AU609750B2

AU609750B2 - Shaft seal device for a slurry pump

Info

Publication number: AU609750B2
Application number: AU81851/87A
Authority: AU
Inventors: Yoichi Ogata
Original assignee: Eagle Industry Co Ltd
Current assignee: Eagle Industry Co Ltd
Priority date: 1987-08-05
Filing date: 1987-11-27
Publication date: 1991-05-09
Anticipated expiration: 2007-11-27
Also published as: JPS6425569U; AU8185187A

Description

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AUSTRALIA

Patents Act COMPLETE SPECIFICATIO 9 7 5 0

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: SAccepted: Published: Priority amnendmnc;ts rn e i- r.

L 3La'uin iA is cur cct for printing t 9.

Related Art: APPLICANT'S REFERENCE: U-8721 S Name(s) of Applicant(s): Eagle Industry Co. Ltd.

Address(es) of Applicant(s): 6-15, Shibakoen 2-chome, Minato-ku, Tokyo,

JAPAN.

Address for Service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Complete Specification for the invention entitled: SHAFT SEAL DEVICE FOR A SLURRY PUMP Our Ref 72644 POF Code: 1342/66191 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 6003q/1 1 P18/7/78 PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne, Australia .iL1

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*Il ft (2 The present invention relates to an improvement in a shaft seal device mounted on a slurry pump which feeds under pressure a liquid containing a large amount of slurries.

As one example of a slurry pump used to pump up muddy water produced in mining ores for example or to transport muddy water in waste w;..ter disposal facilities, a slurry pump has been known in whaich as shown in Fig. 2, an impeller 3 is mounted on the en!- of a shaft 2 which extends from a driving source such as motor 1, and upon the rotational operation of the impeller 3, slurry liquids containing a large amount of bauxite, powdery coal, sediments or the like are fed under pressure. A mechanical seal 11 having a S function as a shaft seal device is provided in a boundary

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between an internal space 4 of pump on the side of the impeller 3 and an external space 5 of pump on the side of the motor 1 in order that said slurry liquids may not be flown from the periphery of the shaft 2 to the external space 5 of pump.

This mechanical seal indicated generally as at 11 has, 2 as shown in Fig. 3, a stationary-side seal ring 12 airtightly carried on the side of a pump housing 6 and a rotating-side seal ring 13 carried on the side of said shaft 2, both the seal rings 12 and 13 being axially disposed opposedly to each other to prevent a slurry liquid S present on the outside diameter side of said opposed portion from passing toward the inside diameter of said opposed portion.

More specifically, a flange 14 is airtightly secured to the inner peripheral portion of the pump housing 6, and a seal cover 16 is airtightly secured to the outer peripheral portion of the shaft 2 through a sleeve 15. The stationary-side seal ring 12 is fitted through a rubber spring 17 into an annular recess 14' formed in the opposed portion with respect to the seal cover 16 in the flange 14.

The rotating-side seal ring 13 is fitted through a rubber ring 18 into an annular recess 16' formed in the opposed portion with respect to the flange 14 in the seal cover 16.

The rubber springs 17 and 18 impart as a shaft sealing force a contact load between both the seal rings 12 and 13 as 39 needed, and the stationary-side rubber spring 17 has

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It projections 17a and 17b formed on the both ends thereof in a peripherally equally spaced relation, said projections engaging a notch formed in the annular recess 14' of the flange and a notch formed in the stationary-side seal ring 12 to effect locking of the seal ring 12 and also having a function as a packing for maintaining airtightness between the flange 14 and the seal ring 12. Likewise, the rotating-side rubber sleeve 18 has projections 18a and 18b provided on both ends thereof which engage a notch formed in an annular recess 18' of the seal cover and a notch formed in the rotating-side seal ring 13 to transmit torque from a S shaft 2 to the seal ring 13 and having a function as a S packing for maintaining airtightness between the seal cover

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16 and the seal ring 13.

A baffle sleeve 19 is loosely interposed coaxial with Sthe shaft 2 in a space between both the seals 12 and 13 and the sleeve 15, and one end thereof is fitted onto the inner peripheral end of the flange 14 integral with the pump housing 6. A quenching hole 20 having an opening at the f lower end thereof fronted on an outer peripheral space 21 of the baffle sleeve 19 is bored in the flange 14. The upper

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end of the quenching hole 20 is connected to an external water supply tank not shown through a pipeline, and water stored in the water supply tank flows down into the pipeline and the quenching hole 20 due to the potential energy thereof and passes through the outer peripheral space 21 of the baffle sleeve 19, during which heat generated as both the seal rings 12 and 13 slide is removed and lubrication of the sliding surfaces is effected, and then the water flows out into the external space 5 via the inner peripheral space 22 of the baffle sleeve 19.

However, in the slurry pump of the present invention, water from the water supply tank flows down into the quenching hole 20, rapidly flows through a flowpassage leading to the inner peripheral space 22 of the baffle sleeve without being fully moved round the sliding surface between both the seal rings 12 and 13, and finally is discharged outside. fo-kthe effect is small for 39 consumed amount of water, and in the case the pump is used f: 'i a:

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.44 5 *1i S ai S CSr in places where water is hard to secure such as inland areas, dry regions, etc., quenching water becomes insufficient, and therefore the service life of the shaft seal device was short.

In the light of the foregoing, an object of the present invention is to effectively effect quenching with a small amount of water.

According to the present invention there is provided a shaft seal device having a construction in which a stationary-side seal ring fitted through a rubber spring onto a flange secured to an inner peripheral portion of a slurry pump housing and a rotating-side seal ring fitted through a rubber spring onto a seal cover secured to an outer peripheral portion of a shaft which is rotatably inserted into said housing are disposed opposedly to each other, a baffle sleeve defining an inner and an outer peripheral space, is loosely interposed between both the seal rings and the shaft, with one end thereof secured on the side of the pump housing including said flange, a 20 quenching liquid passage fronting the outer peripheral space is tended through on the side of the pump housing including the flange to form a flowpassage which allows quenching liquid to flow down into the quenching liquid passage due to its potential energy and to escape outside from the outer peripheral space via the inner peripheral space, wherein spirals are formed on either the outer peripheral surface of the shaft or the outer peripheral surface of a shaft sleeve when fitted to the shaft or on the inner peripheral surface of said baffle sleeve radially 30 opposed thereto, said spirals having the effect to impede a flow of the quenching water flowing from the outer peripheral space of the baffle sleeve upon rotation of the shaft to generate pressure in a direction opposed to said flow of water.

Since the afprementioned spirals generate pressure in a direction of impeding a flow of quenching water, the flowpassage is filled with water to lubricate the sliding surface between both the seal rings and absorb sliding heat generated in the sliding surface, whereby an outflow amount -4rp~ 5 of water per unit time may be extremely reduced.

The following description refers in more detail to the various features of the shaft seal device of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the shaft seal device is illustrated in a preferred embodiment. It is to be understood that the shaft seal device of the present invention is not limited to the preferred embodiment as illustrated in the drawings.

Fig. 1 is a half sectional view showing the mounted state of a shaft seal device for a slurry pump according to c^t" one embodiment of the present invention; Fig. 2 is a sectional view of an essential part showing one example of a S slurry pump; and Fig. 3 is a half sectional view showing the S mounted state of a shaft seal device for a slurry pump according to prior art.

In the shaft seal device according to the present t invention, spirals 23 for effecting apparent motion in the S direction as indicated at arrow X upon rotation of the shaft -Q-i-n---ef-jrafejr n d i-ni eda^felarovTR are formed on the outer peripher 1 surface opposed to the baffle sleeve 19 of the sleeve 15 irtightly fitted in the outer peripheral t surface of the sh ft 2. Accordingly, the quenching water, which flows down *nto the quenching hole 20 from the S external water supply tank not shown, passes through the outer peripheral space 1 of the baffle sleeve and flows out into the external space 5\from the inner peripheral space 22 of the baffle sleeve, i impeded in its flow by pump pressure generated by the motion of the spirals 23, and therefore, a space 24 in the vicinity of the sliding surface of the inner peripheral portions'\of the seal rings 12 and 13 is fully filled with water from the quenching hole 20 to lubricate the sliding surface an effect heat exchange (cooling). Although water temperature is risen due to the heat absorption from the sliding surface, this water is not sealed off and therefore will not rise o a level above a i given boiling point (approximately 100 C) and has a satisfactory cooling action. The pitch, height and the like 39 ~f the s-p-i-r-a4-s- -2-3-a-re--swi-t-ably-set-i--eni atin of the ~L

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4 41 2 in the direction as indicated at arrow R are formed either on the outer peripheral surface opposed to the baffle sleeve 19 of the sleeve 15 airtightly fitted in the outer peripheral surface of the shaft 2 or the outer peripheral surface opposed to the baffle sleeve 19 of the shaft 2 when sleeve 15 is not fitved, or the surface of the baffle sleeve 19 which faces the shaft 2, or which faces the sleeve 15 when fitted to the shaft 2. Accordingly, the quenching liquid, which flows down into the quenching liquid passage 20 from the external water supply tank not shown, passes through the outer peripheral space 21 of the baffle sleeve and flows out into the external space 5 from the inner peripheral space 22 of the baffle sleeve, is impeded in its flow by pump pressure generated by the motion of the spirals 23, and therefore, a space 24 in the vicinity of the sliding surface of the inner peripheral portions of the seal rings 12 and 13 is fully filled with water from the quenching liquid passage 20 to lubricate the sliding surface and effect heat exchange (cooling).

20 Although water temperature is risen due to the heat absorption from the sliding surface, this water is not sealed off and therefore will not rise to a level above a given boiling point (approximately 100 C) and has a satisfactory cooling action. The pitch, height and the like of the spirals 23 are suitably set in consideration of the I _i j 6 number of revolutions of the shaft 2, the range of flow velocity of water from said water supply tank, and the like so as not to have their magnitudes enough to seal the outflow of water toward the external space 5 by the pump pressure caused by the rotation thereof. Water having cooled and lubricated the sliding surface is gradually discharged into the external space 5 from the outer peripheral space 21 of the baffle sleeve via and between the baffle sleeve 19 and the spirals 23, the space 22.

Accordingly, the slurry liquid S which slightly leaks from the internal space 4 of pump to the space in the inner periphery of the mechanical seal 11 will not cause the quenching water to be contaminated, resulting in the staying of the thus contaminated water.

In the shaft seal device for the slurry pump according SW." to the present invention, as described above, the quenching water is not consumed in a large quantity by the action of the spirals which controls the outflow of the quenching water. Thus, the device is useful in saving water and in 2 0' addition, the device can be used in inland areas and dry regions where water is hard to secure. Cooling and lubrication of the seal sliding surfaces may be performed satisfactorily, thus providing an excellent effect that the service life thereof may be extended.

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Claims

1. A shaft seal device having a construction in which a j stationary-side seal ring fitted through a rubber -pring onto a flange secured to an inner peripheral portion of a slurry pump housing and a rotating-side seal ring fitted through a rubber spring onto a seal cover secured to an outer peripheral portion of a shaft which is rotatably inserted into said housing are disposed opposedly to each other, a baffle sleeve defining an inner and an outer peripheral space, is loosely interposed between both the seal rings and the shaft, with one end thereof secured on the side of the pump housing including said flange, a quenching liquid passage fronting the outer peripheral space is extended through on the side of the pump housing C o including the flange to form a flowpassage which allows I quenching liquid to flow down into the quenching liquid passage due to its potential energy and to escape outside S c o° from the outer peripheral space via the inner peripheral c space, wherein spirals are formed on either the outer peripheral surface of the shaft or the outer peripheral o G surface of a shaft sleeve when fitted to the shaft or on the inner peripheral surface of said baffle sleeve radially opposed thereto, said spirals having the effect to impede a fcc cC flow of the quenching water flowing from the outer peripheral space of the baffle sleeve upon rotation of the shaft to generate pressure in a direction opposed to said flow of water.

2. A shaft seal device substantially as herein particularly described with reference to Figures 1 and 2 of 1 30 the accompanying drawings. t e DATED: 24 JANUARY, 1991 PHILLIPS ORMONDE FITZPATRICK Attorneys For: EAGLE INDUSTRY CO. LTD. 0080Z 7 '6 7 f s y i T