An agricultural solutions company, American Peat Technology, transforms locally harvested unprocessed peat into a consistent granular media. The media is used as a natural microbial carrier to inoculate millions of acres of food crops each year. The transformation process relies on drying harvested material in industrial rotary dryers. A fraction of the material becomes entrained in the flue gas as particulate emissions. The facility is expanding operations to double the capacity. A scrubber solution is needed to reduce total plant particulate emissions.
The customer selected two identical Envitech horizontal Venturi scrubbers. The scrubbers are comprised of a variable throat Venturi scrubber and a chevron style entrainment separator mounted on an equipment skid. The scope of supply for each scrubber includes a control system, re-circulation pump with pre-assembled piping, valves and fittings. Instruments are pre-mounted in the piping where possible and pre-wired to a junction box on the skid. The horizontal configuration provides a compact design to fit inside the building with easy maintenance access to valves and instruments.
The skid arrangement allows the scrubbers to be shop assembled and tested prior to shipment. The combination of a variable throat Venturi with a chevron style mist eliminator allows a wide turn-down ratio while maintaining high performance. The use of a wet scrubber instead of a bag-house eliminates the potential for bag fires that could be caused by occasional hot embers entrained in the gas. The facility is also able to make use of the latent heat absorbed by the scrubber, making use of hot recirculated scrubber water to thaw out frozen peat in the winter before it is fed to the dryers.
The scrubbers were commissioned in December 2019 and are now operational. Both scrubbers are used for two dryers providing a wide operating range. The scrubbers meet the design parameters listed below:
- Inlet flow rate: 25,000 acfm
- Inlet temperature: 185oF
- Inlet Particulate: 15 lbs/hr
- Particulate Removal: > 99%
Click on the link below to download a case study and other Venturi scrubbing literature.