JPH10284454A - Method for detecting non-content heating of fluid heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the detection precision, and its speed, of unloaded heating of a fluid heating device, by leading-out a part of the light projected from a lamp heater applied to the fluid heating device outside an outer tube through a space between the outer tube and an inner tube, and detecting a thermal energy of the led-out light. SOLUTION: Relating to a fluid heating device 10, a halogen lamp 40 which is a lamp heater is inserted into an inner tube 30 penetrating an outer tube 20. Between the inside surface of the outer tube 20 and the outer periphery surface of the inner tube 30, a communication space 21 for a to-be-heated fluid is formed. When the halogen lamp 40 is continuously energized with the space 21 not filled with a chemical liquid, a radiation heat or the halogen lamp 40 is not absorbed into the chemical liquid, thus, the heating device 10 comes into so called non-content heating condition. The light led-out of a light leading- out part 24 provided at the outer tube 20 comprises a thermal energy proportional to its intensity so, an unloaded heating condition is detected based on the thermal energy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting empty cooking of a fluid heating device using a lamp heater as a heating source.

[0002]

2. Description of the Related Art So-called RCA for cleaning semiconductor wafers
In the cleaning step, organic substances and particles are removed by washing with ammonia and hydrogen peroxide, and metal ions are removed by washing with hydrochloric acid and hydrogen peroxide.

[0003] In the above-mentioned cleaning treatment, it is necessary to heat the above-mentioned cleaning solution such as ammonia-hydrogen peroxide solution and hydrochloric acid-hydrogen peroxide solution to about 80 ° C. Therefore, a fluid heating device for heating the cleaning solution while flowing the cleaning solution has been put into practical use. .

This fluid heating device includes an inner tube made of a transparent material, an outer tube arranged so as to surround the inner tube, and a lamp heater housed in the inner tube. The cleaning liquid flows through the space defined between the inner tube and the outer tube,
At that time, the lamp is heated by the radiant heat of the lamp heater.

By the way, when the flow space of the cleaning liquid is empty, the radiant heat of the lamp heater is not absorbed by the cleaning liquid, so that the fluid heating device is in an empty state.
In this empty cooking state, the temperature of the inner and outer tubes rises rapidly,
As a result, burnout of the heat insulating material wound around the outer tube, deformation or melting of the resin casing housing the heating elements such as the inner and outer tubes, and the like occur.

Therefore, the empty cooking is detected based on the temperature of the outer tube, and the power supply to the lamp heater is stopped at the time of the detection.

[0007]

The temperature of the outer tube is K
Although the temperature is detected by a temperature sensor such as a mold thermocouple, the temperature sensor contacts not only the outer peripheral surface of the outer tube but also the heat insulating material wound around the outer peripheral surface.

However, it is practically necessary to keep the temperature sensor in contact with the outer surface of the outer tube and the heat insulating material.
It is impossible, and this variation in the contact mode makes the detected temperature of the temperature sensor uncertain.

[0009] Therefore, the method of detecting empty cooking based on the temperature of the outer tube has a problem in reliability. Further, the detection time of the empty cooking by the above-described method is not the time when the cleaning liquid no longer exists in the circulation space, but the time when the temperature of the outer tube reaches a high temperature caused by the empty cooking, and therefore,
With the above method, empty cooking cannot be detected immediately.

An object of the present invention is to provide a method for detecting empty cooking in a fluid heating device, which can accurately and promptly detect empty cooking of a fluid heating device in view of such circumstances.

[0011]

A first invention of the present invention comprises an outer tube, an inner tube made of a transparent material penetrating the outer tube, and a lamp heater inserted into the inner tube. A fluid to be heated is circulated in a space defined between the inner pipe and the inner pipe, and the fluid to be heated is applied to a fluid heating device that is heated by the radiant heat of the lamp heater. A part of the emitted light is led out of the outer tube through the space, and an empty state of the fluid heating device is detected based on the heat energy of the led light.

[0012] A second invention of the present invention is characterized in that the idle state of the fluid heating device is detected based on the wavelength of the light thus derived.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fluid heating device 10 shown in FIG.
An outer tube 20, an inner tube 30 penetrating the outer tube 20, and a halogen lamp 40 as a lamp heater inserted into the inner tube 30 are provided.

The outer tube 20 is formed of a transparent quartz glass tube having one end and the other end sealed, and defines a flow space 21 for a fluid to be heated between the inner surface and the outer peripheral surface of the inner tube 30. I have. The outer pipe 20 has an inflow pipe 22 and an outflow pipe 23 below one end and above the other end, respectively, as shown in FIG. 2 and FIG. A light guiding portion 24 on a cylinder projects from the upper central portion.

The pipes 22 and 23 are shown in FIG.
As shown in FIG. Also,
The periphery of the outer tube 20 is covered with a heat insulating material 50.

The inner tube 30 is formed of a transparent quartz glass tube, and one end and the other end of the inner tube 30 projecting from the outer tube 20 are both open.

As shown in FIG. 1 and FIG. 4 which is a cross-sectional view taken along the line BB of FIG. 1, the halogen lamp 40 has a pair of adjacent transparent quartz glass tubes 41 and is disposed in the glass tubes 41, respectively. A ceramic base 43 connecting the filament 42 and one end of each glass tube 41 to each other, and a ceramic base 44 connecting the other end of each glass tube 41 to each other.
And

In the ceramic base 43, lead wires 45 connected to one end of each of the filaments 42 are led out, and in the ceramic base 44, lead wires 45 are provided. The other ends of the filaments 42 are connected to each other. That is, the halogen lamp 40 has a single-ended structure in which power is supplied from one end.

Each quartz glass tube 41 of the halogen lamp 40
An inert gas such as nitrogen, argon, and krypton and a small amount of halogen gas are sealed therein. Therefore, when a predetermined voltage is applied between the lead wires 45, the filaments 42 emit light and generate heat stably for a long period of time by the so-called halogen cycle action. The halogen lamp 40 is, for example, a 3 KW lamp.

As shown in FIG. 1, the pipe 22 of the outer pipe 20
A pump 60, a chemical solution storage tank 61, and a filter 62 are interposed between and.

The chemical in the storage tank 61 passes through the pipe 22 and the circulation space 21 with the operation of the pump 60, and
3 and then pass through the filter 62 and into the storage tank 6
Returned to 1.

Therefore, if the halogen lamp 40 is heated to heat the chemical solution flowing through the space 21, the heated chemical solution flows into the tank 61, and as a result, the temperature of the chemical solution in the tank 61 decreases. To rise.

The temperature sensor 70 provided in the storage tank 61
The temperature of the chemical in the tank 61 is detected, and the detection signal is applied to the controller 80. Therefore, the controller 80
Based on the output of the temperature sensor 70, the power supplied to the halogen lamp 40 is controlled so that the temperature of the chemical solution is maintained at a target temperature (for example, 80 ° C.).

If the halogen lamp 40 is continuously energized in a state where the chemical solution is not flowing through the space 21, the radiant heat of the halogen lamp 40 is not absorbed by the chemical solution. It will be empty cooked. Then, in this empty cooking state, the temperature of the outer tube 20 abnormally rises, and as a result, burning of the heat insulating material 50 or
Deformation, melting, and the like of a resin casing (not shown) that accommodates the elements such as the outer tube 20 and the inner tube 30 occur.

The light guiding section 24 provided on the outer tube 20 is provided for the purpose of detecting the empty cooking state, and the principle of the detection will be described below.

The halogen lamp 40 emits visible light and infrared light. In a state in which the chemical is flowing through the circulation space 21, most of the infrared light is absorbed by the chemical as heat energy. However, in an empty cooking state in which the chemical is not flowing, red light caused by the chemical is used. The external light absorption function disappears. The intensity of the radiant light is maximum in the near infrared region.

As is clear from the above reasons, in the non-empty state, light mainly consisting of low-intensity visible light is extracted from the light guide section 24, but in the empty state, the light is high. Light including intense near-infrared light is derived.

Since the light led out from the light lead-out section 24 has a heat energy proportional to the intensity thereof, it is possible to detect the state of the empty cooking based on this heat energy.

That is, for example, as shown in FIG. 1, a temperature switch 90 such as a bimetal is provided in the irradiation area of the light led out from the light lead-out section 24, and this temperature switch 90
By performing a switch operation with the thermal energy of the above-mentioned derived light in the empty cooking state, the empty cooking state can be detected.

The temperature switch 90 is directly connected to a relay (not shown) built in the controller 80, and the switching of the temperature switch 90 turns off the relay.

Since power is supplied to the halogen lamp 40 when the relay is turned on, the power is stopped at the same time as the relay is turned off. As a result, the continuation of the empty cooking state is prevented, and the heat insulating material 50 is prevented. Inconveniences such as burnout can be prevented beforehand.

Instead of the temperature switch 90, a temperature sensor such as a K-type thermocouple for detecting the temperature in an analog manner can be used. In this case, the detected temperature has reached the temperature at the time of empty cooking. It is necessary to use an electric circuit to judge this.

Therefore, when the temperature sensor is used, the controller 80 includes the electric circuit, and turns off the relay based on a logic level judgment signal output from the circuit.

In consideration of the trouble of the electric circuit, it is advantageous to use the temperature switch 90 which does not require the circuit in order to increase the reliability of the detection of the empty state.

By the way, in the empty cooking state, since high-intensity near-infrared light is led out from the light lead-out section 24, the light for sensing light in the wavelength range of near-infrared light is used instead of the temperature switch 90. If a sensor is arranged, the above-mentioned empty cooking can be detected.

Since the output of the optical sensor is proportional to the intensity of light in the above wavelength range, when this optical sensor is applied, an electric circuit for judging that the output has reached the size at the time of empty cooking. To be used together.

In the embodiment shown in FIG. 5, the light guiding section 24 is provided on the side wall of the outer tube 20. According to this embodiment, the intensity of the light led out from the light lead-out unit 24 is lower than in the case of FIG.
Can be used at a lower operating temperature than that shown in FIG.

Further, in the embodiment shown in FIG. 6, a light guide 100 having a desired length made of a quartz fiber or the like is connected to the light guide section 24. According to this embodiment, the light guided from the light guiding section 24 can be guided to a position separated from the outer tube 20. Therefore, the temperature switch 90 or the optical sensor can be disposed near the outer tube 20. This is advantageous when it is difficult. Further, there is an advantage that the temperature switch 90 and the optical sensor are not affected by the heat of the chemical solution in the outer tube 20.

Examples of the chemicals used in the semiconductor manufacturing process include ammonia peroxide and hydrochloric acid used for the RCA cleaning, phosphoric acid as a nitride film removing solution, and sulfuric acid and peroxide as a resist stripping solution. is there. Further, as a chemical solution used in other fields, there is a plating solution and the like.

Although the embodiment shown in FIG. 1 employs a halogen lamp 40 as a lamp heater, the present invention provides another lamp heater having characteristics similar to the characteristics of the radiated light of the halogen lamp 40. It is applicable even if adopted.

[0041]

According to the first aspect of the present invention, a part of the light projected from the lamp heater is led to the outside of the outer tube of the heating device through the fluid flow space of the heating device, and the emitted light is Based on the heat energy, empty cooking of the fluid heating device is detected. Further, in the second aspect of the present invention, empty cooking is detected based on the wavelength of the light derived above. Therefore, compared to the method of detecting the empty cooking based on the temperature of the outer tube, the detection accuracy of the empty cooking is improved, and the time lag until the temperature of the outer tube reaches the temperature caused by the empty cooking is reduced. Since there is no cooking, empty cooking can be detected quickly.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of an outer tube of the heating device.

FIG. 3 is a view taken in the direction of arrow A in FIG. 2;

FIG. 4 is a sectional view taken along line BB of FIG. 1;

FIG. 5 is a sectional view of a main part showing another embodiment of the present invention.

FIG. 6 is a sectional view of a main part showing still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fluid heating device 20 Outer tube 21 Space 24 Light guide part 30 Inner tube 40 Halogen lamp 60 Pump 61 Storage tank 70 Temperature sensor 80 Controller 90 Temperature switch 100 Light guide

Claims (5)

[Claims] 1. A space defined between the outer tube and the inner tube, comprising an outer tube, an inner tube made of a transparent material penetrating the outer tube, and a lamp heater inserted into the inner tube. Applied to a fluid heating device that causes the fluid to be heated to flow at the same time and heats the fluid to be heated by the radiant heat of the lamp heater, and a part of the light projected from the lamp heater through the space. A method for detecting empty cooking of a fluid heating device, wherein the method detects the empty cooking of the fluid heating device based on the heat energy of the derived light. 2. The method according to claim 1, wherein the guided light is transmitted to a position separated from the outer tube by a light guide means. 3. The air-cooking detection of the fluid heating device according to claim 1, wherein the air-cooking is detected by a temperature switch that operates when the heat energy of the derived light becomes equal to or greater than a predetermined value. Method. 4. A space defined between the outer tube and the inner tube, comprising an outer tube, an inner tube made of a transparent material penetrating the outer tube, and a lamp heater inserted into the inner tube. Applied to a fluid heating device that causes the fluid to be heated to flow at the same time and heats the fluid to be heated by the radiant heat of the lamp heater, and a part of the light projected from the lamp heater through the space. A method for detecting empty cooking of a fluid heating device, wherein the method is conducted outside the outer tube, and detects empty cooking of the fluid heating device based on the wavelength of the derived light. 5. The method according to claim 4, wherein the guided light is transmitted to a position separated from the outer tube by a light guide means.