Apparatus for the internal treatment of pipes

Abstract

The invention relates to a device for the internal treatment of pipes, in particular for coolant tubes of steam condensers and heat exchangers, comprising a supply unit (V) for feeding and conveying treatment media, an application unit (A) to apply the treatment media fed in by the supply unit, as well as a control unit to monitor and control the supplied treatment media and the application of treatment media to the inner wall of the pipes, wherein the application unit (A) is provided with a guiding hose (21) through which an application hose (18) extends designed so as to be inserted into the pipe to be treated, said application hose (18) terminating in a nozzle, wherein the application hose (18) can be wound up in a single layer on a driven reel (17) and secured on the reel (17) by means of tensioning belts, the application hose (18) is capable of moving forward and back via guide rollers (27) arranged on a traversing carriage (55), the guide rollers (27) are powered by a drive operating synchronously with the drive (19) of the reel (17), and the traversing carriage (55) moves parallelly to the reel axis relative to the extended position of the application hose (18).

Claims

1. A dual use device for the internal treatment of pipes for coolant tubes of steam condensers and heat exchangers, the device being designed for internal high pressure cleaning and coating of pipes comprising a supply unit (V) for feeding and conveying treatment media capable of said dual use by in one use providing a cleaning medium at a pressure of between 1,500 and 2,500 bar and in a second use providing a coating material at up to 500 bar, an application unit (A) to apply the treatment media fed in by the supply unit, as well as a control unit to monitor and control the supplied treatment media and the application of treatment media to the inner wall of the pipes, wherein the application unit (A) is provided with a guiding hose (21) through which an application hose (18) extends designed so as to be inserted into the pipe to be treated, said application hose (18) terminating in a nozzle, characterized in that, the application hose (18) can be wound up in a single layer on a driven reel (17) and secured on the reel (17) by means of tensioning belts, the application hose (18) is capable of moving forward and back via guide rollers (27) arranged on a traversing carriage (55), the guide rollers (27) are powered by a drive (24) operating synchronously with the drive (19) of the reel (17), and the traversing carriage (55) moves parallelly to the reel axis relative to the extended position of the application hose (18), and wherein the cleaning medium is water and the coating material is hardening plastic.

2. Device according to claim 1, characterized in that the reel (17) is designed to be brought to a standard temperature.

3. Device according to claim 2, characterized in that the reel (17) is provided with a heating/cooling water supply system.

4. Device according to claim 1, characterized in that the reel (17) is provided with a guiding system for the application hose (18).

5. Device according to claim 1, characterized in that the tensioning belts are movably guided via rollers (56).

6. Device according to claim 5, characterized in that the tensioning belts are moved as a result of frictional contact with the application hose (18) when the reel (17) is rotating.

7. Device according to claim 1, characterized in that the tensioning belts embrace more than 270 of the circumference of the reel.

8. Device according to claim 1, characterized in that the application hose (18) is a high-pressure hose having a pressure resistance of up to 2,500 bar.

9. Device according to claim 1, characterized in that the application hose (18) can be controllably extended and retracted over the entire length of the pipe to be treated.

10. Device according to claim 1, characterized in that the application hose (18) is equipped with a coating nozzle designed so as to enable coating to be effected during return travel, wherein the spraying angle amounts to between 60 and 120 in relation to the longitudinal direction of the pipe to be treated.

11. Device according to claim 1, characterized in that the supply unit (V) is provided with an intake hose (2) equipped with a coarse filter, said hose being connected with a backpressure-dependently operating supply pump (3).

12. Device according to claim 1, characterized by a non-return valve (5) and a dual filtering system (11a/11b) in the area where material is supplied to the application unit (A).

13. Device according to claim 1, characterized in that the control unit monitors and controls the intake/discharge volume of the treatment agent as well as the operating pressure.

14. Device according to claim 13, characterized in that the control unit is programmable with respect to feed length, feed speed, and/or retraction speed of the application hose.

Description

(1) The invention is explained in more detail by way of the enclosed figures where

(2) FIG. 1 shows the circuit diagram of the material supply unit;

(3) FIG. 2 is a side view of the application unit;

(4) FIG. 3 is a frontal view of the application unit and

(5) FIG. 4 shows the roller fixation system of the tensioning belts.

(6) FIG. 1 shows the supply unit with intake hose 2 through which the coating material is withdrawn from a reservoir 1 by means of pump 3. Hose 2 must not be of pressure-resistant design and may for instance have a diameter of 19 mm.

(7) Pump 3 advantageously a compressed-air driven double-acting piston pump capable of taking in material and discharging it under pressure. The pump operates backpressure-dependent in a self-acting manner, i.e. material is conveyed only if spraying material is discharged or withdrawn, for instance when the coating operation is initiated. For example, a pump capacity of 27 l/rain at 0 bar will be sufficient to easily achieve pressure rates of up to 500 bar.

(8) The piston pump conveys the material through a pressure-resistant line 4 having for example a diameter of 10 mm via a non-return valve 5 and a ball valve 6 to a dual filtering unit 11a/11b. Between non-return valve 5 and ball valve 6 a return line 9 is arranged which serves to feed material back into the reservoir via pneumatically actuated ball valve 7 and a backpressure control group 8 provided with pressure controller.

(9) The dual filtering unit 11a/11b is provided with two pressure sensors 10a/10b which enable differential pressure monitoring to be effected via the central control unit. As a rule, the differential pressure monitoring function is intended to serve as filter clogging detector so that when one filter is clogged the unit can switch over to the other filter in good time and steps can be taken early enough to make sure a given coating operation can be completed in an orderly way. The filtering units can be replaced without difficulty by appropriately actuating ball valves 6a/12a and 6b/12b. A commercially available measuring cell 13, for example a gear-type measuring cell or an ultrasonic measuring cell, makes sure the flow of material can be reliably monitored and visualized in the central control unit to which the data needed to control the coating operation are transferred, said data being obtained by evaluating the differential pressure measurement, measuring cell data and the capacity data of pump 3.

(10) From measuring cell 13 the conveyed material is transferred via line 14 to application unit A as illustrated in accordance with FIGS. 2 and 3.

(11) Application unit A is arranged on base 15 provided with rollers 16, wherein reel 17 is mounted on said base. Reel 17 accommodates the application hose 18 capable of being unwound and retracted by means of motor 19. Material is supplied via feed connection 20 to which hose 14 of the supply unit V is attached. From feed connection 20 material is conveyed via a rotary feedthrough to application hose 18 and further on to the application nozzle (not shown).

(12) The mobile base 15 is provided with a frame 51 which accommodates, if thought necessary, corrugated wire mesh 52. A power supply appliance is shown against reference number 53 while reel 17 is supported by a retaining element 54.

(13) From reel 17 the application hose 18 extends through a guiding hose 21a. Guiding hose 21a is located at intake element 22 in the upper part of the reel 17, said hose being moved by means of a traversing carriage 55 along a stationary guide system 23 so that it is capable of following the windings of application hose 18 in horizontal direction on reel 17 when the application hose 18 is unwound or retracted. Drive 24 of the traversing carriage is coupled to the motor 19 via a toothed belt 28 which enables the traversing carriage 55 with the guiding hose intake element 22 to be moved synchronously with the unwinding and retraction operation. The process of unwinding and rewinding the hose can be terminated by limit switches arranged at the ends of guide system 23.

(14) From the reel the application hose 18 extends into guiding hose 21a. The guiding hose 21 is subdivided, with the drive unit 26 for application hose 18 being arranged within the gap, said drive unit comprising a total of 6 guide and drive rollers 27. Drive unit 26 is movably arranged on traversing carriage 55 and follows the windings of the application hose 18 on reel 17, Drive 24 of the traversing carriage 55 is brought about via a toothed belt 28 which is driven by reel motor 19 and in this manner ensures the traversing carriage moves synchronously via a spindle with trapezoidal thread. Rollers 27 of the application hose drive are rotated by servomotor 29 coupled with the reel motor 19 so that in this case as well the feed movement of the application hose is synchronous with the hose unwinding from reel 17. Maximum feed/retraction speed rates of up to 4.5 m/sec are achieved.

(15) At the end of application hose 18 a nozzle is arranged by means of which the coating agent can be applied to the inner wall of a cleaned pipe; however, via the nozzle the pipe can also be blast-cleaned inside under high pressure in which case a cleaning agent is to be fed into the application unit A. Normally, the cleaning agent is water applied to the inner wall of the pipes at a high pressure of up to 2,500 bar.

(16) The reel 17 may be provided with a heating or cooling water supply system intended to heat or cool the coating agent passing through the hose to a temperature conducive to the relevant application. However, the application unit may also be equipped for this purpose with a separate heating or cooling coil arranged upstream of the reel.

(17) FIG. 4 illustrates application unit A with base 15, retaining element 54 for the reel 17 and the motor 19, the application hose 18 wound up on reel 17, and three rollers 56 via which the tensioning belts are secured.

(18) Expediently, the tensioning belts embrace the reel 17 over 270 of its circumference, wherein that portion of the reel remains clear/uncovered through which the application hose 18 is passed on to the hose drive unit 26. At least one of the rollers 56 securing the tensioning belts is movably arranged so that the tensioning belts passing around the rollers can be retightened.

(19) Rollers 56 are equally spaced over the circumference of the reel, advantageously spaced at 90 over the circumference. Passing over and around the rollers is a belt of elastic material, for example rubber or plastic material, said belt between retaining rollers 56 being positioned onto and in close contact with the wound-up application hose 18 and in this way holds the hose in place on the reel and in the guide grooves arranged on the reel. The tensioning belt or belts pass over the movable rollers and rotate together with the hose reel 17 as soon as the reel starts moving. The belt is driven by the rotating reel. In this way any displacement of the application hose is ruled out when the tensioning belts have been properly tightened so that the hose cannot leave the guide grooves arranged on the reel. Said tensioning belts are essential for the precise and smooth operation, i.e. unwinding/retracting, of the application hose.