WO2019047522A1

WO2019047522A1 - Plate glass convection heating method

Info

Publication number: WO2019047522A1
Application number: PCT/CN2018/082665
Authority: WO
Inventors: 赵雁; 窦高峰
Original assignee: 洛阳兰迪玻璃机器股份有限公司
Priority date: 2017-09-07
Filing date: 2018-04-11
Publication date: 2019-03-14
Also published as: CN107572764A

Abstract

A plate glass convection heating method. In a convection heating process, plate glass alternates between two end points of a motion path on a roller bed in a heating furnace. In an alternation cycle, the process by which the glass plate decelerates in a direction approaching the two end points until becoming stationary and then accelerates in a direction away from the two end points is defined as a reversing process of the plate glass, and movement processes of the plate glass on the roller bed other than the reversing process are defined as operational processes of the plate glass. During the operational processes of the plate glass, a high temperature fan operates at a set rotational speed, and the rotational speed of the high temperature fan is decreased during the operational processes and/or during the reversing process of the plate glass, such that when the plate glass rests at the end of the motion path, the rotational speed of the high temperature fan is less than an average rotational speed of the high temperature fan during the operational processes of the plate glass.

Description

Glass plate convection heating method

Technical field

The invention belongs to the field of glass processing, and particularly relates to a convection heating method for a glass plate, which is used for controlling the convection heating process of the glass plate in the heating furnace.

Background technique

Convection heating is a method of spraying a glass plate with a high-temperature gas to heat the glass plate. The advantage is that the heating efficiency is high, especially when heating the low-emission coated glass plate. As shown in Fig. 1 and Fig. 2, after the glass plate 8 enters the heating furnace, the high temperature fan 3 sprays high temperature gas onto the surface of the glass plate 8 at a certain rotational speed, and at the same time, the glass plate 8 reciprocates in the direction indicated by the arrow on the roller table. It is gradually heated during exercise. As shown in FIG. 3, in the prior art, the operation process of the high temperature fan 3 is divided into several heating stages according to the heating time of the glass plate, and the high temperature fan 3 operates at a constant rotational speed in each heating stage, which is only exemplary. A rotation speed control mode of the high temperature fan 3 is shown, that is, as the heating time elapses, the rotation speed of the high temperature fan 3 in each of the above heating stages is continuously reduced. In each of the above heating stages, when the glass sheet is moved to a position near the left end point 7 of the furnace inlet or the right end point 5 of the outlet, the deceleration motion is started until the stationary motion continues in the opposite direction. When the glass plate is in a stationary process, the high temperature and high pressure gas are continuously sprayed on the fixed area of the surface of the glass plate, and it is very easy to form hot spots on the glass plate 8. When the heated glass plate is cooled by tempering, a hot spot is formed. Significant stress spots appear in the area, which seriously affects the finished product quality of tempered glass.

Summary of the invention

The object of the present invention is to provide a convection heating method for a glass plate, which is used for controlling the convection heating process of the glass plate in the heating furnace to avoid the formation of hot spots in the heating process of the glass, and effectively reducing the surface of the glass plate after tempering. Stress spots improve the quality of finished products of tempered glass.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a glass plate convection heating method for controlling the convection heating process of the glass plate in the heating furnace, in the convection heating process, the glass plate is in the heating furnace Reciprocating between the two end points of the moving path on the inner roller path; during a reciprocating cycle, defining the decelerating motion of the glass plate toward the two end points until the stationary and moving away from the two end points is accelerated. The reversing process of the glass plate defines that the movement process of the glass plate on the roller table except the reversing process is the operation process of the glass plate; during the operation of the glass plate, the high temperature fan operates at the set rotation speed and runs on the glass plate During the process and/or during the commutation process, the rotational speed of the high temperature fan is lowered, so that when the glass plate is stationary at the end of the motion path, the rotation speed of the high temperature fan is smaller than the average rotation speed of the high temperature fan during the operation of the glass plate.

Further, when the distance between the front end of the glass plate and the end point of the moving path is 100 mm to 800 mm, the rotation speed of the high temperature fan is lowered, so that the rotation speed of the high temperature fan is smaller than that of the high temperature fan when the glass plate is stationary at the two end points of the moving path. The average rotational speed during the operation of the board.

Further, when the front end of the glass plate reaches the end of the moving path, the rotation speed of the high temperature fan is lowered during the process of 1 second to 8 seconds, so that the rotation speed of the high temperature fan is lower than that of the high temperature fan when the glass plate is stationary at the two end points of the moving path. The average rotational speed during operation of the glass sheet.

Further, the rotational speed of the high temperature fan is adjusted by a frequency converter connected to the high temperature fan.

Further, the roller is provided with an encoder, and the encoder sends the movement and position information of the glass plate on the roller table to the control unit of the heating furnace, and the control unit sends a signal to the inverter according to the movement and position information of the glass plate. To adjust the rotation speed of the high temperature fan.

Further, when the glass plate is stationary at the end of the motion path, the rotation speed of the high temperature fan is not more than 100 rpm; during the operation of the glass plate, the average rotation speed of the high temperature fan is 100 rpm to 3000 rpm.

In the present invention, a reciprocating cycle refers to a process in which a glass plate reciprocates between two end points of a moving path, and the glass plate starts from a certain point of the moving path, passes through two end points, and returns to the point again.

Compared with the prior art, the beneficial effects of the present invention are:

When the glass plate is subjected to convection heating by the method of the present invention, the glass is avoided by adjusting and reducing the rotational speed of the high temperature fan before decelerating in the direction of the left end and the right end of the moving path and before stationary. When the plate is at the left end or the right end and is at rest, the high temperature and high pressure gas are continuously sprayed on the fixed area of the surface of the glass plate, thereby forming hot spots on the glass plate, effectively reducing the stress spots on the surface of the glass plate after tempering, and improving the stress spot. The finished product quality of tempered glass.

DRAWINGS

Figure 1 is a schematic view showing a state in which the glass plate is at the left end of the roller path in the heating furnace;

Figure 2 is a schematic view showing a state in which the glass plate is at the right end of the roller path in the heating furnace;

3 is a graph showing a rotational speed of a high temperature fan in the prior art;

Marked in the figure: 1, heating furnace, 2, roller, 3, high temperature fan, 4, outlet, 5, right end, 6, into the furnace, 7, left end, 8, glass plate.

Detailed ways

The technical solution of the present invention will be further described by way of specific embodiments with reference to the accompanying drawings.

Example 1:

A convection heating method for a glass plate for controlling the convection heating process of the glass plate 8 in the heating furnace 1, in the convection heating process, the two end points of the movement path of the glass plate 8 on the roller table 2 in the heating furnace 1 During the reciprocating motion, in a reciprocating cycle, as shown in Figs. 1 and 2, the glass plate 8 reciprocates between the left end point 7 and the right end point 5; the glass plate 8 is defined to be oriented in the direction of approaching the two end points. The process of decelerating motion until the stationary and away from the two end points is accelerated. The process of reversing the glass plate 8 defines the operation of the glass plate 8 on the roller table 2 except for the reversing process. During operation, the high temperature fan 3 operates at a set rotational speed, and the rotational speed of the high temperature blower 3 is lowered during operation of the glass plate 8 and/or during the commutation process so that the glass plate 8 is in the path of motion. When the end point is stationary, the rotation speed of the high temperature fan 3 is smaller than the average rotation speed of the high temperature fan 3 during the operation of the glass plate 8.

Preferably, during the movement of the glass plate 8 to the left end point 7, when the distance between the front end of the glass plate 8 and the left end point 7 of the moving path is 800 mm, at this time, the glass plate 8 is at the end of the running process until the glass plate 8 is reversed. During the process, the rotation speed of the high temperature fan 3 is continuously lowered, so that when the glass plate 8 is stationary at the left end point 7 of the movement path, the rotation speed of the high temperature fan 3 is 30 rpm, 50 rpm, or 100 rpm; 8 During the movement to the right end point 5, when the distance between the front end of the glass plate 8 and the right end point 5 of the moving path is 800 mm, at this time, the glass plate 8 is at the end of the running process until the glass plate 8 is continuously reduced during the commutation process. The rotational speed of the high temperature blower 3 is such that when the glass plate 8 is stationary at the left end point 7 of the moving path, the rotational speed of the high temperature blower 3 is 30 rpm, 50 rpm, or 100 rpm. When the glass plate 8 enters the operation process, the high temperature fan 3 continues to operate at the set rotation speed, and the average rotation speed of the high temperature fan 3 during the operation of the glass plate 8 is 2000 rpm. It should be noted that the set rotational speed of the high temperature blower 3 during the operation of the glass plate 8 may be a constant value or may vary with time, and is an average rotational speed of 100 rpm to 3000 rpm, but is preferably constant. value.

In this embodiment, the rotation speed of the high-temperature fan 3 is adjusted by the inverter connected thereto; the roller 2 of the heating furnace is provided with an encoder, and the encoder is electrically connected with the control unit of the heating furnace, and when working, coding The device sends the movement and position information of the glass plate 8 on the roller table 2 to the control unit of the heating furnace 1. The control unit sends a signal to the frequency converter to adjust the rotation speed of the high temperature fan 3 according to the movement and position of the glass plate 8. .

Example 2:

This embodiment is basically the same as Embodiment 1, except that during the movement of the glass plate 8 to the left end point 7, when the distance from the front end of the glass plate 8 to the left end point 7 of the movement path is 100 mm, at this time, the glass plate 8 During the reversing process, the rotation speed of the high temperature fan 3 is lowered, so that when the glass plate 8 is stationary at the left end point 7 of the movement path, the rotation speed of the high temperature fan 3 is 30 rpm, 50 rpm, or 100 rpm; During the movement of the glass plate to the right end point 5, when the distance between the front end of the glass plate 8 and the right end point 5 of the moving path is 100 mm, at this time, the glass plate 8 is in the process of reversing, and the rotation speed of the high temperature fan 3 is lowered to make the glass When the plate 8 is stationary at the left end point 7 of the movement path, the rotation speed of the high temperature fan 3 is 30 rpm, 50 rpm or 100 rpm. When the glass plate 8 enters the operation process, the high temperature fan 3 continues to operate at the set rotation speed, and the average rotation speed of the high temperature fan 3 during the operation of the glass plate 8 is 800 rpm.

Example 3

A convection heating method for a glass plate for controlling the convection heating process of the glass plate 8 in the heating furnace 1, in the convection heating process, the two end points of the movement path of the glass plate 8 on the roller table 2 in the heating furnace 1 During the reciprocating motion, in a reciprocating cycle, as shown in Figs. 1 and 2, the glass plate 8 reciprocates between the left end point 7 and the right end point 5; the glass plate 8 is defined to be oriented in the direction of approaching the two end points. The process of decelerating motion until the stationary and away from the two end points is accelerated. The process of reversing the glass plate 8 defines the operation of the glass plate 8 on the roller table except for the reversing process. During operation of the plate 8, the high temperature fan 3 operates at a set rotational speed, reducing the rotational speed of the high temperature fan 3 during operation of the glass plate 8 and/or during the commutation, such that the glass plate 8 is stationary at the end of the path of motion At this time, the rotational speed of the high temperature blower 3 is smaller than the average rotational speed of the high temperature blower 3 during the operation of the glass plate 8.

During the movement of the glass plate 8 to the

left end point

7, 8 seconds before the front end of the glass plate 8 reaches the left end point 7 of the movement path, at this time, the glass plate 8 is at the end of the running process until the glass plate 8 is reversing, continuing The rotation speed of the high temperature fan 3 is lowered so that the rotation speed of the high temperature fan 3 is 30 rpm, 50 rpm, or 100 rpm when the left end 7 of the movement path is stationary; the glass plate 8 is to the right end. 5 During the movement, when the front end of the glass plate 8 reaches the right end point 5 of the movement path 8 seconds, at this time, the glass plate is at the end of the running process until the glass plate 8 is reversed, and the rotation speed of the high temperature fan 3 is continuously lowered. When the glass plate 8 is stationary at the left end point 7 of the moving path, the high-speed fan 3 has a rotational speed of 30 rpm, 50 rpm, or 100 rpm. When the glass plate 8 enters the operation process, the high temperature fan 3 continues to operate at the set rotation speed, and the average rotation speed of the high temperature fan 3 during the operation of the glass plate 8 is 1000 rpm. The rotational speed of the high temperature blower 3 during operation of the glass sheet 8 may be constant or may vary over time, but is preferably constant.

In this embodiment, the rotational speed of the high temperature blower 3 is adjusted by the frequency converter connected thereto, and the control unit sends a signal to the frequency converter in advance according to the movement of the glass plate 8 and the time of reaching the left end point 7 and the right end point 5 The rotational speed of the high temperature blower 3 is adjusted.

Example 4

This embodiment is basically the same as Embodiment 3 except that the glass plate 8 is in the process of moving to the

left end point

7, and 3 seconds before the front end of the glass plate 8 reaches the left end point 7 of the moving path, at this time, the glass plate 8 is at During the reversing process, the rotation speed of the high temperature fan 3 is lowered, so that the rotation speed of the high temperature fan 3 is 30 rpm, 50 rpm, or 100 rpm when the glass plate 8 is stationary at the left end point 7 of the movement path; During the movement of the plate 8 to the

right end point

5, 3 seconds before the front end of the glass plate 8 reaches the right end point 5 of the movement path, at this time, the glass plate 8 is in the process of reversing, reducing the rotation speed of the high temperature fan 3, so that the glass plate 8 When the left end point 7 of the motion path is stationary, the rotational speed of the high temperature blower 3 is 30 rpm, 50 rpm, or 100 rpm. When the glass plate 8 enters the operation process, the high temperature fan 3 continues to operate at the set rotation speed, and the average rotation speed of the high temperature fan 3 during the operation of the glass plate 8 is 400 rpm. The rotational speed of the high temperature blower 3 during the operation of the glass plate 8 may be a constant value or may vary with time, and is an average rotational speed of 100 rpm to 3000 rpm, but is preferably a constant value.

Claims

A glass plate convection heating method for controlling the convection heating process of a glass plate in a heating furnace (1), characterized in that: in the convection heating process, the glass plate (8) is rolled in the heating furnace (1) (2) Reciprocating between the two end points of the upper motion path; during a reciprocating cycle, the glass plate (8) is defined to decelerate toward the two end points until it is stationary and away from the two end points. The process of movement is the reversing process of the glass plate (8), defining the operation process of the glass plate (8) on the roller table (2) except the reversing process as the operation of the glass plate (8); the glass plate (8) During operation, the high temperature fan (3) operates at a set rotational speed, reducing the rotational speed of the high temperature fan (3) during operation of the glass plate (8) and/or during the commutation process, such that the glass plate (8) When the end of the motion path is stationary, the rotation speed of the high temperature fan (3) is smaller than the average rotation speed of the high temperature fan (3) during the operation of the glass plate (8).
A convection heating method for a glass plate according to claim 1, wherein when the distance between the front end of the glass plate (8) and the end point of the moving path is 100 mm to 800 mm, the rotation speed of the high temperature fan (3) is lowered. When the glass plate (8) is stationary at the two end points of the moving path, the rotation speed of the high temperature fan (3) is smaller than the average rotation speed of the high temperature fan (3) during the operation of the glass plate (8).
A convection heating method for a glass plate according to claim 1, wherein the rotation of the high temperature fan (3) is lowered during a process from 1 second to 8 seconds before the front end of the glass plate (8) reaches the end of the moving path. The speed is such that when the glass plate (8) is stationary at the two end points of the moving path, the rotation speed of the high temperature fan (3) is smaller than the average rotation speed of the high temperature fan (3) during the operation of the glass plate (8).
A convection heating method for a glass plate according to claim 1, characterized in that the rotational speed of the high temperature fan (3) is adjusted by a frequency converter connected to the high temperature fan (3).
A convection heating method for a glass plate according to claim 4, characterized in that the roller table (2) is provided with an encoder, and the encoder moves the glass plate (8) on the roller table (2). And the position information is sent to the control unit of the heating furnace (1), and the control unit sends a signal to the frequency converter to adjust the rotation speed of the high temperature fan (3) according to the movement and position information of the glass plate (8).
The convection heating method for a glass plate according to claim 1, characterized in that: when the glass plate (8) is stationary at the end of the moving path, the rotating speed of the high temperature fan (3) is not more than 100 rpm; the glass plate (8) During operation, the average rotating speed of the high temperature fan (3) is 100 rpm to 3000 rpm.