but the flow rate at the bottom is high only near the gap at the bottom of the weir, and dirt that falls to a place away from the weir is expected to accumulate as it is. In addition, the heat transfer tube cleaning device only cleans the heat transfer tube, and cannot clean other structures in the hot water tank (such as the inner wall surface of the tank, the bottom surface, the weir, and the cleaning plate). Therefore, it is estimated that regular manual cleaning will be necessary because the concentration of dirt in the hot water tank increases and the rate at which dirt adheres to the heat transfer tube increases. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-207813 A [Patent Document 2] JP 2013-032889 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a method for cleaning the outer surfaces of a heat exchanger and heat transfer tubes, which is capable of scraping off dirt adhering to the outer surfaces of the heat transfer tubes and efficiently discharging the scraped off dirt outside the equipment system. [Means for solving the problem]

[0007] The heat exchanger of the present invention comprises a body tube, a plurality of heat transfer tubes arranged in parallel within the body tube, a scraper plate having through holes through which the heat transfer tubes are inserted and capable of moving back and forth in the extension direction of the heat transfer tubes, a drive means for moving the scraper plate back and forth, a first fluid circulating means for circulating a first fluid within the heat transfer tubes, and a second fluid circulating means for circulating a second fluid within a chamber between the inner surface of the body tube and the heat transfer tubes, and the scraper plate is moved such that the inner peripheral surface of the through hole slides against the outer peripheral surface of the heat transfer tubes to move the heat transfer tubes. In a heat exchanger in which deposits on the outer peripheral surface are scraped off, the second fluid circulation means has an inlet / outlet (8) provided at one end side in the axial direction of the body tube and an inlet / outlet (9) provided at the other end side, the inlet / outlet (8) comprises a plurality of inlet / outlet ports (8a, 8b) arranged at different positions in the circumferential direction of the body tube, and the inlet / outlet (9) comprises a plurality of inlet / outlet ports (9a, 9b) arranged at different positions in the circumferential direction of the body tube.

[0008] In one aspect of the present invention, the supply and discharge openings (8) are provided as supply and discharge openings (8a, 8b) arranged on either side of the tube axis of the body tube, and the supply and discharge openings (9) are provided as supply and discharge openings (9a, 9b) arranged on either side of the tube axis of the body tube.

[0009] In one embodiment of the present invention, tube sheets are provided on one end and the other end of the chamber, the side of the tube sheet opposite the chamber serves as a supply and discharge chamber for the first fluid, and the inside of the heat transfer tube is connected to the supply and discharge chamber.

[0010] In one aspect of the present invention, the scraper plate is provided with a protrusion for forming a space between the scraper plates or between the scraper plate and the tube sheet when the scraper plates or the scraper plate and the tube sheet are brought close to each other.

[0011] In one aspect of the present invention, the driving means is a cylinder mechanism having a cylinder and a piston rod, and the tip of the piston rod is connected to the scraper plate.

[0012] In one aspect of the present invention, a rod insertion tube is provided that penetrates the supply and discharge chamber on one end side of the body tube, the piston rod is inserted into the rod insertion tube, and the cylinder is arranged outside the body tube.

[0013] In one aspect of the present invention, the drive means includes a wire rope having one end connected to the scraper plate and a winch for winding up the wire rope.

[0014] In one aspect of the present invention, a wire rope guide tube is provided which penetrates the supply and discharge chamber on one end side of the body tube, the wire rope is inserted into the wire rope guide tube, and the winch is arranged outside the body tube.

[0015] In one embodiment of the present invention, first through nth (n is an integer greater than or equal to 2) scraping plates are arranged from one end side to the other end side of the body tube, and each scraping plate is provided with a small hole through which the wire rope can be passed.

[0016] In one embodiment of the present invention, n is 3 or more, and a first wire rope having a tip connected to a first scraper plate and an nth wire rope having a tip connected to the nth scraper plate are provided to drive the first and nth scraper plates, and the scraper plates other than the first and nth scraper plates are connected to adjacent scraper plates by connecting wire ropes.

[0017] In one aspect of the present invention, the scraper plate is provided with a flow hole that connects one side of the scraper plate to the other side, in addition to the through hole, so that the scraper plate functions as a baffle for the heat exchanger.

[0018] The method for cleaning the outer surface of a heat transfer tube of the present invention is a method for cleaning the outer surface of a heat transfer tube of a heat exchanger of the present invention, and includes a first moving step of moving the scraper plate to one end side of the body tube, and then a first blowing step of supplying cleaning water into the chamber through the supply and discharge port (8a) on the one end side and causing the cleaning wastewater to flow out of the chamber through the supply and discharge port (8b).

[0019] One embodiment of the method for cleaning the outer surface of a heat transfer tube of the present invention further includes a second moving step of moving the scraper plate from the one end side to the other end side, and then a second blowing step of supplying cleaning water into the chamber through the supply and discharge port (9a) on the other end side and causing the cleaning wastewater to flow out of the chamber through the supply and discharge port (9b).

[0020] In one embodiment of the method for cleaning the outer surface of a heat transfer tube of the present invention, by performing the first moving step, the tube sheet on the one end side and the convex portion of the scraper plate closest to the one end side come into contact, and the convex portions of adjacent scraper plates come into contact with each other, and by performing the second moving step, the tube sheet on the other end side and the convex portion of the scraper plate closest to the other end side come into contact. Effect of the Invention

[0021] According to the method for cleaning the outer surface of a heat exchanger and a heat transfer tube of the present invention, dirt is scraped off from the outer surface of the heat transfer tube by moving the scraping plate to the end side of the body tube. The scraped off dirt is efficiently discharged outside the body tube by blowing cleaning water from the supply and discharge port. [Brief description of the drawings]

[0022] [Figure 1] 1A and 1B are a front view and a rear view, respectively, showing the inside of a body tube of a heat exchanger according to an embodiment in a see-through state. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. [Figure 4] FIG. 4 is a perspective view showing the configuration of a heat transfer tube and a scraper plate. [Diagram 5] FIG. 2 is a front view showing a scraping process of the heat exchanger of FIG. [Figure 6] FIG. 11 is a front view showing the inside of a body tube of a heat exchanger according to another embodiment in a see-through state. [Figure 7] FIG. 7 is a perspective view showing the configuration of the heat transfer tube and scraper plate in FIG. 6. [Figure 8] FIG. 7 is a front view showing a scraping process of the heat exchanger of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, an embodiment will be described with reference to the drawings.

[0024] <Cylinder type> 1 to 5 show a first embodiment using a cylinder system. As shown in Fig. 1, a heat exchanger 1 according to this embodiment includes a cylindrical body tube 2 and a plurality of heat transfer tubes 3 provided in the body tube 2. In this embodiment, the axial direction of the cylindrical body tube 2 is configured to be the up-down direction, but in the heat exchanger of the present invention, the axial direction of the body tube may be horizontal or oblique.

[0025] Supply and discharge ports 4, 5 for the first fluid are provided in the end plate portions at both axial ends of the body tube 2. Near the supply and discharge port 4 on the top side of the body tube 2, an upper tube plate 6 is provided with its plate surface oriented horizontally.

[0026] The outer peripheral edge of the upper tube plate 6 is watertightly fixed to the inner peripheral surface of the body tube 2 by welding or the like. A lower tube plate 7 is provided with its plate surface oriented horizontally near the supply and discharge port 5 on the bottom side of the body tube 2. The outer peripheral edge of the lower tube plate 7 is watertightly fixed to the inner surface of the body tube 2 by welding or the like.

[0027] The upper side of the upper tube plate 6 is a supply and discharge chamber 21, and the lower side of the lower tube plate 7 is a supply and discharge chamber 22. A chamber 20 is formed between the upper tube plate 6 and the lower tube plate 7.

[0028] Supply and discharge ports 8 (8a, 8b) for the second fluid are provided at the upper part of the side of the body tube 2 (directly below the upper tube plate 6), and supply and discharge ports 9 (9a, 9b) for the second fluid are provided at the lower part of the side of the body tube 2 (directly above the lower tube plate 7). The second fluid flows from supply and discharge port 8 to supply and discharge port 9 (or vice versa) within the chamber 20.

[0029] As described later, it is desirable to provide two or more supply and discharge ports 8, 9 for the second fluid in order to discharge dirt from the outer surface of the heat transfer tube, and to arrange them at equal intervals in the circumferential direction of the body tube 2 and at the same height in the horizontal plane. However, since an excessive number of supply and discharge ports complicates the structure and increases costs, it is desirable to provide two to four supply and discharge ports 8, 9. In this embodiment, two supply and discharge ports 8a, 8b, 9a, 9b are provided as the supply and discharge ports 8, 9, facing each other in the diametric direction of the body tube 2.

[0030] The multiple heat transfer tubes 3 are arranged vertically in parallel within the chamber 20 of the body tube 2. The upper ends of the heat transfer tubes 3 penetrate the upper tube plate 6, and the insides of the heat transfer tubes 3 communicate with the supply and discharge chamber 21. The lower ends of the heat transfer tubes 3 penetrate the lower tube plate 7, and the insides of the heat transfer tubes 3 communicate with the supply and discharge chamber 22. The first fluid flowing in from the supply and discharge port 4 passes through the supply and discharge chamber 21 and the insides of the multiple heat transfer tubes 3 to exchange heat with the second fluid, passes through the supply and discharge chamber 22, and flows out from the supply and discharge port 5. The flow direction of the first fluid may be reversed.

[0031] A plurality of scraping plates 10 (three in this embodiment) that can move in the vertical direction are provided horizontally in the chamber 20 of the body tube 2. The scraping plates 10 are circular in plan view, and their diameter is slightly smaller (approximately 2 mm or less) than the inner diameter of the body tube 2.

[0032] The scraper plate 10 is provided with through holes 14 for the heat transfer tubes 3, and the heat transfer tubes 3 are inserted through the through holes 14. The diameter of the through holes 14 is the same as the outer diameter of the heat transfer tubes 3 or is slightly larger (approximately 2 mm or less). As the scraper plate 10 moves up and down, the outer surface of the heat transfer tube 3 slides against the inner peripheral edge of the through holes 14, scraping off dirt on the outer surface.

[0033] The scraper plate 10 is also provided with flow holes 13 so that the second fluid can pass from the upper side to the lower side of the scraper plate 10 or from the lower side to the upper side.

[0034] In this embodiment, as shown in Figures 2 to 4, the flow holes 13 are chord-arc-shaped openings that run along the outer edge of the scraper plate 10, but they may also be cut-out portions formed by cutting the outer edge of the scraper plate 10 in the chord direction.

[0035] The size of the through hole 13 is preferably about 5 to 30% of the area of ​​the scraper plate 10. The heat transfer tube 3 may or may not be inserted into the through hole 13.

[0036] In this embodiment, one through hole 13 is provided in one scraper plate 10. The through holes 13 of the adjacent scraper plates 10 are preferably located opposite each other across the axial center line of the body tube 2. For example, in the odd-numbered scraper plates 10 from the top, the through hole 13 is located on the right side in FIG. 1, and in the even-numbered scraper plates 10, the through hole 13 is located on the left side in FIG. 1.

[0037] Also, as shown in FIG. 4, by providing a flow hole 13 at the position of the opposing heat transfer tube 3, the provision of the corresponding through hole 14 in the heat transfer tube 3 can be omitted.

[0038] The scraper plate 10 having the flow holes 13 functions as a baffle plate to increase the flow path length of the second fluid when it flows from the supply / discharge port 8 to the supply / discharge port 9 (or vice versa) within the chamber 20 during normal operation of the heat exchanger 1.

[0039] 1, in a normal operating state, the second fluid that flows into the chamber 20 from the supply / discharge port 8 or 9 passes through each of the communication holes 13, flows in a zigzag pattern within the chamber 20, and flows out from the supply / discharge port 9 or 8. The first and second fluids exchange heat with each other via the walls of the heat transfer tubes 3.

[0040] The first and second fluids may flow in parallel or countercurrent directions. Countercurrent flow can improve the heat transfer efficiency more than parallel flow.

[0041] In this embodiment, three scraper plates 10 are installed, but the number may be about 2 to 7, and is not limited to this number. Increasing the number of scraper plates 10 improves the ability to remove dirt from the heat transfer tubes 3. In a steady operating state of the heat exchanger 1, the intervals between the scraper plates 10, 10 are approximately uniform, and are preferably about 10 to 35%, and more preferably about 15 to 25%, of the distance between the upper tube plate 6 and the lower tube plate 7 of the body tube 2. The thickness of the scraper plate 10 is preferably about 1 mm to 20 mm, and more preferably about 2 mm to 10 mm.

[0042] A protrusion 11 is provided on the upper surface of the scraper plate 10. This protrusion 11 functions as a spacer to prevent the scraper plates 10 from overlapping each other or the upper tube plate 6 and the scraper plate 10 when the scraper plate 10 moves to the upper limit as shown in FIG.

[0043] A protrusion 12 is provided on the lower surface of the scraper plate 10. This protrusion 12 functions as a spacer to prevent the scraper plates 10 or the lower tube plate 7 and the scraper plate 10 from overlapping each other in close contact when the scraper plate 10 moves to the lower limit.

[0044] In this embodiment, the protrusions 11, 12 are arranged coaxially in the center of each scraper plate 10, but they do not have to be in the center, and they do not have to be coaxial, and are not limited to this.

[0045] The drive device for moving the scraper plate 10 may be a cylinder system using a hydraulic cylinder or a pneumatic cylinder as a power source, or a traction system using a wire or the like.

[0046] 1 to 5 show a cylinder system. As shown in Fig. 1, cylinders 16 (16A, 16B, 16C) equal to the number of scraping plates 10 are installed at one end of the body tube 2 so that the longitudinal direction of the rods is parallel to the axis of the body tube 2. Scraping plates 10A, 10B, 10C are fixed to the tips of piston rods 15 (15A, 15B, 15C) extending from each cylinder 16.

[0047] Although not shown in Fig. 3, the scraper plate 10A has insertion holes for loosely inserting the piston rods 15B and 15C, and the scraper plate 10B has an insertion hole for loosely inserting the piston rod 15C. The diameter of the insertion hole is slightly (approximately 2 mm or less) larger than the outer diameter of the piston rod 15.

[0048] As shown in FIG. 1(a), a rod insertion pipe 15p is installed between the head plate on the top side of the body pipe 2 and the upper tube plate 6, and the inside of the rod insertion pipe 15p is isolated from the inside of the supply and discharge chamber 21. The inside of the rod insertion pipe 15p is connected to the inside of the chamber 20. Each piston rod 15 extends into the chamber 20 through the rod insertion pipe 15p. A seal material is provided between the inner peripheral surface of the rod insertion pipe 15p and the outer peripheral surface of the piston rod 15, thereby preventing the second fluid in the chamber 20 from leaking through the rod insertion pipe 15p.

[0049] In the heat exchanger configured as above, to perform cleaning to remove the dirt substances adhering to the outer peripheral surface of the heat transfer tube 3, the cylinder 16 is operated to move the scraper plate 10 upward while the flow of the first and second fluids is stopped in FIG. 1. Then, the inner peripheral surface of the through hole 14 and the outer peripheral surface of the heat transfer tube 3 rub against each other, and the dirt substances (adhering matter) on the outer peripheral surface of the heat transfer tube 3 are scraped off. The scraped off dirt substances fall onto the scraper plate 10. Moreover, the dirt substances adhering to the inner peripheral surface of the body tube 2 are also scraped off by the outer peripheral edge of the scraper plate 10 and fall onto the scraper plate 10.

[0050] After all the scraper plates 10A-10C are raised to their respective upper limits, i.e., to the state shown in Fig. 5, they are maintained in the state shown in Fig. 5. In this embodiment, a gap is provided between each of the scraper plates 10A-10C equal to the total height of the protrusions 11, 12, and a gap is provided between the heat exchanger 10A and the upper tube plate 6 equal to the height of the protrusion 11. The upper surface of the scraper plate 10C is located at approximately the same level as or higher than the lower edges of the supply and discharge ports 8a, 8b.

[0051] In this state, a blow is performed to flow a fluid from one supply / discharge port 8a to the other supply / discharge port 8b. Then, the dirt that has accumulated on each scraper plate 10 flows out from the supply / discharge port 8b along with the fluid, and almost no dirt remains on each scraper plate 10.

[0052] In order to realize this mechanism, when the scraper plates 10A to 10C are raised to the state shown in Figure 5, the upper surface of the lowest scraper plate 10C must be positioned higher than the lower ends of the supply and discharge openings 8a, 8b, so the number of scraper plates and the height of the convex parts must be designed taking this into consideration.

[0053] When blowing, it is desirable to switch the flow direction between the inflow supply / discharge port 8a and the outflow supply / discharge port 8b in order to prevent dirt from accumulating in the same place.

[0054] After the blowing of the dirty materials in the state of Fig. 5 is completed, each piston rod 15 may be extended to move the scraper plate 10 downward to return to the original state of Fig. 1 and return to normal operation, or each scraper plate 10 may be further moved to its lower limit after passing through the state of Fig. 1 and placed on the bottom of the lower tube plate 7. The dirty materials scraped off while the scraper plate 10 is moving to the bottom-placed state are accumulated on the scraper plate 10 and the lower tube plate 7. Therefore, after the bottom-placed state is reached, a fluid is made to flow from one supply / discharge port 9a to the other supply / discharge port 9b to blow out the dirty materials.

[0055] In order to realize this mechanism, when the scraper plates 10A to 10C are lowered to the bottom, the underside of the top scraper plate 10A must be positioned lower than the upper ends of the supply and discharge ports 9a, 9b; therefore, the number of scraper plates and the height of the convex portions must be designed taking this into consideration.

[0056] After the blowing has stopped, the original state of FIG. 1 is restored and normal operation is resumed, or the scraping and blowing steps described above are further repeated.

[0057] In this manner, the dirt substances adhering to the heat transfer tubes 3 and the like can be sufficiently removed, and the scraped dirt substances can be quickly discharged outside the body tube 2.

[0058] The second fluid may be, but is not limited to, the inlet water of the biological treatment device or hot water pumped up from underground. The second fluid may be used as the washing water for blowing, or a different fluid may be used.

[0059] <Wire drive system> 6 to 8 show a heat exchanger 1' according to a second embodiment that uses a wire-driven system in which the scraper plate 10 is moved by a wire rope (hereinafter referred to as "wire") 17 and a winch (not shown) as a winding device.

[0060] In this embodiment, a scraper plate is used that does not have a through hole for loosely inserting the piston rod 15, which is not shown in Fig. 3. Also, the scraper plate 10 is provided with a small hole 18 having a diameter of about 10 mm that passes through the axial center of the protrusions 11 and 12 and penetrates the scraper plate 10 in the vertical direction.

[0061] From the viewpoint of corrosion, it is desirable that the wire 17 is not made of metal, or is coated with a corrosion-resistant material such as resin.

[0062] In this embodiment, the number of wires 17 is the same as the number of scraping plates 10, and in the illustrated example, three wires 17A, 17B, and 17C are used.

[0063] A wire guide tube 19A is provided for extending the wire 17 upward, and a wire guide tube 19B is provided for extending the wire 17 downward.

[0064] The lower end of the wire guide tube 19A penetrates the upper tube plate 6, and its interior communicates with the inside of the chamber 20. The upper part of the wire guide tube 19A extends upward, penetrating the upper end plate of the body tube 2. A valve 20A is provided at the upper end of the wire guide tube 19A.

[0065] The upper end of the wire guide pipe 19B penetrates the lower tube plate 7, and its interior is in communication with the chamber 20. The lower part of the wire guide pipe 19B extends downwardly, penetrating the lower end plate of the body tube 2. A valve 20B is provided at the lower end of the wire guide pipe 19B.

[0066] Each wire 17 is routed through a valve 20A, a wire guide tube 19A, a chamber 20, a small hole 18 in each scraper plate 10, a wire guide tube 19B and a valve 20B.

[0067] The valves 20A, 20B are configured so that the wire 17 moves freely when the valves are open, and so that the outflow of fluid from the chamber 20 is prevented when the valves are closed. The valves 20A, 20B each have a pair of valve bodies made of an elastic material such as rubber that can move forward and backward in the radial direction, and an advancing and retreating mechanism for advancing and retreating the valve bodies. When the pair of valve bodies are advanced forward and their front end faces come into contact with each other, the tips of the valve bodies come into close contact with each other with the wire 17 sandwiched therebetween, and the valves are closed. When the valve bodies are advanced backward, the valves 20A, 20B are opened, and the wire 17 can move freely.

[0068] Of the three wires 17, the first wire 17A is fastened to the small hole 18 portion of the upper scraper plate 10A, the second wire 17B is fastened to the small hole 18 portion of the middle scraper plate 10B, and the third wire 17C is fastened to the small hole 18 portion of the lower scraper plate 10C.

[0069] An example of a structure for fastening the wire 17 to the small hole 18 of the scraper plate 10 will now be described.

[0070] In this example, the wire 17 is divided into two wires, an upper wire and a lower wire, and an eye is provided at the lower end of the upper wire and the upper end of the lower wire. Each eye is fixed to the small hole 18 of the scraper plate 10 by a bolt or the like.

[0071] Instead of using bolts, the wires 17 can be fastened to the scraper plate 10 by detachably mounting pins in the small holes 18 in the diametrical direction, inserting the pins through each eye portion, and fixing the pins in the small holes 18.

[0072] The wire 17 can also be fastened to the small hole 18 by providing a hook-shaped portion instead of the eye portion and engaging the hook portion with a hook engaging member previously provided on the protrusion 11 or 12.

[0073] As winches for moving the scraper plate 10, an upper winch for winding up the upper end side of the wire 17 and a lower winch for winding up the lower end side (both not shown) are provided.

[0074] The upper winches and lower winches are installed in the same number as the number of wires 17, and each wire 17 can be wound and released separately.

[0075] When the upper winch winds up the upper part of the wire 17A and the lower winch unwinds the lower part of the wire 17A, the scraper plate 10A moves upward.

[0076] Similarly, when the upper portion of the wire 17B or 17C is wound by the upper winch and the lower portion is unwound from the lower winch, the wire 17B or 17C is sent upward, and the scraper plate 10B or 10C moves upward.

[0077] When the winding and unwinding of each winch is reversed, the scraper plate 10 moves downward.

[0078] In the heat exchanger 1' thus configured, in order to perform cleaning to remove contaminants adhering to the outer peripheral surface of the heat transfer tube 3, the flow of the first and second fluids is stopped, and the wires 17A, 17B, 17C are moved upward by operating the winch to move the scraping plates 10A, 10B, 10C to the upper limit position shown in Figure 8.

[0079] The state of FIG. 8 is similar to that of FIG.

[0080] In the state shown in FIG. 8, a fluid is caused to flow from the supply / discharge port 8a to the supply / discharge port 8b to perform blowing.

[0081] After the blowing is completed, the scraper plate 10 may be moved downward to return to the original state shown in FIG. 6 to return to normal operation, or each scraper plate 10 may be moved downward again after passing through the state shown in FIG. 6 to a bottom-mounted state in which each scraper plate 10 is placed on the lower tube plate 7, and fluid may be allowed to flow from the supply and discharge port 9a to the supply and discharge port 9b to blow.

[0082] In this way, even according to the embodiment of FIGS. 6 to 8, the dirt substances adhering to the heat transfer tubes 3 and the like can be sufficiently removed, and the scraped dirt substances can be quickly discharged to the outside of the body tube 2.

[0083] <Another Wire Drive System> In Figures 6 to 8, moving wires 17A, 17B, and 17C are connected to each of the scraping plates 10A, 10B, and 10C, respectively, and winches are provided above and below each wire to move each of the scraping plates 10A to 10C individually, but the scraping plate 10B may also be configured with a wire that follows the movement of the scraping plates 10A and 10C.

[0084] For example, the moving wire 17B may be omitted, and instead, the scraper plate 10B may be suspended continuously from the scraper plate 10A by a connecting wire, and the scraper plates 10B and 10C may be connected to each other by the connecting wire.

[0085] In this embodiment, when the scraping plates 10A and 10C are moved upward by the winch operation, the scraping plate 10A first comes into contact with the upper tube plate 6 during the movement, and the winch for the wire 17A is stopped. Then, the scraping plate 10B also stops temporarily. The wire 17C continues to be moved upward by the winch.

[0086] As scraper plate 10C moves upward in this manner, it comes into contact with scraper plate 10B, and thereafter scraper plates 10B and 10C move upward together. When scraper plate 10B rises until it comes into contact with scraper plate 10A, the state shown in FIG. 8 is reached.

[0087] In addition, in the state shown in Fig. 8, the winch is operated to feed only the wire 17C downward, and the scraping plates 10C and 10B are moved downward. Eventually, the connecting wire between the scraping plates 10B and the scraping plates 10A and 10C becomes taut, so the winch is operated to feed the wire 17A downward as well, and the scraping plate 10A is also moved downward. This eventually returns the system to the original state shown in Fig. 6.

[0088] Thereafter, the wires 17A and 17C are further fed downward, so that the scraping plates 10A to 10C reach the bottom.

[0089] 6 to 8, a winch is provided above and below each wire, but it is also possible to use a common winch for the upper and lower wires. In other words, when the upper part of the wire is wound up by the winch, the lower part of the wire is unwound accordingly.

[0090] In this way, by adopting a driven movement type for the scraper plate 10B or a type in which the upper and lower winches are common, the number of winches can be reduced. Also, the winch operation for moving the scraper plate is simplified.

[0091] The above embodiment is one example of the present invention, and the present invention may have other configurations. For example, four supply and discharge ports for the second fluid may be provided at equally spaced positions in the circumferential direction, and blowing may be performed in a direction perpendicular to the blowing direction in the case of two ports. [Explanation of symbols]

[0092] 1,1' heat exchanger 2 Body tube 3. Heat transfer tubes 4,5 First fluid supply / discharge port 6 Upper tube plate 7 Lower tube plate 8,9 Second fluid supply / discharge port 10 Scraping board 11,12 Convex part 13 Flow hole 14 Through hole 15 Piston rod 15p Rod insertion tube 16 cylinders 17 Wire 20 Chamber 21,22 Supply / discharge room

Claims

1. A body tube and A plurality of heat transfer tubes arranged in parallel within the body tube; a scraping plate having a through hole through which the heat transfer tube is inserted and capable of moving back and forth in the extension direction of the heat transfer tube; A driving means for moving the scraping plate back and forth; a first fluid flow means for flowing a first fluid through the heat transfer tube; a second fluid flow means for flowing a second fluid into a chamber between an inner surface of the body tube and the heat transfer tube; In a heat exchanger having a scraper plate, the inner peripheral surface of the through hole slides against the outer peripheral surface of the heat transfer tube by moving the scraper plate to scrape off deposits on the outer peripheral surface of the heat transfer tube, the second fluid flow means has an inlet / outlet port (8) provided at one end side in the axial direction of the body tube, and an inlet / outlet port (9) provided at the other end side, As the supply and discharge port (8), a plurality of supply and discharge ports (8a, 8b) are provided at different positions in the circumferential direction of the body tube, As the supply and discharge port (9), a plurality of supply and discharge ports (9a, 9b) are provided at different positions in the circumferential direction of the body tube. A heat exchanger characterized by:

2. As the supply and discharge port (8), supply and discharge ports (8a, 8b) are provided, which are arranged on either side of the tube axis of the body tube, The supply and discharge ports (9a, 9b) are provided on either side of the axis of the body tube as the supply and discharge ports (9).

2. The heat exchanger of claim 1.

3. A tube sheet is provided on one end side and the other end side of the chamber, and the side of the tube sheet opposite to the chamber serves as a supply and discharge chamber for the first fluid, 2. A heat exchanger according to claim 1, wherein the inside of said heat transfer tube communicates with said supply and exhaust chamber.

4. 2. A heat exchanger according to claim 1, wherein the scraper plate is provided with a protrusion for forming a space between the scraper plates or between the scraper plate and the tube sheet when the scraper plates or the scraper plate and the tube sheet are brought into close proximity to each other.

5. 4. The heat exchanger according to claim 3, wherein said driving means is a cylinder mechanism having a cylinder and a piston rod, the tip of said piston rod being connected to said scraper plate.

6. A rod insertion tube is provided which penetrates the supply / discharge chamber on one end side of the body tube, The piston rod is inserted into the rod insertion tube, 6. A heat exchanger according to claim 5, wherein said cylinder is disposed outside said body tube.

7. 4. The heat exchanger of claim 3, wherein said drive means comprises a wire rope having one end connected to said scraper plate and a winch for winding up said wire rope.

8. A wire rope guide pipe is provided which passes through the supply / discharge chamber on one end side of the body pipe, The wire rope is inserted into the wire rope guide tube, 8. The heat exchanger according to claim 7, wherein said winch is disposed outside said body tube.

9. 9. A heat exchanger as claimed in claim 8, wherein the first through nth (n is an integer of 2 or more) scraping plates are arranged from one end side to the other end side of the body tube, and each scraping plate is provided with a small hole through which the wire rope is passed.

10. n is 3 or more, and a first wire rope having a tip connected to the first scraper plate and an nth wire rope having a tip connected to the nth scraper plate are provided to drive the first and nth scraper plates; 10. The heat exchanger of claim 9, wherein each scraper plate other than the first and nth scraper plates is connected to an adjacent scraper plate by a connecting wire rope.

11. 2. The heat exchanger of claim 1, wherein the scraper plate has, in addition to the through holes, flow holes connecting one side and the other side of the scraper plate, so that the scraper plate functions as a baffle for the heat exchanger.

12. A method for cleaning an outer surface of a heat transfer tube of a heat exchanger according to any one of claims 1 to 11, comprising the steps of: a first moving step of moving the scraping plate toward one end side of the body tube; Thereafter, a first blowing step is performed in which cleaning water is supplied into the chamber through the supply and discharge port (8a) at the one end side, and cleaning wastewater is discharged out of the chamber through the supply and discharge port (8b). A method for cleaning the outer surface of a heat transfer tube of a heat exchanger having a heat exchanger tube.

13. Further, a second moving step of moving the scraping plate from the one end side to the other end side; Thereafter, a second blowing step is performed in which washing water is supplied into the chamber through the supply / discharge port (9a) on the other end side, and washing wastewater is discharged out of the chamber through the supply / discharge port (9b). The method for cleaning the outer surface of a heat transfer tube of a heat exchanger according to claim 12.

14. The heat exchanger is a heat exchanger according to claim 4, By performing the first moving step, the tube sheet on the one end side and the convex portion of the scraper plate closest to the one end side come into contact with each other, and the convex portions of adjacent scraper plates come into contact with each other, By carrying out the second moving step, the tube sheet on the other end side and the protruding portion of the scraper plate closest to the other end side come into contact with each other. The method for cleaning the outer surface of a heat transfer tube of a heat exchanger according to claim 13.

Images