What Does The Slow Cooling Section of A Glass Tempering Furnace Mean? The Role of The Slow Cooling Section

What does the slow cooling section of a tempering furnace mean? The slow cooling section of the glass tempering furnace, also known as the through section, is mainly located at the position where the segments are taken, and consists of an integral welding frame, upper and lower air quenchings, and an air box to form an overall cooling system. Glass can be removed from the air quenching by oscillating back and forth in the slow cooling section and dropping to the specified temperature within the set time.

Below, we will introduce the function of the slow cooling section of the glass tempering furnace.

1. The role of the slow cooling section in the glass tempering furnace

1.1. Auxiliary cooling

Tempered glass needs to go through a process of heating and tempering. After the glass completes the tempering process through cooling, it will follow the direction of the roller conveyor to reach the slow cooling section. At this time, the glass does not drop to the standard temperature before it can be discharged. However, relying solely on the longer natural cooling time cycle and limited roller position, in order to improve the efficiency of production equipment operation, tempered glass needs to pass through the upper and lower air quenchings in the slow cooling section, and small air boxes to assist the glass in cooling. By accelerating air flow, the finished product of tempered glass can be discharged from the quenching at a faster speed.

1.2. Motion control

(1) Cooling swing: The roller conveyor of the slow cooling section is wrapped with high-temperature resistant aramid rope, and the air quenching and the air collection box in the air path system are connected through soft connections. The transmission mechanism is equipped with an encoder to detect the speed, direction, and length of glass movement. The working mode of the slow cooling section mainly relies on the detection and control of the encoder to make the glass running from the tempered section to the slow cooling section swing back and forth at the designated roller position, completing the cooling of the glass after reaching the cooling time. One of the main functions of the slow cooling section is to control the movement of the tempered glass.

(2) Air outlet quenching: After reaching the set cooling time, the glass cooling is completed. Tempered glass undergoes an air outlet quenching action, and the slow cooling section transmission and segment extraction transmission move synchronously to send the glass to the set position for segment extraction, stop, and wait for segment extraction. The function of the cooling section is also to facilitate the transportation of glass by workers.

2. The reason for glass breakage in the slow cooling stage

Under normal circumstances, the slow cooling section of the tempering furnace assists in cooling the glass and does not affect the quality of the glass. However, occasional glass breakage may occur in the slow cooling section. Let's explore the specific reasons and solutions together.

2.1.Glass raw material quality: Poor quality glass raw materials may have issues such as firmness, chipping, and impurities, which may cause breakage during the cooling process due to changes in surface temperature. Therefore, the quality of the glass raw material should be carefully checked before tempering to avoid secondary tempering or defective raw materials entering the tempering furnace.

2.2. Water droplets: There are water droplets in the air duct of the cold air section quenching, which cause uneven temperature on the glass surface and cause breakage.

2.3. The influence of opening position: If the opening position of the glass is close to the edge, it may also cause breakage. Generally, the distance between the opening position of the glass and the edge should be maintained at 1.5 to 2 times the thickness of the glass.

2.4. Excessive wind pressure: Generally, glass breaks after tempering. Consider whether it is related to high heating temperature or high wind pressure in the air-cooled section. Consider reducing the cooling wind pressure, lowering the heating temperature, or shortening the heating time.

There are many reasons for the breakage, bouncing, and pitting of glass during the heating process of the glass tempering furnace. If you encounter any other problems during use, please feel free to contact us by phone.