DE2011852A1 - Centrifugal pump with vertical shaft - Google Patents

Description

Westinghouse Electric Corporation, 3 Gateway Centers, Pittsburgh, Pennsylvania, United States of America

Centrifugal pump with vertical shaft

The invention relates to centrifugal pumps with vertical Shaft and an impeller attached to the lower end of the shaft, a drive motor arranged at the upper end of the shaft and with a cylindrical shaft and impeller surrounding it Housing which is provided with a radial outlet opening at the upper end and a suction opening at the lower end is.

Known pumps of this type have a shell housing with a cooler, a pool bearing arrangement, Bushing spacer rings and shaft seals, which are all located above the main flange of the pump and which are therefore expensive Housing and a relatively large pump height required do.

The object of the invention is to be achieved, the construction of a centrifugal pump which is used for working fluids is suitable, which are under high pressure and have a high temperature, without renouncing one to simplify good pump efficiency.

In terms of solving this problem, the invention includes a centrifugal pump with a vertical shaft and an impeller attached to the lower shaft end, a drive motor arranged at the upper shaft end and a cylindrical housing surrounding the shaft and impeller, which has a radial outlet opening at the upper end and a radial outlet opening at the lower end End is provided with a suction opening which, according to the invention, is passed through a main flange which has a neck extending downwardly into the housing and encompassing the shaft, further through a flange attached to the lower end of the neck

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Bearing arrangement for the shaft and finally through ·. at least one shaft seal attached to the main flange above the bearing arrangement, whose Leakage flow losses are manageable, marked is. .

The following is a preferred embodiment of the invention, which is illustrated by way of example in the accompanying drawings, which show in detail demonstrate: .

■ * ■ ■

Fig. 1 is an axial section through a

Centrifugal pump according to the invention,

2 on the basis of an enlarged section

along the line II-II in Fig. 1 details of one in the invention Pump used thermal jacket, and

3 and 4 each in a simplified representation

in plan view or in side view, the housing of the centrifugal pump according to the invention.

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According to the illustration in FIG. 1, a Centrifugal pump 10 has a cylindrical housing 11, which with a radial outlet opening 12 near the upper end of the housing and with a suction opening 13 on the is provided lower end of the housing, and a circular main flange 14- with a downward cylindrical neck extending into housing 11, one through flange 14 and one through neck 15 shaft 16 extending therethrough and one by means of an impeller nut 18 and a screw 19 at the lower end of the shaft attached impeller 17 on. The shaft 16 is, for example, from one not shown in the drawings Electric motor driven, which is mounted on a by means of screws 22 on the top of the main flange 14- Motor support frame 21 is attached. The motor shaft is connected to the pump shaft 16 via a coupling 23. That The upper end of the housing 11 is secured by means of studs 24 · which pass through the main flange 14- into the housing are screwed in, attached to the main flange 14.

From the presentation in the years. 3 and 4 can be seen that the housing 11 has a fairly simple structure. The housing 11 consists, for example, of a high-strength carbon steel and the inside wall of the housing

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is "if necessary with a lining made of corrosion-resistant Material, such as Inconel, provided. Due to the cylindrical shape of the housing the housing or lining material can be stressed "up to the permissible limit".

As shown in Fig. 1 is by means of screws 26 at the lower end of the neck 15 is a Badiallager arrangement 25 for the .Welle 16 attached. The type of bearing arrangement 25 can be selected as desired. The bearing arrangement has one which is pressed onto the shaft 16 Bush 27, a bearing shell 28 made of suitable storage material and a bearing housing 29 encompassing the bearing shell 28.

The shaft 16 is coaxially surrounded by intermediate bushing rings 31 within the neck 15 and above the bearing arrangement 25. The type of design of such bushing rings 31 is very well known. Shaft seals, the leakage flow losses of which are controlled, are arranged above the intermediate rings in the main flange 14. The seals are held in this position by "a seal housing 32, which is fastened to the top of the main flange 14 by means of screws 33. A vapor seal housing is fastened ^{to the seal housing 32 by means of screws 35 *}

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A housing cover 36 is fastened to the housing 34 by means of screws 37 &&. The shaft seals within 'the housing 32 and 34- can be designed in a known manner or in a manner already described. In the form of a pipe coupling 38 and a pipe 39, a suitable connection for removing the leakage losses is attached to the housing 32. In the same way, a connection for discharging leakage losses is provided on the housing 34, which connection has a pipe coupling 41 and a pipe 42. The leakage losses, ie the losses of working fluid, are fed back into the working fluid circuit in a known manner.

The pump according to the invention is particularly suitable for pumping a working fluid in a circulatory system suitable at relatively high temperature and at high pressure. In the presence of suitable connections of the circulatory system with the suction opening 13 and with the outlet opening 12, the pump is able to supply the working fluid to pump around in the system.

In addition to the impeller 17, the pump is still provided with a main impeller sealing ring 42, one from the Impeller 17 out into the interior of the housing 11

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upwardly extending diffuser 43 and provided with a · · deflection bend 44, which the diffuser 4-3 connects to the radial outlet opening 12. Accordingly, that of the impeller 17 is through the suction port 13 working fluid sucked into the pump by means of the diffuser 4-3 and the Deflection elbow 44 passed to the outlet opening 12.

To protect the bearing assembly 25 and the shaft seals in the housings 32 and 34 against

the temperature of the hot, circulated by the pump >

held working fluid is around the bearing assembly around .. 'a cylindrical thermal jacket 45 and moreover A cooler 46 is arranged between the impeller 17 and the bearing arrangement 25 '. The cylindrical thermal jacket has an inner wall 47 and one at a certain distance Outer wall 48 arranged concentrically from this inner wall to * the upper ends of each of the walls and 48 are attached to one, for example by welding Heat protection jacket flange 49 employed. The flange is by means of the flange or stud bolts 24 between the main flange 14 and the housing 11 clamped. The lower end of that cylinder, which through the inner wall 47 is formed by a base plate

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closed, through which the shaft 16 protrudes. In the base plate 51 on the shaft 16 is a Labyrinth seal 52 is arranged. The outer wall 48 runs up to a flange 55 on the inner wall 47 The diffuser 43 is, for example by welding, attached to the flange 53. The deflection bend 44 is provided with upwardly directed support ribs 54 and 55, which is fastened to the flange 49 by means of screws 56 are.

Devices are provided which allow cooling liquid, for example water, to be passed through the heat protection jacket 45 and the cooler 46. According to the illustration in FIG. 1, passage channels 57 and 58 respectively formed in the flange 49 are in communication with semicylindrical tubes and 70, respectively. These tubes run through the annular space between the inner wall 47 and the outer wall of the heat protection jacket. The tube 60 communicates with a chamber 75 via an opening 76 in the flange 53. In the same way, the tube 70 is connected to a chamber 77 via an opening 78 in the flange 53. The chamber 75 is enclosed by a jacket 79 which is welded to the flange 53 and to the base plate 51. Similarly, the chamber 77 of FIG

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enclosed in a jacket 81. Chambers 75 and 77 are by means of suitable locking devices, which are not shown in the drawings, from each other separated.

The passage 57 can be connected to a suitable supply source by means of a pipe 59. An outlet pipe 61 is connected to the passage 58. ·

The cooler 46 has a multiplicity of cooling coils, each of which is arranged _{around a U 1n} ^ Ie shaft 16 within the inner wall 47 of the heat protection jacket 45 and between the base plate 51 of the heat protection jacket and a cover plate 66, the latter by screws 67 screwed into the base plate 51 is held in this position. The cooling coils 65 are in communication with the chambers 75 and 77 in such a way that the coolant then circulates in the cooling coils 65 as it flows from the chamber 75 into the chamber 77, from which the coolant flows through the tubes 70 and 61 through exit. Part of the working fluid conveyed by the impeller 17 is passed through openings 82 in the outer wall 48 from the pump housing 11 into the

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Heat protection jacket 45 dissipated. The thermal jacket is therefore filled with working fluid which flows through the pipes 60 and 70 Liquid is cooled a little.

To increase the efficiency of the heat protection jacket 45, a plurality of concentric bushings 62 arranged at a certain spatial distance from one another is provided between the inner wall 47 and the outer wall 48. As shown in E ¹ Ig. 2, the spatial distance between the bushings 62 is maintained by means of spacers or nuts 63, the latter being arranged on screws 64 which each protrude through the outer wall 48 and are screwed into the inner wall 47. The sleeves 62 subdivide the liquid located inside the heat protection jacket into separate vertical "layers", which results in a better efficiency of the heat protection jacket 45.

According to the illustration in FIG. 1, relatively small openings 71 and 72 are formed in the impeller 17, through which working fluid enters a chamber above the impeller. Also between the cover plate 66 and the shaft 16 a ring gap 74

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.educated. In this way, only a relative ■ ■ small amount of the conveyed by the impeller 17 Working fluid through the labyrinth seal 52 and through the cooler 4-6 into the environment the bearing assembly 25 · Besides, the there Any small amount of working fluid arriving has already been cooled by the cooling coil 65. The bearing arrangement and the shaft seals are therefore in front of the high Protected temperature of the working fluid, which is conveyed through the impeller 17 through the pump will.

The centrifugal pump according to the invention is constructed in such a way that that the high pressure part of the pump extends only up to the main flange 14 and not over the main flange goes beyond what is the case with pumps of previous design, in which the intermediate rings and the shaft seals above the main flange are arranged .. There is accordingly a reduction of the material that has to withstand high pressure. In addition, there is a reduction the total pump height, because the shaft bearing, the Cooler, the heat protection jacket, the intermediate bushing rings and die'well seals within the housing and are arranged below the main flange. As previously

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already explained, the cylindrical housing is a fairly simple construction. Compared With "known pumps of the same design, the centrifugal pump according to the invention is therefore smaller and cheaper.

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Claims (6)

Patent claims: Π .) Centrifugal pump with a vertical shaft and an impeller attached to the lower shaft end, a drive motor arranged at the upper shaft end and a cylindrical housing surrounding the shaft and impeller, which is provided with a radial outlet opening at the upper end and a suction opening at the lower end, characterized by a main flange (14) having a neck (15) extending downwardly into the housing (11) and encompassing the shaft (16), further by a bearing arrangement (25) for the shaft mounted at the lower end of the neck and finally by at least one shaft seal attached to the main flange above the bearing arrangement, the leakage flow losses of which can be controlled. 2. Pump according to claim 1, characterized in that a diffuser (43) extends from the impeller (17) extends upward into the housing (11) and that a deflection elbow (44) connects the diffuser with the radial Outlet opening (12) connects. 3. Pump according to claim 1 or 2, characterized - 13 009840/1374 .by a seal housing (32 "or 34-), which the Shaft seal encloses and is attached to the main flange (14). 4. Pump according to claim 3? characterized, that devices (38, 39 "or 4-1, 42) for discharge are attached to the seal housing (32 or 34) from leakage losses occurring at the shaft seal, and that the shaft (16) between the seal housing (32) and the bearing arrangement (25) of intermediate grommets (31) is surrounded. 5. Pump according to one of claims 1 to 4, characterized in that a cylindrical heat protection jacket (45), which is concentrically provided with an inner wall (47) and an outer wall (48), the bearing arrangement (25) encompasses, with the thermal jacket at its upper end is provided with an outer flange (49) and also has devices (82) which allow access from Allow working fluid from the pump housing (11) into the heat protection jacket. 6. Pump according to claim 5>. characterized in that at least one cooling coil (65) below the bearing arrangement (25) surrounds the shaft (16), this being _ 14 - 009840/1374 JS ■■ · Cooling coil within the inner wall (4-7) of the Heat school; zmant eis (4-5) "is located, and that facilities (75 »76) ι which are connected to the cooling coil stand, through the annular space between the inner wall (47) and the outer wall (4-8) of the Heat protection jacket run through and thus. cause a liquid to flow through the cooling coil. 7 · 3? Umpe according to claim 5 or 6, characterized in that that between the inner wall (4-7) and the outer wall (4-8) a plurality of spaced apart arranged concentric bushings (62) located to one another. - .15 - 0 09 84071374