DE2028521A1 - Mechanical seal for pulp pumps - Google Patents

Description

. HAMBURG- MÜNCHEN DELIVERY ADDRESS; HAMBURG 36 NEW WALI. 41

200 South Michigan Avenue _TBL . ₈₃ 8o ₅ 8e

Chicago, Ilio 60604 / üSA teibgh. negehapatent Munich

Hamburg, June 9, 1970

Mechanical seal for pulp pumps

In the manufacture of paper, pulps are made up of from a mixture of different liquids with suspended solids in the order of magnitude of relatively large pieces of wood "up to heavily shredded and partially broken down fiber material by means of Pumps moved through the treatment stations. The seals of these pumps cause difficulties in operation.

Up to now, these pumps have been fitted with the usual stuffing box packings, for example used; however, large amounts of clean liquid or water are required to get around the glands to rinse free of the pulp. Mechanical seals have been used for this purpose, but have these proved unsatisfactory as the sealing arrangement easily suffers from the firmness present in the pulp Material clogs and becomes ineffective

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The present invention provides a seal for use in the mecliamische Stopfbucnse bucket pump _:: for paper pulp, wherein the mechanical Bichtimg for such operation is particularly suitable ·

In detail, the present mechanical seal has a construction that allows rinsing off the balpe from the Sealing arrangement with a small amount of flushing liquid, ZoB. Water enables.

In order to achieve the above object, a mechanical sealing arrangement is provided according to the invention, in which a rotary sealing ring assembly is carried by a Bmapeuwelle, a fixed section of the bicomponent assembly carries a stationary sealing ring. Äirehflußkanäle are provided to the rinsing liquid _a such as water at a higher pressure than that prevailing inside the stuffing box between the Dichiningsflädtem sam. In particular, the channels for fluid are located in the non-rotating sealing device According to a certain embodiment of the ErfiEKämais, a further channel or path is provided, -am. to allow the stasis of the rinsing liquid to flow irorlseistrom the outer circumference of the sealing rings, which simi »

The mechanical sealing arrangement is a "ler" invention is intended for use in a. © r S ^ pftonchse 'a Pump for pumping a solids smälemae. Liquid,

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like ZoB. Paper pulp. The arrangement is simple in the Production, easy to install and requires considerably less flushing water than before with the known packs was required

The invention has many other advantages and features, which are to be explained on the basis of the embodiments. These Embodiments are illustrated in the accompanying drawings, which form a part of the specification. It There now follows a description of the drawings for purposes of explanation the general principles of the invention; however, it should be noted that such detailed descriptions are not to be regarded as a restriction.

Fig. 1 shows a longitudinal section through a pump stuffing box and a mechanical manufactured according to the invention Poetry;

Fig. 2 is a vertical section along the line 2-2 of Λ Fig. 1,

3 shows an enlarged partial section along the line 3-3 2 to show the details of the mechanical sealing elements, and

4- a section corresponding to FIG. 3 "but one modified embodiment of the invention,

1-3 show an embodiment of the under consideration

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standing mechanical seal when used in a pump housing 1 with a stuffing box 2. In the stuffing box 2 a pump shaft 3 is rotatably arranged, on the inner end 4 of the hub 5 of the usual pump wheel (not shown) is located.

In detail, the sealing arrangement comprises a hollow shaft of cylindrical shape which surrounds the vifelle 3. In in a key slot 8 of the shaft 3 and in a keyway in the inner circumference of the hollow shaft 6 there is a key 7 » whereby the shaft 3 and the hollow shaft 6 rotate as one unit. An end flange is formed from the impeller hub 5 10 of the hollow shaft 6 held against a shaft shoulder 11, and between the surface 10 and the shoulder 11 is a Suitable sealing ring washer 12 switched on to prevent leakage flow from the pump housing between the hollow shaft 6 and turn off shaft 3.

The leakage flow from the pump housing through the stuffing box is through a stationary sealing ring 13 and a rotating sealing ring 14 turned off, each with radial, facing each other and preferably for Formation of a plane lapped sealing surfaces 15 and are provided, as is common practice with mechanical seals.

The stationary sealing ring 13 is supported by the usual sealing flange. 17 supported on the pump housing for example by several screw fasteners

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is attached. An appropriate seal 19 is inserted between the sealing flange 17 and the pump housing 1 in order to prevent leakage therebetween. Of the Sealing flange 17 is provided with a bore 20 in which the sealing ring 13 is arranged, one Axial movement of the sealing ring 13 is prevented by an edge lip 21 of the sealing flange 17 which forms an opening 22 through which the hollow shaft 6 extends.

According to the invention, a rinsing liquid is used to the pulp or other solids entrained in the pump housing liquid from the area of the opposing surfaces 15 and 16 and from the area of the Flushing the stuffing box 2 away. Accordingly, the sealing flange 17 comprises a flushing liquid inlet channel 23 »of the an annular channel 24 formed in the bore 20 of the flange 17 leads. The sealing ring 13 has a plurality of radial channels 25 with an annular channel

24 and also has several with Circumferentially spaced channels 26, which the channels

25 connect to an equal number of circumferentially spaced curved flow medium channels 27, soft rinsing fluids between the sealing surfaces 15 and 16 form. In the illustrated embodiment

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shape are the chambers or channels 27 in the sealing surface 15 of the sealing ring 13 is formed; Of course, however, these chambers can optionally also be formed in the sealing surface 16 of the rotary ring 14.

In the embodiment now to be described, the flushing nozzle is limited to the path that passes through the inlet channel 23, the annular channel 24 », the radial channels 25» and the connecting channels 26 leading to the chambers 27 are formed. In detail, the stationary sealing ring 13 is with two axially spaced, extending on the circumference elastic sealing rings 28 and 29 are provided which engage sealingly in the bore 20 on opposite sides of the annular channel 24.

The rotating seal ring 14 is driven by a spring carrier 30 which has an annular main section 31 includes. This main section 31 of the spring carrier 30 is secured to the hollow shaft 6 by one or more adjusting screws 32 clamped; the adjusting screws are on one side of the diametrical line running across the spring carrier 30 in the main part 31 screwed. In the embodiment shown, two of the set screws are 90 ° apart Arranged at a distance and cause when screwing inward sar interaction with the hollow shaft 6 a jamming

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the opposite side of the Eederträgers 30 against the Hollow shaft 6, creating a gap between for a purpose to be described later in this description the Pederträger 30 and the hollow shaft 6 is formed.

The rotary sealing ring 14 is arranged within an axially extending band section 34 of the spring carrier 30; the edge section 34 leaves it at a cylindrical bore 35 in which λ the outer circumference of the sealing ring 14 slides. The rotary sealing ring 14 carries an elastic sealing ring 36 which engages in the bore 35 in a sealing manner. In addition, the rotary seal ungsr Ing 14 carries an elastic inner seal ring 37 which surrounds the hollow shaft 6 in a sealing manner.

In the spring pockets 39 of the spring carrier 30 there is a suitable number of helical compression springs 38 arranged with a circumferential spacing provided which engage the end wall of the rotating seal ring 14 so as to normally provide a load that axially engages the rotating seal ring 14 Direction of the stationary sealing ring 13 prints. Ee are Means are provided that the rotary movement of the spring carrier * 30 transferred to the rotating sealing ring 14 and there are for this purpose in the illustrated Ausführungsfora Drive pins 41 In a suitable view! in old scope

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spaced pockets 42 of the toe carrier 30 are provided and engage in recesses 43 of the sealing ring 14 a.

It is now clearly evident that the stationary seal 13 with reference to the rotating sealing ring 14 remains stationary, the duxh the pins 41 depending on the rotation of the pump shaft 3 is driven. If desired or necessary, the sealing ring 13 can accordingly be wedged on the Plansch 17, but in the embodiment shown, the ring 13 is a snug fit in the Bore 20 of the planch 17 introduced

If necessary, the bore 35 of the pedal carrier 30 can also be located behind the sealing ring 14 and within the spring pockets 39 and the propellant bag 42 with a suitable one Lubricant to be filled.

Since the present seal design can be used in pumps in which pulp is pumped, the AnBenaiafang 44 of Peder carrier 30 preferably as a frustum of a long, is formed in the direction of the inner® Eide of Peäerträgers 30 to tapered cone ₉ which Aich the spaces 45 inside the stuffing box 2 each Ιββθβ widen® in order to displace the palpate or other »fiber material

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to favor from the spaces 45 during the operation of the sealing arrangement.

In operation with the sealing arrangement described up to then the rotating sealing ring 14 is urged by the springs 38 in the direction of the stationary sealing ring 13, to maintain the sealing relationship between the sealing surfaces 15 and 16. This spring force is generated by the Pump housing fluid pressure created by the gap 33 formed between the spring carrier 30 and the shaft 6 Access to the rear side 40 of the rotating sealing ring

14 finds, reinforced. However, this gap 33 is so small that fiber material or solids in the pulp are not can go through the gap so easily.

The rinsing liquid, such. B. clean pulp fluid or Water is let into the inlet channel 23 of the sealing flange 17 and flows from there through the openings or channels 25, 26 and 27. This flushing liquid is at a pressure slightly above the housing or pump flow pressure kept so a film of between the sealing surfaces

15 and 16 to maintain flowing flushing liquid. A Part of this flushing fluid flows radially inwards across the sealing surfaces 15 and 16 and flows away from the arrangement through the opening 22 around the hollow shaft 6, however

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the remaining part of the flushing liquid flows radially outwards, between the sealing surfaces 15 and 16 into the space 45 and mixes from there with the pulp or other liquid in the pump housing. The plus of this flushing liquid prevents clogging of the mechanical seal by solid components of the pump fluid or pulp, if this liquid flows through the diverging space 45 into the pump housing. The volume of the flushing liquid does not need to be large, so that hot use of water the pulp liquid or fluid in the pump housing is not significantly diluted.

fig. 4 shows a modified construction. In this embodiment For example, the sealing ring 28 of the embodiment described first is omitted and instead a flow path 128 for the flow of the flushing liquid from the annular channel 24 in the flange 17 along the outer circumference of the stationary sealing ring 13 is provided. Otherwise, the construction is according to Pig. 4 the same as that previously described.

Through flow path 128 the Pig. 4 a rope of the flushing liquid flows directly from the source into the stuffing box 2, without flowing between the sealing surfaces 15 and 16 to

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thereby the space 45 between the spring carrier 30 and the Flush the gland wall more effectively. Such an arrangement is better suited for use in pumping pulps or other liquids in which large particles of pesticides are present are present, and which therefore require a greater flow of flushing liquid to remove the Keep blockages clear.

The clear tree formed by the space 128 should be sufficiently small to allow the flow of the rinsing liquid to throttle therethrough, so that a sufficient flushing liquid pressure can be maintained in the annular channel can to cause at least a certain flow between surfaces 15 and 16.

In each of the embodiments described above, it can be clearly seen that the suffering portion 34 of the conveyor beam 30 with the outer circumference of the hollow shaft 6 an annular piston | chamber forms. The rotating sealing ring 14 forms with its sealing rings 36 and 37, respectively, with the bore of the band 34 are in sealing engagement, and with the Hollow shaft 6 has an annular piston, which is supported by the springs 33 in the direction of the stationary sealing ring 13 spring pressure is available. In addition, the Druok of the Current

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by means of the gland 2 through the gap 33 entrance into the basket chamber behind the end wall or surface 40 of the itself rotating sighting ring 14 and is effective over the effective end face of the sighting ring to the latter in the direction to daäfcken on the stationary sighting ring 13. Of the Gap 33 is small in order to exclude the entry of solids into the account chamber, and if this chamber with a Lubricant is filled, so this serves as a pressure medium for transferring the liquid from the stuffing box 2 to the ring sight surface 40; The lubricant also prevents solids from entering the leather area 33 · The force acting in the opposite direction pushes the flushing liquid between the viewing surfaces 15 and is a function of the flushing fluid pressure in the channels 27 running on the circumference. This pressure should be such that it creates a pressure gradient at the viewing surfaces 15 and 16 forms and the flow of at least one film that maintains flushing fluid between these sifting surfaces.

It can now be seen that the invention is mechanical This creates a viewing arrangement that is ideal for a Use in paper pulp pumps is suitable; but can this sighting is also used in other areas of application

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find where the likelihood of clogging the mechanical Visibility is given with solids in the pump fluid.

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Claims (7)

1.) Mechanical sealing arrangement with a stuffing box with a rotatably mounted »shaft and old mechanical sealing means for sealing this shaft in the stuffing box, characterized in that the mechanical sealing means a stationary! Bearing (17), a stationary sealing ring (13), the is supported won the! bearing and surrounds the shaft (3), and including a rotating seal ring (14) disposed around the shaft, wherein the stationary seal ring and the rotary seal ring miteinanier engageable radial the & tangsfläehen (15 » 16), a spring carrier (30) has a section arranged on the shaft, and means (3S) for achieving a seal between the spring carrier? and the outer circumference of the drebenäais sealing ring are provided, further means (37) to build a seal between the inner circumference of the rotating Diciitungsrlnges (14) and the shaft, each means (38) _for the tos & θβ Eeder- '■ Carrier worn and with Sen sl @ M teekeidea screening ring (14) in cooperation g @ 1i £ a © U werdei ^ in tee the latter 009851 / 1Ü3 towards the stationary sealing ring (13) pressurize, as well as fluid channels (24 »25, 26, 27) for guiding a coil of fluid between the radial sealing surfaces (15 »16). 2. A mechanical seal assembly according to claim 1, characterized in that the StrömungSMittelkanaleinricbtung comprises a channel (26) in the stationary seal ring (13) ä, the zwiaiien performs the sealing surfaces. 3 · Mechanical sealing arrangement according to claim 2, characterized characterized that around the outer surface of the stationary Sealing ring (13) is formed around a channel (24). 4 · Mechanical sealing arrangement according to spoke 1, thereby characterized in that the fluid passage means a number of arc-shaped ones arranged at a distance from one another Channels (27) in the radial sealing surface of one of these rings, as well as supply channels (26), which lead to the arched canals. 5 · Mechanical sealing arrangement according to any one of claims 1 to 4 »characterized in that the device to form a seal between the spring carrier - 16 - 009851/1503 (30) and the rotating sealing ring (14) includes a cylindrical rim (34) on the spring support which extends around the outer circumference of the rotating sighting ring, as well as an elastic lifebuoy (36) between the edge and the outer circumference of the rotating Sealing ring » 6. Mechanical seal arrangement according to any one of the claims 1 to 5, characterized «that the gate direction to Form a seal between the inner periphery of the rotating seal ring and the shaft one on the shaft located hollow shaft (16) which extends through the rotating sealing ring (14) hinetorc hers, and one elastic sealing ring (37) between the inner circumference of the rotating sealing ring and the hollow shaft. 7. Mechanical seal according to any one of claims 1 to 6, characterized in that the spring carrier (30) has a channel for letting in a fluid rack aas the stuffing box (2) provides into the spring carrier. β. Mechanical seal according to claim 6, characterized in that the spring carrier (30) extends around the hollow shaft (6) extends around and at least one adjusting screw (32) - 17 - 009851/1 503 one side has a * diagonal through the spring carrier, around the other side of the spring carrier against the hollow shaft (6) featzuklemsen and an access for the StopfbuchaenströmuQgSMitteldruci: in the vein carrier (30) into it create. BAD ORIGINAL 009851/1503