JPH0634272A - Far infrared heater - Google Patents

Abstract

PURPOSE:To obtain a far infrared heater which is capable of drying a material subjected to the heating efficiently and speedily for a small consumption of electric power. CONSTITUTION:A far infrared heater 1 is for drying a material 2 subjected to the heating, such as a ceramic body or the like. This heater comprises ceramic heaters 3a, 3b, 3c which irradiate the material 2 with far infrared rays, a detector 4 which measures the wavelength indicating the maximum infrared absorption intensity of the material 2, and a controller 5 which selectively outputs signals for applying power to the ceramic heaters 3a, 3b, 3c on the basis of detection signals inputted from the detector 4. At any time during heating the detector 4 detects, as the infrared absorption intensity characteristic of the material 2 changes, a wavelength indicating the maximum infrared radiation intensity of the material 2; subsequently the controller 5 applies power to any or all of the ceramic heaters 3a, 3b, 3c selected for radiation of a wavelength relatively high in infrared absorption efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a far-infrared heating device and is applied to, for example, a drying device for removing water from raw materials and molded bodies.

[0002]

2. Description of the Related Art Generally, a radiant heating type drying device using far infrared rays is known as a drying device for a raw material such as ceramics or a molded body. This type of drying device has a ceramic heating element at a predetermined position in the drying chamber, and heats the object to be heated by far infrared rays emitted from the ceramic heating element. Conventionally, as the ceramic heating element, a kind of ceramic heating element having a radiation region at a predetermined wavelength has been used.

[0003]

However, when the object to be heated is dried by such a conventional far-infrared heating device, if the temperature of the object to be heated, the amount of water retained, etc. changes during the heating process, the infrared rays of the object to be heated are changed. Absorption strength characteristics change every moment.
Therefore, when the difference between the infrared radiation wavelength range of the ceramic heating element and the infrared absorption wavelength range of the heated body is relatively small, the heated body is efficiently heated. If the difference between and becomes large, there is a problem that the heating efficiency of the object to be heated is lowered and the power consumption tends to increase.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a far infrared heating device capable of efficiently and quickly drying an object to be heated with low power consumption. To do.

[0005]

A far-infrared heating apparatus according to the present invention for solving the above-mentioned problems includes a plurality of ceramic heating elements which are arranged so that far-infrared rays can be irradiated onto a heated object and have different radiation wavelength regions from each other. A detection device for detecting a wavelength showing a predetermined infrared absorption intensity of the object to be heated, and at least one or more ceramics of the plurality of ceramic heating elements so as to have maximum thermal efficiency based on an output signal of the detection device. And a control device for selectively energizing the heating element.

[0006]

According to the far infrared heating device of the present invention,
As the infrared absorption property of the object to be heated changes, the detection device always detects the wavelength indicating the maximum infrared radiation intensity of the object to be heated. Then, the controller selects a ceramic heating element that emits a wavelength having a relatively high infrared absorption efficiency. Therefore, the object to be heated is efficiently dried in a short time.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the far-infrared heating device 1 is for drying a heated body 2 made of a ceramic molded body or the like.
Ceramic heater 3 for irradiating far-infrared rays on the object 2 to be heated
a, 3b, 3c, the detection device 4 for measuring the wavelength showing the maximum infrared absorption intensity of the object to be heated 2, and the ceramic heaters 3a, 3 based on the detection signal output from the detection device 4.
The control device 5 selectively outputs the energization signal to b and 3c. When the object to be heated 2 is placed at a predetermined position in the drying chamber and, for example, a timer is set, the ceramic heater 3a,
The object 2 to be heated by the far infrared rays emitted by 3b and 3c.
Is heated until the water retention amount reaches a predetermined value.

The ceramic heaters 3a, 3b, 3c are S
i quality, MoSi ₂ quality, LaCrO ₃ quality, ZrO ₂ quality, T
As shown in FIG. 2, far infrared wavelengths λ _a , λ _b , and λ of the maximum infrared radiation intensity at the same temperature T ° C. are formed from ceramics having a semiconducting property such as hO ₂ quality and BaTiO ₃ quality.
_c is different step by step. That is, the ceramic heaters 3a, 3b, and 3c have relatively short wavelength regions,
The infrared radiation intensity is set to be high in the medium wavelength region and the relatively long wavelength region.

The detection device 4 measures the temperature, the amount of water retained, the infrared absorption wavelength, etc. of the object to be heated 2 and detects the infrared absorption characteristics of the object to be heated 2 every predetermined time. In this case, for example, 1
Far-infrared rays of μm to 1000 μm are instantly irradiated to the object to be heated 2 and the absorption rate of each wavelength is measured. And the heated object 2
The wavelength indicating the maximum infrared absorption intensity of is detected, and this detection signal is transmitted to the control device 5.

The control device 5 electrically connected to each of the ceramic heaters 3a, 3b, 3c processes the detection signal from the detection device 4 and the ceramic heater 3a having a relatively high heating efficiency for the heated body 2, Select 3b and 3c. During heating, as shown in FIG. 2, when the infrared absorption wavelength region of the object to be heated 2 changes in the direction of arrow d in FIG. 2, the ceramic heaters 3a, 3b, 3c are sequentially energized. in this case,
For example, the wavelength λ indicating the maximum infrared absorption intensity of the heated body 2
_{When d} exceeds the wavelength λ _{e at} which the infrared radiation intensities of the ceramic heaters 3a and 3b are equal, the ceramic heater 3a is switched to the ceramic heater 3b. When the wavelength λ _d exceeds the wavelength λ _{f at} which the infrared radiation intensities of the ceramic heaters 3b and 3c are equal, the ceramic heater 3b is switched to the ceramic heater 3c.

As described above, according to the infrared heating apparatus 1 of the above-described embodiment, the ceramic heaters 3a, 3b, 3c for heating the heated body 2 most efficiently according to the change of the infrared absorption characteristics of the heated body are provided. To be selected. Therefore, the drying time of the heated body 2 can be shortened, and the power consumption of the ceramic heaters 3a, 3b, 3c can be significantly reduced.

In the above embodiment, the ceramic heater 3a,
Although 3b and 3c are sequentially switched, in the present invention, a plurality of ceramic heaters may be energized at the same time in order to prevent the infrared absorption amount of the object to be heated from decreasing.
Further, when the ceramic heater is selected, the infrared absorption characteristic may be estimated by the weight change due to the evaporation of the moisture of the object to be heated, and the ceramic heater may be selected.

[0013]

As described above, according to the far-infrared heating device of the present invention, the ceramic heater that heats the object to be heated relatively efficiently in accordance with the change in the infrared absorption characteristics of the object to be heated is selectively used. Since it is configured to be energized, the object to be heated can be quickly dried with low power consumption, and there is an effect that energy saving of the drying device can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a far infrared heating device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the wavelength of far infrared rays and the infrared radiation intensity and infrared absorption intensity according to the example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Far-infrared heating device 2 Heated objects 3a, 3b, 3c Ceramic heater (ceramic heating element) 4 Detection device 5 Control device

Claims (1)

[Claims] 1. A plurality of ceramic heating elements which are arranged so as to be capable of irradiating far infrared rays to a heated object and have different emission wavelength regions, and a detection device which detects a wavelength showing a predetermined infrared absorption intensity of the heated object. At least one of the plurality of ceramic heating elements having a maximum thermal efficiency based on the output signal of the detection device
A far-infrared heating device comprising: the control device for selectively energizing the ceramic heating element.