Curing Device Comprising a Lamp that Produces UV Light

Abstract

The invention relates to a curing apparatus having at least one UV module (3), wherein the UV module (3) has at least one UV light source (6) for irradiating the inner wall of a pipe (1), wherein the UV module (3) that has been introduced into the pipe (1) is connected, by means of a cable (7), to a control device (9) that is situated outside of the pipe (1). It is an object of the invention to provide a curing apparatus in which the cable (7) for connecting the UV modules (3) to the control device (9) has a cross section that is reduced in comparison with the prior art. As a result, longer pipeline portions should be able to be renovated in one piece. Moreover, the electrical power losses in the cable (7) should be reduced. To this end, the invention suggests that at least one operating appliance (10) that is connected to the cable (7) and the UV light source (6) is arranged at each UV module (3), wherein the control device (9) actuates the operating appliance (10) by way of the cable (7) for the purposes of operating the UV light source (6).

Claims

1. A curing apparatus having at least one UV module (3), wherein the UV module (3) has at least one UV light source (6) for irradiating the inner wall of a pipe (1), wherein the UV module (3) that has been introduced into the pipe (1) is connected, by means of a cable (7), to a control device (9) that is situated outside of the pipe (1), characterized in that each UV module (3) has at least one operating appliance (10) that is connected to the cable (7) and the UV light source (6), wherein the control device (9) actuates the operating appliance (10) by way of the cable (7) for the purposes of operating the UV light source (6).

2. The curing apparatus as claimed in claim 1, characterized in that the operating appliance (10) has an ignition device for igniting the UV light source (6) that is embodied as a discharge lamp.

3. The curing apparatus as claimed in claim 1 or 2, characterized in that the operating appliance (10) has a power supply circuit which controls or regulates the operating current of the UV light source.

4. The curing apparatus as claimed in any one of claims 1 to 3, characterized in that the cable (7) has two or more wires as a power supply line (11) and two or more further wires as a data line (12).

5. The curing apparatus as claimed in claim 4, characterized in that two or more operating appliances (10) are connected in parallel with the wires of the power supply line (11) and the wires of the data line (12).

6. The curing apparatus as claimed in either of claims 4 and 5, characterized in that the operating appliance (10) has a serial data interface (21), preferably an RS 485 interface, which uses the wires of the data line (12) for data transfer between the operating appliance (10) and the control device (9).

7. The curing apparatus as claimed in any one of claims 4 to 6, characterized in that the operating appliance (10) has an input-side rectifier (17) that is connected to the power supply line (11), and an inverter (18) that is connected to the rectifier (17) and actuated by microcontroller (19), said inverter being connected on the output side to the UV light source (6).

8. The curing apparatus as claimed in claim 7, characterized in that the inverter (18) is connected, on the output side, to a voltage overshoot circuit (L, C), the latter producing at the input of the UV light source (6) an ignition voltage that has overshot an operating voltage of the UV light source (6), depending on the frequency of the output voltage of the inverter (18).

9. The curing apparatus as claimed in claim 7, characterized in that the inverter (18) is connected, on the output side, to a voltage overshoot circuit (20) that, by way of an impulsive discharge of a capacitor (C) via an additional winding of a choke (L) connected on the output side to the inverter (18), produces an ignition voltage that has overshot an operating voltage of the UV light source (6) at the UV light source (6).

10. The curing apparatus as claimed in claim 7, 8 or 9, characterized in that the operating appliance (10) has a current measuring device (A) that is connected to, or integrated in, the microcontroller (19), said current measuring device measuring the current flowing through the UV light source (6).

11. The curing apparatus as claimed in any one of claims 1 to 10, characterized in that the cable (7) is embodied as a pull cable, by means of which a plurality of similar UV modules (3) that are strung in succession and coupled to one another are movable through the pipe (1).

12. The curing apparatus as claimed in any one of claims 1 to 11, characterized in that each UV module (3) has one or more temperature detectors that are connected to, or integrated in, the operating appliance (10).

13. The curing apparatus as claimed in claim 12, characterized in that the temperature detectors measure the surface temperature of the inner wall of the pipe (1).

14. The curing apparatus as claimed in any one of claims 1 to 13, characterized in that the operating appliance (10) has further sensors that are connected to, or integrated in, the microcontroller (19), to be precise a photosensor for measuring the produced UV light intensity, a temperature sensor for measuring the system temperature of the respective UV module (3) or the air temperature in the surroundings of the UV module (3), a spatial orientation sensor for capturing the longitudinal or transverse tilt of the UV module (3), and/or a position sensor for capturing the position of the respective UV module in the pipe (1).

Description

[0020] Exemplary embodiments of the invention will be explained in more detail on the basis of the drawings. In the drawings:

[0021] FIG. 1: shows a schematic illustration of a curing apparatus according to the invention;

[0022] FIG. 2: shows a sketched circuit diagram of an operating appliance according to the invention in a first configuration; and

[0023] FIG. 3: shows a sketched circuit diagram of an operating appliance according to the invention in a second configuration.

[0024] FIG. 1 schematically shows a curing apparatus according to the invention. A pipe 1 laid underground should be renovated. To this end, a liner 2 is pulled into the pipe and expanded with the aid of compressed air and said liner rests against the inner wall of the pipe 1. The liner 2 is soaked with resin that is curable by way of irradiation with UV light.

[0025] The curing apparatus according to the invention is used for curing the artificial resin. Said curing apparatus comprises, as illustrated in FIG. 1, a plurality of UV modules 3 that are coupled to one another in a hinged fashion, wherein each UV module 3 has, arranged on spring-mounted arms 4, wheels or sliding runners 5 that serve to guide the modules 3 within the pipe 2 and allow an adaptation to different pipe diameters.

[0026] Each UV module 3 has a UV light source 6, which is a discharge lamp (e.g. mercury vapor lamp) with a conventional design. In the illustrated exemplary embodiment, each UV module 3 has exactly one UV light source 6. However, depending on the application, it is also possible for a plurality of UV light sources 6 to be provided for each UV module 3. By way of example, in order to irradiate the inner wall of the pipe 2, a plurality of UV light sources 6 may be arranged on a UV module 3 with a uniform distribution about the circumference thereof.

[0027] The UV modules 3 introduced into the pipe 2 are connected to a control device 9 situated outside of the pipe 2 by way of a common cable 7, which is guided through the pipe 2 and out of the pipe and to the surface of the ground through an inspection shaft 8.

[0028] According to the invention, each UV module 3 has at least one operating appliance 10, which is assigned to the corresponding UV light source 6. In each case, the operating appliance 10 serves for ignition purposes and for regulating the operating current of the UV light source 6. Each operating appliance 10 is connected to the control device 9 via the cable 7. The control device 9 actuates the operating appliances 10 of the individual UV light sources 6 by way of the cable 7. For the purposes of supplying the UV light sources 6 with power, the cable 7 comprises two or more wires that form a power supply line 11. Furthermore, the cable 7 comprises two or more wires that form a data line 12. It is clear from FIG. 1 that the operating appliances 10 are connected in parallel to the power supply line 11 and the data line 12. In the control device 9, the power supply line 11 is connected to a mains connector 13, and so the UV light sources 6 are appropriately supplied with energy by way of the operating appliances 10. The data line 12 is connected to a microcomputer 14 of the control device 9. The operating appliances 10 communicate in bidirectional fashion with the microcomputer 14 via the data line 12. By way of the data line 12, the microcomputer 14 controls the ignition of the UV light sources 6 and monitors the operational parameters thereof. Moreover, measurement data of optionally provided sensors (e.g. temperature sensors) of the UV modules 3 are transmitted via the data line 12 to the microcomputer 14, where they are suitably processed further.

[0029] FIGS. 2 and 3 show sketched circuit diagrams of possible embodiments of the operating appliances 10 illustrated in FIG. 1. The operating appliance 10 is connected to the power supply line 11, i.e. to the power grid, by way of terminals 15. The mains voltage is filtered by means of a mains filter 16 and then converted into DC voltage by means of a rectifier 17. The rectifier 17 is connected to an inverter 18 that is disposed downstream thereof and respectively realized by an H-bridge circuit with four field-effect transistors in the illustrated exemplary embodiments. At the outputs of the bridge circuit, the inverter 18 is connected to the discharge lamp that forms the UV light source 6. The field-effect transistors of the inverter 18 are actuated by a microcontroller 19 of the operating appliance 10 in order to control or regulate the operating voltage and the operating current of the UV light source 6 by way of controlling the frequency at which the inverter 18 is operated and/or by way of pulse width modulation. For the purposes of igniting the UV light source 6, a voltage overshoot circuit in the form of a resonant circuit is provided as an ignition device in FIG. 2, said resonant circuit being formed by a choke L and a capacitor C. For the purposes of ignition, the inverter 18 is actuated in such a way that the choke L and the capacitor C are in resonance. The voltage drop over the capacitor C in the process suffices for igniting the UV light source 6. Deviating therefrom, the choke L contains a second winding in the exemplary embodiment illustrated in FIG. 3. A voltage doubling circuit 20 charges the ignition capacitor C by means of the applied AC voltage. When the DC voltage at the ignition capacitor C exceeds the ignition voltage of a spark gap contained in the voltage doubling circuit, the latter ignites and discharges the capacitor C in impulsive fashion by way of the second winding of the choke L. The high voltage in the choke L arising thereby ignites the UV light source 6. After ignition, the frequency of the inverter 18 is modified by means of the microcontroller 19 and the operating current is regulated to a desired setpoint value. To this end, a current measuring device A that is connected to the microcontroller 19 is provided in the circuit of the UV light source 6. For initiating the ignition process, for predetermining the setpoint value of the operating current and for transmitting the other data arising in the operating appliance 10 (temperature, operating current, operating voltage of the UV light source 6, etc.), the microcontroller 19 is connected via a data interface 21 (e.g. an RS485 interface) to the wires of the data line 12. For the purposes of supplying the microcontroller 19 with power, provision is made of a power supply circuit 22 that is operated with rectified mains voltage.

[0030] According to the invention, the operating appliances 10 consequently control the operating current regulation and the ignition of the respective discharge lamps that are used as UV light sources 6. The operating appliances 10 are placed directly at the respective UV light source 6 within the associated UV module 3. A plurality of operating appliances can be connected in parallel to the wires of the cable 7. What emerges therefrom is that the cable 7 may have a smaller number of wires with, moreover, a smaller cross section in relation to the prior art. Consequently, the cable 7 overall can have a significantly reduced cross section in relation to the prior art. The result of this is that a cable drum, which is usually used in pipe renovation work, can receive a substantially longer cable 7. Accordingly, it is possible to renovate longer pipeline portions in one piece. Moreover, the line losses in relation to the prior art are lower on account of the higher voltages on the wires of the power supply line of the cable 7.