JPH0961041A - Glass pipe heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the possibility of explosion owing to leakage of a refrigerant by fully closing with a pair of caps opposite ends of a glass pipe in which a heater is disposed for defrosting an evaporator. SOLUTION: A heater 7 is disposed in a glass pipe 6, and opposite ends of the glass pipe are covered with a pair of silicon rubber caps 8, 8. The caps 8 are tightened with bolts 10 and nuts 11 at several positions peripherally of the glass pipe 6 together with a press plate 9, and are brought into close contact with the glass pipe 6 to close the interior of the pipe. The caps 8 and a lead wire 12 are melted, and outlets thereof are closed. Hereby, combustible gas used as a refrigerant is prevented from entering the glass pipe 6 and coming into contact with the heater 7 to cause explosion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass tube heater used in a refrigerator that uses a flammable gas as a refrigerant.

[0002]

2. Description of the Related Art Refrigerators equipped with conventional glass tube heaters are disclosed in Japanese Utility Model Publication No. 2-144385 and Japanese Utility Model Publication No. 4-382.
A refrigerator provided with these conventional glass tube heaters, which is disclosed in Japanese Patent Publication No. 21 No. 21, will be described with reference to FIG. In FIG. 3, 1 is a refrigerator main body, 2 is a compressor, 3 is a glass tube heater, 4 is an evaporator, and 5 is a fan for cooling the inside of the refrigerator. Then, the glass tube heater 3 is installed below the evaporator 4, and the compressor 2 is energized after a certain period of operation and defrosts the frost adhering to the evaporator 4.

Further, the glass tube heater 4 is constructed as shown in FIG. 4, and in FIG. 4, 6 is a glass tube,
Reference numeral 7 is a heater wire, and 8 is a cap. The heater wire 7 is arranged in the glass tube 6, and both ends of the glass tube 6 are closed by heat-resistant silicone rubber caps 8. However, the glass tube 4 is not completely sealed by the cap 8.

As the refrigerant used in the refrigerating cycle of the refrigerator, it is not possible to use the specified CFC due to the CFC regulation. Therefore, it is considered to use a refrigerant that replaces the specified CFC. Refrigerators used as refrigerants have already been commercialized.

[0005]

When the glass tube heater for defrosting configured as described above is used in a refrigerator, hydrocarbon gas used as a refrigerant leaks and the leaked gas fills the periphery of the glass tube heater. In this case, the glass tube heater is not completely sealed, so gas enters the glass tube,
There was a risk of gas contacting the heater and exploding.

An object of the present invention is to prevent the explosion due to the refrigerant leakage by completely sealing the inside of the glass tube heater.

[0007]

In order to achieve the above object, the glass tube heater of the present invention has the following features.
In a refrigerator including a glass tube heater for defrosting an evaporator and using a flammable gas as a refrigerant, the glass tube heater includes a glass tube, a pair of caps covering both ends of the glass tube, and an inside of the glass tube. And a sealing means for sealing between the glass tube and the cap.

According to a second aspect of the invention, the sealing means according to the first aspect comprises a bolt and a nut for pressing the pair of caps against the glass tube.

Further, the invention according to claim 3 is the invention according to claim 1.
The described sealing means has a structure in which the pair of caps and both ends of the glass tube are screwed together.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the explosion-proof structure for a glass tube heater according to the present invention will be described with reference to FIG. 1 or FIG. The refrigerator used is the same as that of the conventional example described above.

The glass tube heater of the present invention is constructed as shown in FIG. 1 in the first embodiment. In FIG. 1, 6 is a glass tube and 7 is a heater arranged inside the glass tube 6. Wires, 8 and 8 are a pair of silicon rubber caps that cover both ends of the glass tube 6, 9 and 9 are pressing plates that press the caps 8 and 8 against the glass tube 6, respectively, and 10 is a bolt and
Is a nut, and 12 is a lead wire connected to the heater wire 7.

Further, at both ends of the glass tube 6, the cap 8 is tightened together with the pressing plate 9 with bolts 10 and nuts 11 at several positions in the circumferential direction of the glass tube 6 so as to be closely attached to the glass tube 6 and hermetically seal the inside. . The cap 8 and the lead wire 12 are welded to each other, and the outlet of the lead wire 12 in the cap 8 is sealed.

In the glass tube heater of the first embodiment, the caps 8 at both ends are mechanically pressed against the glass tube heater to seal the space between the glass tube 6 and the caps 8 and serve as a refrigerant. The inflammable gas used is prevented from entering the glass tube 6.

The second embodiment of the glass tube heater according to the present invention is constructed as shown in FIG. 2. In FIG. 2, 12 is a lead wire connected to the heater wire 7, 13 is a glass tube, Reference numeral 13a is a screw thread integrally formed on the outer surface of both ends of the glass tube 13, 14 is a cap that covers both ends of the glass tube 13 and has a hard female thread structure, and 15 is an elastic member such as silicon rubber and is made of both ends of the glass tube 13. Is a sealing material that seals.

Then, when the cap 14 and the glass tube 13 are screwed together, the sealing material 1 disposed inside the cap 14
The reference numerals 5 and 15 closely adhere to both ends of the glass tube 13, thereby sealing the inside of the glass tube 13. The cap 14 and the lead wire 12 are welded to each other, and the outlet of the lead wire 12 in the cap 8 is sealed.

[0016]

Since the glass tube heater of the present invention has the above-mentioned structure, the invention according to claim 1 presses the glass tube heater with a cap that covers both ends of the glass tube to press the glass tube. Since the sealing means for sealing the space between the cap and the cap is provided, when the flammable gas used as the refrigerant leaks, the gas can be prevented from entering the glass tube and coming into contact with the heater to cause an explosion.

Also, According to the second aspect of the present invention, the inside of the glass tube heater can be reliably sealed by pressing the pair of caps from both ends with the bolt and the nut against the glass tube.

Further, according to the third aspect of the present invention, since the pair of caps and the both ends of the glass tube are screwed together, the cap and the glass tube can be reliably sealed.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a first embodiment of a glass tube heater of the present invention.

FIG. 2 is a sectional view of an essential part showing a second embodiment of a glass tube heater of the present invention.

FIG. 3 is a sectional view of a conventional refrigerator.

FIG. 4 is a cross-sectional view of a main part of a conventional glass tube heater.

[Explanation of symbols]

 6 Glass Tube 7 Heater Wire 8 Cap 9 Holding Plate 10 Bolt 11 Nut 12 Lead Wire 13 Glass Tube 14 Cap 15 Sealing Material

Claims (3)

[Claims] 1. A refrigerator comprising a glass tube heater for defrosting an evaporator and using a flammable gas as a refrigerant, wherein the glass tube heater comprises a glass tube and a pair of caps covering both ends of the glass tube. A glass tube heater comprising: a heater disposed inside the glass tube; and a sealing means for sealing between the glass tube and the cap. 2. The glass tube heater according to claim 1, wherein the sealing means comprises a bolt and a nut for pressing the pair of caps against the glass tube. 3. The glass tube heater according to claim 1, wherein the sealing means has a structure in which the pair of caps and both ends of the glass tube are screwed together.