Abstract
In order to remove snow from an area where application of conventional techniques encounters difficulties, hydraulic conveying of the snow using a pump and pipe-line is beginning to be considered an alternative. However, instruments and engineering principles for such a technique are still to be developed. With this aim, the improvement of a water separator, a device to control snow fraction, was attained and consequently, investigations were conducted on its applicability as a gate valve for a snow/water mixture and on the mechanism of snow choking the channel. The water separator designed in this research was successfully applied to raise the snow fraction up to 40%, or to concentrate the mixture to make the snow fraction higher by a factor of 3. The mixing of granulated-snow did not increase the pressure drop at the gate valve and choking was avoided, providing that the ice blocks contained in the mixture, were not larger than the opening at the gate. The choking of the channel due to snow was classified into two categories and consequently, the relevant mechanisms for each of them were also clarified. These results provide useful engineering information on avoiding choking of the channel with snow, which is one of the greatest obstacles in the practical application of hydraulic covering of snow.
