DE7430262U - Shaft seal for upright cylindrical mixing tanks - Google Patents

Description

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RHEINSTAHL Kassel, September 5, 197 ^ Joint stock company PSRP / Fr / P

PK 2752

Shaft seal for upright cylindrical mixing tanks

The innovation concerns a shaft seal for upright cylindrical mixing containers for powdery, granular, pasty or liquid material, with a vertical drive shaft for the bottom side that passes through the bottom of the container arranged mixing tools and several superimposed radial sealing rings, in front of which to A gap seal is located inside the container as a compression.

Such shaft covers should face the mixing container both when the drive shaft is running and when the drive shaft is at a standstill seal the drive shaft through the bottom of the container. While with the drive shaft running, the Pre-seal directed towards the interior of the container in the form of gap seals the risk of direct contact between the Mixture and the sealing lip of the upper radial sealing ring is significantly reduced, this contact can be with the stationary Drive shaft in known shaft seals with a gap seal arranged near the bottom of the mixing container Do not avoid pre-sealing. When the drive shaft is stationary, the short gap lengths are not sufficient to allow Liquid mix or cleaning fluids or the penetration of the smallest particles, e.g. when filling the mixing container to prevent with powdery material. Once material has penetrated it will sooner or later reach the sealing lip of the upper radial cicb / Lring and leads to damage there.

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A self-cleaning of the column of material that has penetrated when the drive shaft is at a standstill does not take place because the vertical column of the pre-seal when the drive shaft is running do not have any conveying effect to the outside. Therefore, the innovation is based on the task of designing a shaft seal of the type mentioned at the beginning, that prevents mixed material from passing through from the container interior to the upper radial sealing ring when the drive shaft is stationary and a cleaning of the sealing gap of the pre-seal can be achieved while the drive shaft is running.

This object is achieved according to the invention in that the radial sealing rings in three groups one above the other in one two tubular, flanged, centered one inside the other and with the upper planar surface flush with the floor surface then fastened in a recess in the bottom of the tank with screws passed through the flanges Housing parts existing housing are arranged, the upper housing part protrudes beyond the container bottom and the top Outer surface has the outer surface of a truncated cone tapering upwards and together with the surface of the conical Free rotation in the upwardly elongated hub of the mixing tool arranged on the bottom side creates a movement from top to bottom in the Outside diameter and in the gap width enlarging annular gap forms, at the bottom between the flat container bottom and the underside of the mixing tool arranged at the bottom, which rises slightly towards the outside, is joined by a sealing gap, whose gap width increases from the inside to the outside.

In order to be able to clean the sealing gap of solidified mix, a further development of the innovations provides that an opening for the supply of a flushing liquid is arranged in the upper housing part between the upper and the middle group of radial sealing rings, the sealing lips of which are all directed upwards. .

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In order to prevent the flushing liquid from escaping downwards and at the same time to make the shaft seal suitable for vacuum operation in the mixing container, it is also provided that between the middle group of radial sealing rings, whose sealing lips are directed upwards, and the lower group of radial sealing rings, whose sealing lips are directed upwards directed downwards, a fat chamber is arranged.

In order to prevent flushing liquid from escaping along the vertical drive shaft, it is also provided that the im Area of the radial sealing rings on the vertical drive shaft fastened liners with elastic seals against the Drive shaft are sealed.

To protect the bearing of the vertical drive shaft against the ingress of mixed material or rinsing liquid in the event of a leak the shaft seal as a result of wear is finally provided that below the liners on the vertical Drive shaft a Schleudertellei is attached, which of a is surrounded upwardly open channel with a bottom pipe connection.

An embodiment of the innovation is shown in the drawing and is described in more detail below.

In a recess in the container bottom 1, the tubular housing parts 2 and 3 are fastened with their flanges by screws k. The flanges of the housing parts 2 and 3 are secured in their position relative to one another by a centering 5. In the upper housing part 3, the upper group A and the middle group B, in the lower housing part 2, the lower group C of radial sealing rings are arranged, the sealing lips of which in groups A and B point upwards, in group C downwards and on the vertical drive shaft 10 tightly mounted liners 6a and 6b run.

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In the upper group A there are three, in the middle group B and the lower group C there are two radial sealing rings. The upper housing part 3 with the groups A and S of the radial sealing rings is flush with the upper side of its flange with the upper side of the container body 1 and protrudes with its free end over the container base J upwards. The outer surface of the upper housing part 3 protruding beyond the container bottom 1 has the shape of the lateral surface of a truncated cone that tapers upward. The upwardly elongated hub 11a of the mixing tool 11 arranged at the bottom has a conical free rotation on the inside. The inclinations of the upwardly tapered housing part and the conical free rotation in the raised hub 11a are selected so that the gap width S of the annular gap, which increases in outer diameter from top to bottom, increases from top to bottom. The underside of the bottom-side tool 11a rises slightly towards the outside and, together with the flat container base or with the top of the flange of the upper housing part 3 that is flush with the container base, forms a sealing gap, the gap width T of which increases from the inside to the outside. From the interior of the container to the upper radial seal of the upper Gi-Upe A, two consecutive and narrowing sealing gaps are thus formed, the gap length of which is significantly greater than the gap length in known gap seals with vertical and horizontal sealing gaps. The material flowing into the sealing gaps when the mixing container is filled with the drive shaft at a standstill builds up as a result of the narrowing of the gap, even after a shallow penetration depth, even from. the air cushion remaining in the still free sealing gap emanates an additional damming effect. In operating the drive shaft and is then conveyed into the vorgedrungene located upwardly tapering annulus material down to the outside, since such have a pronounced conical column Föräerwirkung between a stationary and rotating part ein.m in the direction of increase in diameter.

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Between the upper group A and the middle group B of the radial sealing rings, an opening is made in the upper housing part 3 through which rinsing fluid for rinsing the radial sealing rings in the upper group A and further for rinsing the pre-seal via a longitudinal bore 13 and a pipe connection lk serving annular gap can be supplied. The space between group D and group C of the radial sealing rings is filled with grease as a warp chamber 19. The liners 6a and 6b fastened in the area of the radial sealing rings on the vertical drive shaft 10 serve to protect the drive shaft against wear. The lower liner 6b is sealed against the drive shaft 10 with elastic seals 15, for example O-rings, in order to prevent flushing liquid from escaping, which can seep down along the drive shaft.

As the flushing liquids for flushing the upper radial sealing rings and the two annular gaps are reliably kept away from the bearing of the drive shaft 10 even when the radial sealing rings are worn are to be, is between the lower liner 6b and a shoulder of the drive shaft, a centrifugal plate attached, which is surrounded by an upwardly open channel. This channel 17 has a downwardly leading away pipe connection l8 provided.

The advantages achieved with the innovation are that the risk of powdery, granular, pasty or liquid mixture penetrating deeply into the sealing gaps of the compression when the drive shaft is at a standstill; is significantly reduced and the mix that has penetrated into the sealing gap is reliably conveyed out of the sealing gaps while the drive shaft is running. This increases the service life of the. Radial sealing rings enlarged.

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Claims (5)

RHEIN ST AHL Kassel, September 5, 197 * 1 Aktiengesellschaft PSRP / Fr / P PK 2752 Protection claims 1. Shaft seal for standing cylindrical wiping containers for powdery, granular, pasty or liquid material, with a vertical drive shaft passing through the container bottom for the mixing tools arranged on the bottom and several radial sealing rings arranged one above the other, in front of which there is a gap seal as a pre-seal towards the container interior, characterized in that that the radial sealing rings in three groups (A, B and C) one above the other in one of two tubular, flanged, centered one in the other and with the upper flange surface flush with the bottom surface finally in a recess in the container bottom (l) passed through the flanges Screws (4) attached housing parts (2 and 3) existing housing are arranged, the upper housing part (3) protrudes above the container bottom (l) and the outer surface has the outer surface of an upwardly tapering truncated cone and together with the surface of the cone chen free rotation in the upwardly extended hub (lla) of the bottom-mounted mixing tool (ll) forms an annular gap increasing from top to bottom in the outer diameter and in the gap width (S), at the bottom between the flat container bottom (l) and the a sealing gap, the gap width (T) of which increases from the inside to the outside, adjoins the underside of the mixing tool (II) arranged at the bottom, which rises slightly towards the outside. 743026219.1Z74 2. Shaft seal according to claim 1, characterized in that between the upper group (A) and the middle Group (B) of the radial sealing rings whose sealing lips are all directed upwards, one in the upper housing part (3) Opening '.12) is arranged for supplying a rinsing liquid. 3 · Shaft seal according to claim 1 and 2, characterized characterized in that between the middle group (B) of the radial sealing rings, the sealing lips of which are directed upwards and the fourth group (C) of radial sealing rings, the sealing lips of which are directed downwards, a Fettkanuner (19) is arranged. k. Shaft seal according to Claims 1 to 3i, characterized in that the bushings (6b) fastened on the vertical drive shaft in the area of the radial sealing rings are sealed against the drive shaft (10) with elastic seals (15). 5. Shaft sealing according to the. previous claims, characterized in that below the liners (6a, 6b) on the vertical drive shaft (JO) a centrifugal plate (l6) is attached, which is followed by a Open-top channel (l7) with a bottom-side pipe connection {18) is surrounded. 743026219.1174