JPH1030898A - Automatic tube internal surface washing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously and automatically wash the internal surface of a tube by a button control only by a method wherein washing load applied at the time of washing the internal surface of the tube by inserting a plurality of nozzle-mounted lances in the tube is detected, and a lance longitudinal feeding pedestal is made to travel by step feed automatically in response to the detected washing load. SOLUTION: A lance 4 which is fixed to a lance feeding pedestal 7, is moved in the longitudinal direction by an inching operation, and whether the lance 4 can be smoothly inserted in a tube or not is confirmed to complete an adjustment. Then, by pressing a washing start button on a control panel 11, the lance 4 advances while washing, and after confirming the advancing end by a limit switch, the lance 4 retracts at a quick returning speed, and stops by the confirmation of the retracting end. At a data setting part of the control panel 11, a washing stroke, a washing load, a lance advancing and retracting speeds of the lance 4 are set, and the washing load is detected corresponding to a scale clogging degree of the internal surface of the tube, and the internal surface of the tube can be washed while performing a step feeding by sensing the detected washing load when necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic cleaning apparatus for jetting high-pressure water from a deposit (scale) adhered to the inner surface of a heat exchanger electric heating tube (tube), particularly a straight tube.

[0002]

2. Description of the Related Art Heat exchangers are widely used mainly in the petrochemical industry and the general chemical industry, and with technological advances, operating conditions such as pressure, temperature, fluid, and capacity are becoming increasingly severe. The heat exchanger is formed of an assembly of several hundred tubes, and heat exchange is performed using fluid as a medium on the inner and outer surfaces.In use, various scales adhere to the inner and outer surfaces of the tube, resulting in a decrease in thermal efficiency. If the operation efficiency of the entire plant is reduced, and if the pipes are completely blocked or completely filled between the pipe bundles, the equipment may be damaged or an explosion may occur. Therefore, it is an important factor to periodically inspect the condition of the pipe, and to perform cleaning to remove scale as soon as possible.

Conventionally, tube cleaning of a heat exchanger is generally performed by water jet cleaning. However, a worker is still equipped with heavy equipment such as a waterproof cupper and a waterproof mask, and directly carries a lance or a gun to hold the lance or a gun to spray the reaction force of high-pressure water. The current situation is to go while enduring sewage. In particular, when cleaning the inner surface of the tube, lance nozzles are inserted one by one into hundreds of tubes for cleaning. Automatic cleaning using a water jet has been carried out in all fields, and there has been a trend toward ultra-high pressure, but the automation of cleaning has been delayed both inside and outside of a heat exchanger.

Although a simple automatic cleaning device is actually being studied, a single lance is placed on a table so that it can be moved back and forth, left and right, and has a simple structure that moves the table up and down. Met.

[0005]

However, in the cleaning of the inner surface of the pipe, however, a simple operation in which an operator pushes and pulls a lance nozzle one by one into hundreds of tubes one by one, which is a simple operation coming from repetitive operations. Due to a mistake in the operation, the tube may be mistaken, leaving an uncleaned portion, or the degree of cleaning may be uneven due to the difference in the operator level. Further, in cleaning the closed tube, a considerable amount of labor is required only by pushing the lance nozzle. In particular, the operation while covering the cleaning wastewater mixed with scale is a problem in terms of safety and health.

Further, since one of the insides of the tube is closed by the scale, if the washed scale is entangled with the lance insertion port during the washing, the washing pressure instantaneously stays in the tube, and this becomes the internal pressure. Therefore, it is conceivable that the worker may face the worker as a reaction force (as an impact), and the worker himself must perform the work with due care.

[0007] In addition, in the simple automatic cleaning device, since a centering operation for inserting the lance portion into the center of the tube is required, there are many devices provided with one lance in order to improve the centering accuracy as much as possible. The device could not be used when the tube was completely closed because it could only control the movement of the body, and it was somewhat improved in terms of the reduction of the physical burden on workers and safety and health. Efficiency, workability, and detergency were still low.

The present invention has been made in order to solve the conventional problems as described above. The present invention relieves the worker from the bad environment and the heavy labor in the current cleaning of the inner surface of the pipe, and uses only a simple operation of button operation. An object of the present invention is to provide an apparatus for automatically and automatically cleaning the inner surface of a pipe with three or four lances.

[0009]

According to a first aspect of the present invention, there is provided an automatic pipe inner surface cleaning apparatus according to the present invention, which comprises a solid lance having a nozzle for spraying high-pressure water at a tip thereof. An automatic pipe inner surface cleaning apparatus for cleaning the inner surface of a pipe by inserting it into a pipe of a heat exchanger, wherein a plurality of nozzle mounting lances and a distance between the lances are adjusted according to the pipe pitch of the heat exchanger. A pitch adjusting means for connecting, one end of the plurality of nozzle mounting lances, and a lance front-rear feed frame that can move the lance back and forth; and a lance left-right movement that mounts the lance front-rear feed frame and can move left and right. A gantry, comprising a lance moving portion comprising a base gantry on which the lance left / right moving gantry is mounted and whose height is adjustable,
And a detecting means for detecting the cleaning load applied when the plurality of nozzle mounting lances are inserted into the pipe to clean the inner surface of the pipe, and automatically detecting the cleaning load detected by the detecting means. A control means for step-feeding the lance front-rear feed frame is provided.

According to another aspect of the present invention, there is provided an automatic pipe inner surface cleaning apparatus according to the first aspect of the present invention, wherein the control means for step-feeding detects a cleaning load when a control load value exceeds a set load value during cleaning. The control is such that the control is performed such that the lance longitudinal feed frame is moved backward for a set time and then advanced again, and at the end of the entire cleaning stroke, the lance longitudinal feed frame is rapidly returned to the retracted end.

In the second invention, if the degree of blockage of the inner surface of the tube to be cleaned is large and the repetitive operation of the step feed exceeds a predetermined number of repetitions, the lance front-rear feed frame is moved to the retreat end even during the cleaning. It is characterized by comprising a control for returning by fast-forwarding and generating an alarm for notifying an abnormality.

[0012]

With the automatic pipe inner surface cleaning apparatus according to the present invention, the operator can arbitrarily select or set parameters necessary for cleaning (cleaning pressure, flow rate, nozzle feed speed, nozzle pushing force, cleaning stroke, etc.). This makes it possible to automatically clean the inner surface of the pipe. You will be free from working in bad environment.

Further, the pitch adjusting means and the inching operation control can achieve adjustment of the lance interval in accordance with the pitch of the tube and simplification of the centering operation. In other words, after adjusting the distance between each of the plurality of lances with nozzles by the lance guide means, inching operation control was adopted for each of the left-right up-down movement and the back-and-forth movement of the nozzle unit by remote control, so positioning accuracy was required. Simplification of the positioning work is possible, and cleaning that shortens the working time by simultaneously inserting a plurality of lances with nozzles, such as 3 to 4 nozzles, into the tubes constituting each size of heat exchanger in one cleaning operation. Because it became possible, the cleaning efficiency was much better than before.

Further, in the present cleaning apparatus, the lance with a nozzle inserted into the tube performs cleaning by spraying high-pressure water while advancing at a constant speed in the tube, but when the object to be cleaned is a closed tube. When the set load value of the device control is detected by the detecting means for detecting the washing load at the scale closed portion in the pipe, the lance portion with the nozzle is step-feeded to gradually advance the cleaning while gradually removing the scale of the closed portion. The control that completes the process was adopted, so that the work efficiency was improved and accurate cleaning was enabled.

Although a nozzle can be attached to a high-pressure hose or a flexible lance and sent into the tube, it is often difficult to clean the scale closing portion because the rigidity is low and the workability is very poor. Since the lance used in this cleaning device is a solid pipe, it has sufficient rigidity even when inserted into a pipe closed with a scale, and can be used semipermanently except for deformation due to erroneous operation.

Further, when the cleaning of the entire length of the tube to be cleaned is completed, the lance is returned from the advancing end to the retreating end at a speed faster than the advancing speed. The cleaning time can be reduced.

If there is an occluded tube from which scale cannot be removed by the step feed, the washing may not be completed even if the steps are repeated during the washing in the tube. Therefore, as the operation control of the cleaning device, the number of repetitions of the step operation is also set in advance, and when the step feed operation exceeding the set value is performed, the device is returned to the original position and stopped, and a warning is issued. It has become possible to operate the apparatus unnecessarily in operation and not to shorten the life of the equipment parts, and to cope with saving of jetted water.

[0018]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention. The tube inner surface cleaning device of the heat exchanger 1 composed of a tube bundle formed of an aggregate of several hundred tubes and a tube plate in which the tube ends at both ends are expanded and sealed, with the nozzle 2 at the tip end Lance 4 attached
, A high-pressure water generator (jet pump) 15, an operation panel 11, and a control panel 1
0, an electric control device including a distribution panel 12, a limit switch, a high pressure hose 14, a joint piping unit, a cylinder valve 13, and a water supply tank 16 constitute a basic configuration.

The objects to be cleaned of the apparatus of the present invention are tubes of each size used in heat exchangers of each size. As an example of the tube specification, each tube has an inner diameter of 18 mm to 32 mm,
Length from 3m (3000mm) to 6m (6000mm)
Each tube bundle is formed with a single tube size within the range of above, and the tube pitch in each size is generally in the range of 32 mm to 48 mm, but special products are also available. It is not limited to this because it can be considered.

For reference, Table 1 shows data on the tube specifications actually used in the washing test and the lances used in the apparatus of the present invention.

[0021]

[Table 1]

The cleaning apparatus according to this embodiment uses four lances 4 to which the nozzles 2 are attached. The high-pressure water supply port side of each of the lances 4 is locked to the lance front-rear feed frame 7 and The lances can be moved back and forth in accordance with the movement of the gantry 7 and are mounted on the lance left / right moving gantry 5, and the lances 3 are adjusted by the lance guides 3 to adjust the interval between the lances to match the tube pitch of the heat exchanger 1 to be cleaned. 4 is held so as to be movable back and forth. Although the detailed structure will be described later, the four lances 4 with nozzles are respectively inserted into the tubes of the heat exchanger 1 whose pitch has been adjusted in accordance with the forward and backward movement of the lance forward and backward pedestal 7, and the nozzle at the leading end of the lance 4 The part is operated and controlled to move the entire length of the tube from the tube inlet end to the tube outlet end.

The actual cleaning of the inside of the tube is performed by spraying high-pressure water forward from the nozzle 2 at the tip of the lance toward the inner wall surface of the tube, and the scale attached to the inner wall surface of the tube or the scale closing the inside of the tube due to the impact force. And is configured to perform cleaning. That is, the nozzle 2 for injecting high-pressure water is attached to the tip of the lance 4, and the other end is connected to a high-pressure hose 14 via a joint fixed on the lance front / rear feed frame 7. The unit is connected via a cylinder valve 13 to a separately provided jet pump 15. At the time of cleaning, the operation panel 11 installed near the apparatus is used to sequentially press the "operation preparation" button, the "jet pump operation" button, and the "cleaning start" button, and the drain valve of the cylinder valve 13 closes. The washing valve is opened and the water supplied from the water supply tank 16 to the jet pump 15 has a pressure of 300 to 700 kg.
The pressure is raised to f / cm ² , discharged from the jet pump 15 as high-pressure water, passed through the cylinder valve 13, the high-pressure hose 14, and the lance 4, guided to the nozzle 2 and jetted from the nozzle hole, and the inner surface of the heat exchanger tube. Is to wash.

The lance guide 3 has an inner surface V-shaped split type clamp or a V-shaped groove roller arranged up and down in accordance with the number of lances, and is held so that the outer diameter of each lance is sandwiched by the V-shaped groove portion inside. In addition, a ball screw mechanism, a rack and a pinion mechanism are adopted so that the right and left movements can be adjusted independently of each other, and the lance interval is adjusted in accordance with the tube pitch.

The main body of the cleaning device mainly including the lance moving part is mounted on the base gantry 6 (lance vertical movement-Y axis) installed on the hydraulic table lifter and on the base gantry, and adopts a moving screw mechanism. Lance left / right moving platform 5 (Lance left / right movement −
X-axis) and a lance front-rear gantry mounted on a guide rail provided on a lance left-right moving gantry 5 to lock the high-pressure water supply side of the lance 4 and to be able to move back and forth integrally with the lance 4 7 (L / L movement-Z axis) and a limit switch for detecting each moving end.

The X axis drives the variable speed hydraulic motor 8, and the lance 4 can be aligned in the left and right direction by inching operation via a rack and a pinion. The Y axis moves the cylinder by a hydraulic unit for a table lifter. The lance 4 can be moved up and down and the lance 4 can be vertically aligned by an inching operation. After positioning the X and Y axes of the Z axis, the electric motor 9 with a continuously variable transmission is driven, and the output shaft and the lance front / rear feed frame 7 are connected by a chain so as to be movable. The lance 4 locked to the gantry 7 is moved back and forth, and it is confirmed that the lance 4 can be smoothly inserted into the tube to complete the adjustment. Then, by pressing the "cleaning start" button on the operation panel 11, the lance 4 advances while cleaning, and after confirming the forward end by the limit switch, retreats at a rapid return speed and stops by confirming the retreat end by the limit switch. .

The data setting section of the operation panel 11 digitally sets the cleaning stroke, the cleaning load, the lance forward speed and the lance retreat speed of the lance 4, and selects the cleaning mode to select the cleaning load in accordance with the degree of scale blockage on the inner surface of the tube. In response to this, it was possible to perform washing while step-feeding as necessary.

FIG. 2A is a diagram showing the operation of the apparatus cleaning in the normal mode when there is a space that can pass through the lance 4 to which the nozzle 2 is attached in the tube, and shows a step feed when the inside of the tube is closed. FIG. 2B is a diagram illustrating the apparatus cleaning operation in the mode, and FIG. 3 is a flowchart illustrating an operation control procedure in the step feed mode. When the number of repetitions of the step operation exceeds the set number, the operation returns to the retreat end by rapid traverse, and an alarm is generated as abnormal.

Since the scale starts to be attached from the inner side of the inner surface of the tube, there are many tubes that need to be cleaned and have sufficient space for inserting the lance 4 with the nozzle 2. In this case, after adjusting the nozzle position, as shown in FIG. 2A, the lance 4 which is a basic cleaning operation of the apparatus of the present invention is automatically inserted into the tube and advanced, and the lance tip is advanced. Cleaning is completed sufficiently and efficiently only by operating the apparatus under normal mode control in which high-pressure water is injected from the nozzle 2 attached to the section to remove scale in the tube and return faster than the forward speed.

However, the apparatus is operated in the step feed mode for a closed tube having a large amount of scale in the tube and little space in the tube. In the step feed mode, as shown in FIG. 2B, at first, the nozzle 2 is advanced and inserted into the tube to start washing as in the normal mode, but the load acting on the electric motor 9 at that time is reduced. If the load is set and the load set by the load sensor and the power monitor installed in the device control panel 10 is exceeded, the lance 4 is held for a certain period of time, the time set by the timer is retracted, and then the vehicle is moved forward again. The step feed operation is automatically repeated to advance while gradually removing the scale in the pipe.

However, when the degree of blockage of the scale in the tube is large, the cleaning may not be completed even if the number of step feed operations is increased. Therefore, as shown in the flowchart of FIG. The number of repetitions is set (step 301). When the number of times exceeds the set number, useless operation is immediately stopped, the lance is returned to the original position (step 302), and an alarm is generated (step 303). .

The operation procedure of the cleaning system using the automatic pipe inner surface cleaning apparatus will be described again.
This will be described with reference to FIG. First, the water supply valve is opened, and the cleaning water is filled in the water supply tank 16. The nozzle 2 mounting lance 4 corresponding to the heat exchanger tube to be cleaned is connected to the lance front-rear feed frame 7. The heat exchanger 1 is set on a cart unit (not shown) outside the building. Fully open the air source valve and perform air purge for protection of control equipment.
Pull the dolly unit into the building and fix it in the washing position.
Turn on the power and check that the power lamp is lit. The amount of forward and backward movement of the lance is set by a digital switch according to the entire length of the heat exchanger 1. The lance feed rate and the washing mode are selected according to the degree of blockage of the heat exchanger tube. First, the position of the tube to be washed is determined, and the lance 4 is aligned with a remote control (not shown). Perform the inching operation in the vertical and horizontal directions to adjust the origin, and adjust the spacing between a plurality of lances according to the tube pitch of the heat exchanger 1 with the lance guide 3 so that the lance 4 enters the tube smoothly or performs the inching operation similarly. Make sure. After confirmation, return the lance 4 to the retreat end, and
1 Set the select switch on the top to "Automatic" and
The jet pump 15 is operated by pressing each button of “jet pump operation” and “start of cleaning” to switch the cleaning valve of the cylinder valve 13 to the open side, and then the “automatic operation” button on the operation panel 11 is pressed. The lance 4 stops automatically after "lance forward → confirm forward end → lance retract → confirm reverse end". Operation panel 1
1 Press the "Stop cleaning" button on the
Switch to the side where the drain valve is opened. Next, the positioning of the lance 4 in the tube to be cleaned is performed, and the above-described cleaning operation is repeated.

[0033]

As described above, by using the automatic pipe inner surface cleaning apparatus of the present invention, the inside of a plurality of tubes of the heat exchanger can be automatically cleaned at once, thereby reducing the burden on the operator.
Furthermore, reliable and uniform washing can be performed without depending on the experience of the operator, and additionally, the safety of the operator can be ensured. In addition, a lance guide that can easily adjust the interval between each lance according to the pitch of the tube was provided, and in addition, the inching operation could be controlled in the lance moving part, so that the centering work of multiple lances was performed. Work became easier and work efficiency improved. In addition, since the movement of the lance can be controlled by changing the cleaning mode, it is possible to perform cleaning according to the state of adhesion of the scale inside the tube. It is possible to not only increase work efficiency but also save unnecessary movement and washing water, which is effective for cost reduction.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of a tube inner surface cleaning apparatus of a heat exchanger according to the present invention.

FIGS. 2A and 2B are operation diagrams of the lance portion of the cleaning device according to the present invention in each cleaning mode, in which FIG. 2A shows an operation in a normal mode, and FIG. 2B shows an operation in a step feed mode.

FIG. 3 is a flowchart showing an operation control procedure of the cleaning device in a step feed mode.

[Explanation of symbols]

 1. Heat exchanger 2. Nozzle 3. Lance guide 4. Lance 5. Lance left / right moving platform 6. Base stand 7. 7. Lance front and rear feed stand Hydraulic motor 9. Electric motor with continuously variable transmission 10. Electric control panel 11. Operation panel 12. Distribution panel 13. Cylinder valve 14. High pressure hose 15. Jet pump

Claims (2)

[Claims] 1. An automatic pipe inner surface cleaning apparatus for cleaning a pipe inner surface by inserting a rigid lance having a nozzle for injecting high-pressure water into a tip thereof into a pipe of a heat exchanger, comprising a plurality of nozzle mounting lances. Pitch adjusting means for adjusting the lance interval by adjusting the plurality of lances to the pipe pitch of the heat exchanger, and a lance front-rear feed frame connecting one end of the plurality of nozzle mounting lances so that the lance can be moved back and forth. When,
The lance has a lance left and right feed gantry on which the lance left and right movable gantry can be moved to the left and right, and a lance moving part comprising a base gantry on which the lance left and right gantry can be mounted and whose height can be adjusted, and Detecting means for detecting a cleaning load applied when the plurality of nozzle mounting lances are inserted into the pipe to clean the inner surface of the pipe; and automatically detecting the cleaning load detected by the detecting means before and after the lance. An automatic pipe inner surface cleaning apparatus, comprising: a control unit for step-feeding a feed gantry. 2. The control means for step-feeding, if the load exceeds a set load value during washing, retreats the lance front-rear feed gantry responding to the washing load for a set time and repeats the control to advance again, so that the entire washing is performed. 2. The automatic pipe inner surface cleaning apparatus according to claim 1, wherein the control is such that the lance front-rear feed frame is returned to the retreat end by rapid feed at the end of a stroke or when a set value of the number of repetitions of the step operation is exceeded.