JPS6228570A - Cooling device for multistage mechanical seal - Google Patents

Abstract

PURPOSE:To cool the cooling liquid in each sealing ring by one cooler by allowing said cooler to be equipped with a passage for feeding and discharging an external cooling heat source and equipped with the heat exchangers in the equal number to the mechanical seals and connecting the inflow pipes and effluence pipes to these heat exchangers. CONSTITUTION:The inflow pipes 11a and 11b for introducing the cooling liquid for cooling the mechanical seals 9a and 9b into a sealing chamber 5 and the effluence pipes 12a and 12b are connection-opened onto a cylindrical wall 4, and the other edges are connected to the heat exchangers 10a and 10b. The circulation of cooling liquid between the heat exchangers 10a and 10b and the division chambers 5a and 5b in which the mechanical seals 9a and 9b are arranged is carried out by the auxiliary pumps 13a and 13b installed in the vicinity of the mechanical seals 9a and 9b, respectively. Further, the charge and discharge of an external cooling heat source to the cooler 10 are carried out through an effluence pipe 15 and an inflow passage 14 connection-opened to the cooler 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a cooling device for a mechanical seal.

[Background of the invention]

A mechanical seal for sealing a rotating shaft passing through a pressure vessel is disclosed in Japanese Patent Publication No. 49-9131, in which one sealing element rotates together with the shaft, and the other sealing element facing is fixed. These two sealing elements have a mating surface with one pressed against the other, and one sealing element rotates relative to the other sealing element. However, when sealing high-temperature, high-pressure hydraulic fluid under high-speed rotation conditions, a single-stage mechanical seal does not provide the desired sealing performance, so a system in which multiple mechanical seals are installed in series has been adopted. .

When a cooling device is provided in such a multi-stage mechanical seal, the number of coolers equal to the number of mechanical seals is provided externally, or a cooler is attached only to the mechanical seal that has the most severe usage conditions. However, the former method requires a plurality of coolers and requires a large space for installing the coolers. In addition, the latter method has problems such as insufficient cooling of the mechanical seal without a cooler, making it impossible to achieve the expected multi-stage sealing performance.

[Purpose of the invention]

The present invention was invented in view of the above-mentioned problems, and an object of the present invention is to provide a cooling device for a multi-stage mechanical seal that uses only one cooler and has sufficient cooling performance.

[Summary of the invention]

In order to achieve the above object, the present invention provides inflow and outflow pipes that open into the seal chamber corresponding to the seal rings of each mechanical seal, and combines mechanical seals and It has the feature that the same number of heat exchangers are built in, and the inflow and outflow pipes are respectively connected to the heat exchangers, and the cooling fluid of each seal ring of the multistage mechanical seal is cooled by one cooler.

[Embodiments of the invention]

An embodiment of the present invention will be described below based on FIG. 1
2 is the casing of the high-pressure pump, 2 is the impeller placed in the casing, and the 0-rotation shaft 3 is connected to the 1-rotation shaft 3.
The outer periphery of the casing is covered with a cylindrical wall 4 connected to the casing to form a seal chamber 5, and the one-rotation shaft 3 passes through the seal chamber 5 and extends to the outside. Two annular rotary seal rings 6 are protruded from the rotating shaft 3 at appropriate intervals, while a spring 7 fixed to the protruding wall 4a and the side wall 4b is attached to the cylindrical wall 4 side.
An annular fixed seal ring 8 is disposed, and this fixed seal ring 8 is arranged opposite to the rotary seal ring 6 and is in contact with the rotary seal ring 6 by the pressing force of a spring 7.

(The illustration shows an exaggerated gap.) The rotary seal ring 6 and the fixed seal ring 8 form a mechanical seal 9a.
, 9b are formed, and this embodiment shows a multi-stage mechanical seal having two mechanical seals. 1o is one cooler, and this cooler includes two heat exchangers 10a.

10b are arranged in parallel. The mechanical seal 9a,
Inflow pipes 11a and llb and an outflow pipe 12a for introducing the cooling liquid for cooling the seal chamber 5 into the seal chamber 5.

12b is connected to the cylindrical wall 4, and the other end is connected to the heat exchanger 1.
It is connected to 0a and 10b. Heat exchangers 10a, 10
b and mechanical seals 9a and 9b are arranged in the compartment 5.
The circulation of the cooling liquid with each mechanical seal 9a and 5b is
, 9b are installed in the vicinity of the auxiliary pumps 13a and 13b. In addition, an external cold source is supplied to and discharged from the cooler 10 through an inlet passage 14 which opens in contact with the cooler 10. Outflow passage 1
5. 14a indicates a pump. Seal chamber 5
The pressure in each compartment 5a, 5b within the orifice 16a,
Inlet pipes 17a, 17b with 16b interposed, orifice 1
The purge liquid discharged from the purge liquid pump 20 is supplied to and discharged from the respective compartments 5a and 5b through the outlet pipe 19 via the purge liquid pump 8, thereby controlling the pressure. In addition, as described above, the two mechanical seals 9a and 9b are cooled by the cooling liquid cooled by the cold heat source supplied from the outside by the cooler 10 via the heat exchangers 10a and 10b. llb to each compartment 5a, 5b, and auxiliary bumps 13a, 13.
b and the heat exchanger 10a again at the outlet pipes 12a, 12b,
It is returned to 10b and a cooling effect is performed.

As shown in FIG. 2, the structure of the above-mentioned cooler includes inlet passages 24 on the upper and lower end surfaces for supplying and discharging a cold source. Coiled heat exchange tubes 30a, 30 are installed in the cylindrical body 30 connecting the outflow passage 25.
b, and the heat exchange pipes 30a and 30b are inlet pipes 31a and 30b.
, 31b are connected to outflow pipes 32a, 32b, and the other ends of the inflow and outflow pipes are connected to the seal chamber 5 shown in FIG.

The cooling liquid in the seal chamber flows through inflow pipes 31a, 31b and outflow pipe 32a.
, 32b into the heat exchange tubes 30a, 30b, and is cooled by a cold heat source flowing outside the tubes.

FIG. 3 shows another embodiment of the cooler. This cooler is a shell and tube type cooler, with heat exchange tubes 41a and 44 placed between tube plates 42a and 42b disposed near both ends of the shell 40.
1b, and the interior of the cooler is divided into two by a partition plate 43, connecting inflow pipes 44a and 44b through which cooling liquid enters and exits, respectively, to form a chamber 45a.

The bath tube 47a communicates with the heat exchange tubes 41a and 41b through 45b, and through chambers 46a and 46b at the other end.

It communicates with 47b. The shell 40 also includes an inlet passage 48 for supplying and discharging a cold source. An outflow passage 49 is connected. The other ends of the inflow pipes 44a + 44b *outflow pipes 47a and 47b are connected to the seal chamber 5 in FIG. 1 and opened. The cooling liquid in the seal chamber flows through inflow pipes 44a, 44b,
It flows into the heat exchange tubes 41a, 41b via the outflow tubes 47a, 47b, and is cooled by the cold heat source flowing inside the shell 40.

Note that the cooler may have various other modified structures, and the present invention also includes these modified structures.

〔Effect of the invention〕

As explained above, according to the present invention, regenerative cooling of the cooling liquid for each mechanical seal unit that cools the multi-stage mechanical seal can be performed with one cooler, and the cooling device can be made smaller and lower in price. It has the effect that it can.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a multi-stage mechanical seal cooling device showing one embodiment of the present invention, Fig. 2 is a sectional view of a cooler showing another embodiment, and Fig. 3 is a diagram of a cooler showing still another embodiment. FIG. 5... Seal room, 5a, 5b... Separate room, 6...
- Rotating seal ring, 7... Spring, 8... Fixed seal ring, 10... Cooler, 10a, 10b - Heat exchange tube, 11a.

Claims (1)

[Scope of Claims] 1. A plurality of rotating seal rings installed at appropriate intervals on a rotating shaft passing through the seal chamber, and a plurality of stationary seal rings connected to each of the rotating seal rings facing each other. In a cooling device for a multi-stage mechanical seal, in which a multi-stage mechanical seal is formed and a cooling liquid is supplied to the seal chamber to lubricate and cool each mechanical seal, an opening is provided in the seal chamber corresponding to the seal ring of each mechanical seal. One cooler is equipped with inflow and outflow pipes for supplying and discharging an external cold source, and has the same number of heat exchangers as mechanical seals built-in, and each upstream inflow and outflow pipe is connected to this heat exchanger. A multi-stage mechanical seal cooling device featuring: 2. A cooling device for a multi-stage mechanical seal according to claim 1, wherein the seal chamber is provided with an auxiliary pump for inflowing and outflowing a cooling liquid. 3. The cooling device for a multi-stage mechanical seal according to claim 1, wherein an inlet and outlet pipe for supplying and discharging purge liquid is connected to the inflow and outflow pipes of the cooling liquid. 4. The cooling device for a multi-stage mechanical seal according to claim 3, wherein an orifice is interposed in the inlet and outlet pipes.