The standard demand for compressed air in the glass industry is mainly reflected in the pressure, flow, dryness, cleanliness, temperature, etc. The specific requirements are as follows:
pressure and flow
- pressure: The pressure requirements of compressed air in the glass industry vary depending on the specific application scenario. For example, there are certain requirements on the pressure of compressed air in scenarios such as combustion-supporting during the combustion of molten glass in the production line, purging of residual materials in the cavity of idle oil (powder and natural gas) and cooling and cooling protection of the cavity during the fire exchange process. Generally speaking, the gas pressure at each gas point in most flat glass factories does not exceed 5~7kgf/cm² gauge pressure (about 0.5~0.7MPa), so an air compressor unit with a gas supply pressure of 8kgf/cm² gauge pressure (about 0.8MPa) can meet the requirements. For glass plants that use natural gas as fuel, the pressure requirement of compressed air for furnace fuel injection is relatively low, and it is only 2kgf/cm² gauge pressure (about 0.2MPa) to reach the user. Therefore, an air compressor unit with a gas supply pressure of 3~3.5kgf/cm² gauge pressure (about 0.3~0.35MPa) can be configured.
- Flow: The flow demand depends on the scale of the production line and the process requirements. For example, a TFT-LCD glass substrate production line with an annual production capacity of 1 million pieces, the total gas demand of clean compressed air (CDA) is 120Nm & sup3;/min.
dryness
- moisture in compressed air can adversely affect pneumatic instrumentation, equipment and product quality in the glass production process. Therefore, the glass industry has higher requirements for the dryness of compressed air.
- Generally speaking, the pressure dew point of compressed air should reach -33 ℃ or even lower to ensure that the moisture content in the compressed air is extremely low. For example, in a TFT-LCD glass substrate production line, the pressure dew point of compressed air is required to be -33°C, and the corresponding humidity is 100 mg/m & sup3;.
Cleanliness
- the cleanliness requirements of the compressed air industry are also very high, because the dust particles, oil and other impurities in the compressed air will pollute the product or affect the normal operation of the production equipment.
- Cleanliness requirements usually include two indicators of dust particle diameter and dust content. For example, in a TFT-LCD glass substrate production line, compressed air is required to have a dust particle diameter of ≤ 0.3 μm and a dust content of ≤ 1000 particles/m & sup3;.
Temperature
- the temperature of the compressed air will also affect its use. Generally speaking, the glass industry requires the temperature of compressed air to be controlled within a certain range to ensure the stability of the production process and product quality.
- For example, in a TFT-LCD glass substrate production line, the temperature of the compressed air is required to be 25±5°C.
Other Requirements
- oil-free requirements: In order to ensure the purity of compressed air, the glass industry usually requires the use of oil-free compressors or compressed air that has been strictly filtered to avoid oil pollution to products and equipment.
- stable supply the glass production process requires high stability in the supply of compressed air, so it is necessary to configure sufficient air storage tanks and spare air compressors to ensure a continuous supply of compressed air in the event of equipment failure or maintenance.
