Large Pipe-Cleaning System Tackles Nashville Challenge

By Jeff Griffin, Senior Editor | November 2012, Vol. 67, No. 11

Keeping sanitary sewer lines clear by regular cleaning is an important element in ongoing sewer system maintenance.

A variety of proven cleaning methods are available for pipes in diameters to 36 inches, but none are generally effective for very-large collectors. Pipe 36-inches and larger requires a totally different process for cleaning, said Joe Schotthoefer, vice president of operations, Doetsch Environmental Services, Warren, MI.

Conventional cleaning equipment is very effective for smaller sewer lines, he continues. But as the pipe graduates to larger diameter sizes, cleaning objectives can be insurmountable using traditional cleaning methods because of increased pipe flow, increased debris levels, increased pipe lengths and increased manhole depths.

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“There is more water and subsequent flow in large diameter pipes,” said Schotthoefer. “Debris quantities are much greater in large-diameter pipes, and suspended materials do not magically stop at the extraction point -- effective and efficient methods must remove them on a continuing basis. The types of debris found in larger pipes also are larger, and can vary from standard grit to small to large rocks, concrete pieces, bricks, construction debris, car parts, bicycles, rags, logs and hardened debris that is adhered to the pipe.”

Special cleaning technology

Doetsch Environmental Services has developed technology and specialized equipment specifically to effectively clean large-diameter sewer pipes. The entire process can be utilized in live sewer conditions, without the need for bypass pumping.

During the Doetsch process, wastewater and debris are vacuumed, separated and transported to a disposal facility. The water is filtered several times and then used as jetting water.

The equipment consists of two major components: a Grand Volumetric Recycler and the Hyjector.

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“The Grand Volumetric Recycler extracts debris and water, separates the debris and acts as primary filtration for the water,” explained Schotthoefer. “Water is then pumped to the Hyjector where it is final-filtered, pressurized and sent through the hose reel to the cleaning head. The cleaning head is then propelled through the pipe to a pre-determined point and retracted.”

The method can clean pipe in lengths to 6,000 feet.

Nashville project
A project to clean approximately 9,000 feet of 72-inch diameter pipe in Nashville, TN, provides a good example of the Doetsch method’s capabilities.