Double-flow type volute casing having structure for changing direction of flow in turbine inlet

A double-flow type volute casing having a structure for changing the direction of flow in a turbine inlet, the volute casing having a turbine formed therein, the volute casing constituting a volute casing comprising a volute inlet provided as a vertical section thereof and a volute provided as a curved section thereof, wherein

• an inner flow channel and an outer flow channel are partitioned from each other through a partition plate so as to extend from the volute inlet to the volute section,
• a ratio in sectional area of the inner flow channel to the outer flow channel, the inner flow channel and the outer flow channel corresponding to the volute inlet and the volute section, is 4:6, whereby a pressure of fluid flowing in the outer flow channel is greater than a pressure of fluid flowing in the inner flow channel and thus a flow rate in the outer flow channel is greater than a flow rate in the inner flow channel,
• a partition plate is formed so as to extend from the volute inlet to the volute, and a plurality of flow-rate adjustment holes is formed throughout a 180-degree section of the partition plate, assuming that a start point of a tongue section, which is a point at which the fluid is initially introduced, from a center of the turbine is 0 degrees,
• a plurality of guide vanes for applying the pressure of the fluid to turbine blades is provided along a curvature of the partition plate at positions deviating from the 180-degree section of the partition plate in the rotational direction of the turbine so as to be spaced apart from each other by a predetermined distance, and
• the pressure of the fluid in the outer flow channel is applied to the inner flow channel through the flow-rate adjustment holes, whereby a ratio of the flow rate in the inner flow channel to the flow rate in the outer flow channel is 5:5 at an end point of the 180-degree section of the partition plate.