JPH03283287A - Heater equipped with mechanism for detecting brokage - Google Patents

Abstract

PURPOSE:To immediately detect even slight brokage of a heater in the event that the heater is broken during operation by providing in a sensor box communicated with one part of a heater pipe by a conduit a detector for detecting gas components. CONSTITUTION:A washing liquid 5 of ammonium-hydrogen peroxide water which serves as a subject to be heated for use during washing process of semiconductors is contained in a washing vessel 4. A sensor box 9 communicated with a gas phase portion inside a heater pipe by a conduit 8 is provided at the end portion 7 of a heater 1. The conduit 8 and the end portion 7 of the heater 1 are hermetically sealed against each other by packing 10. A detector 11 for ammonium gas which is a gas component contained in a sensor box 9 is provided inside the sensor box 9. An indication alarm 12 for indicating the result of the detection is provided outside the sensor box 9. It is about 1000mm from a heater end portion 13 to the detector 11.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a heater in which a heating element is inserted into a tube and a liquid substance is directly heated through the tube by electrical heating. This system is equipped with a detector for detecting gaseous components inside the pipe, and is capable of detecting minute damage such as pinholes and cracks in the pipe at an early stage.

[Prior art] Conventionally, for example, an immersion type heater in which a heating element is inserted into a tube loses heat over time due to direct contact with the object to be heated or exposure to the same temperature. The pipe surface deteriorates easily, and therefore inspections are required to check the state of deterioration. Further, even if there is no damage at the time of inspection, if damage occurs during operation, it is usually difficult to detect if the damage is minute.

[Problem to be solved by the invention] Damage during operation can result from impurities in the heating element or tube flowing into the heated object, causing contamination, or conversely, when the heated object enters the heater tube. This is dangerous as it may reduce heat generation efficiency or cause further damage.

In order to solve these problems, for example,
Japanese Patent No. 6323 discloses a heater tube made of corrosion-resistant platinum. However, platinum itself is expensive and cannot be applied to large-scale projects, making it impractical. In addition, some methods cover the surface of the heater tube with fluororesin or the like, but the heating efficiency inevitably deteriorates. In either case, the damage itself that occurs during operation is
Especially when the damage is minute, it is difficult to catch the moment the damage occurs.

[Means for Solving the Problems] The present invention is configured such that if damage occurs in the heater during operation, even if it is minute, it can be detected instantly, and the heater tube can be immediately detected. It is characterized by having a sensor box that communicates with the pipe in part, and this sensor box is equipped with a detector that detects gas components. Another feature is that it is equipped with a suction device that maintains the inside of this sensor box at a reduced pressure.

[Operations] The heater with a damage detection mechanism according to the present invention may cause minute damage such as pinholes during operation, causing objects to be heated or
For example, it utilizes the phenomenon that liquid enters and vaporizes when it comes into direct contact with a heating element, and by detecting this gas with a gas detector, it instantly detects that damage has occurred. Therefore, if the sensor box equipped with the gas detector is kept at a reduced pressure, the time from damage to detection will be shortened and the sensitivity will be improved.

[Example 1] FIG. 1 is a schematic diagram showing an example of a heater with a damage detection mechanism of the present invention.

In the figure, reference numeral 1 is a heater, 2 is a tube, 3 is a heating element, and 4 is a cleaning tank.In the cleaning tank, there is ammonia-hydrogen peroxide, which is a heated substance used in the semiconductor cleaning process shown by 5. -Contains water cleaning solution. Moreover, at the end 7 of the heater 1,
A sensor box 9 is provided which communicates with the gas phase within the heater tube by a conduit 8. Here, conduit 8 and heater 1
The end portion 7 is kept airtight by a gasket 10.

The sensor box 9 is provided with a detector for gas components within the sensor box, in this embodiment, a detector 11 for ammonia gas. A display/alarm device 12 for displaying the detection results is provided externally.

The distance from the heater tip 13 to the detector 11 is approximately 1000 m.
There is +n.

[Example 2] Using the heater with a damage detection mechanism of Example 1, the cleaning liquid 6 was energized and heated as usual, and when the liquid temperature reached an equilibrium state of 80°C, a spot on the wall of the pipe 2 in the liquid was heated. , 0.5mmφ
When the pinhole was opened, the display alarm 12 was activated approximately 15 seconds after the pinhole was opened.

[Embodiment 3] FIG. 2 is a schematic diagram showing a different embodiment of the heater with a damage detection mechanism of the present invention.

In this embodiment, the same parts as in the first embodiment are given the same reference numerals, and redundant explanation will be omitted.

This embodiment differs from the first embodiment in that the sensor box 9 is provided with a suction device 14 that sucks the sensor box to a reduced pressure.

As a result, a reduced pressure of approximately 40+nmHg is maintained from the inside of the heater tube to the inside of the sensor box.

Note that the distance from the heater tip 13 to the detector 11 is approximately 1000 mm, as in the first embodiment.

[Example 4] Using the heater with a breakage detection mechanism of Example 3, the cleaning liquid 6 was energized and heated in the usual manner, and when the liquid temperature reached an equilibrium state of 80°C, a spot on the wall of the pipe 2 in the liquid was heated. , 0.5mφ0
When the pinhole was opened, the display alarm 12 was activated about 2 seconds after the pinhole was opened.

As is clear from this embodiment, if the inside of the sensor box 9 is maintained at a reduced pressure, an airflow is generated from the location where the damage occurs to the detector 11 located downstream, so that the detection sensitivity is improved.

Note that in order to improve the detection sensitivity, it is preferable to take the following first-order measures.

1. Adopt a highly sensitive gas detector itself.

2. Increase the degree of vacuum inside the heater tube.

3. By improving the sealing performance, the gas concentration inside the heater tube in normal conditions is kept as low as possible, and the difference in gas concentration between abnormal conditions is increased.

4. Reduce the volume inside the heater tube and sensor box as much as possible.

5. Place the gas detector as close as possible to the wetted part of the heater tube.

6. The gas detector is located downstream of the airflow within the heater tube.

[Effects] According to the heater with a breakage detection mechanism of the present invention, a sensor box communicating with the pipe is provided in a part of the pipe, and this sensor box is equipped with a detector for detecting gas components, so that there is no pin in the heater pipe. When a hole or the like is open and the object to be heated comes into contact with one heating element and vaporizes, this vaporized substance is detected by a detector installed in the sensor box, so that damage can be detected instantly. Therefore, contamination spreading from inside the heater to the object to be heated can be minimized, and troubles in the manufacturing process can be prevented. In particular, if the object to be heated is something like a cleaning solution used in the semiconductor industry, contaminants contained in the cleaning solution can have a very serious effect on the performance of single-conductor elements, which can reduce productivity. The effect on In particular, those equipped with a suction device that maintains a reduced pressure inside the sensor box improve detection speed and can almost completely prevent contamination and the occurrence of dangerous conditions.

The heater with a damage detection mechanism of the present invention can be applied to any of these types as long as the object to be heated is gasified by the heat of the heater and detected by a gas detector. Of course, if the detector is a humidity sensor, it will be possible to detect most of the objects to be heated that contain water, thus providing versatility.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a heater with a damage detection mechanism of the present invention. FIG. 2 is a schematic diagram showing a different embodiment of the heater with a damage detection mechanism of the present invention. 1... Heater 2... Tube 3... Heating element 4... Cleaning tank 5... Cleaning liquid 7... End 8... Conduit 9... Sensor box 10...Packing 11...Detector 14...Suction device drawing

Claims (1)

[Claims] 1. In a heater that directly heats an object to be heated through the tube by inserting a heating element into the tube, a sensor box communicating with the tube is provided in a part of the tube, and a gas component is supplied to the sensor box. A heater with a breakage detection mechanism, characterized by being equipped with a detector. 2. The heater with a damage detection mechanism according to claim 1, further comprising a suction device that maintains the inside of the sensor box at a reduced pressure.