JPH01269097A - Concentrating and drying device for radioactive liquid waste - Google Patents

Abstract

PURPOSE:To curtail the energy consumption and to prevent electric discharge by executing an automatic control of the microwave irradiation quantity by an output signal of an infrared-ray temperature detector which has been installed in a concentrating and drying device of radioactive liquid waste by microwave irradiation. CONSTITUTION:An object to be concentrated passes through a supply pipe 3 from a supply tank 1 and supplied to a concentrating and drying device 4, is concentrated by radiating a microwave which is led by a waveguide 6 from a microwave oscillator 5, and as a concentrated state advances, a temperature is varied. This temperature variation is detected by an infrared-ray temperature detector 14, this output signal 14a is converted to a control signal 15a through a controller 15, inputted to an oscillator 5 and a microwave output is brought to automatic control. In such a way, the energy consumption of the device can be saved, and also, electric discharge in the drier 4 caused by an excessive microwave can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a radioactive liquid waste concentrating and drying apparatus for concentrating and drying radioactive liquid waste by microwave irradiation.

(Prior art) The heating/concentration drying method using microwaves utilizes the phenomenon of heat generation and temperature rise of the substance itself due to the molecular motion of the constituent molecules of the dielectric liquid concentrate and the intermolecular bond resistance. Compared to other types, such as radiant heat and heat conduction, this method has higher energy efficiency and is capable of uniformly heating the entire material to be concentrated. For this reason, it is used as an effective method for concentrating and drying radioactive liquid waste discharged from nuclear facilities, etc.

In the conventional radioactive liquid waste concentration drying apparatus, as shown in FIG. 5, the material to be concentrated is introduced into the supply tank 1 from the material to be concentrated supply section 20. The stored substance to be concentrated is supplied from the supply tank 1 to the concentration dryer 4 via a supply pipe 3 in which a valve 2 is provided. The supplied substance to be concentrated is concentrated by irradiating it with microwaves guided by a waveguide 6 from a microwave oscillator 5. Concentration dryer 4
The concentrate concentrated therein is extracted from the transfer device 7 via a transfer pipe 8. Further, the waste gas generated in the concentration drying process is led into the waste gas processing device 13.

This led waste gas is condensed in a condenser 9.

The non-condensable gas generated here is discharged to the outside of the system from the blower 10, and the condensed water is discharged from the condensate tank 11 to the outside of the system via the pump 12.

(Problems to be Solved by the Invention) However, in the concentration drying apparatus using the conventional method, as shown in curve A in FIG. Currently, the amount of microwave irradiation is not automatically controlled, such as by inputting a fixed amount of microwave regardless of fluctuations, but it is necessary to automatically control the amount of microwave irradiation according to the amount of concentrated material loaded. is requested.

The present invention has been made to meet the above-mentioned needs, and by providing a device that automatically controls the amount of microwave irradiation in accordance with the amount of loaded material to be concentrated in the aforementioned concentration drying process, energy consumption of the device can be reduced. The purpose is to save energy and prevent discharge caused by excessive microwaves.

[Structure of the invention]

(Means for solving the problem) The above purpose is to install an infrared temperature detector in a device for concentrating and drying radioactive liquid waste using microwave irradiation, and automatically control the amount of microwave irradiation based on the output signal of the temperature detector. This is achieved by providing a controller that performs this.

(Function) In the apparatus for concentrating and drying radioactive liquid waste using microwave irradiation according to the present invention, the temperature of the substance to be concentrated changes as the concentration state progresses. That is, immediately after the start of the concentration process, the temperature of the substance to be concentrated increases with the amount of microwave irradiation, but thereafter the temperature becomes constant and becomes a latent heat state. Then, when the concentration and drying of the substance to be concentrated is completed, the substance to be concentrated shifts from a latent heat state to a sensible heat state, and the temperature of the substance to be concentrated rises again. At that time, the infrared temperature detector installed in the concentration drying equipment detects the temperature change mentioned above, and by sending the output signal of this infrared temperature detector to the controller, it is possible to automatically control the amount of microwave irradiation. Become.

(Example) A first embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, the same parts as in FIG. 5 are given the same reference numerals, and the explanation of the structure of the parts will be omitted. The radioactive liquid waste concentration drying device shown in Figure 1! 4, the concentration dryer 4 is provided with an infrared temperature detector 14, and the temperature signal 14a transmitted from the infrared temperature detector 14 is
is input to the controller 15, and the output of the microwave oscillator 5 is controlled according to this signal. With this configuration, the material to be concentrated is supplied from the supply tank 1 through the supply pipe 3 to the concentration dryer 4, and is concentrated by irradiating microwaves guided by the waveguide 6 from the microwave oscillator 5. The temperature changes as the state of concentration progresses. This temperature change is detected by the infrared temperature detector 14, and the output signal 14a from the infrared temperature detector 14 is
is converted into a control signal 15a via the controller 15 and inputted to the microwave oscillator 58, thereby automatically controlling the microwave output.

Next, a second embodiment of the present invention will be described with reference to FIG.

In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals, and the explanation of the structure of the parts will be omitted.

In FIG. 2, the waveguide 6 has a microwave input regulator 1.
6 are arranged. The concentration dryer 4 is provided with an infrared temperature detector 14, and a temperature signal 14a from the infrared temperature detector 14 is sent to a control signal 15 via a controller 15.
a and is input to the microwave input regulator 16. With the configuration shown in FIG. 2, the material to be concentrated is supplied from the supply tank 1 through the supply pipe 3 to the concentration dryer 4, and is concentrated by irradiating it with microwaves guided by the waveguide 6 from the microwave oscillator 5. Ru. The temperature change of the substance to be concentrated at this time is detected by the infrared temperature detector 14, and the temperature signal 14a from the infrared temperature detector 14 is sent to the controller 1.
The amount of microwave irradiation is automatically controlled by inputting it to the microwave manual Ws regulator 16 via step 5.

Further, a third embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same parts as in FIG. 1 are given the same reference numerals, and the explanation of the structure of the parts will be omitted.

In FIG. 3, an infrared temperature detector 1 is installed in the concentration dryer 4.
4 are provided. The output signal 14a from the infrared temperature detector 14 is converted into a control signal 15a by a controller 15 and is input to the drive section of the flow control valve 2. In FIG. 3, the material to be concentrated is supplied from a supply tank 1 through a communication pipe 3 to a concentration dryer 4, and is concentrated by being irradiated with microwaves guided by a waveguide 6 from a microwave oscillator 5. At that time, the temperature change of the material to be concentrated is detected by the infrared temperature detector 14, and the output signal 14a from the infrared temperature detector 14 is converted into a control signal 15a by the controller 5, and the control signal 15a is sent to the flow rate regulating valve 2. signal 15a
By inputting , the supply amount of the concentrate is adjusted.

An embodiment of the operation mode of the apparatus for concentrating and drying radioactive liquid waste by microwave irradiation according to the present invention is shown using FIG. 4.

In the concentration drying apparatus, the temperature of the substance to be concentrated varies from microwave irradiation time T=O to T, as shown in Figure 4.
In the region up to =T□, it increases with the microwave irradiation time, but from the microwave irradiation time T1, the temperature of the concentrate 1 = 1. Therefore, it becomes a state of latent heat. Then, the microwave irradiation time T=T, which completes the concentration drying of the substance to be concentrated,
As a result, the substance to be concentrated shifts from a latent heat state to a sensible heat state, and the temperature t of the substance to be concentrated rises again. In the continuous operation of the concentration drying apparatus, the microwave irradiation time is from T=O to T=T1.
A certain amount of microwave is irradiated in the area up to, and after the microwave irradiation time T=T1 has elapsed, the temperature of the concentrate 1=1
The amount of microwave irradiation is controlled by the temperature detector and the controller so as to maintain the temperature at 1.

In the batch operation of the concentration drying apparatus, a certain amount of microwave is irradiated in the range from microwave irradiation time T=O to T=T1, and after the microwave irradiation time T=71 has elapsed, the temperature of the material to be concentrated increases. The amount of microwave irradiation is controlled by the temperature detector and the controller so as to maintain 1=11. After the microwave irradiation time T=72, the temperature t of the concentrate rises again, and the temperature 1 of the concentrate becomes 1. At the microwave irradiation time T=73, the temperature detector is combined with the controller and, if necessary, a timer to serve as a control means for detecting the end of the concentration and drying batch process.

In the detailed explanation of the present invention, an example is shown in which an infrared sensor is used as a temperature detector. It can be used in embodiments of the invention.

〔Effect of the invention〕

As explained above, according to the apparatus for concentrating and drying radioactive liquid waste according to the present invention, automatic control of the irradiation amount corresponding to the loading amount of the material to be concentrated by microwaves, or automatic adjustment of the supply amount of the material to be concentrated is possible. As a result, the energy consumption of the device can be reduced, and discharge in the concentration dryer due to excessive microwaves can be prevented.

[Brief explanation of the drawing]

1, 2, and 3 are system diagrams showing the radioactive liquid waste concentration drying apparatus according to the first to third embodiments of the present invention, respectively, and FIG. A characteristic diagram showing the relationship between concentrate temperature, Figure 5 is a system diagram showing a conventional example of a radioactive liquid waste concentration drying device, and Figure 6 shows the amount of concentrated material loaded against microwave irradiation time and the microwave in the conventional device. FIG. 3 is a characteristic diagram showing the relationship between irradiation amounts. 1... Supply tank 3... Supply pipe 4... Concentration dryer 5... Microwave oscillator 6... Waveguide 13... Waste gas treatment device 14...
Infrared temperature detector 15...Controller agent Patent attorney
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Claims (1)

[Claims] a microwave oscillator, a concentration dryer for introducing radioactive liquid waste, a waveguide that connects the microwave excavator and the concentration dryer and guides the microwave to the irradiation section, and a waveguide for introducing the radioactive liquid waste into the concentration dryer. A microwave condensing and drying device comprising: a supply tank for supplying gas; a supply pipe communicating the supply tank and the concentrating dryer; and a waste gas treatment device for treating waste gas generated from the concentrating and drying device. An apparatus for concentrating and drying radioactive liquid waste, characterized in that the concentrating and drying device is provided with an infrared temperature detector, and a controller that automatically controls the amount of microwave irradiation based on the output signal of the infrared temperature detector.