Hydraulic conveying of snow

II. Snow feeder to pipelines

Abstract

A swirl mixing type snow feeder has been studied to develop a hydraulic snow conveying system for urban use. The device consisted of a mixing tank equipped with turbine impeller and a centrifugal feed pump commonly used for slurry conveying. The performance was evaluated in terms of critical snow fraction (maximum fraction of snow attainable at a given mixing condition), power consumption for mixing, and snow fraction difference between the tank and the pipe. The effects of dimensions of feeder and operating conditions were also investigated. The optimum diameter ratio of the impeller to the tank is found to be about 2.5. The optimum slurry volume for a given impeller diameter, for example 0.1 m³ in volume for a 200 mm impeller diameter is found. The optimum rotation rate of the impeller was 600 rpm for all the experiments. The performance of the pump was also studied; the pumping head and efficiency decreased about 15% with a 20% increase of the snow fraction in the pipe. It was found that common slurry pumps are useful for snow feeding.