Patent ID: 12203475

DETAILED DESCRIPTION

Embodiments described herein are directed to a magnetic drive sealless pump having a containment shell, wherein a steam jacket is provided over an outer side of the containment shell, which will thereby reduce the chance of solidification inside the magnetic drive sealless pump, for example, when pumping sulfur.

The magnetic drive sealless pump includes a pump casing, a containment shell sealed against the pump casing to define an internal pump volume, a steam inlet provided proximate to the containment shell to permit introduction of steam to an exterior of the containment shell, and a pair of steam outlets. A first of the steam outlets is in fluid communication with the internal pump volume and the second of the steam outlets is provided between a dry seal and a bearing isolator. Various embodiments of the magnetic drive sealless pump and the operation of the magnetic drive sealless pump are described in more detail herein. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts.

Directional terms as used herein—for example up, down, right, left, front, back, top, bottom—are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.

As used herein, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise.

Referring now toFIG.1, a magnetic drive sealless pump100(hereinafter, the pump100) is illustrated according to one or more embodiments described herein. The pump100may generally include a casing102and a frame106. The pump100may also include a motor assembly (not illustrated inFIG.1) that is coupled to the casing102via the frame106and which drives the internal components of the pump100. For example, as described below, the motor assembly may be operatively coupled to a pump shaft104that drives operation of the pump100as hereinafter described.

The casing102includes a suction flange110and a discharge flange112. In the illustrated embodiment, both the suction flange110and the discharge flange112are provided as flange structures. In the illustrated embodiment, the suction flange110is provided on a front side116of the casing102. The casing102defines an internal casing volume118that is in fluid communication with an opening of the suction flange110and an opening of the discharge flange112.

The pump100includes a containment shell120provided on a rear side122of the casing102. In the illustrated embodiment, the containment shell120includes a flange portion124and a cup portion126extending from the flange portion124. The containment shell120is attached to the casing102such that a seal is formed between the containment shell120and the casing102. In this manner, the containment shell120is sealed against the casing102. Here, the flange portion124of the containment shell120is sealingly attached at the rear side122of the casing102. In embodiments, the containment shell120is statically sealed against the casing102via a gasket or other sealing means. When the frame106is attached to the casing102, the cup portion126of the containment shell120extends into an interior volume128of the frame106, with an exterior surface130of the cup portion126being exposed to the environment, which may include jacketed steam as described below, within the interior volume128of the frame106. As hereinafter described, the frame106houses the magnet coupling components of the pump100.

The containment shell120also defines an internal shell volume132. In the illustrated embodiment, the internal shell volume132extends through both the flange portion124and the cup portion126of the containment shell120. When the containment shell120is attached to the rear side122of the casing102, the internal casing volume118and the internal shell volume132together define an internal pump volume. The containment shell120may comprise a high-strength non-magnetic corrosion resistant alloy. As hereinafter described, the containment shell120functions as a containment shell and is a barrier between the internal pump volume and the interior volume128of the frame106, with the exterior surface130of the containment shell120being exposable to materials introduced within the interior volume128of the frame106and inhibiting such materials from entering the internal pump volume.

The pump100includes a bush assembly134for operatively supporting various internal components of the pump100within the internal pump volume. The bush assembly134includes a mounting flange136and a rigid holder138extending from the mounting flange136. In the illustrated embodiment, the mounting flange136of the bush assembly134is secured within an opening of the flange portion124of the containment shell120, such that the rigid holder138of the bush assembly134extends towards the cup portion126of the containment shell120and is suspended within the internal shell volume132of the containment shell120. In this manner, an annular and cup-shaped gap is defined between an exterior surface of the rigid holder138and an inner surface of the cup portion126. In embodiments, the bush assembly134is attached to an inner surface of the internal shell volume132of the containment shell120.

The pump100includes an impeller shaft140and an impeller142provided on the impeller shaft140. The impeller shaft140is rotatably supported by the rigid holder138such that the impeller shaft140may rotate relative to the rigid holder138. In embodiments, the impeller shaft140is coupled within a bore of the rigid holder138via one or more bushings, such that the impeller shaft140may rotate relative to and within the rigid holder138of the bush assembly134.

The impeller shaft140has a bush attachment section that extends into the internal shell volume132of the containment shell120and which is rotatably supported by the rigid holder138via the bushings. The impeller shaft140also has stub shaft section extending from the bush attachment section and outward from the internal shell volume132of the containment shell120, wherein the stub shaft section of the impeller shaft140supports the impeller142such that the impeller142is rotatable with the impeller shaft140. The stub shaft section of the impeller shaft140extends into the internal casing volume118of the casing102such that the impeller142is positioned within the internal casing volume118of the internal pump volume. As described herein, rotation of the impeller142imparts energy to the fluid or liquid causing the pump100to operate.

The pump100includes a magnetic assembly comprising an inner magnetic ring144and an outer magnetic ring170. The inner magnetic ring144is provided on the impeller shaft140such that the inner ring144is rotatable with the impeller shaft140. The inner magnetic ring144is arranged coaxially over the impeller shaft140and suspended in the annular and cup-shaped gap defined between the exterior surface of the rigid holder138and the inner surface of the cup portion126. In this manner, the containment shell120is provided over and arranged around the inner magnetic ring144. The inner magnetic ring144includes a coaxially arranged outward facing permanent magnet146. In embodiments, the coaxially arranged outward facing permanent magnet146of the inner magnetic ring144comprises an individual coaxially arranged outward facing permanent magnet that extends around a circumference of the inner magnetic ring144. In other embodiments, the coaxially arranged outward facing permanent magnet146of the inner magnetic ring144comprises a plurality of coaxially arranged outward facing permanent magnets positioned around the circumference of the inner magnetic ring144. In embodiments, the inner magnetic ring144or its coaxially arranged outward facing permanent magnet(s) is encapsulated with a protective sheathing.

The frame106comprises a bearing housing150that rotatably supports the pump shaft104. A motor (not illustrated) may be operatively coupled to the pump shaft104such that activation of the motor rotates the pump shaft104clockwise or counterclockwise. In the illustrated example, the frame106includes a first open end, at which the frame106is coupled to the rear side122of the casing102, and a second open end that is opposite the first open end, with the bearing housing150being attached to the second open end of the frame106. In this manner, the bearing housing150encloses the second open end of the frame106, thereby enclosing the interior volume128of the frame106. The pump shaft104may be supported within the bearing housing150via bearings156which rotatably couple the pump shaft104to the bearing housing150such that the pump shaft104may rotate relative to the bearing housing150. The pump shaft104includes a motor end152, which may be engaged by the motor (not illustrated), and an opposite end154attached to the outer magnetic ring170. As illustrated, the pump shaft104extends through the bearing housing150, such that the motor end152of the pump shaft104is positioned exterior of the interior volume128and such that the opposite end154of the pump shaft104extends through the second end of the frame106and into the interior volume128of the frame106. In embodiments, the frame106is coupled directly to the rear side122of the casing102. In other embodiments, the containment shell120is sealingly attached to the rear side122of the casing102and the frame106is coupled directly a side of the containment shell120that is opposite the casing102. For example, the flange portion124of the containment shell120may include a casing side and a motor side that is opposite the casing side, wherein the casing side of the flange portion124is sealed on the rear side122of the casing102and the frame106is attached to the motor side of the flange portion124.

A bearing isolator160and a dry gas seal162are provided in the bearing housing150. In embodiments, the dry gas seal162is a mechanical seal for sealing the interior volume128of the frame106and inhibiting ingression of steam therefrom into the bearing housing150or to the atmosphere surrounding the pump100. The dry gas seal162will contain the steam within the interior volume128and minimize any potential leakage of steam to the atmospheric side of the pump100or into the bearing housing150to thereby prevent the steam from contaminating the oil or lubricant within the bearing housing150. Also, as mentioned below, an outlet may be provided in the bearing housing150for drainage and the dry gas seal162minimizes the steam from escaping to the external atmosphere through that outlet.

The bearing isolator160and the dry gas seal162may be supported by the bearing housing150and abut or contact the pump shaft104so as to form a barrier between the bearing housing150and the pump shaft104. Thus, the bearing isolator160and the dry gas seal162may operate to inhibit ingression of contaminants, which may be introduced in the interior volume128of the frame106as described herein, into the bearing block150. The dry gas seal162is mounted to a face of the bearing housing150that covers the second open end of the frame106, and the face of the bearing housing150is configured to receive the dry gas seal162. In the illustrated embodiment, the dry gas seal162includes a flange portion164and an protruding portion166extending from the flange portion164, and the bearing housing150includes a recess168configured to receive the protruding portion166of the dry gas seal162. Here, the flange portion164is mounted to the face of the bearing housing150(e.g., via one more fasteners) such that the protruding portion166of the dry gas seal162extends into, and is set within, the recess168formed in the face of the bearing housing150. In this manner, the dry gas seal162seals the bearing isolator160and other interior components of the bearing housing150from the interior volume128of the frame106. Also, when the drive gas seal162is mounted to the bearing housing150, a space169is defined between sidewalls of the bearing housing150that define the recess168, the protruding portion166of the dry gas seal162, and the bearing isolator160, and water, steam, and/or bearing grease may accumulate in the space169as described herein.

As mentioned above, the magnetic assembly of the pump100includes the inner magnetic ring144and the outer magnetic ring170, with the outer magnetic ring170being provided on the pump shaft104such that the outer magnetic ring170is rotatable with the pump shaft104. The outer magnetic ring170comprises a coaxially arranged inward facing permanent magnet172that is attracted to the coaxially arranged outward facing permanent magnet146of the inner magnetic ring144such the inner magnetic ring144rotates with the outer magnetic ring170upon rotation of the pump shaft104via the motor152. Thus, the coaxially arranged inward facing permanent magnet172and the coaxially arranged outward facing permanent magnet146may be arranged such that they are magnetically attracted to each other. Thus, the coaxially arranged inward facing permanent magnet172is arranged such that its inward oriented pole has opposite polarity of the outward oriented pole of the coaxially arranged outward facing permanent magnet146.

The outer magnetic ring170includes a connection portion174and a cup portion176. The connection portion174is secured to the opposite end154of the pump shaft104. The coaxially arranged inward facing permanent magnet172is supported by the cup portion176, for example, within an interior volume of the cup portion176. When supported on the pump shaft104, the cup portion176is suspended over at least a portion of the exterior surface130of the cup portion126of the containment shell120, such that the coaxially arranged inward facing permanent magnet172of the outer magnetic ring170is oriented over, and in sufficient proximity to, the outward facing permanent magnet146of the inner magnetic ring144. In this manner, rotation of the outer magnetic ring170causes rotation of the inner magnetic ring144, even when separate by the containment shell120. When the cup portion176of the outer magnetic ring170is suspended over the containment shell120, an annular and cup-shaped gap is defined between the exterior surface130of the containment shell120and an inner surface of the cup portion176. Openings or slots may be formed in the outer magnetic ring170, for example, on the cup portion176thereof for providing a pathway for steam to pass through the outer magnetic ring170and contact the exterior surface130of the containment shell120.

In embodiments, the coaxially arranged inward facing permanent magnet172comprises an individual coaxially arranged inward facing permanent magnet that extends around an inner circumference of the outer magnetic ring170. In other embodiments, the coaxially arranged inward facing permanent magnet172comprises a plurality of inward facing permanent magnets positioned around the inner circumference of the outer magnetic ring170. In embodiments, the outer magnetic ring170or its inner facing permanent magnet(s) is encapsulated with a protective sheathing.

The pump100is configured to provide a steam jacket on the exterior surface130of the containment shell120to control temperature of the material being pumped by the impeller142. In this manner, the pump100is able to maintain the material being pumped in a liquid or fluid phase and inhibit its solidification which would otherwise impair operability of the pump100. In embodiments, the frame106includes a steam inlet180through which steam may be introduced into the interior volume128of the frame106. In embodiments, steam is introduced through the steam inlet180via a steam system182. In embodiments, the frame106includes a steam outlet184through which steam, or liquid resulting therefrom, may exit the interior volume128of the frame106. In embodiments, the steam system182is configured to also remove the steam (or resulting fluid) through the steam outlet184.

The steam inlet180is positioned such that steam may be introduced into the interior volume128of the frame106and contact components of the pump100within the interior volume128. For example, steam may be introduced into the interior volume128through the steam inlet180to contact the exterior surface130of the containment shell120and/or the outer magnetic ring170. In embodiments, steam is introduced into the interior volume128of the frame106via the steam inlet180and then contacts the exterior surface130of the containment shell120by passing through slots or openings formed in the outer magnetic ring170. The steam inlet180may be provided on the frame106at a location thereon that is proximate to the shell120and/or the outer magnetic ring170so as to optimize the heat transfer. In the illustrated example, the steam inlet180is provided on a top side of the frame106. Similarly, the steam outlet184may be located in appropriate locations in order to optimize the heat transfer.

The pump100also includes the second steam outlet188. As described above, the second steam outlet188provides drainage from within the bearing housing150. During use, for example, the interior volume128of the frame106is filled with steam such that the dry gas seal162operates under a steam condition, and the second steam outlet188drains any steam that may pass there through into the space169to thereby avoid accumulation of water within the bearing housing150. In embodiments, the second steam outlet188is formed at a position in the recess168of the bearing housing150between the bearing isolator160and the dry gas seal162. For example, the second steam outlet188may be formed in the bearing housing150such that the second steam outlet188extends, from an exterior of the pump100, into the space169defined between the bearing isolator160and the protruding portion166of the dry gas seal162. In this manner, the second steam outlet188may operate to drain any water that may accumulate in the bearing isolator160and that may accumulate in the space169defined between the bearing isolator160, the dry gas seal162, and the recess168of the bearing housing150.

FIG.2is a close-up cross-sectional view of an alternate bearing housing200for rotatably supporting the pump shaft104of the pump100, according to one or more embodiments of the present disclosure. In the illustrated embodiment, the bearing housing200comprises a first portion202and a second portion204. The second portion204may be removable from the first portion202, or vice versa, to facilitate installation and/or repair, and a gasket or seal206may be provided between the first portion202and the second portion204. A space208is defined within the bearing housing200, and a bearing assembly210may be provided in the space208of the bearing housing200for rotatably coupling the shaft104to the bearing housing200. As described above, a dry gas seal212and a bearing isolator214may also be provided in the bearing housing200. In the illustrated embodiment, the dry gas seal212includes a stationary face216and a rotating face218. Also in the illustrated embodiment, a seal bushing220and a setting plate222are provided about the bearing assembly210and the pump shaft104. Also, a second steam outlet224is formed in the bearing housing200so as to provide drainage from the space208within the bearing housing200. Thus, as previously described, the second steam outlet224drains any steam that may pass through the dry gas seal212and into the space208to thereby avoid accumulation of water within the bearing housing200.

Embodiments of the pump100described herein may utilized to pump a corrosive and dangerous liquid L, such as sulfur. During such an example operation of the pump, a motor may be operatively coupled to the pump shaft104and the motor may be activated to thereby rotate the pump shaft104and the outer magnetic ring170that is coupled to the pump shaft104. As described above, the inner magnetic ring144is attracted to the outer magnetic ring170, such that rotation of the outer magnetic ring170via the pump shaft104correspondingly rotates the inner magnetic ring144and the impeller shaft140which is coupled to the inner magnetic ring144, and rotation of the impeller shaft140correspondingly rotates the impeller142which is coupled to the impeller shaft140. Rotation of the impeller142sucks the liquid L through the suction flange110and into the internal pump volume, and then discharges the liquid L out of the internal pump volume through an opening at the discharge flange112.

From the above, it is to be appreciated that defined herein is a magnetic drive sealless pump that provides a steam jacket to the exterior of the containment shell to inhibit solidification of the fluid being pumped, such as in molten sulfur pump applications. The steam jacket enhances temperature control and stability of the fluid being pumped.

While particular embodiments have been illustrated and described herein, it should be understood that various other changes and modifications may be made without departing from the scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, such aspects need not be utilized in combination. It is therefore intended that the appended claims cover all such changes and modifications that are within the scope of the claimed subject matter.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.