Glass
Praxair is a leading supplier of oxy-fuel technology and advanced oxygen supply systems to the glass industry. Oxy-fuel combustion, used as a replacement for air-based glass melting, reduces nitrogen oxide emissions to meet tightening regulations, while contributing to improved glass quality and increased productivity. The use of oxygen in furnace firings offers other benefits, including shorter furnace rebuild times and easier furnace maintenance. Together with our alliance partners, we have incorporated oxy-fuel combustion technology into more than 80 glass furnaces worldwide.
Gaseous helium is critical for producing optical fibers used in telecommunication cables, a key component of the information highway, which carries vast amounts of data. Praxair has extensive know-how in fluid dynamics and heat transfer, and the flow control of gases (and in the case of helium; supercritical fluids) and heat transfer are core technologies in our business. We use these technologies in the optical fiber manufacturing industry to assure a high purity flow of helium to our customers. We also assist them in maximizing their production capacity by modeling various optical fiber manufacturing unit operations and suggesting changes or modifications to customer equipment where our experience and expertise indicates it could be beneficial. In general, this approach results in a lower evaluated helium cost when viewed as the cost of helium per meter of fiber produced.
Industrial wastewater must be neutralized before being discharged to the environment. Carbon dioxide replaces harsher acids for the alkaline neutralization process. It's safer and cheaper than sulfuric-acid systems, improves controllability and there's less downtime and no labor to handle chemicals. It also is less corrosive, and easier to handle and store.
Whether your manufacturing processes require oxygen, nitrogen, argon, hydrogen, helium or rare gases, Praxair has the application technologies to help you improve your operating flexibility, efficiency, productivity, and product quality. Equally important, our technologies can help conserve power and reduce nitrogen oxide (Nox) emissions, in line with today's legislative requirements.
Whether your manufacturing processes require oxygen, nitrogen, argon, hydrogen, helium or rare gases, Praxair has the application technologies to help you improve your operating flexibility, efficiency, productivity, and product quality.
Oxygen
Praxair currently provides glassmakers oxygen, through VPSA and cryogenic supply systems, Praxair and its alliance partners have incorporated oxy-fuel combustion technology into glass furnaces worldwide.
Helium
Helium in its gaseous form is used to eliminate impurities and also functions as a heat transfer medium during the production of fiber optic strands. Helium also plays an essential role as a heat transfer fluid and inert carrier gas for applying performance coatings to glass substrates. For large users of helium, Praxair's innovative technology, utilizing pressure swing adsorption or membrane systems, can recover as much as 95 percent of the helium throughput.
Nitrogen
Nature's supply of nitrogen is abundant. With nearly four-fifths of air being nitrogen, it ranks as the most plentiful of all atmospheric gases. But it is nitrogen's versatility that makes it an ideal gas for several applications in glass manufacturing.
Since nitrogen is virtually inert, it is used to blanket furnace electrodes to reduce safety hazards and prevent oxidation. In float glass processing, nitrogen is used in combination with hydrogen as a protective atmosphere to prevent the tin bath from oxidizing.
Because nitrogen boils at -320.4° (-195.8°), it is perfectly suited for the cooling process essential to some glass manufacturing. For example, in making glass containers, liquid nitrogen is injected to cool blow air to temperatures between 50°(10°) and -11°(-30°). This provides the optimum cooling rates needed to simultaneously cool the inside and the outside of a container.
Cooling both surfaces simultaneously stabilizes the container more quickly without inducing excessive stresses in the glass. Quicker stabilization also means the next container can be formed more quickly, increasing production capacity. And, since the nitrogen quantity is controlled automatically, air temperatures remain constant around the clock, ensuring consistent quality, which helps improve the pack rate as well. No matter how you use nitrogen, Praxair has the know-how to ensure its best use in your glass operation.
Hydrogen
Hydrogen is used in the float glass process. An atmosphere of 5-10 percent hydrogen in nitrogen is used to blanket, and prevent from oxidizing, a tin bath. Molten glass flows from the furnace directly into the float bath. In the float bath, glass is floated onto a bath of molten tin (highly oxidizing). This process results in glass that has very low distortion and is used for automotive and architectural applications. Hydrogen reacts with oxygen (air) that diffuses into the float bath atmosphere and keeps the tin from reacting with oxygen. If it reacts with oxygen, tin forms an oxide that will cause flaws in the glass surface. Praxair supplies liquid hydrogen for this application at many float glass plants.
For highly sensitive flame polishing applications, hydrogen is the fuel.
Other Gases
Although not used as extensively as oxygen, nitrogen, and hydrogen, other gases are needed by glass manufacturers.
Argon and the rare gases krypton, xenon, and neon make lighting products such as bulbs possible, and they increase the R value in modern, energy-efficient glass windows. Thermopane windows are made with a space between the glass panes. As the window is manufactured the space between the panes is vacuumed out and back filled with argon or a mixture of argon and rare gases. These rare gases have a very low thermal conductivity which increases the R value of the window.
Silane is used for thin layer deposition on flat glass. These coated glasses exhibit superior solar radiation control and are a growing part of the architectural and automotive glass market.
Gaseous helium is critical for producing optical fibers used in telecommunication cables, a key component of the information highway, which carries vast amounts of data. Praxair has extensive know-how in fluid dynamics and heat transfer, and the flow control of gases (and in the case of helium; supercritical fluids) and heat transfer are core technologies in our business. We use these technologies in the optical fiber manufacturing industry to assure a high purity flow of helium to our customers. We also assist them in maximizing their production capacity by modeling various optical fiber manufacturing unit operations and suggesting changes or modifications to customer equipment where our experience and expertise indicates it could be beneficial. In general, this approach results in a lower evaluated helium cost when viewed as the cost of helium per meter of fiber produced.
Industrial wastewater must be neutralized before being discharged to the environment. Carbon dioxide replaces harsher acids for the alkaline neutralization process. It's safer and cheaper than sulfuric-acid systems, improves controllability and there's less downtime and no labor to handle chemicals. It also is less corrosive, and easier to handle and store.
Whether your manufacturing processes require oxygen, nitrogen, argon, hydrogen, helium or rare gases, Praxair has the application technologies to help you improve your operating flexibility, efficiency, productivity, and product quality. Equally important, our technologies can help conserve power and reduce nitrogen oxide (Nox) emissions, in line with today's legislative requirements.
| Applied Gases for Glass |
Whether your manufacturing processes require oxygen, nitrogen, argon, hydrogen, helium or rare gases, Praxair has the application technologies to help you improve your operating flexibility, efficiency, productivity, and product quality.
Oxygen
Praxair currently provides glassmakers oxygen, through VPSA and cryogenic supply systems, Praxair and its alliance partners have incorporated oxy-fuel combustion technology into glass furnaces worldwide.
Helium
Helium in its gaseous form is used to eliminate impurities and also functions as a heat transfer medium during the production of fiber optic strands. Helium also plays an essential role as a heat transfer fluid and inert carrier gas for applying performance coatings to glass substrates. For large users of helium, Praxair's innovative technology, utilizing pressure swing adsorption or membrane systems, can recover as much as 95 percent of the helium throughput.
Nitrogen
Nature's supply of nitrogen is abundant. With nearly four-fifths of air being nitrogen, it ranks as the most plentiful of all atmospheric gases. But it is nitrogen's versatility that makes it an ideal gas for several applications in glass manufacturing.
Since nitrogen is virtually inert, it is used to blanket furnace electrodes to reduce safety hazards and prevent oxidation. In float glass processing, nitrogen is used in combination with hydrogen as a protective atmosphere to prevent the tin bath from oxidizing.
Because nitrogen boils at -320.4° (-195.8°), it is perfectly suited for the cooling process essential to some glass manufacturing. For example, in making glass containers, liquid nitrogen is injected to cool blow air to temperatures between 50°(10°) and -11°(-30°). This provides the optimum cooling rates needed to simultaneously cool the inside and the outside of a container.
Cooling both surfaces simultaneously stabilizes the container more quickly without inducing excessive stresses in the glass. Quicker stabilization also means the next container can be formed more quickly, increasing production capacity. And, since the nitrogen quantity is controlled automatically, air temperatures remain constant around the clock, ensuring consistent quality, which helps improve the pack rate as well. No matter how you use nitrogen, Praxair has the know-how to ensure its best use in your glass operation.
Hydrogen
Hydrogen is used in the float glass process. An atmosphere of 5-10 percent hydrogen in nitrogen is used to blanket, and prevent from oxidizing, a tin bath. Molten glass flows from the furnace directly into the float bath. In the float bath, glass is floated onto a bath of molten tin (highly oxidizing). This process results in glass that has very low distortion and is used for automotive and architectural applications. Hydrogen reacts with oxygen (air) that diffuses into the float bath atmosphere and keeps the tin from reacting with oxygen. If it reacts with oxygen, tin forms an oxide that will cause flaws in the glass surface. Praxair supplies liquid hydrogen for this application at many float glass plants.
For highly sensitive flame polishing applications, hydrogen is the fuel.
Other Gases
Although not used as extensively as oxygen, nitrogen, and hydrogen, other gases are needed by glass manufacturers.
Argon and the rare gases krypton, xenon, and neon make lighting products such as bulbs possible, and they increase the R value in modern, energy-efficient glass windows. Thermopane windows are made with a space between the glass panes. As the window is manufactured the space between the panes is vacuumed out and back filled with argon or a mixture of argon and rare gases. These rare gases have a very low thermal conductivity which increases the R value of the window.
Silane is used for thin layer deposition on flat glass. These coated glasses exhibit superior solar radiation control and are a growing part of the architectural and automotive glass market.
