WO2020104050A1

WO2020104050A1 - Pump device

Info

Publication number: WO2020104050A1
Application number: PCT/EP2019/000313
Authority: WO
Inventors: Zoran Vujic; Frank Steiner; Álvaro PÉREZ-SAJADO KAMPS; Felix Sassen; Paul BELZ; Emil Kostov
Original assignee: Westinghouse Electric Germany Gmbh
Priority date: 2018-11-24
Filing date: 2019-11-13
Publication date: 2020-05-28
Also published as: UA126030C2; EP3884165A1; DE102018009260A1

Abstract

The invention relates to a pump device (50) for conveying a contaminated liquid by means of a pump which is driven by a hydraulic drive, said hydraulic drive being driven by a drive liquid and the pump and the hydraulic drive being connected mechanically. In addition, a pump shaft of the pump and a hydraulic drive shaft of the hydraulic drive are mounted by means of plain bearings (62, 64, 66, 100, 102). The drive liquid is a lubricating medium for the plain bearing (62, 64, 66). Drive liquid is thus carried to the plain bearings (62, 64, 66, 100, 102) by at least one lubricating medium conduit (78, 80) and the drive liquid, after flowing through the sliding bearings (62, 64, 66, 100, 102), can be conducted out of the pump device.

Description

Pump device

description

The invention relates to a pumping device for conveying a contaminated liquid with a pump which is driven by a flydraulic drive, the flydraulic drive being drivable by a drive fluid, and the pump and the fluid drive being mechanically connected.

Pumping devices for conveying contaminated liquids are very special devices that have to meet a variety of extreme design conditions. For example, such devices are also used at high pressures and high temperatures. The type of contamination of the liquid also plays a role. Essentially, radioactive contaminated liquids or liquids which are contaminated by chemical substances, for example toxic, caustic or acidic substances, come into consideration.

An important application for a pumping device for conveying contaminated liquids is therefore the conveying of liquids contaminated with radioactive substances, in particular water. It is generally known that a large number of precautions are taken to protect the environment from possible damage in the event of a malfunction in nuclear plants. An accident can be accompanied by an increased temperature development within a nuclear reactor if the intended nuclear reactor safety cooling systems fail. In such In some cases, the thermal energy generated on the reactor side, for example the secondary power, is not dissipated to a sufficient extent and the nuclear reactor may overheat.

In order to ensure the highest level of safety even in the event of a malfunction, a nuclear reactor is surrounded by a hermetically sealed safety container or a containment / confinement, which means that in the event of a malfunction, the radioactive substances that may escape from the reactor core cannot escape into the environment, but rather be held back in the containment. A safety medium collection area or a so-called reactor sump is usually provided within a security container, in which in the event of a malfunction, for example, radioactive contaminated cooling water escaping from a leaking cooling system is collected, cooled if necessary, and returned to the cooling system or the reactor core or other systems. There are also protection concepts in which a nuclear reactor is arranged in a cooling medium collection area, which is flooded with cooling water in the event of a malfunction in order to achieve increased cooling, the radioactive contaminated cooling water collecting in the cooling medium collection area also having to be cooled here.

In the event of a malfunction, the heat energy then generated by the nuclear reactor or another heat source in the safety container or in its cooling medium collection area must be conducted outside in the form of heated medium to be cooled. If this does not happen, an increased formation of water vapor could create a dangerous overpressure in the safety container, which should be released directly from the safety container into the environment if a critical level is exceeded, if a failure of the safety container is to be avoided.

To ensure adequate cooling, appropriate cooling systems are provided, which typically have a heat exchanger, by means of which it is ensured that radioactive contaminants remain within the containment and are not released into the environment. Such a heat exchanger is cooled on the primary side in a cooling circuit by the heated one Medium flows through, typically in the event of an accident of radioactively contaminated water. The secondary side of such a heat exchanger is flowed through by a coolant, which absorbs heat energy from the heated to cool the medium and cools it, but does not come into direct contact with it, so that it is not contaminated by it. The uncontaminated coolant in turn emits the thermal energy it absorbs to a heat sink outside the containment.

Depending on the type of accident, such cooling systems must be very powerful and able to transport larger amounts of heat from the cooling medium collecting area of a safety container to the outside even over a long period of time, for example two months or more. For this purpose, it is customary in accordance with the prior art to force a flow of the medium to be cooled through the cooling circuit by means of electric motor-driven pumps. This leads to an increased heat throughput of the heat exchanger and thus to an increased cooling effect. Here, the electric motors for the pumps are arranged within the containment.

A disadvantage of this prior art is that, especially in the event of a malfunction, the operation of active drive devices such as motors within the containment can be associated with increased uncertainty due to the conditions prevailing in the event of a malfunction, such as elevated temperature and an atmosphere with radioactive contaminated steam. This contradicts the safety endeavor to maintain the highest level of reliability of the safety container cooling system, especially in the event of a malfunction.

Patent document DE 10 2011 107470 A1 discloses a nuclear reactor cooling system, comprising a reactor pressure vessel, which in turn is arranged within a first spatial area surrounded by a first protective wall, and a second spatial area, which is arranged at a similar geodetic height to the first area and is surrounded by a second protective wall since it is intended to collect cooling water emerging from a primary cooling system interacting with the reactor pressure vessel. The nuclear reactor cooling System has means to flood the first spatial area with cooled cooling water in an emergency.

From a German patent application it has also become known that a safety container cooling system has a heat exchanger and a pump, the pump being driven by a turbine. In this way, the electric motor-driven pump is avoided.

Based on this prior art, it is an object of the invention to provide a pump device for conveying a contaminated liquid with a pump which is driven by a hydraulic drive, which is suitable for trouble-free long-term operation and thereby avoids contamination of the drive fluid of the hydraulic drive.

The object is achieved by a pump device for conveying a contaminated liquid with a pump which is driven by a hydraulic drive, where the hydraulic drive can be driven by a drive liquid, and the pump and the liquid drive are mechanically connected. The pump device is characterized in that a pump shaft of the pump and a hydraulic drive shaft of the hydraulic drive are supported by slide bearings, that a lubricant for the slide bearings is the drive fluid, that drive fluid is guided to the slide bearings by at least one lubricant medium line, and that the drive fluid after one Flow through the plain bearing can be diverted from the pump device.

The pump for conveying a contaminated liquid is driven by a hydraulic drive. A hydraulic drive can be, for example, a drive turbine, a drive pump or a hydraulic motor. In any case, a drive of the pump with electrical auxiliary energy is avoided, the electrical auxiliary energy can fail on the one hand during the operating time and on the other hand, electric motors are comparatively prone to failure. The use of an internal combustion engine as a drive for such a pump is also avoided. An internal combustion engine is also unsuitable for the use of the pump according to the invention. The basic idea of the invention is to provide the movable Chen or rotating parts by plain bearings instead of the usual bearing with rolling elements, such as balls in ball bearings. Slide bearings are also significantly more robust against mechanical influences, for example small particles that could penetrate the slide bearing. Plain bearings are usually lubricated with a lubricant that reduces the friction of a moving surface of the plain bearing against a fixed surface of the plain bearing. The invention provides that the drive fluid of the hydraulic drive is used as the lubricant or lubricant. In this way, the pump device is only dependent on a supply medium that both operates or drives the hydraulic drive of the pump device and also provides the lubricant for the storage of the pump device. This avoids a further possible source of error for the failure of such a pump device, as a result of which the pump device itself becomes more robust and is suitable for long-term operation. In this context, robust is understood to mean that the pumping device can be operated over a long period of time without failure, that is to say in an actionable or functional state. A long period of time, or suitable for long-term operation, is, for example, a period of at least two months or possibly an even longer period of, for example, six or twelve months of uninterrupted operation. In addition, the pump device provides that the drive fluid is not only passed to the slide bearings as a lubricant, but is also discharged from the pump device after the slide bearings have flowed through. This means that a constant volume flow of drive fluid, but a comparatively small partial flow of the drive fluid made available for the hydraulic drive, flows through the slide bearing, for example absorbing the heat generated in the slide bearing by friction, the slide bearing being cooled in this way. After flowing through the plain bearing, which can have two or more plain bearings, the heated drive fluid is discharged from the pump device, thus ensuring effective cooling of the pump device as a whole. Finally, depending on the ambient conditions, the pump device itself can also absorb heat via its housing. The heat absorbed is via the mechanism described above, namely the flow of the drive fluid in the storage area of the pumping device or inside the housing thereof, and the subsequent discharge of the heated drive fluid into an area outside of the Release the pumping device again. This ensures effective cooling for both robust and long-term operation.

In addition, a pressure at which the drive fluid is fed to the hydraulic drive is in any case higher than the pressure at which the contaminated fluid to be conveyed has. In this way it is ensured that, due to the pressure relationships between the drive liquid and the contaminated liquid to be pumped, the drive liquid inside the housing or the bearing housing of the pump device only moves in the direction of the contaminated liquid. A backflow of contaminated liquid in the direction of the drive liquid is not possible due to the pressure conditions - the pressure drop between the drive liquid and contaminated liquid - during operation of the pump device. Contamination of the drive fluid with contaminated fluid is thus prevented. In addition, a backflow preventer, non-return flaps or the like can also be arranged at a suitable point, for example in the housing of the pump device, in order to prevent the backflow of contaminated liquid even when the pump is at a standstill. In addition, the design of a pump impeller ensures that the final pressure of the pump is in any case lower than the pressure prevailing in the drive medium that the hydraulic drive is supplied to. Another constructive possibility to ensure the above-mentioned pressure conditions is also to match the constructive design of the impeller of the hydraulic drive to the design of the pump wheel in such a way that a higher pressure on the outflow side of the pump than the pressure in the drive medium is avoided.

An advantageous embodiment of the pump device is characterized in that the pump and the hydraulic drive have a common rotary shaft. This simplifies the construction. The pump device is made compact and also has fewer parts that could fail during operation of the pump device. This advantageously reduces possible sources of error. This promotes trouble-free long-term operation.

Another variant of the pump device provides that the rotary shaft is arranged in a bearing housing. A common bearing housing in which the common rotary shaft is arranged also simplifies the construction of the pumping direction and enables an even more compact design. For example, this reduces the number of seals required on shafts. This technical measure also favors long-term operation.

The pump device can also be configured such that an axis of rotation of the rotary shaft is arranged vertically, as seen in the geodetic direction. In this way, an intake port of the pump can be positioned at a position that is as low as possible in the geodetic direction. This is advantageous if, for example, the pump device is arranged in a pump sump or liquid sump, so that inlet conditions for the liquid to be pumped into the suction side of the pump are most favorable at this geodetically located point. Such pumps, which are at least partially immersed in the liquid to be pumped, are then also referred to as submersible pumps, for example.

Another advantage of the pump device is obtained if an impeller of the pump and / or a drive wheel of the flydraulic drive are mounted on the fly, i.e. Both the impeller and the drive wheel are attached to one shaft end, in particular to the shaft ends of a common rotary shaft. This provides the constructive possibility of providing both the pump and the hydraulic drive with a common bearing for the common rotary shaft. As a result, a very compact construction is possible, which at the same time is particularly robust because it has the smallest possible number of components.

To supply the bearing of the pump device, it is provided that a lubricant medium line is designed as a recess or bore in the bearing housing. The lubricant line is therefore integrated in the bearing housing. This also serves to further simplify the construction and compact design.

According to a further variant, the pumping device is designed in such a way that a first end of a lubricant medium line is arranged at a point in the bearing housing which is enclosed by a hydraulic drive housing. In this way, the drive liquid is taken directly from a pressure side of the hydraulic drive, that is to say a point in which the pressure of the supplied drive liquid prevails, and directed to a point in the region of the slide bearings, so that the drive flow liquid is fed to the plain bearings as a lubricant and serves as a lubricant for the plain bearings. The supply of the sliding bearing with lubricant is particularly simple and insensitive to failure. This configuration also makes a contribution to trouble-free long-term operation.

As an alternative to discharging drive fluid somewhere on the pump device or on the bearing housing, it is advantageous if a seal or a sealing system is arranged between the bearing housing and the rotary shaft, by means of which the penetration of contaminated liquid into the bearing housing is prevented. In this way, even when the pump device is at a standstill or when it is not in operation or in a transient operating state during starting or stopping the pump device, it is ensured that no contaminated liquid passes through a space between the bearing housing and the rotary shaft penetrates into the inner area of the bearing housing.

A further embodiment of the seal of the pump device provides that the seal is a spring-loaded mechanical seal, that the mechanical seal is closed by spring forces of the spring-loaded mechanical seal when the hydraulic drive is out of operation, that the mechanical seal is opened slightly against a spring force of the spring when the hydraulic drive is in operation, and that a small partial flow of the drive fluid from an inner region of the bearing housing passes through a gap between the slide ring and the counter ring of the mechanical seal into an interior of the pump housing when the hydraulic drive is in operation. In this way, the ingress of contaminated liquid into the inner region of the bearing housing of the pump device is reliably avoided when the pump device is out of operation. In addition, it is ensured that penetration of contaminated liquid into the inner region of the bearing housing during operation of the pump device is avoided by the outflow of a small partial flow of the drive liquid through the gap. At the same time, the mechanical stress on the mechanical seal during operation of the pump device is reduced, since in the operating case the mechanical seal and the counter ring of the mechanical seal are lubricated by the drive fluid and accordingly are not subject to wear. This increases the service life of the mechanical seal and thus of the pump device as a whole. A further embodiment of the seal of the pump device provides that the seal is a spring-loaded mechanical seal, that the mechanical seal is constantly closed by spring forces of the spring-loaded mechanical seal, regardless of whether the hydraulic drive is in operation or not, and that a partial flow of the drive fluid from one Inside the bearing housing through radial holes in the rotating shaft (and rotating components) and a connected axial hole in the rotating shaft enters a low-pressure interior of the hydraulic drive housing when the hydraulic drive is in operation. Due to the permanently sealed mechanical seal, the penetration of contaminated liquid into the inner area of the bearing housing of the pump device is reliably avoided, regardless of whether the pump device is in operation or not. At the same time, the mechanical load on the mechanical seal is reduced during the operation of the pump device, since the force acting on the mechanical seal is reduced and, accordingly, is less loaded. This increases the service life of the mechanical seal and thus of the pump device as a whole. In the case of using the pumping device in a nuclear power plant, a loss of secondary-side cooling medium from the hydraulic housing of the pumping device into the pump housing (ie into the safety container) is avoided in particular.

An advantageously configured pump device is also characterized in that the volume flow of the drive fluid flowing from the hydraulic drive housing through the lubricant medium lines into the bearing housing of the pump device is dimensioned for a defined operating state in such a way that the heat flow resulting from the friction on the slide bearings is generated by this volume flow and / or the heat flow transferred from an environment to the pump device is conveyed through the gap into the pump housing or through the bores in the rotary shaft into the hydraulic drive housing. Are the volume flow of the drive fluid calculated in the above manner and the components designed accordingly, for example, taking into account a gap width of the gap or a diameter of the bores in the rotary shaft, the pressure ratios of drive fluid and contaminated fluid to be conveyed, the pressure and lubricant requirements the slide bearing, etc., the pump device is in partially designed robust and has a correspondingly long trouble-free operating time with full functionality.

A further embodiment of the pump device is achieved if the seal is made of a material and is designed such that it can function with a liquid contaminated by a predetermined radioactive radiation during an operating time of at least two months, but also up to six or twelve months or that it can function as a contaminated liquid during a period of operation of at least two months, but also up to six or twelve months, with a predetermined load of an acid or an alkali. An important property of the pump device is to have a robust design, that is to guarantee a long operating time, although the contaminated liquid to be conveyed often places high demands on the material, in particular the material of the seal. Flierfür proposes to choose a sealing material that can withstand the contaminated liquid to be pumped for a correspondingly long time and at the same time ensures the technical function of the tightness.

These are, for example, acid or alkali-resistant plastics or radiation-resistant elastomers or polymer materials.

Further advantageous design options can be found in the further dependent claims.

The invention, further embodiments and further advantages are to be described in more detail on the basis of the exemplary embodiments illustrated in the drawings.

Show it

Fig. 1 is a schematic diagram of an exemplary safety container cooling system, and

2 shows an exemplary pump device for use in a safety container cooling system.

Figure 1 shows a schematic diagram of an exemplary first safety container cooling system 10 according to a prior art as an application example for an inventive pump device. A security container 12, in this case a con- tainment / confinement made of concrete or steel for a nuclear reactor, encloses an atmospheric area 14 and a cooling medium collecting area 18, for example a reactor sump. The cooling medium collecting area 18 is filled with a medium 16 to be cooled, in this case with cooling water, the surface of which is indicated by a line in the figure. The medium to be cooled is heated by a heat source 40, in this example a nuclear reactor located at least partially in the cooling medium collecting area 18, which in the event of a specific malfunction releases its decay power to the medium 16 to be cooled. Typical pressures and temperatures of the medium to be cooled are, for example, in the range from 1 bar to 4 bar or in the range from 50 ° C. to 110 ° C.

The medium 16 to be cooled is guided in a first cooling circuit through the primary side 22 of a heat exchanger 20 located above the cooling medium collecting area 18. Below the surface of the medium 16 to be cooled, a first pump arrangement 38 is arranged in the cooling medium collecting area 18, which presses the medium to be cooled from below into the primary side 22 of the first heat exchanger 20 via a line 26. There the medium is cooled and exits again as a cooled medium via a line 28. The line 28 can either be returned directly to the cooling medium collection area, but in the drawing it is indicated that the line 28 ends in the atmospheric area 14 and the medium 16 is distributed via crushing or spraying devices, not shown, and is then collected again in the cooling medium collection area 18 .

The secondary side 24 of the heat exchanger 20 is flowed through by a coolant, which is supplied via a second pump arrangement 34 through a line 30 from outside of the security container 12. The second pump arrangement 34 sets the coolant in such a way that a turbine 36 arranged in the line 30 is driven thereby. The first pump arrangement 38 is coupled to the turbine 36 in such a way that it is driven by it. In this case, the first pump arrangement 38 and the turbine 36 are mechanically coupled to one another by a common rotary shaft. Thus, the medium to be cooled in the first cooling circuit is indirectly caused to flow by a motor arranged outside the security container 12 or another drive device of the second pump arrangement 34. This means that an active electric motor, such as a Internal combustion or electric motor for driving the first pump arrangement 38 within the containment 12 is advantageously avoided.

After flowing through the secondary side 24 of the heat exchanger 20, the then heated coolant is passed via a line 32 to the outside of the containment 12, where the thermal energy is then given to any heat sink.

The first safety container cooling system 10 shown in the figure is only intended to serve as an example of how a pump device according to the invention is used in a field of technology which, in the event of a corresponding accident in a nuclear power plant, contaminates liquid, namely essentially water, the radioactive particles or May contain components is used. A corresponding example can, however, also be found easily for a chemical plant in which chemical fluids collect at a geodetically low-lying point and contaminate this area accordingly. Whether the liquid to be conveyed is actually contaminated or not is irrelevant to the operation of the pump device. In any case, the pumping device is designed to convey the contaminated liquid, which also includes the conveyance of normal, ie non-contaminated liquid.

2 shows an exemplary pump device 50 that has a shaft 52 that rotates about an axis of rotation 54. In this top view, a drive wheel 56 is attached to an upper shaft end. In the example selected, a centrifugal pump wheel is selected as the drive wheel 56 and a screw connection is selected as the connection between the drive wheel 56 and the upper shaft end. However, it is also within the inventive concept if a hydraulic turbine with a turbine wheel or another type of pump with an impeller or impeller is used as the hydraulic drive. In addition, a tongue and groove connection or a form-fitting connection type can also be selected as the type of connection between the drive wheel 56 of the shaft 52. In this bottom view, a pump impeller 58 is also attached to a lower shaft end. A centrifugal pump is shown as the type of pump in the exemplary embodiment shown, which means for the pump impeller 58 that it is a centrifugal pump wheel. Both the drive wheel 56 and the pump impeller 58 are attached to one of the shaft ends, so they are overhung.

The shaft 52 is arranged in a bearing housing 60, the bearing being carried out by means of a slide bearing system which transfers both axial and radial bearing forces from the shaft 52 into the bearing housing 60. The bearing housing 60 has fastening means with which it can be connected, attached or mounted on the floor or on a fixed component at the installation location. However, this is not shown in the figure. The plain bearing system has a plain bearing sleeve 62 which has the shape of a tube piece, the inner diameter of which is adapted to an outer diameter of the shaft 62. In addition, the slide bearing sleeve 62 is connected to the shaft 52, so that both components rotate together when the pump device 50 is operating. In addition, the plain bearing system has a first 64 and egg NEN second plain bearing ring 66, which are each connected to the bearing housing 60. Accordingly, the plain bearing rings 64, 66 remain stationary at their installation location in the bearing housing 60, even when the shaft 52 rotates. In addition, the slide bearing system has a third slide bearing ring 100 and a fourth slide bearing ring 102, which are each connected to the shaft 62, so that these slide bearing rings rotate together with the shaft when the pump device 50 is in operation. A length of long-term operation with the pump device 50 can be influenced by selecting the diameter of the shaft 52 to be larger than would be necessary according to a design based on the minimum values of a calculated shaft diameter. In the same way, the length of long-term operation can be increased by selecting the slide bearing system to be larger than would be necessary for the slide bearing system as a minimum size according to a calculation.

On the side of the bearing housing 60 facing the drive wheel 56, a first shoulder 68 is attached to the bearing housing 60. The first paragraph 68 is provided as a connection point for a drive housing, which is not shown in the figure. However, two indicated screws 70 are intended to show that the drive housing can be connected, for example, with screws to the first shoulder 68 and thus to the bearing housing 60. With a mounted drive housing, the drive wheel 56 is completely enclosed by an interior of the drive housing. The drive housing itself has an inlet and at suitable points a drain opening for a drive medium, such as water, oil or other liquids. For use in the nuclear field for the example shown in the figure, however, water is generally used as the driving fluid.

The bearing housing 60 also has a first 72 and a second bore 74. Each of the bores 72, 74 is closed on its side facing the external environment with a screw plug 76. For example, this can be opened temporarily for ventilation purposes. Otherwise, they serve for the liquid-tight sealing of the bores 72, 74. The bores 72, 74 also each have a further opening on the side opposite the locking screws 76 to the inside of the bearing housing 60. The further opening is between the first 64 and second slide bearing rings 66 arranged. In addition, the first bore 72 is connected to a first end of a first lubricant medium line 78, a second end of the first lubricant medium line 78 ending at a point in the bearing housing 60 which faces the interior of the drive housing, so that the interior of the drive housing is hydraulically connected to the other Opening is connected. A correspondingly designed second lubricant medium line 80 also connects the second bore 74 to the interior of the drive housing. In the example shown, the lubricant lines 78, 80 are designed as bores in the bearing housing 60. In addition, a connecting line 82 is shown, which in the exemplary embodiment shown is also designed as a bore in the bearing housing 60, which connects the first bore 72 hydraulically with an inner region of the housing interior of the bearing housing 60 facing the pump impeller 58. In addition, on the side facing the pump impeller 58 of the bearing housing 60, a second shoulder 84 is formed on the bearing housing 60, the second paragraph 84 being provided for positioning and flanging a pump housing which completely surrounds the pump impeller 58. The connection between the pump housing and the second shoulder 84 is indicated by connecting screws 86. The pump housing is not shown in the figure, but has a suction opening and a pressure-side outlet opening for the liquid to be pumped. An essential area of application of the pump device 50 is the conveyance of contaminated liquid. Contaminated liquid is to be understood as a contamination with radioactive substances, as occurs, for example, in the event of a serious accident in a nuclear power plant. A contaminated liquid can also be a contaminated nation with chemical substances, for example acids or alkalis or otherwise harmful substances or poisons or liquids. The materials used for the pumping device must then also be designed in particular for the type of contamination. This means that the materials used endure a radioactive radiation of a fixed amount for a certain period of time, for example 2 or 3 months, but up to six or twelve months, in such a way that the function of the pump device is retained. The same applies to a contamination of the material by chemical contamination. A functional operation of the pump device of at least two months is already considered as trouble-free long-term operation.

An important property of the pump device 50 is to prevent contaminated liquid from getting into the drive liquid. In operation of the pump device 50, this is achieved as follows. A drive fluid is introduced into the interior of the housing via the inlet opening in the drive housing, and the drive wheel 56 is thereby set into a rotational movement by the movement of the drive fluid to be directed. Together with the drive wheel 56, the shaft 52 and the pump impeller 58 rotate. At the same time, the drive fluid under a predetermined drive pressure passes from the housing interior of the drive housing via the lubricant medium lines 78, 80 into the bores 72, 74. A partial flow of the drive fluid in the bores 72, 74 reaches an area formed by the slide bearing sleeve 62, the slide bearing rings 64, 66 and the bearing housing 60. The drive fluid under the drive pressure also flows in the area of sliding surfaces between the plain bearing rings 64, 66 and the plain bearing sleeve 62, or in the area of sliding surfaces between the plain bearing rings 64 and 100, or 66 and 102, so that a lubricating medium film is formed in the sliding bearings by the drive fluid, which is independent of the rotational movement of the shaft 52. As a result, the friction or wear due to friction in the slide bearings is advantageously reduced, regardless of the operation or the rotational movement of the shaft. Even in the operating case of the pump device 50, sufficient lubrication of the sliding surfaces as a whole is ensured by a steady inflow of drive fluid which serves as a lubricant for the sliding bearing system. Another partial flow of the drive fluid passes via the connecting line 82 into the inner region 88 of the bearing housing facing the pump impeller 58. ses 60. Contaminated liquid could get into this inner region, which is sucked in by the pump with its pump impeller 58 during operation and is then in contact with the side of the bearing housing 60 facing the pump impeller 58. However, this is prevented by the further partial flow of the drive fluid. The further partial flow is namely under the same pressure as the drive fluid, which is selected to be higher than the pressure prevailing on the side of the bearing housing 60 facing the pump runner 58. In this way, a steady, low fluid flow of drive fluid from the drive side of the pump device 50 through the bearing housing 60 to the pump side is ensured. The volume flow of the further partial flow is united by the choice of the diameter of the connecting line 82 and by the choice for the pressure of the drive fluid

adjustable. A backflow of contaminated liquid towards the drive side is thus reliably prevented during operation. In the example shown, it is also provided that, due to the design or configuration of the pump impeller 58, no pressure can occur on the pressure side of the pump that is greater than the pressure in the drive fluid. For safety and reliability reasons, the design pressure for the pump impeller is even selected to be lower by a certain pressure difference than the pressure in the drive fluid.

Another application of the pump device 50 is the use as a submersible pump device. Then the case may arise that the pump device 50 is in contaminated liquid while the pump device 50 is not in operation. In this case, too, it is expedient for contaminated liquid to penetrate into the inner region 88, that is to say the inside of the bearing housing 60, and thus for possible mixing of contaminated liquid with the drive liquid to be avoided. To avoid the ingress of contaminated liquid, a mechanical seal 90 is arranged according to the invention between a static component of the bearing housing 60 and a rotating component of the shaft 52 or a rotating shaft. The secure closing between rotating and standing parts of the pump device 50 is shown in FIG. 2 in the view shown on the right half of the figure. In addition, a slide ring system has a plurality of springs, of which a spring 92 is shown. The spring 92 is arranged in a cover 94 and a slide ring holder 96 in such a way that the spring force of the spring 92 causes the mechanical seal 90 against the shaft 52 or against the shaft 52 rotating component is pressed. In this way, the sealing effect of the mechanical seal 90 is improved. In the exemplary embodiment shown, the situation is shown on the right half of the figure when the pump device 50 is out of operation. Then the inner region 88 is depressurized, so that penetration of contaminated liquid into the inner region 88 is prevented by the spring-loaded mechanical seal 90. If the pump device 50 is now put into operation, a pressure builds up in the inner region 88 which corresponds to that of the drive fluid. Since the pressure of the drive fluid is higher than the pressure of the contaminated fluid and is also high enough to act against the spring forces of the springs of the mechanical seal system, the mechanical seal 90 moves in the direction in which the spring 92 is compressed. This removes the sliding surface of the mechanical seal 90 from the rotating component, so that a gap 98 is formed, which is shown on the left half of the figure. In this way, drive fluid in the operating case of the pump device 50 passes from the inner region 88 via the driving pressure gradient into the contaminated liquid. In this way, the mechanical load on the mechanical seal 90 is advantageously prevented or at least reduced during operation of the pump device 50, for example due to friction or abrasion. The mechanical seal 90 is thus lubricated at least in the period of starting the pump device 50 and in the transient phase from the start of the pump device 50 to continuous operation. Finally, the mechanical seal only has to have its sealing effect when the pump device 50 is out of operation or in the transient phase described when starting or ending the operation. In addition, the sealing effect is then supported by the spring action of the springs. During operation of the pump device 50, a steady, small liquid flow of drive liquid from the inner area 88 via the gap 98 into the contaminated liquid ensures the tightness. In this way, the operation of the Pumpvor device 50 under high pressures of, for example, 5 bar, 10 bar, 20 bar, 50 bar or even higher pressures and under high ambient temperatures of, for example, 50 ° C, 90 ° C, 120 ° C or even guaranteed higher without problems. Reference list

10 safety container cooling system

12 security containers

14 atmospheric area

16 medium to be cooled

18 Coolant collection area

20 first heat exchanger

22 primary side

24 secondary side

26 line

28 line

30 line

32 line

34 second pump arrangement

36 turbine

38 first pump arrangement

40 heat source

50 pumping device

52 wave

54 axis of rotation

56 drive wheel

58 pump impeller

60 bearing housings

62 plain bearing sleeve

64 first plain bearing ring

66 second plain bearing ring

68 first paragraph

70 screws

72 first hole

74 second hole

76 screw plugs

78 first lubricant line

80 second lubricant line 82 connecting line 84 second paragraph 86 connecting screws 88 interior

90 mechanical seal

92 spring

94 cover

96 slide ring holder

98 gap

100 third plain bearing ring 102 fourth plain bearing ring

Claims

1. Pump device (50) for conveying a contaminated liquid with a pump which is driven by a hydraulic drive, the hydraulic drive being drivable by a drive liquid, the pump and the hydraulic drive being mechanically connected,

characterized in that

a pump shaft of the pump and a hydraulic drive shaft of the hydraulic drive are mounted by slide bearings (62, 64, 66, 100, 102) that a lubricant for the slide bearings (62, 64, 66, 100, 102) is the drive fluid that by at least one Lubricant line (78, 80) drive fluid to the plain bearings (62, 64,

66, 100, 102) and that the drive fluid can be discharged from the pump device after flowing through the slide bearings (62, 64, 66, 100, 102).

2. Pump device (50) according to claim 1, characterized in that the hyd raulikantrieb is a drive turbine, a drive pump or a hydraulic motor.

3. Pump device (50) according to claim 1 or 2, characterized in that the pump and the hydraulic drive have a common shaft (52).

4. Pump device (50) according to claim 3, characterized in that the shaft (52) is arranged in a bearing housing (60).

5. Pumping device (50) according to claim 3 or 4, characterized in that an axis of rotation (54) of the shaft (52) is arranged vertically as seen in the geodetic direction.

6. Pump device (50) according to one of the preceding claims, characterized in that an impeller of the pump and / or a drive wheel of the hydraulic drive are overhung.

7. Pump device (50) according to claim 4 or 5, characterized in that a lubricant medium line (78, 80) is designed as a recess or bore in the bearing housing (60).

8. Pump device (50) according to one of the preceding claims, characterized in that a first end of a lubricant medium line (78, 80) is arranged at a point in the bearing housing (60) which is enclosed by a hydraulic drive housing.

9. Pump device (50) according to one of the preceding claims, characterized in that a seal or a sealing system is arranged between the bearing housing (60) and the shaft (52), through which penetration of contaminated liquid into the bearing housing (60) is prevented.

10. Pumping device (50) according to claim 9, characterized in that the sealing device is made of a material and is designed such that it is functional during an operating time of at least two months with a liquid contaminated by a predetermined radioactive radiation or or it is functional as a contaminated liquid during a period of operation of at least two months with a predetermined load of an acid or an alkali

11. Pump device (50) according to claim 9 or 10, characterized in that the seal is a spring-loaded mechanical seal (90), that the mechanical seal (90) is closed by spring forces of the spring-loaded mechanical seal (90) when the hydraulic drive is out of operation, that the mechanical seal (90) is opened against a spring force of the spring (92) or springs (90) when the hydraulic drive is in operation, and that a partial flow of the drive fluid from an inner region (88) of the bearing housing (60) through a gap (98) between the mechanical seal (90) and the shaft (52) into an interior (88) of the pump housing when the hydraulic drive is in operation.

12. Pump device (50) according to one of claims 9 to 1 1, characterized in that the seal is a spring-loaded mechanical seal (90) that by Spring forces of the spring-loaded mechanical seal (90), the mechanical seal (90) is constantly closed, regardless of whether the hydraulic drive is in operation or not, and that a partial flow of the drive fluid from an inner region (88) of the bearing housing (60) through at least one radial recess in the shaft (52) or in rotating components and an axial recess connected to the at least one radial recess in the shaft (52) reaches an inner region of the hydraulic drive housing that has a lower pressure than the pressure in the drive fluid that is supplied to the hydraulic drive housing when the hydraulic drive is in operation.

13. Pump device (50) according to claim 1 1, characterized in that a volume flow of the partial flow of the drive liquid for a defined Betriebszu was dimensioned such that the volume of heat generated by the friction on the plain bearings and / or by a The amount of heat transferred to the pump device is absorbed and is conveyed through the gap (98) into the pump housing.

14. Pump device (50) according to any one of the preceding claims, characterized in that a partial volume flow of the drive fluid, which serves as a lubricant, is dimensioned for a defined operating state such that the amount of heat generated by the friction on the slide bearings and / or the amount of heat transferred from an environment to the pump device is absorbed.