JPS63191058A - Insertion method into pipe - Google Patents

Abstract

PURPOSE:To feed-in a probe at a great distance, in a method for inserting a cable having the probe provided to the leading end thereof and a plurality of floats mounted thereto in a pipe under pressure, by applying intermittent flow variation to a pressure fluid. CONSTITUTION:The gas mixing device 11 connected to a compressor 10 is provided to the outlet of a pump 3 for injecting pressure water. The gas from the compressor 10 is sent in a heat transfer pipe 8 through the gas mixing device 11 along with the pressure water from the pump 3 and the cable 6 for feeding a probe 9 is fed by a gas-liquid two-phase stream. At this time, since the flow mode of a slag stream wherein a gaseous phase and a liquid phase are alternately present is shown by the squeezing of the float 7 mounted to the feed cable 6, the propelling force acting on the float 7 changes between at the time of the passage of the gaseous phase and at the time of the passage of the liquid phase. By this method, the feed cable 6 performs varmicular motion and the probe 9 can be fed at a great distance without being obstructed by the projection on the inner surface of a bent pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for inserting into heat transfer tubes applicable to thermal power plants, nuclear couplants, heat exchangers in general, water pipelines, etc., and is not limited to probes. It is used in the technical field to enable transport over long distances.

Conventional technology The conventional technique will be described according to FIG.

Conventional IS+ (in-service inspection...In-8ervi
In the ceInspection) device, a pusher 5 with a seal is used to transport the probe 9 to a distant place inside the heat exchanger tube 8.
Probe 9 and transport cable 6 inserted into the system at
A method has been adopted in which the high-pressure water from the pump 3 is used to generate thrust that is applied to the front and back of the float 7 attached to the cable 6, and this is used to transport the float.

In this method, it was necessary to increase the pressure of the pump 3 in order to send the sensor to a long distance, but there was still a limit to the distance that the sensor could be transported. In addition, when high pressure is required for conveyance, the heat exchanger tube 8 with low pressure resistance cannot be applied.
A new method was needed.

Problems to be Solved by the Invention In the conventional transportation method using a steady high pressure source, the force applied to the float part does not change over time, or when there is an obstacle on the inner wall of the pipe or the float is caught at a bend. Immediately, it becomes impossible to transport the object any further. For heat transfer tubes for gas, the conditions are even more severe, and due to the action of gravity, the float contacts the bottom of the heat transfer tube, creating a frictional force, making it more difficult to transport the tube to a deep location.

Means for Solving the Problems The present invention takes the following measures in order to solve the above-mentioned problems. That is, this is an intra-tube insertion method characterized by adding intermittent flow fluctuations to the first pressure fluid fed from the proximal end of the thin tube into which the cable to which the float is attached is press-fitted.

Floats are attached to the action conveyance cable at regular intervals, but by adding flow fluctuations to these floats, a fluctuating thrust force acts on the floats.

Embodiments Next, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 6.

FIG. 1 shows a first embodiment of the present invention.

A gas mixing device 11 connected to a compressor 10 is provided at the outlet of the pump 3 for injecting pressurized water, and a gas-liquid two-phase flow created by the gas mixing device 11 is added to the conveying cable 6. In the figure, numeral 2 is a tank, 4 is a bar, 8 is a heat exchanger tube, and 9 is a probe.

Air (gas) from the compressor 10 is sent to the heat exchanger tube 8 together with pressurized water from the pump 3 via the gas mixing device 11 .

FIG. 2 shows the effects of the first embodiment. In the figure, A is during thrust F when passing through the liquid phase, B is during thrust F when approaching the gas phase,
C indicates a large thrust force F upon arrival of the liquid phase, and the thrust force F varies over time depending on the conditions of the fluid passing through the float section.

Next, a second embodiment of the present invention is shown in FIG.

The feature of this embodiment is that a pulsation generating device 2I for adding a pulsating flow is provided together with a pump 3 for injecting pressure water.

As a result, a combined flow of a steady flow and a pulsating flow is applied to the conveying cable 6 of the heat exchanger tube 8 section.

The pulsation generating device 21 generates a pulsating flow by, for example, causing a piston provided at the end of a pipe to perform simple vibration. In the figure, numeral 2 is a tank, 4 is a valve, 5 is a pusher device with a seal, 7 is a float, and 9 is a probe.

FIG. 4 shows the effects of this embodiment. The thrust force applied to each float is F=A(ΔP+Δp) ΔP: Constant regardless of position Δp: Changes depending on position Next, a third embodiment of the present invention is shown in FIG.

A gas switching device 3 serves as a device for injecting gas into the transport device.
1 and two types of gas supply devices having different densities, that is, a gas source A12 and a gas source B13 are provided.

The gas switching device 31 allows gases of different densities to periodically pass through the conveyance cable 6 of the heat exchanger tube 8 section. In order to increase the difference in the buoyancy force applied to the flow control vessel due to this density difference, the difference in density between the two gases is selected to be as large as possible, and the transport cable 7 is sealed by filling helium gas in the float 7. Make the whole thing as light as possible.

FIG. 6 shows the effects of this embodiment. The force acting on each float (the resultant force of gravity and buoyancy) changes as the buoyancy changes over time, from large to medium to small to medium to large.

Effect of the invention The effects of the present invention will be described for each example.

a) First embodiment (Figures 1 and 2) When a gas-liquid two-phase flow is applied to the conveying cable 6, due to the throttle of the float 7, a flow pattern of a slug flow in which gas and liquid phases exist alternately is exhibited. Therefore, the thrust acting on the float 7 changes when the gas phase passes through and when the liquid phase passes through. This thrust force varying in the longitudinal direction causes the conveying cable 6 to perform a peristaltic motion. This effect makes it possible to transport the probe 9 to a long distance without being restricted by the protrusions on the inner surface of the curved tube.

Second embodiment (Figures 3 and 4) When the pulsating flow from the pulsation generator 21 is applied to the float 7 of the conveyance cable 6, the thrust force applied to the float 7 is not uniform in the longitudinal direction, and changes depending on the position and time. I come to do it. Therefore, the transport cable 6 performs a peristaltic motion, and even if there are protrusions or bends on the inner surface of the tube, it is possible to transport the probe 9 to a long distance without being hindered by them. τ Therefore, high pressure is not required, and it can also be applied to heat exchanger tubes with low k pressure.

Third Embodiment (FIGS. 5 and 6) When gases of different densities periodically pass through the float 7 of the conveyance cable 6, the buoyancy force applied to the float 7 changes periodically depending on the position. Therefore, the transport cable 6 has parts with high buoyancy and parts with low buoyancy, and the cable 6
becomes peristaltic as a whole. With this effect, even if there are protrusions, bends, etc. on the inner surface of the tube, it is possible to transport the probe 9 to a long distance without being hindered by them.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing the first embodiment of the present invention, FIG. 2 is a diagram showing its effects, and FIG. 3 is a system diagram showing the second embodiment.
FIG. 4 is a chart showing the effect thereof, FIG. 5 is a system diagram showing the third embodiment, FIG. 6 is a chart showing the effect, and FIG. 7 is a system diagram of a conventional example according to the prior art. 2. Tank, 3. Pump, 4. Valve, 5. Butcher device with seal, 6. Conveyance cable, 7.
・Float 1, 8... Heat exchanger tube, 9... Probe, IO
・Compressor, 11...Gas mixing device, 12...Gas source A,
13... Gas source B, 21... Pulsation generator, 31... Gas switching device. Diagram 2, size stitch, force F! Detection power Fノ)＼
Diagram of power and force

Claims (1)

[Claims] A method of pressure-inserting a cable equipped with a probe at its tip and a plurality of floats attached at predetermined intervals into a capillary, the first pressure fluid being fed from the proximal end of the capillary having an intermittent flow. An intracanal insertion method characterized by adding variation.