Regenerative Thermal Oxidizer lowers bad environmental impact
The new environmental goals and directives by the EU, require constant renewal of permits on the grounds of not only technological changes, but also legislative amendments that were encouraged by the latest advancements in technology. Limitations for allowed air emissions and waste water discharges from individual industries are set out in special regulations sector that determine the limitations and rules of management in line with the latest, most advanced techniques available. That said, these provisions of regulations are not limited to devices with a nominal production capacity above the threshold set forth in the directive, but apply to all devices in the particular industries, regardless of their size.
A Thermal Oxidizer (also known as thermal incinerator and often referred to as a direct fired oxidizer or afterburner) is a process unit for air pollution control that decomposes hazardous gases like hydrocarbons, volatile organic compounds (VOC), Hydrogen Sulphide as well as smoke particles and odour. They are used in many chemical plants that decompose hazardous gases at a high temperature and release them into the atmosphere. One of the most popular types is the regenerative thermal oxidizer.
As we already mentioned above, the thermal oxidizers are typically used to destroy hazardous air pollutants and volatile organic compounds from industrial air streams. The pollutants that we are talking about are generally hydrocarbon based and when destroyed via thermal combustion, chemically oxidized to form CO2 and H2O.
The three main factors in designing effective thermal oxidizers are temperature, residence time, and turbulence. The temperature needs to be high enough to ignite the waste gas, as most of the organic compounds ignite at the temperature between 590 °C (1,094 °F) and 650 °C (1,202 °F). To ensure near destruction of hazardous gases, most basic oxidizers are operated at much higher temperature levels. If we use catalyst, the operating temperature range may be lower. The necessity of residence time means that we need certain amount of time to ensure that combustion reaction is going to occur. The turbulence factor is determined by the proportions of the combustion air and the hazardous gases mixture.
One of today's most widely accepted air pollution control technologies across all industry is a regenerative thermal oxidizer, commonly referred to as RTO. Regeneration takes place as part of consecutive cycles, or thermal processes in the ceramic bed (that has an excellent ability to conserve heat and relatively small resistance), heated from a previous oxidation cycle, to preheat and partially oxidize the input gases. The preheated gases enter a combustion chamber, heated by an external fuel source to reach the target oxidation temperature in the range between 760 °C and 820 °C. The final temperature that is needed for some applications that require maximum destruction, may be as high as 1,100 °C.
The air flow rates are 2.4 to 240 standard cubic meters per second. The heating process is followed by the cleaning process when (with some help of a small amount of treated gases) the untreated gases are sucked out of the ceramics, which is now prepared for the cooling process. The operating rhythm is cyclical, which means that there is always one cleaning, one cooling, and one heating process occurring in the device. Each of the three channels includes three flaps (essential for the cycle), that open to individual chambers with ceramic fillers. A device like RTO oxidiser is very limited by its flaps, as they need to move quickly and be tightly spaced.
RTOs are very versatile and extremely efficient. They can achieve thermal efficiency up to 95%. We regularly use them for rendering operations, abating solvent fumes, odours, eliminating VOC-related odours from process air, purifying vapours from cookers and dryers in rendering plants, treatment of non-condensable gases coming from vapours condensation etc., and are suitable for application in a wide range of industries. Regenerative Thermal Oxidizers are ideal in a range of low to high volatile organic compound concentrations, up to 10 g/m3 solvent. On the market there are currently many types of RTOs with the capability of 99.5+ % Volatile organic compound (VOC) oxidization or destruction efficiency. The ceramic heat exchangers in the towers can be designed for thermal efficiencies as high as 97+%.
RTO thermal oxidizer by Procesni Inženiring
Procesni Inženiring started its operation in 1990. They evolved from a company that dealt with area of gas installations and stations, into a successful company that is providing upgrades and replacements for existing industrial oven heating systems, yet at the same time manufacturing its own complex products like ovens, furnaces and air cleaning devices, that can be completely tailored to suit any particular need.
The company’s vision is to become the most widely-known brand dealing with upgrades and solutions of technological processes, and place themselves among the best thermal oxidizer manufacturers in the EU area.