JPS60178998A - Wear ring fixing device for high temperature pump - Google Patents

Abstract

PURPOSE:To maintain a wear ring concentric with the casing at anytime by employing an oval chip having a parallel section in place of a circular chip when fixing a wear ring of high temperature pump. CONSTITUTION:A wear ring 2 is fixed through a micro gap 5 to the casing 1 facing with an impeller 3 of high temperature pump, where the fixing means of wear ring 2 to the casing 1 are the rectangular boards 4a, 4b. Upon temperature rise of pump, rattling will occur at the matching face because of different linear expansion factors of wear ring 2 and casing 1, but the rattling is restricted by the boards 4a, 4b respectively in the up/down direction and the horizontal direction to uniform the gap. Consequently, even upon occurrence of rattling, the wear ring 2 can be maintained concentric with the casing 1.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a pump that uses high-temperature handling liquid, and the casing and wear ring, which are made of members with different coefficients of linear expansion, can be used even if the temperature rises. Concerning pumps in which the wear ring must remain concentric with the casing at all times.

[Background of the invention]

A conventional pump structure will be explained with reference to FIG.

This type of pump is used in nuclear power plants.
The handling liquid is 2850 yen, which is expensive.

The pump takes in the liquid from the front of the casing 1, pressurizes it with the impeller 3, and then discharges it to the outside. A wear ring 2 is attached to the casing 1 between the impeller 3 and the casing 1 so as to form a small gap 5 with the impeller 3 so that the pressurized handling liquid does not return to the impeller 3. There is. As shown in FIG. 2, the wear ring 2 has circular plates 4 attached at four locations around its circumference so that it does not come out from the casing 1.

The material of the casing 1 is austenitic stainless steel in consideration of corrosion resistance since the handling liquid is high temperature, and the wear ring 2 is made of precipitation hardened stainless steel in consideration of sliding resistance. are doing. In this case, the linear expansion coefficient of each member is casing...17.3X 10-
'/C Wearing...i i, a x i
Since the mounting diameter of wear ring 2 is 170 mm at o'''/C, the difference in linear expansion coefficient (17,3X10-6
-11.3X10'4)X170rrRX285tl:
' = 0.29m backlash 6 will be added.

Therefore, in this structure, the minute gap 5 is usually a radius gap of 0.25 to 0.30, and the wear ring (2) falls down due to the backlash 6 that occurs in the wear ring 2, as shown in FIG. There is a good possibility that the impeller 3 and the wear ring 2 will come into contact with each other.

[Purpose of the invention]

An object of the present invention is to maintain the wear ring concentrically with the casing even if the linear expansion coefficients of the casing and the wear ring are different.

[Summary of the invention]

By changing the fixation of the wear ring from a circular piece to an oblong piece with parallel sections, the wear ring is always kept concentric with the casing.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5. The handling liquid that has flowed in from the front of the casing 1 is pressurized by the impeller 3 and then discharged.

The wear ring 2 is attached to the casing 1 and is attached to the impeller 3 to prevent the handling liquid from leaking onto the front surface of the impeller 3.
It has a minute gap 5. The means for fixing the wear ring 2 to the casing 1 is rectangular plates 4a arranged evenly as shown in FIG.

The rectangular plate is welded to the casing 1. When the pump reaches a high temperature, play 6 occurs at the mating surfaces of the wear ring 2 and the casing 1, which have different coefficients of linear expansion. According to this embodiment, the backlash 6 generated in the casing 1 and the wear ring 2 is eliminated by restraining the wear ring 2 in the vertical direction by the two plates 4b, thereby making the vertical clearance even. Furthermore, the horizontal restraint of the wear ring 2 is performed by two plates 4b, so that the horizontal clearance becomes uniform. As described above, the rectangular plates 4a and 4b allow the wear ring 2 to be maintained concentrically with respect to the casing 1 even if backlash 6 occurs.

〔Effect of the invention〕

According to the present invention, since the wear ring can always be kept concentric with the casing, it is effective in preventing a gap from occurring between the two. For example, even if the wear ring and the casing are made of the same material, if the temperature of the pump is decreasing, the wear ring tends to cool down first, so this is effective in this case.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the main parts of a conventional high temperature pump, Figures 2 and 3 are
The figure is a sectional view taken along A-A in Fig. 1, Fig. 2 is a state diagram at low temperature, Fig. 3 is a state diagram at high temperature, and Figs. 4 and 5 are equivalent to A-A cross section in Fig. 1. In the figures, FIG. 4 is a state diagram at low temperatures, and FIG. 5 is a state diagram at high temperatures. 1...Casing, 2...Wear ring, 3...
Impeller, 4.4a, 4b...Mounting plate, 5...Small gap. Agent Patent Attorney Akio Takahashi Figure 1

Claims (1)

[Claims] In a high-temperature pump in which a wear ring is inserted between the inlet of the pump casing and the outer periphery of the impeller facing the opposite side, four rectangular knock pins are fixed evenly along the inner circumference of the pump casing inlet. A wear ring mounting device for a high temperature pump, characterized in that the wear ring is installed by providing a notch on the outer periphery of the wear ring so that the wear ring fits together, and the wear ring is arranged so as to always maintain concentricity with the pump casing.