JPH0142564B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for controlling the water level of cooling water at a constant level in a continuous cable bridging device.

[Prior Art] In a continuous cross-linking device for rubber/plastic insulated cables, a cable extruded and coated with rubber/plastic, etc. using an extruder is run through a heating section of a cross-linked pipe to heat cross-linking, and then passed through cooling water in a cooling section. The cooling water is cooled by running and drawn out of the bridge pipe through the end seal at the end of the cooling section, but since a certain amount of cooling water leaks from this end seal, the amount of leaked water is supplemented and the cooling water is kept at a low temperature. In order to maintain the cooling water level in the cooling section at a predetermined level, cooling water is constantly replenished during continuous crosslinking operation.

For this reason, conventionally, as shown in FIG. 4, cooling water from a water tank 5 is supplied and circulated to the cooling section 3 of the cross-linked pipe 1 by a high-pressure pump 4, and a cable runs between the heating section 2 and the cooling section 3 in the cross-linked pipe 1. C is the end seal 6 at the end of the cooling section
To replenish the amount of cooling water leaking from the end seal 6 when it exits the pipe, the pressures detected by the pressure detection sensor a of the heating section 2 and the pressure detection sensor b of the cooling section 3 are input to the differential pressure oscillator 7, and the cooling water is Using an electro-pneumatic converter that converts electricity to pneumatic pressure, the valve opening adjustment unit 8 is driven by the output of a differential pressure oscillator based on the difference between the two detected pressures based on water level fluctuations, and the opening of the diaphragm valve 9 is adjusted. The amount of water supplied to the cooling section 3 was adjusted.

[Problems to be Solved by the Invention] When the cable starts running in a bridged pipe, a lead wire is connected to the cable tip at the tip of the cable and is pulled to run the cable, so the diameter of the cable tip and the lead wire are If there is a large difference between the diameter of The response speed is slow and it is not possible to immediately follow sudden changes in the water level, resulting in water level hunting. Also, when the internal pressure of the bridge pipe is increased at the start of operation of the continuous bridge equipment, the response of the diaphragm valve 9 is delayed. Therefore, there was a drawback that water level hunting occurred.

As for the above-mentioned fluctuations in cooling water, if the slope of the cross-linked pipe is gentle, even a slight change in the water level will cause a large change in the cooling length and a large change in water volume, so the slope of the cross-linked pipe cannot be made gentler than a certain level. Therefore, the building for installing the bridge pipes had to be raised to account for the slope, or the cooling pipes had to be installed in an underground pit structure, leading to a rise in construction costs.

In addition, when using an oil agent, molten metal salt, etc. as a heating medium to be filled in the heating section of a crosslinked pipe, it is necessary to separate the heating section and cooling section to prevent direct contact between the heating medium and cooling water. If fluctuations or malfunctions in the cooling water level control system occurred, the heat medium and cooling water would instantly mix, causing a serious disaster such as a steam explosion, and potentially damaging the equipment.

Even when the above heating is performed by radiation heating,
If cooling water enters the heated part, the pipe wall will rapidly cool and become distorted, creating a risk of cracking, damage, or a steam explosion.Even if only a light steam is generated, the electrical characteristics of the cable insulation coating There was a risk that this would worsen.

It is extremely important to control and maintain the water level of the cooling water at a predetermined level to prevent rapid fluctuations or runaway of the water level. Therefore, in order to maintain and control the water level at a predetermined level, the applicant has In Utility Model Application Publication No. 55-3863, a device was proposed to detect the level of overflow water stagnant in the overflow section, but there was a problem that the control system became complicated.

Therefore, the present invention has developed a continuous cable bridge that prevents sudden changes in the cooling water level even if any situation such as fluctuations in the internal pressure of the bridge pipe or disturbances occurs, and that the cooling water in the cooling section can always be maintained at a predetermined water level. The object of the present invention is to provide a method for controlling the cooling water level of an apparatus.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides the following features: An overflow section 20 is provided between the heating bridge section 11 and the cooling section 12 of the bridge pipe 10, and an overflow amount of cooling water is provided in the overflow section 20. In addition, a water level stabilizing tank 23 is provided, to which the lower end of the downflow pipe section 22 extending from the lower part of the overflow section is connected, and a water supply pipe 26 communicating with the high pressure pump 24 is connected. 22 and the water supplied from the high pressure pump 24 are stored in the water level stabilizing tank 23, and a cooling water supply pipe 30 with a low pressure line pump 31 installed in the middle is connected between the water level stabilizing tank 23 and the cooling unit 12. The water stored in the water level stabilizing tank 23 is connected to the cooling unit 12.
In addition, a pressure communication pipe 39 is provided to communicate the pressure inside the water level stabilizing tank 23 and the bridge pipe 10, so that the internal pressure of the water level stabilizing tank 23 is the same as the internal pressure of the bridge pipe 10, and the continuous cable bridge system is This constitutes a cooling water level control device.

[Function] The water level stabilizing tank 23 stores the water supplied from the high-pressure pump 24, and the overflow water of the cooling water that has flowed into the overflow portion 20 flows down and is stored therein.

The cooling water in the cooling unit 12 is supplied from the water stored in the water level stabilizing tank 23 to the cooling water supply pipe 3 by the low pressure line pump 31.
0 to the cooling unit 12 and becomes cooling water.

The internal pressure of this water level stabilizing tank 23 becomes the same internal pressure as the internal pressure of the bridge pipe 10 by communicating with the inside of the bridge pipe 10 via the communication pipe 39.

Therefore, the same pressure in the cross-linked pipe is always applied to the suction side and the discharge side of the low-pressure line pump 31, and even if the pressure in the cross-linked pipe fluctuates, the discharge pressure of the pump 31 is always constant and only a small pressure is required. can be downsized.

In addition, the water level stabilization tank 23 stores the overflow water and supplies it again as cooling water to the cooling unit 12, so the amount of water used is saved. The water is mixed with the water supplied from the source and cooled, resulting in a drop in water temperature.

Moreover, since the amount of water to be fed is stabilized, there is no need to use a complicated control system like the device disclosed in the above-mentioned publication.

[Examples] Examples of the present invention will be described below with reference to the drawings. FIG. 1 shows one embodiment of the invention, FIG. 2 shows an overflow section, and FIG. 3 shows another embodiment.

In the embodiment shown in the first figure, 10 is a crosslinked pipe, 11 is a heating crosslinking section thereof, and 12 is a cooling section thereof. The cooling section 12 has an end seal 13 at its end.
The heating cross-linking section 11 is filled with an inert gas or other heat medium 16 from the piping 14 through the valve 15, and the tip of the heating cross-linking section 11 is connected to the extrusion head 18 of the extruder 17. Connect to. The cable C, in which the conductor is fed to the extrusion head 18 via the metering capstan 19 and coated with an uncrosslinked insulator such as rubber or plastic, runs inside the bridge pipe 10 and is heated at the heating bridge section 11. It is heated and crosslinked, cooled by the cooling water W in the cooling section 12, and passes through the end seal 13 to proceed to the outside of the crosslinked pipe.

An overflow section 20 is installed in the bridge pipe 10 at an intermediate portion between the heating bridge section 11 and the cooling section 12 . The overflow section 20 consists of a receiving pipe section 21 connected to the middle part of the bridge pipe 10 and a downstream pipe section 22 extending downward from the bottom of the receiving pipe section 21.
1 is for receiving the overflowing water head of the cooling water W in the cooling section 12 by dropping it into the receiving pipe section 21, and receiving the overflow water that has fallen and flowed into the receiving affected section 21. The water is allowed to flow down into the water level stabilizing tank 23.

The water level stabilizing tank 23 is connected to the above-mentioned downflow pipe section 22, and is connected to a water supply pipe 26 leading to a high pressure pump 24 and a water supply valve 25 to supply water into the tank and store cooling water. In this water level stabilizing tank 23, the amount of water flowing down from the downstream pipe section 22 and the amount of water supplied from the water supply pipe 26 are stored.
7 and the output of the level controller 28 drives the valve opening/closing drive section 29 to control the opening/closing of the water supply valve 25, thereby adjusting the amount of water absorbed and the amount of water stored.

A cooling water supply pipe 30 is connected to the water level stabilizing tank 23 for supplying the cooling water stored in the tank to the cooling section. A total of 32 pipes are connected to the cooling section 12 of the bridge pipe via a valve 33. A bypass pipe 34 is branched in the middle part of the cooling water supply pipe 30 and communicated with the water level stabilizing tank 23 via a bypass valve 35, and the amount of water to be diverted from the cooling water supply pipe 30 to the bypass pipe 34 is controlled by the bypass valve. By adjusting the opening of 35, the amount of cooling water fed from the low pressure line pump 31 to the cooling unit 12 is adjusted.

Reference numeral 36 denotes a riser pipe that stands up from the pipe wall of the cooling section 12, the height of its upper end is adjusted to the permissible water head of the cooling water of the cooling section 12, and the riser pipe 36 is connected to the communication pipe 38 through a valve 37.
It communicates with the water level stabilizing tank 23. As a result, if the overflow section is clogged with foreign matter, the cooling section 1
Even if the cooling water head of No. 2 reaches the allowable water head, safety is ensured because the cooling water in the cooling section 12 is sent to the water level stabilizing tank 23 through the riser pipe 36 and the communication pipe 38.

The water level stabilizing tank 23 and the heating bridge section 1 of the bridge pipe
A pressure communication pipe 39 is provided to communicate with the water level stabilizing tank 23, and the pressure inside the bridge pipe which is pressurized to a high pressure is communicated with the pressure inside the water level stabilizing tank 23 to make them the same pressure.

High pressure pump 24 installed in the water supply pipe 26
It is sufficient that the discharge pressure is higher than the crosslinking pressure in the heating crosslinking section 11 of the crosslinked pipe, for example, approximately 5 kg/cm ² or higher, and a multistage turbine pump or the like is used for this purpose.

Furthermore, it is sufficient that the low-pressure line pump 31 installed in the cooling water supply pipe 30 has the ability to supply cooling water against slight water supply resistance of the supply pipe.
Since the same pressure P1 in the bridge pipe is always applied to the suction side and discharge side of this low pressure line pump 31,
The pressure on the suction side of this pump 31 is P1, and if the head loss due to the resistance of the feed pipe is ΔP, the minimum required pressure on the discharge side is P1 + ΔP.
Therefore, the minimum pressure required for the pump 31 to discharge and feed cooling water is (P1 + ΔP) - P1 = ΔP, and since this ΔP is a constant value determined by the piping, there is no fluctuation in the pressure inside the bridge pipe. Pump 3 even if it occurs
The discharge pressure ΔP of the pump 31 is always constant, and a small pressure is sufficient for the discharge pressure ΔP of the pump 31, so that the low pressure line pump 31 can be downsized.

As mentioned above, the water level stabilization tank 23 is connected to the pressure communication pipe 3.
9 makes the pressure the same as the internal pressure of the cross-linked pipe 10, which not only makes the low-pressure line pump 31 smaller, but also saves water usage by storing overflow water and feeding it again to the cooling unit 12 as cooling water. Ru. Further, the overflow water whose temperature has increased in the cooling section 12 is mixed with the water supplied from the high pressure pump 24 in the water level stabilizing tank 23 and cooled, thereby lowering the water temperature.

In the embodiment shown in the first figure configured as described above, the uncrosslinked insulated cable C is run inside the crosslinked pipe 10, the uncrosslinked insulation sheath is crosslinked by heating in the heating crosslinking section 11, and then cooling water is applied in the cooling section 12. Cool with W. For this reason, the temperature of the cooling water W increases, but a certain amount of water leaks from the end seal 13 as the cable of the cooling unit 12 runs, and the low-pressure line pump 31 constantly pumps water in excess of the leaked water to the cooling unit 12. By feeding, the cooling water W in the cooling unit 12 is always maintained in a cold water state.

As described above, when the amount of water exceeding the amount of water leaking from the end seal 13 is supplied to the cooling part 12 by the low-pressure line pump 31, the cooling water W in the cooling part 12 is
The water head tries to exceed the predetermined water head, but the excess water amount exceeding the predetermined water head overflows into the receiving pipe section 21 of the overflow section 20 and flows into the water level stabilizing tank 23 from the downflow pipe section 22. ,
The cooling water level will be maintained at a predetermined head.
The amount of overflow water flowing into the overflow part 20 is always constant in a stable steady state where the amount of water leaking from the end seal 13 does not change and the amount of water supplied by the low pressure line pump 31 does not change. Seal 13
Even if there is a change in the amount of water leaking from the pipe or a change in the internal pressure of the bridge pipe, the amount of water falling and flowing into the overflow section 20 will only increase or decrease; The water head remains constant without any fluctuation. Therefore, even if there is a sudden change in the amount of leakage water or a sudden change in the internal pressure of the bridge pipe when the cable starts running inside the bridge pipe and the end of the cable with the lead wire connected passes through the end seal, the cooling section Therefore, the water head of the cooling water at 12 can be kept constant at all times.

According to the results of the experiment, the low-pressure line pump 31 that supplies cooling water W to the cooling section 12 has a discharge pressure of 2 kg/
cm ² , a discharge rate of 400 to 500〓/min, and when the end seal 13 is closed, the overflow part 20 has an inner diameter d of approximately 150 mm in Fig. 2.
The inflow width L of the overflow water _W0 flowing down from the bridge pipe cooling section 12 into the receiving pipe section 21 is approximately 200 to 250.
mm, and it was sufficient that the inner diameter D of the receiving tube portion 21 was 300 mm or more.

FIG. 3 shows a heating bridge section 11 formed by curving the bridge pipe 10 downward, and a heating medium 16 filled in the heating bridge section 11.
This is an embodiment in which the present invention is applied to a continuous crosslinking apparatus in which a heating crosslinking section 11 and a cooling section 12 are separated using silicone oil, metal molten salt, etc., and the same reference numerals as in FIG. 1 indicate the same parts. In this embodiment as well, as in the first illustrated embodiment, the overflow portion 20 allows the overflow amount of the cooling water W to flow in to maintain the water level of the cooling water W in the cooling portion 12 at a predetermined level.

In each of the above-described embodiments, two overflow sections can be installed in the cooling section 12, so that the head of cooling water can be varied depending on the cables to be bridged.
Moreover, the receiving pipe part 21 of the overflow part is cylindrical,
It does not matter if it has any shape such as a rectangular cylinder, and even if the cooling part 12 is not tilted but horizontal, the water level can be controlled by the overflow part,
Furthermore, a differential pressure oscillator may be used instead of the level controller 28 shown in FIGS. 1 and 3.

[Effects of the Invention] As described above, the present invention provides an overflow part and a water level stabilizing tank in the cooling part of a cross-linked pipe, and this water level stabilizing tank receives overflow water of cooling water, stores water, and supplies this stored water to the cooling part. Since it is used as feed cooling water, the amount of water used can be saved, and the overflow water whose temperature has increased in the cooling section is stored in this water level stabilization tank and mixed with the water supplied from the pump, reducing the water temperature. Can be done.

In addition, the water level stabilization tank is kept at the same pressure as the internal pressure of the cross-linked pipe by a pressure communication pipe, and the same pressure inside the cross-linked pipe is always applied to the suction and discharge sides of the line pump for supplying cooling water, so the pressure inside the cross-linked pipe fluctuates. Even if this occurs, the discharge pressure of the pump is always constant, so only a small pressure is required, and the pump for supplying cooling water can be downsized.

Furthermore, by allowing the overflow water to flow into the overflow section, even if there are fluctuations in the pressure inside the bridge pipe or the amount of cooling water leaking from the end seal, the cooling water in the cooling section is not affected by the fluctuations. This not only prevents the occurrence of accidents such as steam explosions and damage to bridge pipes due to sudden fluctuations and runaway of the cooling water level, but also prevents the occurrence of accidents such as damage to bridge pipes. Since the length is stabilized at a constant length, a cable with uniform and good characteristics can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention, FIG. 2 is a diagram showing an overflow section, FIG. 3 is a diagram showing another embodiment, and FIG. 4 is a diagram showing a conventional example. 10: crosslinked pipe, 11: heating crosslinking section, 12: cooling section, 20: overflow section, 22: downflow pipe section,
23: Water level stabilization tank, 24: High pressure pump, 26: Water supply pipe, 30: Cooling water supply pipe, 31: Low pressure line pump, 39: Pressure communication pipe.

Claims (1)

[Claims] 1. An overflow part 20 is provided between the heating cross-linking part and the cooling part of the cross-linked pipe to allow the overflow of cooling water to flow in, and the downstream pipe part 22 through which the water of the overflow part flows is connected to the water level stabilizing tank 23. The water supply pipe 26 of the high pressure pump is connected to the water level stabilizing tank, overflow water and supply water are stored in the water level stabilizing tank, and the cooling water supply pipe 30 with the low pressure line pump 31 provided in the middle is connected to the water level stabilizing tank. and a cooling section to supply water stored in the water level stabilizing tank to the cooling section, and connecting the water level stabilizing tank and the bridge pipe with a pressure passage pipe 39 to change the internal pressure of the water level stabilizing tank to the internal pressure of the bridge pipe. A cooling water level control device for continuous cable bridging equipment, characterized by having the same pressure.