摘要 |
A method and system are provided for continuously conveying hard particulate material of non-uniform size, like coal. A high pressure transfer device has high and low pressure feed and discharge lines extending to and from it, and a screen arrangement for allowing liquid and fines to pass from the low pressure feed line to the low pressure discharge line, while stopping large particles. An excess accumulation of fines is prevented by providing a screen assembly vertically above the high pressure transfer device. Level control in a hopper-which provides the low pressure feed line-is accomplished merely utilizing an overflow technique. The concentration of particles in the liquid in the high pressure discharge line is maintained about 50% by withdrawing a portion of the liquid (while still under pressure) from the high pressure discharge line, and returning it to the high pressure feed line. A density measuring device downstream of the liquid withdrawal automatically controls the amount of liquid withdrawal. |