The aromas from savory flavors are detectable even at low concentrations, and pose special challenges for companies who manufacture or use them.
Mastertaste, a Division of Kerry Group plc, is a leader in the development and production of savory flavors and blended seasonings. As part of a plant expansion, Mastertaste needed a system to eliminate odors from savory notes and essential oils to a level undetectable at the stack. The company sought advice from Andy Oiestad, owner of the design engineering firm Richmond Tech-Air, (Clark, N.J.), who recommended a packed tower odor control system developed by Tri-Mer Corporation.
Tri-Mer odor control systems are used by numerous manufacturers of seasonings blends, breading and cheese products. Among Tri-Mer’s odor control projects was a system installed at a processed foods company in the northwest. There, the odor control system achieved a “zero detection” rating in a boundary test done following installation of a Tri-Mer packed tower.
The Tri-Mer packed bed tower was engineered to scrub gases, odors and fumes, while consuming significantly less energy than “bubble cap” (sieve tray tower) or impingement baffle plate systems. This is due primarily to the substantially lower pressure drop realized by the Tri-Mer system.
Gas streams containing particulate are also a practical application for these systems: Tri-Mer odor control systems can be engineered to also handle particulate. Because many odors are detectable at 1 ppm or less, Tri-Mer odor control systems provide elimination efficiencies of 99% and higher regardless of the character – or concentration – of the loading.
Tri-Mer odor control system performance is based on intense gas/liquid mixing, low pressure drop, and a positive pressure design.
Individual odor control systems are usually configured based on four sets of process information. The first is air flow through the scrubber. Capacities of the Tri-Mer packed tower range to 150,000 cfm and larger; they can also be scaled for airflow down to 35 cfm.
A second set of considerations includes the choice of internal vs. external recirculation and fan, and their respective locations relative to the tower; duct sizes, inlet and outlet loadings, the location of pumps and access ports, and service platform requirements.
Construction of the scrubber column is UV white polypropylene or stainless steel. Removal efficiency targets – the final specification – are calculated as inlet vs. outlet requirement, based on mass emission as expressed in lbs./hr. incoming, and lbs./hr. outgoing.
Tri-Mer packed tower Industrial odor control systems are generally single-stage. Incoming odors contact, and are chemically oxidized, by a liquid sodium hypochlorite / caustic mixture. A pH of 8-12 is maintained to prevent free chlorine ions from being driven off by the air stream.
The tower uses Tri-Packs random dump packing media.
Tri-Packs provides maximum surface contact between the gas and the scrubbing liquid by facilitating continuous droplet formation. This promotes highest scrubbing efficiency.
The distinctive shaping of ribs, struts and drip rods gives Tri-Packs excellent wetting characteristics, and the ability to maintain uniform liquid distribution throughout the packed bed.
A 20,000 cfm packed tower was installed at a savory and essential oils line at Mastertaste. The tower serves four cookers, as well fugitive emissions from tank vents, weigh scales and other secondary emission points.
Boundary tests done following start-up, at full production, resulted in zero error detection at the stack. Mastertaste subsequently ordered an additional system, a 20,000 cfm packed tower. It will have dust collection ahead of odor control.