One of the largest U.S. dairy farm operations in the Pacific Northwest recently contacted Mitchell Lewis & Staver to help them resolve ongoing pump maintenance problems and pump failures at their dairy’s methane digester installation. The farm’s innovative methane digester reduces greenhouse gas emissions by converting dairy waste into fuel.
Collecting the methane gas from the manure and using the fuel at the dairy is a key goal of the farm’s sustainable farming practices. The manure collected from the dairy’s flushing systems is stored in agitated in-ground holding tanks. The original installation employed above ground, self-priming horizontal end suction process pumps that transferred the manure to the digesters. Due to the very high suction lift conditions coupled with a high temperature fluid, the transfer pumps were subject to constant cavitation and all of the associated problems such as limited parts wear life, excessive downtime, vibration and noise. The inability of the horizontal pumps to pick up the solids from the bottom of the tank also meant that the holding tanks required periodic cleaning with vacuum trucks every 30 days.
After evaluating the available options, an 8” Series TBM 200LH-PBO submersible pump from Polaris Pumps was selected to be installed in the tank. The pump was started and gradually lowered into the slurry and accumulated solids until it came to rest at the bottom of the now cleaned out holding tank. The original horizontal pumps had an average run time of 2 weeks or less whereas the TBM 200LH submersible has now been operating continuously for the last 14 weeks of the initial 100 day trial period without any diminished performance or downtime.
This is just one of many examples where the joint efforts between Mitchell Lewis, our manufacturers and the end user produce innovative solutions to solve pump maintenance and process problems.