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Thermal Oxidizers (thermal + oxidizer)

Distribution by Scientific Domains
Engineering83%

Selected Abstracts

Selection of refractory for thermal oxidizers on gas streams containing fluorine

ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 2 2002
Stanley C. Che
Thermal oxidizers for destruction of fluorine-containing chemicals are typically operated between 1,100° to 1,400° C. Fluorine is converted to hydrogen fluoride (HF) during the combustion process. At high temperatures, HF will react with almost all materials. Proper selection of the refractory material used by the thermal oxidizer is essential for long-term use, and to protect the metal shell from corrosion. Selection criteria should include analysis of chemical composition, physical properties, morphology, and bonding phases. A high alumina brick from a thermal oxidizer was analyzed after it had been in service for one year. The brick surface underwent significant changes of its chemical and micro-structural compositions. Silica in the mullite phase had reacted with HF, leaving only corundum. In the inner part of the brick, both mullite and corundum crystals still existed. Refractory selection guidelines are suggested. [source]

The influence of rotary valve distribution systems on the energetic efficiency of regenerative thermal oxidizers (RTO)

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 1 2008
Mario Amelio
Abstract On,off valve systems, commonly used in regenerative thermal oxidizer (RTO) plants, generate, during the opening time, a mass flow rate (MFR) which is constant. On the contrary, rotary valve systems, which are increasingly adopted in RTO plants, are characterized by variable MFR profiles. In this work, the energy requirements of two RTO systems, equipped with on,off or rotary valves, were determined using a home-developed numerical code. Energy performances were evaluated by calculating the thermal efficiency and pressure drop within structured or random packed bed RTO systems, at the same mean MFR. The results demonstrated that thermal efficiency was only moderately influenced by the valve system, and is slightly lower for the RTO with on,off valve. On the other hand, the study revealed that energy requirements of all RTO systems were basically unaffected by cycle duration, allowing valve rotational velocity to be freely set to maximize for other technical requirements. On the contrary, pressure drop was greatly influenced by the valve type and increased as variability in MFR function augmented. Moreover, the type of regenerator, structured or random packed bed, affected differently the total energy requirements (basically pumping energy plus auxiliary fuel). Energy requirements of structured and random regenerators were comparable only when volatile organic compounds concentration was lower than typical values encountered in the industrial practise. In other cases, structured regenerators RTO were more competitive. Finally, structured regenerators are usually the best choice when rotating valve distribution systems are adopted. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Selection of refractory for thermal oxidizers on gas streams containing fluorine

ENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 2 2002
Stanley C. Che
Thermal oxidizers for destruction of fluorine-containing chemicals are typically operated between 1,100° to 1,400° C. Fluorine is converted to hydrogen fluoride (HF) during the combustion process. At high temperatures, HF will react with almost all materials. Proper selection of the refractory material used by the thermal oxidizer is essential for long-term use, and to protect the metal shell from corrosion. Selection criteria should include analysis of chemical composition, physical properties, morphology, and bonding phases. A high alumina brick from a thermal oxidizer was analyzed after it had been in service for one year. The brick surface underwent significant changes of its chemical and micro-structural compositions. Silica in the mullite phase had reacted with HF, leaving only corundum. In the inner part of the brick, both mullite and corundum crystals still existed. Refractory selection guidelines are suggested. [source]

The influence of rotary valve distribution systems on the energetic efficiency of regenerative thermal oxidizers (RTO)

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 1 2008
Mario Amelio
Abstract On,off valve systems, commonly used in regenerative thermal oxidizer (RTO) plants, generate, during the opening time, a mass flow rate (MFR) which is constant. On the contrary, rotary valve systems, which are increasingly adopted in RTO plants, are characterized by variable MFR profiles. In this work, the energy requirements of two RTO systems, equipped with on,off or rotary valves, were determined using a home-developed numerical code. Energy performances were evaluated by calculating the thermal efficiency and pressure drop within structured or random packed bed RTO systems, at the same mean MFR. The results demonstrated that thermal efficiency was only moderately influenced by the valve system, and is slightly lower for the RTO with on,off valve. On the other hand, the study revealed that energy requirements of all RTO systems were basically unaffected by cycle duration, allowing valve rotational velocity to be freely set to maximize for other technical requirements. On the contrary, pressure drop was greatly influenced by the valve type and increased as variability in MFR function augmented. Moreover, the type of regenerator, structured or random packed bed, affected differently the total energy requirements (basically pumping energy plus auxiliary fuel). Energy requirements of structured and random regenerators were comparable only when volatile organic compounds concentration was lower than typical values encountered in the industrial practise. In other cases, structured regenerators RTO were more competitive. Finally, structured regenerators are usually the best choice when rotating valve distribution systems are adopted. Copyright © 2007 John Wiley & Sons, Ltd. [source]

When you cut down a tree, keep an eye on the forest

PROCESS SAFETY PROGRESS, Issue 1 2000
Stanley E. Anderson
Since the EPA began mandating controls on atmospheric discharges of organic materials, there have been a number of fires, explosions and other types of incidents of varying significance involving the emissions control devices. While these kinds of repetitive incidents are common throughout the industry, this paper discusses a number of incidents in one corporation, including thermal oxidizers, flares, and charcoal beds. We then discuss the common causes that seem to rise up to catch the operators of such devices unaware in spite of the history. Reasons why these avoidable incidents keep repeating are also explored. [source]