Using mass flow in oxygen concentrators for glass production

Using mass flow in oxygen concentrators for glass production

Designing oxygen concentrators for glass aid in applications ranging ranging from manufacturing chemically hardened glass to drawing fiber optic cables. These oxygen concentration systems can adsorb pressure swings, allowing manufacturers to replace oxygen cylinders or dewars, which are more expensive and potentially dangerous.

Pressure swing adsorption systems work by passing air through an adsorbent bed at a high pressure, followed by desorption of nitrogen at lower pressure. Many of these systems include Alicat Whisper-Series low pressure drop mass flow controllers and/or bidirectional mass flow controllers, enabling the systems to operate at very low pressures (typically less than 10 PSIG) and to rapidly switch between high-pressure adsorption and low-pressure desorption (typically in less than 30 ms).

Oxygen concentrators improve process efficiency

Efficiency is key in modern glass manufacturing, where hundreds of millions of kilometers of optical fibers are drawn each year for applications ranging from specialty medical lasers to building the infrastructure to support 5G communication. Oxygen concentrators act as oxidizers which can generate high-temperature flames without the presence of nitrogen, which would absorb the heat.

Melting & shaping glass

Unlike water, glass has no melting or freezing point. Instead, melting constitutes a transition from a stiff solid into a viscous mass.  During conventional glass manufacturing, the glass shaping process begins with a melted gob of glass dropped into a blank mold. In the blow and blow method of glass shaping, air is precisely delivered into the system by a mass flow controller in order to properly shape and transfer the molten glass material.

High-temperature flames are critical here, as most types of glass can only be melted or shaped at temperatures of 1400-1600 °C (2500-2900 °F). Oxygen concentrators therefore allow for simultaneous finer process control and lowered fuel costs.

Manufacturing optical fiber

Producing optical fibers requires specialized glass lathes, specific dopants, and precisely-controlled burners in order to create a preform with the desired characteristics. Mass flow control plays an end-to-end role both preform manufacturing and the production of fiber optic cables.

Industrial-scale oxygen concentrator systems typically operate at less than 10 PSIG, with requirements for high accuracy. Instruments that can accurately control flows at these low pressures, without introducing an impactful pressure drop, are necessary to automate process control in these instances.

Further, bidirectional flow controllers can consolidate high- and low-pressure lines for adsorption and desorption into a single flow devices. When using Alicat mass flow controllers, this effect is particularly powerful given the 0.01-100% control range of the devices mean that low-, medium-, and high-flow processes can all be consolidated into fewer flow lines.

Finally, the ability to easily change between controlling different gases or mixtures without compromising accuracy or requiring recalibration enables in-field process control based on the results of external analyzers.

Customization to your process

Alicat mass flow and pressure devices focus on customization. We design instruments specifically to your glass manufacturing process and with your choice of control system (analog, digital, EtherNet/IP, Profibus, or another protocol). The standup interface display provides a simple means of process monitoring and preventative maintenance. Our goal is to tailor your devices to let your oxygen concentrator glass system operate at peak efficiency.

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