JPS6229601Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a back-pressure turbine in which a drain is formed in the rotary blade to more effectively remove leaked steam.

As is well known, in a steam turbine, a turbine shaft with an impeller and turbine blades attached is housed in a casing and rotates while being supported by a bearing outside the casing. To prevent steam leakage and air leakage, gaskets such as labyrinth gaskets are provided. in this case,
In a condensing turbine, leaked steam is sucked in from the outermost room of the casing by a gland ejector and converted into condensate, so there is relatively little leakage of steam into the atmosphere.However, back pressure is widely used in general factories. Turbines, which discharge steam at a pressure higher than atmospheric pressure and supply this steam to other equipment, do not have equipment such as a grand ejector, and there is a lot of leakage into the atmosphere. The water enters the inside of the bearing, which is installed close to the casing penetration part, and condenses, causing water to get mixed into the lubricating oil.
For this reason, conventionally, a disk-shaped water drainer is fixedly installed on the turbine shaft in front of the bearing to prevent steam from flowing toward the bearing. However, with this water drainer, a portion of the steam ejected along the turbine shaft comes into contact with the turbine shaft surface, turns into liquid vapor, and is blown outward from the circumferential surface of the disk by centrifugal force, but most of the steam is turned into gas. Since it remains as it is, it moves forward beyond the disk toward the bearing casing, and is sucked into the bearing by the rotation of the shaft.

On the other hand, this invention is such that the above-mentioned conventional drainer is formed on a rotary blade to forcefully disperse steam. In the figure,
1 is a turbine shaft, 2 is a casing, 3 is a bearing, 4 is a bearing casing, and 5 is a labyrinth packing provided where the turbine shaft passes through the casing. A disk-shaped rotary blade 6 is attached to the turbine shaft 1 at a portion between the casing 2 and the bearing casing 4 and close to the casing 2 via a mounting screw 7 . This rotating blade 6
In this case, one ridge 9 or a plurality of ridges 9 arranged radially are attached to the surface of the disc 8 facing the vehicle interior along the radius. Although the tip of this ridge 9 reaches the peripheral edge of the disk 8, the base end does not necessarily have to reach the turbine shaft 1 because the liquid vapor accumulates at the base end, as described above. In addition, if the degree of protrusion of the ridge 9 is too large, it will simply disturb the steam, so the disc 8
It only needs to be slightly raised above the surface, and is usually manufactured integrally with the disk 8.

This invention has the above-mentioned structure, and since the conventional simple disk-shaped water drainer is formed on the rotary blade 6 having ridges 9 along the radius on the plate surface of the disk 8, leakage from the passenger compartment penetration part is prevented. The ridges 9 apply centrifugal force to the steam blown onto the rotating blades by the same principle as in the runners of a rotary pump in fluid, and the steam is forcibly blown outward, thereby reducing the lubrication of the conventional bearing. Further, since this action is instantaneous, there is almost no heating of the rotating blade 6 itself, and conversely, since the rotating blade 6 acts as a cooling fin, the casing 2 The temperature of the portion of the bearing 3 that is heated due to the heat dissipation can be significantly reduced.

[Brief explanation of the drawing]

Figure 1 is a side view of the draining part of this invention, Figure 2
The figure is a front view of the rotating disk. In the figure, reference numerals 1 indicate a turbine shaft, 2 indicates a casing, 3 indicates a bearing, 4 indicates a bearing casing, 6 indicates a rotating blade, 8 indicates a disc, and 9 indicates a ridge.

Claims (1)

[Scope of utility model registration request] In the case where the turbine shaft 1 is provided with a disc-shaped water cutter located between the casing 2 penetration part and the bearing casing 4, the water cutter is located close to and opposite to the casing 2 penetration part of the disc 8. A water drain in a back pressure turbine, in which a ridge 9 extending from the outer periphery to the center near the center along the radius of a disk 8 is formed on a raised rotary blade 6 slightly protruding from the plate surface.