JP6531385B2 - Cleaning device for inner surface of heat exchanger tube - Google Patents

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a cleaning device in the inner surface of a capillary of a heat exchanger, and more particularly to an apparatus for inserting a nozzle into the capillary and cleaning.

  As a method of cleaning the inner surface of a thin tube such as a heat transfer tube, a high pressure washing water supplied from a flexible hose connected to the rear end of the nozzle by inserting a nozzle from the heat transfer tube opening exposed to the tube plate There is a method in which the nozzle is jetted from the nozzle toward the inner surface of the heat transfer tube.

In the past, the cleaning work was manually performed by a cleaning worker having a nozzle, which is an operation requiring experience as well as a physically demanding operation.
Patent document 1 describes that a flexible hose is moved by a motor in order to increase the efficiency of the cleaning operation and to save labor in the cleaning operation. In Patent Document 1, the flexible hose is wound around a drum. After inserting the nozzle into the heat transfer tube, the nozzle is advanced while spouting high-pressure cleaning water. After the nozzle has advanced to the set position, the nozzle is retracted by winding it on the drum.

  In Patent Document 1, a mark is attached to a flexible hose, and the mark is detected by an optical sensor to detect the amount of delivery of the flexible hose, thereby detecting the position of the nozzle.

Japanese Patent Application Laid-Open No. 7-019793

  In the cleaning apparatus of Patent Document 1, when cleaning dirt attached to the inner surface of a thin tube of a heat exchanger such as an oil refining plant, a mark provided on a flexible hose is hard to be detected by an optical sensor, and detection of a nozzle position is not possible. It may be accurate.

  An object of the present invention is to provide an apparatus for cleaning the inner surface of a thin tube of a heat exchanger capable of reliably stopping the nozzle at a prescribed position.

  The apparatus for cleaning the inner surface of a thin tube of a heat exchanger according to the present invention comprises a nozzle holder coaxially arranged with respect to the opening of the thin tube exposed to the tube plate, a nozzle advancing from inside the nozzle holder into the thin tube, and the nozzle An apparatus for cleaning the inner surface of a thin tube of a heat exchanger, comprising: a lance connected to the rear end of the lance, a flexible hose connected to the rear end of the lance, and a flexible hose drive for advancing and retracting the flexible hose A stopper, and a stopping mechanism for stopping the flexible hose from advancing and retracting when the stopper abuts against the stopper locking portion.

  In one aspect of the present invention, the outer peripheral surface of the lance is provided with a convex portion, and the inner peripheral surface of the nozzle holder is provided with a small diameter portion with which the convex portion abuts from the thin tube side The mechanism stops the flexible hose from advancing and retracting when the convex portion hits the small diameter portion.

  In one aspect of the present invention, the outer shape of the protrusion in a cross section perpendicular to the axial line of the lance is non-circular.

  In one aspect of the present invention, the nozzle holder has a double pipe structure having an inner pipe and an outer pipe that surrounds the inner pipe with a gap, and the inner pipe and the outer pipe have the inner pipe and the inner pipe. An opening communicating the inside of the pipe and the outside of the outer pipe with the gap is provided, and the opening of the inner pipe and the opening of the outer pipe are provided so as not to face each other.

  In one aspect of the present invention, a guide tube is provided between the nozzle holder and the flexible hose drive coaxially with the nozzle holder, and the flexible hose is inserted into the guide tube.

  In the apparatus for cleaning the inner surface of the capillary of the heat exchanger according to the present invention, the nozzle holder is disposed facing the opening of the capillary to be cleaned, and the nozzle is inserted into the capillary to be cleaned from this nozzle holder. Can be advanced to be inserted into the tubule to be cleaned, and the tubule can be efficiently cleaned. In addition, when the flexible hose advances by a specified length, the stopper abuts on the stopper engagement portion, and the motor stops, so that the nozzle can be reliably advanced by the specified distance.

  After the nozzle stops moving forward, retract the flexible hose. In one aspect of the present invention, since the nozzle is retracted until the convex portion of the lance abuts on the small diameter portion of the nozzle holder, the position at the time of the reverse stop also becomes the prescribed position.

  If the outer shape of the convex portion is non-circular, drainage and foreign matter generated by washing easily pass between the convex portion and the inner surface of the nozzle holder or the inner surface of the thin tube.

  The nozzle holder has a double-pipe structure having an inner pipe and an outer pipe, and by providing the openings in the inner pipe and the outer pipe in a non-faced positional relationship, jet water from the nozzle is directly transmitted to the outer periphery. It is prevented from spouting.

It is a schematic explanatory drawing of the washing | cleaning apparatus in the capillary inner surface of the heat exchanger which concerns on embodiment. It is sectional drawing which follows the II-II line of FIG. (A) is a side view of a lance, (b) is a front view of a lance. It is sectional drawing of the longitudinal direction of a nozzle holder.

  Hereinafter, an embodiment will be described with reference to FIGS.

  As shown in FIG. 1, one end of a large number of heat transfer tubes (thin tubes) 3 is fixed to the tube sheet 2 of the heat exchanger bundle 1 by welding. The heat transfer tube 3 penetrates the tube sheet 2, and an opening at one end side of the heat transfer tube 3 is open to the outside of the bundle 1.

  In the thin-tube washing device, the tip of the cylindrical nozzle holder 10 is brought into contact with the tube sheet 2 so as to be coaxial with the heat transfer pipe 3 to be cleaned, and the nozzle 5 disposed in the nozzle holder 10 is The high-pressure water supplied from the holder 10 into the heat transfer pipe 3 and supplied via the flexible hose (flexible hose) 6 and the lance 7 is jetted obliquely backward from the jet hole of the nozzle 5. The rear end of the flexible hose 6 is connected to a high pressure pump (not shown).

  The nozzle 5 is attached to the tip of the lance 7. As shown enlarged in FIG. 3, the lance 7 is cylindrical. A convex portion 7 a is provided on the outer peripheral surface of the rear of the lance 7 in a circulating manner. As shown in FIG. 3B, the convex portion 7a has a non-circular outer shape (in this embodiment, a substantially quadrilateral in which four corners are arc-shaped) in cross section orthogonal to the axial center of the lance 7, A gap is formed between the inner circumferential surface of the nozzle holder 10 or the heat transfer tube 3 and the convex portion 7 a.

  The nozzle holder 10 has a double pipe structure having an inner pipe 11 and an outer pipe 12 provided outside the inner pipe 11 as shown in FIG. The inner pipe 11 is cylindrical, but a small diameter portion 11a is provided on the inner peripheral surface near the rear end. The inner diameter of the small diameter portion 11a is smaller than the maximum diameter of the convex portion 7a. Further, a female screw 11b for connection of the guide tube 14 is engraved on the inner peripheral surface of the rearmost portion of the inner pipe 11 on the rear side of the small diameter portion 11a.

  The rear outer peripheral surface of the inner pipe 11 is a large diameter portion 11c, and the rear portion of the outer pipe 12 is fitted to the large diameter portion 11c. A gap is open between the inner pipe 11 and the outer pipe 12 on the front side of the large diameter portion 11c. The inner pipe 11 and the outer pipe 12 are provided with openings 11e and 12e for discharging foreign matter and washing drainage so as to face the gap. The tip of the outer pipe 12 is slightly retracted from the tip of the inner pipe 11.

  The front end side of the guide tube 14 coaxial with the inner pipe 11 is connected to the rear end side of the inner pipe 11. The rear end side of the guide tube 14 is connected to the front surface of the machine frame 21 of the flexible hose drive device 20 as shown in FIG.

  On the rear surface portion of the machine frame 21, a cylindrical portion 21e through which the flexible hose 6 is inserted is provided. The cylindrical portion 21e is provided as a stopper locking portion. The inner diameter of the cylindrical portion 21 e is smaller than the outer diameter of the stopper 50 described later.

  The flexible hose drive device 20 includes two pairs of lower roller 22 and upper roller 23 which sandwich the flexible hose 6. The lower roller 22 is a drive roller, and is driven by the torque sensor motor 30 via the chain 24. The front side lower roller 22 and the rear side lower roller 22 are configured to be interlocked by a chain 25.

  As shown in FIG. 2, the lower roller 22 is fixed to the shaft 26, and the shaft 26 is supported by the machine frame side portion 21 a via a bearing 27. Sprocket wheels 28 are fixed at both ends of the shaft 26 respectively. One sprocket wheel 28 is driven by a motor 30 through a chain 24, and a chain 25 for interlocking the lower rollers 22 is suspended on the other sprocket wheel 28.

  The upper roller 23 is a driven roller, and is configured to be pressed against the upper surface side of the flexible hose 6 by the air cylinder 33. As shown in FIG. 2, the air cylinder 33 is attached to the top portion 21 b of the machine frame, and the piston rod 33 a is arranged to stroke downward in the vertical direction.

  The hanging support member 34 is connected to the lower end of the piston rod 33a. The hanging member 34 has a pair of legs 34 a, 34 a hanging down along the side surface of the upper roller 23. A shaft 35 is bridged between the legs 34a, 34a. A boss plate 38 is fixed to both side surfaces of the upper roller 23, and the boss plate 38 is rotatably held by a shaft 35 via a bearing (not shown).

  Although not shown, vertical through holes are provided on both end sides of the shaft 35, and the through holes are slidably fitted in guide rods (not shown) vertically provided from the machine frame top 21b. doing. As a result, the shaft 35 and the upper roller 23 supported thereon move smoothly up and down while maintaining the horizontal posture by advancing and retracting the rod of the air cylinder 33, and the reaction force from the flexible hose 6 to the flexible hose 6 is also received. It is immobile in the direction of advance and withdrawal.

  The motor 30 of the flexible hose drive device 20 is controlled by the control panel 40. The control panel 40 includes a feed switch 41 for advancing the flexible hose 6 forward by rotating the motor 30 forward, a withdrawal switch 42 for reversing the motor 30 backward and reversing the motor 30, and an emergency stop switch 43. It is provided. Further, the control panel 40 is configured to supply and discharge compressed air to the air cylinder 33 via the air pipe 48 in conjunction with the switch operation.

  A stopper 50 is attached to the flexible hose 6. The stopper 50 is attached at a position where the stopper 50 abuts on the rear end surface of the cylindrical portion 21e of the rear surface of the machine frame when the nozzle 5 advances in the heat transfer tube 3 and reaches the end position. The stopper 50 is fixed to the flexible hose 6 by, for example, bonding, caulking, a U-bolt or the like.

  When cleaning the heat transfer tube 3, as shown in FIG. 1, the nozzle 5 is disposed in the nozzle holder 10, and the nozzle holder 10 is in contact with the tube sheet 2 so as to be coaxial with the heat transfer tube 3. Let In this state, the feed switch 41 is pressed. As a result, the high-pressure pump is started, high-pressure water is fed into the flexible hose 6, and the motor 30 rotates forward, and the flexible hose 6 starts to move forward. In addition, the propulsive force in the forward direction is applied to the nozzle 5 when the nozzle 5 ejects high pressure water obliquely backward.

  The nozzle 5 moves from the nozzle holder 10 into the heat transfer tube 3 while spouting high pressure water, and further advances in the heat transfer tube 3. When the flexible hose 6 is fed by a predetermined length, the stopper 50 contacts the cylindrical portion 21 e of the machine frame, and the further advance of the flexible hose 6 is blocked. At this time, the torque of the motor 30 rapidly increases. However, when the cleaning operator turns the feed switch 41 OFF or switches the extraction switch 42 ON, a failure due to an overload of the motor can be prevented. Preferably, when the control circuit of the control board 40 detects this increase in torque, it has a mechanism for stopping the motor 30.

  Next, when the pullout switch 42 is pressed, the motor 30 is reversely rotated, and the nozzle 5 and the flexible hose 6 are retracted. The nozzle 5 is retracted until the convex portion 7 a of the lance 7 abuts on the small diameter portion 11 a of the nozzle holder 10. When the convex portion 7a strikes the small diameter portion 11a, the further backward movement of the flexible hose 6 is prevented. Also in this case, the torque of the motor 30 rapidly increases, but the motor operator can release the overload state by turning off the pullout switch 42. Preferably, the control circuit of the control board 40 has a mechanism for stopping the motor 30 and stopping the high pressure pump and stopping the supply of high pressure water to the flexible hose 6 when detecting the increase in torque. good.

  By the above procedure, the cleaning of the first heat transfer tube 3 is completed, so the nozzle holder 10 is transferred to the heat transfer tube 3 next to the heat transfer tube 3 whose cleaning has been completed, and the heat transfer tube 3 is cleaned similarly. This process is performed one after another to clean all the heat transfer tubes 3.

  According to this embodiment, since the nozzle 5 is advanced in a state in which the nozzle holder 10 is in contact with the tube sheet 2 coaxially with the heat transfer pipe 3 to be cleaned, high pressure water is spouted from the nozzle 5 Even if there is, the nozzle 5 can be smoothly inserted into the heat transfer tube 3. For this reason, the cleaning operation efficiency of the heat transfer tube is improved. Further, by setting the speed of the nozzle 5 to a constant speed, the cleaning state becomes uniform and non-uniform.

  In this embodiment, the nozzle 5 ejecting high pressure water is moved from the nozzle holder 10 into the heat transfer tube 3, and the nozzle 5 ejecting high pressure water is withdrawn from the heat transfer tube 3 into the nozzle holder 10. Thus, the end portion of the heat transfer tube 3 is sufficiently cleaned.

  The nozzle holder 10 is provided with openings 11e and 12e for removing foreign matter and water, and the convex portion 7a of the lance 7 is non-circular, so that foreign matter and cleaning drainage in the heat transfer tube 3 can be discharged smoothly. . Therefore, it is also prevented that the foreign matter adheres to the inner surface of the nozzle holder 10 and the stop position of the lance 7 fluctuates. In addition, since the openings 11e and 12e of the inner pipe 11 and the outer pipe 12 of the nozzle holder 10 are offset from each other, even if high pressure water is spouted from the nozzle 5 in the nozzle holder 10, this water is scattered around There is no. Therefore, the working environment is also good.

  As a preferable mode of the above embodiment, it is detected that the nozzle 5 has moved to the forward limit or the reverse limit based on the torque of the motor 30, but a detection switch such as a limit switch or a proximity sensor or electrical A detection means or the like for detecting such conduction may be employed.

  In the present invention, it is preferable to stop the motor 30 when the torque of the motor 30 exceeds the reference value, and to prevent the nozzle 5 from being pushed excessively excessively into the capillary 3.

  Although the present invention is not particularly limited, the moving speed of the nozzle is preferably about 1 to 2 m / sec. The pressure of high pressure water is preferably about 20 to 40 MPa.

  In addition, when the thin tubes (thin tube outer diameter 19 mm, narrow tube inner diameter 13.46 mm, length 6100 mm) of the bundle extracted from the heat exchanger were sequentially washed using the apparatus shown in FIG. It was possible to wash safely and easily in 8.4 seconds.

  Incidentally, in the conventional method in which the nozzle man performs manual cleaning with a high pressure water nozzle, even a skilled worker takes 9.5 seconds per capillary, and the physical load of the worker is also large.

1 bundle 2 tube sheet 3 heat transfer tube (thin tube)
DESCRIPTION OF SYMBOLS 5 nozzle 6 flexible hose 7 lance 7a convex part 10 nozzle holder 11 inner pipe 11a small diameter part 11e opening 12 outer pipe 12e opening 14 guide tube 20 flexible hose drive device 22,23 roller 24,25 chain 30 motor 33 air cylinder 40 control board 50 stopper

Claims (4)

A nozzle holder disposed coaxially with the opening of the thin tube exposed to the tube sheet;
A nozzle advancing from inside the nozzle holder into the thin tube;
A lance connected to the rear end of the nozzle,
Flexible hoses connected to the rear end of the lance,
What is claimed is: 1. A cleaning device for the inner surface of a capillary of a heat exchanger, comprising: a flexible hose driving device for advancing and retracting the flexible hose,
A stopper provided in the middle of the flexible hose,
And a stop mechanism that stops the flexible hose from advancing and retracting when the stopper abuts against the stopper locking portion ,
The nozzle holder has a double-pipe structure having an inner pipe and an outer pipe surrounding the inner pipe with a gap therebetween.
The inner pipe and the outer pipe are provided with an opening that communicates the inside of the inner pipe and the outside of the outer pipe with the gap,
The apparatus for cleaning the inside of a thin tube of a heat exchanger, wherein the opening of the inner pipe and the opening of the outer pipe are provided in a non-face-to-face manner . The projection according to claim 1, wherein a convex portion is provided on an outer peripheral surface of the lance, and a small diameter portion in which the convex portion abuts from the thin tube side is provided on an inner peripheral surface of the nozzle holder.
The apparatus for cleaning the inner surface of a thin tube of a heat exchanger according to claim 1, wherein the stop mechanism stops the flexible hose from advancing and retracting when the convex portion abuts on the small diameter portion.   The apparatus for cleaning the inner surface of a thin tube of a heat exchanger according to claim 2, wherein the outer shape of the convex portion in a cross section perpendicular to the axial line of the lance is non-circular. In any one of claims 1 to 3 , a guide tube is provided between the nozzle holder and the flexible hose drive coaxially with the nozzle holder, and the flexible hose is inserted into the guide tube. An apparatus for cleaning the inner surface of a capillary of a heat exchanger characterized by

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