JPH037586Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a regeneration device that heats gas molecules condensed and adsorbed on the ultra-low temperature cooling surface of a cryopump to regenerate the condensation and adsorption ability of the cooling surface. Regarding heaters.

(Prior art) Conventionally, in order to regenerate a cryopump, the pump case is heated from the outside using a heater, and the gas molecules adsorbed and condensed on the cooling surface are evaporated and discharged using a rotary pump. As the cold head of the cryopump's refrigerator cannot withstand temperatures above about 70°C, a nichrome wire heater is used, which is controlled to below about 70°C by a temperature controller.

Since malfunction of the temperature regulator may cause the pump to malfunction, it is preferable for safety to use a low-temperature heater without a temperature regulator.

A low-temperature heater suitable for this purpose has a pair of silver paste electrodes inside a polyester insulating member, and a heat generating part made of a resistance paste whose main component is ethylene vinyl acetate copolymer etc. in the area between the two electrodes. According to this structure, when the temperature reaches about 70°C, the resistance of the heating part increases and the flow of current stops, making it possible to control the temperature in a self-regulating manner.

(Problem to be solved by the invention) A heater with a temperature regulator is expensive, and it is desirable to use a low-temperature heater that does not require a temperature regulator. There is nothing that can be installed closely.

The object of the present invention is to provide a regeneration heater that can be easily attached to a cryopump and does not require a temperature controller.

(Means for solving the problem) In this invention, the flexible belt made of SUS and other
A fastener is provided to fix this in a ring around the outer circumference of the pump case of the cryopump, and a rubber heat insulating plate, which is slightly smaller than this, is placed along the inner surface of the flexible belt, and placed in the center of the flexible belt in the longitudinal direction. The flexible belt and the rubber heat insulating plate are fixed to each other by pins, and the rubber heat insulating plate is freely movably held by holding pieces formed on the upper and lower edges of the flexible belt, The above-mentioned problem was solved by attaching a self-temperature-controlled sheet heating element to the inner surface of the rubber heat insulating plate.

(Function) When the operation of the cryopump is stopped, a flexible belt is looped around the outer circumference of the pump case, fixed to the outer circumference with a fastener, and energized, the self-temperature of the rubber heat insulating plate provided on the inner surface of the belt is increased. The controlled planar heating element generates heat to warm the cooling surface inside the pump case.
The gas molecules that have been condensed and adsorbed on the surface of the cooling surface evaporate due to the rise in temperature of the surface, and the evaporated components are discharged outside the case by a pump such as a rotary pump connected to the pump case, and the cooling surface is will be played.

A heat insulating plate is provided on the back of the planar heating element to prevent its heat from dissipating, so when the belt is wound around the pump case, there will be a difference in winding diameter and the inner heating element will come loose from the case. There is a possibility that the heating element may become wavy and cannot be heated properly, but since the rubber heat insulating plate is held by a holding piece on the flexible belt so that it can freely move, and the heat insulating plate has plasticity, It can be wound closely around the pump case, and the cryopump can be regenerated with high thermal efficiency.

(Example) To explain the example of the present invention with reference to the drawings, the first example is as follows.
In the figure, 1 is a cryopump, 2 is a helium refrigerator, 3 is a cooling surface on which gas molecules are condensed and adsorbed by the refrigerator 2, and 4 is a cylindrical pump case 5 of the pump 1 on its outer periphery. a regeneration heater that evaporates gas molecules condensed on the cooling surface 3 by heating the case 5 in an annular manner;
It is a rotary pump that eliminates gas molecules that evaporate during regeneration.

As shown in FIGS. 2 to 5, details of the regeneration heater 4 include an SUS heat insulating board 10 provided with fasteners 8 and 8 having bolts 7 at both ends, and the insulating board 10. It is composed of a self-temperature control type sheet heating element 11 attached to the inner surface with an adhesive.

The rubber heat insulating plate 10 has a similar shape that is slightly smaller than the belt 9, and is attached to the belt 9 by a pin 12 at the center of its length, and its both ends are attached to the upper and lower ends of the belt 9. It is held movably by holding pieces 13, 13 formed on the edges.

Further, the details of the heating element 11 are as shown in FIGS. 4 and 5, in which a pair of silver paste electrodes 15 are arranged in a ring shape within a polyester insulating member 14, and both electrodes 15 are disposed in a ring shape.
A heat generating portion 16 was formed by providing a layer of resistance paste mainly composed of ethylene vinyl acetate copolymer or the like in the area between 5 and 15.

A flexible belt 9 is wrapped around the outer circumference of the pump case 5 and fixed by a fastener 8. At this time, a rubber heat insulating plate 10 is attached to the belt 9 by holding pieces 13, 1.
3, it is free to move and has plasticity, so that the heating element 11 on the inner surface can be wrapped closely to the pump case 5 even if there is a difference in radius, resulting in good thermal efficiency.

In addition, when the temperature of the heating element 11 rises to 70°C or higher, which can damage the cold head of the refrigerator 2, the resistance of the heating element 16 increases and stops the flow of current, and the temperature is adjusted in a self-control manner. Temperature can be controlled inexpensively and safely without the need for a regulator.

(Effect of the invention) As described above, according to the invention, the pins are used to engage the inner surface of the flexible belt provided with the fasteners to the pump case of the cryopump, and the upper and lower edges of the flexible belt A rubber heat insulating plate is freely movable while being supported by a holding piece formed in the shape of a rubber heat insulating plate, and a self-temperature-controlling planar heating element is attached to the inner surface of the heat insulating plate.
A heating element that does not require a temperature controller can be easily installed in close contact with the pump case with good thermal efficiency, eliminating the risk of damage to the cryopump due to temperature controller failure during cryopump regeneration.
This has the effect of providing a safe and inexpensive cryopump regeneration heater.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an embodiment of the present invention, Fig. 2 is a perspective view of an embodiment of the present invention, and Fig. 3 is a -
4 is a front view of the main part thereof, and FIG. 5 is a sectional view taken along the line -- of FIG. 4. 1... Cryopump, 4... Regeneration heater,
5... Pump case, 8... Fastener, 9... Flexible belt, 10... Rubber heat insulating plate, 11... Self-temperature-controlled planar heating element, 13... Holding piece.

Claims (1)

[Scope of utility model registration request] A fastener that fixes the SUS or other flexible belt around the outer periphery of the pump case of the cryopump is provided, and a somewhat smaller rubber heat insulating plate is placed along the inner surface of the flexible belt. At the same time, the flexible belt and the rubber heat insulating plate are fixed to each other by a pin at the central part in the longitudinal direction, and the rubber A cryopump regeneration heater comprising a heat insulating board made of rubber that is freely movable and a self-temperature control type sheet heating element affixed to the inner surface of the heat insulating board made of rubber.