SU1150234A1 - Arrangement for heating material,mainly sheet glass - Google Patents

Abstract

A DEVICE FOR HEATING A MATERIAL, A PREPARATELY SHEET GLASS, containing a microwave generator and an electromagnetic retarding system, characterized in that, in order to create a temperature gradient across the thickness of the glass ribbon, the electromagnetic retardant system is filled as a two-sided frame with gathry glass that has a telescopic temperature retardant system, the electromagnetic retardant each other and with a gap allowing the glass to pass through the pin of the lower base, noKi Jth dielectric and mounted for rotation.

Description

The invention relates to construction materials, in particular to equipment for the production of tempered sheet glass. The purpose of the invention is to provide a temperature gradient across the thickness of a glass ribbon. The drawing shows an inductive (microwave) heating furnace, a transverse section. The device contains a base 1 of a retarding system, a lower base 2 of the system, counter pins 3 with a heat-resistant dielectric coating, made on the bottom base with rotation (position 4 indicates the hardened sheet glass), shaft 5 with a power-driven device, providing rotation the bottom base of the rollers, which are simultaneously a roller table; -, a coaxial cable 6 for supplying microwave energy to the system, a roller shaft 7, a metal case 8, a lining 9, heat reflecting screens 10. The device works their way. The glass preheated to 200300 ° C enters the induction heating furnace, where a retarding system located in the horizontal plane is installed. The rotation of the shaft 5 and the pins 3 of the lower base made with the possibility of rotation causes the glass to move in the direction indicated by the arrow. The electromagnetic field, excited in a metal periodic structure with a coaxial cable 6, is absorbed in the glass and causes it to heat up, which is performed more efficiently as the glass temperature rises (the arrows represent the electric field in the decelerating system that heats the glass) . The present invention provides the following advantages. The tangent of the angle of loss of glass (tgS), which is a measure of the absorption of electromagnetic energy by the dielectric medium, and consequently, a measure of the efficiency of its heating in an electromagnetic field, for the absolute majority of glasses increases sharply with increasing frequency. The tangent of the loss angle of glass at 10–10 Hz rises sharply with increasing temperature (for window glass with a temperature change from 200 to 600 C, it varies from 150-10 to 120–10). Thus, in terms of avnenmo with HF heating, taking into account the temperature p of the frequency dependence tg 6 (C-const), the power consumed for heating the glass can be reduced. 10-15 times. The use of a periodic system as a heating microwave element allows, due to the propagation of electromagnetic waves near the surface of the heating element, to avoid losses due to heating of the lining (unlike RF heating) and to reduce radiation through the holes. Changing the distance between the bases of the periodic system, adjusting the distribution of the floor in the region of the glass, to achieve a predetermined gradient of the floor, and consequently, a predetermined temperature gradient across the thickness of the glass to eliminate rubbing on the bottom surface of the glass and deformation of the sheet. The combination of this factor with traditional methods of cooling the surface makes it possible to achieve significant temperature differences and high quenching quality. The characteristic spatial scale in this process is determined by the wavelength of the electromagnetic waves used to heat the glass. This means that any variation in the thickness of the heated glass sheet, according to its effect on the proposed process, should be correlated with this parameter. Choosing the frequency range in accordance with the output of the domestic industrial microwave oscillators 915i25 MHz, we obtain the spatial scale of the problem mm. The effect of the glass thickness id on the heating process is slightly determined by the ratio - nn The advantage of this method of tempering glass is the thermal inertia of the microwave heating, i.e. the ability to almost instantly turn off the heat

311-502344

processed material. Therefore, the shape of the pulse, its duration and the specified temperature difference on the duty cycle,

the thickness of the glass can be created by the compactness of the microwave oven

the use of a pulse mode of operation significantly reduces the total length of the device according to the program defining the device j

Claims (1)

DEVICE FOR HEATING MATERIAL, PREFERREDLY FOR SHEET GLASS, containing a microwave generator and an electromagnetic slowdown system, characterized in that, in order to ensure the creation of a temperature gradient across the thickness of the glass tape, the electromagnetic slowdown system is made in the form of two bases with pins located parallel to each other and with a gap that allows the glass to pass through the pins of the lower base, covered with a dielectric and mounted for rotation.