A producer and supplier of corrosion resistant piping systems was looking to improve the reliability and lower operating expenses of an existing air pollution control system at their facility. During their manufacturing process, centrifugally cast mortar pipe systems are reinforced with a fiberglass polymer. This makes the pipe ideally suited for most corrosive piping applications but also produces a significant amount of styrene emissions that need to be destroyed. Plant personnel knew that their existing 40,000 SCFM (64,200 Nm3/hr) fixed-bed concentrator and catalytic oxidizer could not handle future expansion plans and the decision was made to look for a replacement.
After speaking with several vendors, the Regenerative Thermal Oxidizer (RTO) was selected as the best available control technology. It not only far exceeded the 95% destruction efficiency required in their permit but also dramatically reduced operating costs. The pipe manufacturer then identified what qualifications they were looking for in a solution provider:
- Styrene Experience
- Proven Performance
- Stable Supplier
- Cost-Effective Equipment
- Turnkey Capabilities
Anguil was selected based on their ability to meet these equipment and supplier requirements.
Anguil’s engineering staff worked closely with the customer throughout the design and manufacturing processes to ensure that the system precisely met their requirements and expectations. An Anguil Model 500 RTO (50,000 SCFM, 80,250 Nm3/hr) was selected based on the process airflow concentrations, destruction rate requirements, and for its overall energy-efficient operation.
Special considerations were taken to deal with the particulate in the process stream. A 48-cartridge collector was put upstream of the oxidizer to collect fiberglass pieces that could clog the RTO. Once filtered, process gases with Volatile Organic Compound (VOC) contaminants enter the oxidizer through an inlet manifold. Dual disk poppet valves direct this gas into energy recovery chambers where the process gas is preheated, then progressively heated in the ceramic beds as they move toward the combustion chamber.
The VOCs are oxidized in the combustion chamber, releasing thermal energy in the structured ceramic media beds that are in the outlet flow direction from the combustion chamber. These outlet beds are heated and the gas is cooled so that the outlet gas temperature is only slightly higher than the process inlet temperature. Fasting acting, vertical poppet valves alternate the airflow direction into the ceramic beds to maximize energy recovery within the oxidizer. The VOC oxidation and high energy recovery within the oxidizer reduces the auxiliary fuel demands and operating costs. For example, at 95% thermal energy recovery, the outlet temperature may be only 70`F (40`C) higher than the inlet process gas temperature with an RTO. The oxidizer can reach self-sustaining operation with no auxiliary fuel usage at low concentrations.
Allen Bradley Programmable Logic Controllers (PLCs) control the automatic operation of the oxidizer from startup to shutdown, so minimal operator interface is required. These controls also provide for remote telemetry to enable the system’s operation to be viewed and altered via a modem connection to reduce maintenance costs.
The customer is achieving 98% destruction rate efficiency and the oxidizer is operating extremely efficiently at 95% thermal rate efficiency. Low operating costs and equipment reliability have resulted in another satisfied Anguil customer.