JPH0426877Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a furnace for efficiently heat-treating glass products, such as cathode ray tubes and containers, in a furnace configured with a gas-fired far-infrared panel heater.

Conventionally, this type of furnace has only been a Matsufuru type furnace using gas, oil, etc. as fuel, a radiant tube type internal hot air recirculation type furnace, or an electric heating type radiant and hot air recirculation type furnace. However, when using these furnaces to heat-treat glass that is thick or has a different thickness, there is a temperature difference between the heat-receiving surface and the back surface that tends to cause cracks, the heat treatment takes a long time, and the installation space of the furnace is limited. There were drawbacks such as being large and, in the case of electric heating, the heat source unit was expensive.

In addition, in the case of a continuous furnace, the temperature distribution for each module was uneven, and there was room for improvement in terms of product quality control.

The present invention is intended to completely solve these conventional drawbacks, and will be described below with reference to drawings showing an embodiment of a cathode ray tube degassed lehr.

Reference numeral 1 indicates a cathode ray tube that undergoes heat treatment by air extraction and slow cooling, 2 indicates the outer surface of the cathode ray tube glass, and 3 indicates the inner surface of the cathode ray tube glass.

When heating this now, a gas-fired far-infrared panel heater shown in 4 is installed so as to surround the outer periphery of the cathode ray tube 1 to be heat-treated. The gas-fired far-infrared panel heater 4 includes a radiation tube group (combustion tube) 5
A fuel inlet 6 for mixing air, gas, and air, and a combustion exhaust gas outlet 7.

The inner surface of the radiant tube group 5 is coated with a special ceramic material, and most of the heat rays radiated from this surface are converted into far-infrared rays with a wavelength of 5 μ to 50 μ. Because this far-infrared rays match the far-infrared absorption characteristics of the object, it can penetrate deep into thick glass, allowing it to uniformly coat the inner and outer surfaces in a short time, similar to heating food in a microwave oven. It can be heated to. Therefore, not only can the upper surface, side surfaces, and lower surface of the cathode ray tube glass be uniformly heated, but also the temperature of the outer surface 2 of the cathode ray tube glass and the inner surface 3 of the cathode ray tube glass is increased with almost no temporal temperature difference.

For this reason, it has become possible to completely eliminate defects due to temperature differences between tubes and bulbs, which accounted for 20 to 30% of the production volume in conventional convection heating systems in hot air recirculation furnaces.

8 is a heat insulating material, 9 is a reinforcing furnace frame hardware, and 10 is a trolley that serves to remove air from the cathode ray tube and transport it.

As mentioned above, the present invention is extremely ideal for heating glass products for heat treatment such as strain relief slow cooling, coating, baking, molding, and strengthening by utilizing a gas-fired far-infrared panel heater. It yields immeasurable benefits such as improved management, b. yield improvement, c. energy savings, d. reduction in both initial and running costs by not using recirculation fans, and e. simplification of the furnace model.

[Brief explanation of the drawing]

The drawing is a perspective sectional view of the furnace. 1 is a cathode ray tube to be heat treated, 2 is the outer surface of the cathode ray tube glass, 3 is the inner surface of the cathode ray tube glass, 4 is a gas-fired far-infrared panel heater, 5 is a combustion pipe for far-infrared radiation with a built-in panel heater, 6 is an air mixture gas for combustion 7 is an inlet, 7 is a combustion exhaust gas outlet, 8 is a heat insulating material, 9 is a reinforcing furnace frame hardware, and 10 is a transport vehicle with a built-in air extraction device.

Claims (1)

[Scope of Claim for Utility Model Registration] A cylindrical furnace part whose inner circumferential surface is made up of a ceiling wall, side walls, and a bottom wall whose inner circumferential surface is composed of a gas-fired far-infrared panel heater; a moving means for moving the glass to be heat treated in the axial direction of the furnace section, and the furnace section is provided with a part of the bottom wall in the axial direction for moving the glass that is moved within the furnace section by the moving means. A gas heat treatment furnace characterized by having an opening provided along.