JPS6018925B2 - Electric antifreeze water level gauge - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a water level gauge for a reservoir, etc.
In particular, when detecting the water level, the inside of the protective tube to prevent the water level detection element, such as the float, from being affected by wind and waves - prevents the float from being unable to follow water level fluctuations due to freezing in winter in extremely cold regions. It is something.

(Prior Art) Generally, in relatively warm regions, it is sufficient to cover the protective tube with a heat insulating material even in winter to prevent freezing, but in extremely cold regions, this alone is insufficient.

Therefore, it is necessary to heat it with an appropriate heat source, but in cases where a relatively small amount of heat is sufficient, such as in the case of water level gauges, electricity is the most easily available and economical heat source. Therefore, it is thought that it is usually caused by electric heating. (Problems to be Solved by the Invention) However, when using the above heat source, so-called sheathed wires, which have a metal sheath and use an inorganic material such as magnesia powder as an insulator, cannot be used in low temperature and humid places. The insulation of the terminal part becomes defective in a short period of time, making it unusable.
In particular, with plastic-insulated heating wires, it is difficult to prevent the insulation from deteriorating over time due to sunlight or outside air, and the mechanical strength of the wire is 4.5, making it susceptible to damage.

(Means for Solving the Problems) In order to avoid the above-mentioned difficulties associated with various heating wires, the present invention uses a skin current heating tube as an electric heat source, and also makes the skin current heating tube act as a vibrating body. This is intended to effectively prevent the formation of ice and promote ice detachment.In other words, in a water level gauge with a protection tube, at least one of the inner and outer surfaces of the protection tube is provided with a surface that is approximately equal to the length of the protection tube and relatively free. It is characterized by vertically providing a required number of skin current heating tubes with insulated wires or cables passed through them.

(Example) First, a skin current heating tube used in the present invention will be described.

There are various types of skin current heating tubes, but there are two main types: series skin current heating tubes and concessional skin current heating tubes. It's been said before, but I'll explain it easily here.

Figure 1 shows a series skin current heating tube, and Figure 2 shows an induced skin current heating tube. In both figures, 1 and 1' are ferromagnetic heating tubes, and 2 is a heating tube made of this steel tube. The insulated wires or cables 3, which are passed relatively freely through 1 and 1', are AC power sources, usually commercial frequency being sufficient.

4, 4', 4r' are the connecting wires, and the connection between the power source 3, the insulated wire 2, and the heat generating tubes 1, 1' is as follows. The tubes 1 are connected in series, and in the induced skin current heating tube shown in FIG. 2, the insulated wire 2 is the primary circuit for the power source 3, and the heating tubes 1 and 1' have shorting pieces 7 and 8 at both ends, respectively. Since the insulated wire 2 is electrically connected to the insulated wire 2, a secondary induction circuit is formed for the insulated wire 2.

In the above case, the wall thickness of the heating tube 1 or 1' is t, the length is 1, and the inner diameter of the heating tube is D, and the alternating current i flows through the inner skin of the heating tube within a corresponding range. The thickness of the epidermis is S
If t> is 1》D, D》S, almost no alternating current i flows out of the heating tube 1, so it is However, it can be used as a heat generating tube without causing arcing or harming the human body or animals.

This invention uses a plurality of such skin current heating tubes according to the required amount. To explain this with drawings, Figure 3 shows a typical water level gauge, and 9 is a protection tube. The water level detection element, in the figure, protects a float 11 and its balance weight 12.

15 is a water level converter, and the converted signal indicates the water level or is sent as a signal to others.

Reference numeral 10 indicates pond water to be measured, reference numeral 13 indicates a water guide hole for guiding the pond water into the protective tube, and reference numerals 14 and 14' indicate upper and lower end boxes of the insulated wire 2.

16 is a lead-in power supply, and 17 is a quay of the pond that supports the above-mentioned water level gauge.

Figures 5 and 6 show two types of embodiments of the antifreeze device of the present invention using the concessional skin current heating tube shown in Figure 2 with the upper and lower end boxes 14 and 14'removed; The first shown in the figure
In the embodiment, the protection tube 9 is made of metal and made of a material that can be welded to the heating tubes 1, 1' made of ferromagnetic steel pipes, etc. In the second embodiment shown in FIG. Is it difficult to weld with heat generating pipes 1, 1' etc. made of steel pipes such as plastic pipes?
This is the case when the material is made of impossible material. In the first embodiment, heating tubes 1, 1', etc. (six in the figure) constituting the required number of skin current heating tubes approximately equal to the length of the protective tube 9 are welded 20, and each Both ends are connected by shorting pieces 7 and 8, but in this case, the protective tube 9 is made of metal and has electrical conductivity, so it can be omitted.

However, when fixing with heat transfer cement or the like instead of welding 20, the shorting pieces 7 and 8 of the heat generating tubes 1 and 1' cannot be omitted. Although both ends of the insulated wire 2 are visible in the figure, they are stored in end boxes 14 and 14' shown in FIG. In the first embodiment, the heat insulating layers on the outside of the protection tube 9, heating tubes 1, 1', etc. are omitted, but they are normally provided to improve efficiency.

Next, a second embodiment shown in FIG. 6 is for a case where the protection tube 9 is a plastic tube, and it is difficult to directly weld the heating tubes 1, 1' which are steel tubes into an integral structure. The required number of steel pipes, that is, heat generating pipes 1, 1', etc. (six in the figure) constituting the skin current heat generating tube, which is approximately equal to the length of the protection tube 9, is electrically and mechanically controlled so as to satisfy the conditions shown in FIG. The case is shown in which the outer circumferential surface of the chestnut cage-shaped cage assembled in 1 is placed concentrically on the inner surface of the protective tube 9, with the outer peripheral surface of the cage being brought into close contact with the outer circumferential surface of the cage.

Although FIG. 6 shows the case where the chestnut cage is attached only to the inside of the protection tube 9, it is also possible to attach it to the outside or both the inside and outside. (Function) Before explaining the function of the embodiment of the present invention, let us first explain the functions shown in FIGS.
To explain the case where a water level gauge with the structure shown in the figure is equipped with an antifreeze device but not, as shown in Figure 4,
During winter in extremely cold regions, the float 11 not only changes its weight due to the ice 18 formed on the pond water 10, but also sometimes becomes fixed to the protection tube 9 due to the ice 19.

On the other hand, in this invention, the anti-freezing device constructed as in the first embodiment shown in FIG.
When connected to the insulated wire 2, an alternating current i flows through the insulated wire 2, and as a result, an alternating current i also flows through the inner skin of the steel pipes, that is, the heating tubes 1, 1', etc., and heat is generated in this part. As a result, freezing 18, 19, etc. shown in FIG. 4 can be prevented.

The operation of the second embodiment shown in FIG. 6 can be easily inferred from the explanation shown in FIG. 5, so a description thereof will be omitted.

Although the above description has only been about the function of the skin current heating tube as a type of heating element, the anti-freezing of this invention can exhibit another function and effect. This is because the skin current heating tube is a type of electromagnetic equipment like a transformer, and therefore electromagnetic vibrations that can be seen in transformer cores occur.

In other words, the insulated wires 2 passed through the steel pipes, i.e., the heating pipes 1, 1', etc., are not fixed at the center of the steel pipe and are passed through relatively freely, so that they are not fixed to the magnetic center of the steel pipe (in this case, the center of the steel pipe). Due to the electromagnetic force caused by the absence of the current i, it vibrates slightly at a frequency twice the frequency of the current i.

When used at low temperatures as in this case, even if the same insulated wire 2 is used, a larger allowable current can be obtained than at room temperature, so it is not possible to increase the amount of heat generated. The slight vibration becomes louder. This micro-vibration is transmitted to the heating tubes 1, 1', etc., and prevents the formation of ice on the surface of the protection tube 9 at the initial stage of freezing, or facilitates the peeling off of the formed ice. In the case shown in FIG. 6, as described above, unless the circumferential surface of the cage is brought into close contact with the protective tube 9, the effect cannot be expected to be very great. The electric power required to prevent the solid from freezing as described above varies depending on the weather conditions, but since it is less than a few hundred watts per square meter of the surface of the protective tube 9, it is not very large, making it possible to prevent freezing economically. . In addition, although the case where an induced skin current heating tube was used was described in the embodiment, it is also possible to use a series skin current heating tube. In addition, although we have only explained single-phase circuits above, multi-phase circuits are also possible by combining them, and
The cross section of the heating tubes 1, 1' etc. is not limited to a circle, but various cross sections can be used as long as it is possible to construct a magnetic circuit. (Effects of the Invention) Since the present invention has the above-mentioned configuration, it can not only exhibit an anti-freezing effect due to the heat generation effect of the skin current heating tube, but also can be placed in a low temperature and humid place without any problem. It can avoid aging due to sunlight or outside air,
It has high mechanical strength and uses a skin current heating tube with relatively freely passed insulated wires or cables to produce a vibration effect, which prevents ice formation and facilitates ice peeling. It can effectively protect the water level gauge.

[Brief explanation of drawings]

Figure 1 is a principle diagram of a series skin current heating tube, Figure 2 is a principle diagram of an induced skin current heating tube, Figure 3 is a vertical cross-sectional view of a float type water level gauge, and Figure 4 is a diagram of the freezing of a float type water level gauge. An explanatory diagram showing the situation. Figure 5 is a perspective view of a steel pipe that constitutes a skin current heating tube welded directly to a metal protection tube. Figure 6 is a pipe made of a material that is difficult to weld with steel pipes, such as a plastic protection tube. FIG. 3 is a perspective view of a state in which chestnut cage-shaped antifreeze devices are attached to each other at the same angle inside the protective tube. 1, 1'... Heat generating tube, 2... Insulated wire, 3... AC power supply, 4, 4', 4''...
・Connection wire, 5, 6... terminal, 7, 8...
...Short-circuiting piece, 9...Protection tube, 11...
Water level detection element (float), 12... Balance weight, 13... Water guide hole, 14, 14'...
... Upper and lower end boxes, 15 ... Water level converter or water level indicator, 16 ... Power supply, 17 ... Quay,
20...Welding. Figure 1 Figure 2 Figure 3 Figure 5 Figure 4 Figure 6

Claims (1)

[Scope of Claims] 1. A water level gauge with a protection tube, which has an insulated wire or cable on at least one of the inner and outer surfaces of the protection tube, the length of which is approximately equal to the length of the protection tube, and which is passed through relatively freely. An electric antifreeze water level gauge characterized by the required number of heating tubes installed vertically. 2. The electric antifreeze water level gauge according to claim 1, wherein the protection tube is made of metal, and the skin current heating tube is directly welded to at least one of the inner and outer surfaces of the protection tube. 3. The protective tube is made of a material, such as a plastic tube, to which the ferromagnetic steel tube constituting the skin current heating tube cannot be directly welded or is difficult to weld, and the skin current heating tube is formed in the shape of a chestnut and mouse cage, and the skin current heating tube is The electric antifreeze water level gauge according to claim 1, wherein the inner peripheral surface or outer peripheral surface of the protective tube is provided as close as possible to the outer peripheral surface or inner peripheral surface of the protection tube.