JPS581603Y2 - Low pressure turbine atmospheric release valve - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a structure for extending the life of the atmosphere release lead plate of the atmosphere release valve of a low pressure turbine.

When the internal steam pressure in the low-pressure turbine exhaust chamber rises above the maximum safe value, the low-pressure turbine casing is designed to automatically vent any residual steam to the atmosphere to prevent the low-pressure turbine casing from rupturing due to the internal pressure. The atmosphere release valve shown in Figure 1 is installed on the exhaust side of the upper half.

In this atmospheric release valve, external atmospheric pressure is supported by a thin floating disk 4, and a lead plate 5 is placed on top of the floating disk 4 between the holding plate 2 and the seat plate 3 with a stud bolt 7. and is tightened by a tightening nut 8.

If the exhaust pressure rises above a predetermined point (usually around 400 rnr/L of mercury), the floating disk 4 will push the lead plate 5. It is cut circumferentially in between and extruded outward.

When this lead plate 5 is broken, the exhaust pressure of the turbine decreases.

The low pressure turbine casing 6 allows the torrential steam to flow upward,
The protection plate 1 prevents the lead plate 5 and the floating disk 4 from scattering.

In a turbine that is normally operated under a constant load, the floating disc 4 and the lead plate 5 are relatively stable, with little variation in the degree of vacuum or temperature difference. In a prime mover that repeatedly stops, increases load, and decreases, the portion of the lead plate 5 that is responsible for cutting may become distorted and wrinkled, and the cut may break due to repeated stress before the load actually increases.

The present invention was developed in view of the above-mentioned drawbacks of the conventional example, and in order to extend the life of the lead plate 5 as much as possible when the turbine starts and stops, repeated stress on the corner portions of the lead plate 5 and the floating disk 4 is avoided. Therefore, the purpose is to provide a bulge, that is, an expansion part 9, on the lead plate 5 at a position corresponding to the peripheral edge of the floating disk 4, thereby preventing damage to the lead plate 5 and extending its life.

Next, a preferred embodiment of the present invention will be described in detail with reference to FIG.

In FIG. 2, the lid of the valve chamber communicating with the low-pressure turbine exhaust chamber has a floating disk 4 and a lead plate 5 that presses the floating disk 4 as its main members.

The floating disk 4 is preferably approximately 16r/1 so as not to be distorted.
The thickness is r/L, and the peripheral edge is an annular seat plate 3.
It is placed on the inner notch.

The lead plate 5 that presses down the floating disc 4 has an annular bulge or expansion part 9 formed at a position exactly corresponding to the peripheral edge of the disc 4, and has a thickness of 1. □Mi lead plate 5
The peripheral edge of the expansion part 9 is held down by a holding plate 2 having an inner diameter larger than the diameter of the expansion part 9.

The holding plate 2 and the seat plate 3 are fixed to the passenger compartment 6 in this state with stud bolts 7 and tightening nuts 8.

With this configuration, in this low-pressure turbine atmospheric release valve, when the vacuum disappears from the vacuum state and the turbine internal pressure reaches +0.2 kg/crn 2 V, the floating disk 4 pops out and the lead is released. Break the plate 5 to release the internal pressure.

At this time, the destroyed disk 4 and lead plate 5 are prevented from scattering due to the presence of the protective plate 1.

When a vacuum exists in the low pressure turbine casing 6, the floating disk 4 is in close contact with the seat plate 3, and the lead plate 5 is also in close contact with the floating disk 4.

When the vacuum disappears, the floating disk 4 simply rests on the seat plate 3 due to its own weight and inevitably floats.

In addition, due to temperature differences, it is easier to hang the ring in a floating direction,
Corners tend to be affected.

According to the present invention, in order to prevent the floating disk 4 at the corner portion from floating, an expansion section 9 is provided on the lead plate 5, so there is a space, so that the floating disk 4 may float to some extent or the lead plate 5 may float.
Even if the lead plate 5 shrinks, it can escape through the expansion part 9, and damage to the lead plate 5 can be prevented.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional atmosphere release valve for a low pressure turbine, and FIG. 2 is a sectional view showing the configuration of an atmosphere release valve according to the present invention. 1... Protective plate, 2... Holding plate, 3... Seat plate, 4...
・・Floating disk, 5・Lead plate, 6・Low pressure turbine casing, 7・Inset bolt, 8・Tightening nut, 9・・
・Expansion section.

Claims (1)

[Scope of utility model registration request] The lid of the valve chamber that communicates with the low-pressure turbine exhaust chamber is formed of a floating disk and a soft plate that presses the floating disk, and an expansion that extends in the circumferential direction of the soft plate corresponds to the edge of the floating disk. 1. An atmospheric release valve for a low-pressure turbine, characterized in that an outlet is provided and a protection plate is disposed on the outside of the lid.