WO2017097898A1

WO2017097898A1 - Heatable screw spindle pump

Info

Publication number: WO2017097898A1
Application number: PCT/EP2016/080246
Authority: WO
Inventors: Thomas Eschner
Original assignee: Klaus Union Gmbh & Co. Kg
Priority date: 2015-12-08
Filing date: 2016-12-08
Publication date: 2017-06-15
Also published as: DE102015121372A1

Abstract

The invention relates to a heatable screw spindle pump (10) comprising a housing (12) surrounding a delivery chamber, at least one rotor (18) having a thread-type profile, a housing insert (20) arranged in the housing (12) and surrounding the rotor (18), and at least one separating wall (22) that divides the the delivery chamber into a suction chamber (14) and a pressure chamber (16), wherein the rotor (18) delivers a fluid axially from the suction chamber (14) into the pressure chamber (16). The object of the invention is to provide a screw spindle pump that is improved in relation to the state of the art, by means of which the fluid to be delivered can be reliably heated. The heating is to be cost-effective and safe. For this purpose, according to the invention, the delivery chamber also has a heating chamber (24) that is sealed in relation to the suction chamber (14) and the pressure chamber (16), which can be supplied with a heating medium, wherein the heating medium in the heating chamber (24) comes into heat-conducting contact with the housing insert (20).

Description

The invention relates to a heatable screw pump with a housing which surrounds a delivery chamber, at least one rotor with thread-shaped profiling, a housing insert which is arranged in the housing and surrounds the rotor, and at least one partition wall which moves the delivery chamber into a suction chamber. and a pressure space divided, wherein the rotor promotes a fluid axially from the suction to the pressure chamber.

Screw pumps are known in various configurations from the prior art. These are positive displacement pumps. Screw pumps each comprise at least one rotor with thread-shaped profiling (screw conveyor), a housing and a housing insert or liner which encloses the at least one rotor without contact. Generic screw pump preferably have two or more counter-rotating rotors that mesh with each other like a gear. By the rotor / rotors or by its / their thread-shaped profiles and the housing insert delivery chambers for the fluid are formed. During rotor rotation, they migrate axially in one machine direction and thus convey the medium from the suction space into the pressure space. The housing of the pump encloses a delivery chamber, which is divided by partitions in suction and pressure chamber. Most of the partitions are integrally formed with the housing insert. The housing insert is usually held over the partitions in the housing. Screw pumps are used in particular in the promotion of highly viscous fluids (eg bitumen). In order to promote the viscous and poorly flowing fluid, high forces must be applied. Furthermore, the poor flowability leads to high wear of the pump components. In order to improve the fluidity of the fluid, it is therefore known to heat the pumps and thus the fluid. For some fluids, heating is a prerequisite for their ability to be conveyed. This plays an important role especially when starting the pumps after a standstill. If the viscosity of the fluid cooled in the stationary pump is too high, the pump can no longer start up and the required forces can not be applied.

The heating takes place in the prior art, in particular by means of a heating jacket arranged outside the housing. In this case, heating elements (for example in the form of chambers to be acted upon by a heating medium, which are heat-transmittingly connected to the housing) are arranged on the housing and heat the entire pump and thus indirectly also the fluid in the housing insert. Another known way to heat the fluid is the use of a Heizfußes on which the housing is. Here, the heat in the lower part of the pump, in turn, introduced through the housing.

A disadvantage of the known heaters is that the heating elements used are removed from the housing insert to be heated or the fluid. The heat generated by the heating elements must be transported through the housing and the delivery chamber to the housing insert therein by heat conduction before it can eventually heat the fluid inside, in the field of conveying screws. This requires a comparatively high energy input. Furthermore, the housing can no longer be reliably checked for signs of corrosion or wear by the heating jacket covering the housing. In addition, the equipment of the housing with heating jacket is complicated and expensive. This is especially true when using superheated steam as the heating medium, since in this case must be meticulously paid attention to the tightness. Escaping hot steam is a significant source of danger. Against this background, it is an object of the invention to provide an improved over the prior art screw pump with which the fluid to be delivered can be reliably heated. The heating should be inexpensive and safe. This object is achieved by a screw pump with the features of claim 1. Advantageous embodiments are the subject of the dependent claims. It should be noted that the features listed individually in the claims can also be combined with one another in any desired and technologically sensible manner and thus show further embodiments of the invention.

The screw pump according to the invention comprises a housing which surrounds a delivery chamber, at least one rotor with thread-shaped profiling, a housing insert which is arranged in the housing and surrounds the rotor, and at least one partition which divides the delivery chamber into a suction and a pressure chamber, wherein the rotor delivers fluid axially from the suction to the pressure space. The above object is achieved in that the delivery chamber additionally has a relative to the suction and the pressure chamber sealed heating chamber, which is acted upon by a heating medium, wherein the heating medium in the heating chamber with the housing insert heat transfer (preferably directly) comes into contact.

The screw pump according to the invention has the advantage over the prior art that the heat is introduced directly at the required location. The heating medium comes directly in heat transfer with the housing insert, in which the fluid to be heated is in contact. As a result, the energy costs are lowered and the fluidity of the fluid is effectively improved by reducing the viscosity. The usual in the art, outside the housing mounted heating jacket can be omitted. A special sealing of the boiler room with respect to the environment is not required, since the pump room, of which the boiler room is a part, is anyway tight to the environment. It is essential that the heating chamber is sealed against the suction chamber and the pressure chamber, so that it does not come to a mixing of the heating medium with the fluid to be delivered. Leaks in this area are undesirable, but in any case with regard to the use of superheated steam as a heating medium no danger to people staying in the vicinity of the pump.

Preferably, the partition may have bores or channels for receiving the heating medium. The holes then represent the heating chamber according to the invention. In a preferred embodiment of the screw pump according to the invention, the partition wall is integrally formed with the housing insert, wherein the partition is double-walled and having a first and a second wall. Between the two walls of the double-walled partition is then the boiler room. For the purposes of the invention, walls are basically disk-shaped elements which essentially extend from the housing insert, the liner, to an inner circumferential surface of the housing and have a greater extent in the radial direction of the pump than in the axial direction. The walls are not defined according to the invention to specific wall thicknesses. The wall thickness is measured in particular according to the pressure conditions in the spaces separated by the walls.

The partition or the partitions is / are inventively preferably in one piece with the housing insert, for example formed as a cast part. This simplifies the production. It is conceivable, for example, that the heating chamber is introduced by machining in the partition wall made with the housing insert as a casting. Alternatively, separate partitions to form suction, pressure and heating chamber can be generated by appropriate design of the mold, so that no further processing is necessary. In order to realize the seal between the heating chamber and the suction or pressure chamber, at least one circumferential seal is advantageously arranged on each partition or on each wall of the respective double-walled partition. The seal is arranged in particular on the respective outer circumference of the wall / the partition wall and lies on the inside of the housing. As seals preferably O-rings are used.

In an advantageous embodiment of the screw pump according to the invention two seals are arranged parallel to each other on the outer circumference of at least one wall or a partition wall. As a result, the separation between the heating medium and fluid to be conveyed can be further improved. Furthermore, the space located between the two seals can be advantageously used for receiving a measuring sensor. Ideally, a pressure measurement sensor may be disposed in the gap. This makes it possible to check the tightness between the suction or pressure chamber and the heating chamber during operation of the pump.

Furthermore, the heating chamber can be sealed off from the suction or pressure chamber by arranging an annular element, preferably by means of a material connection, on a side of the heating chamber facing the housing. The annular element has at least one inlet and one outlet opening for the heating medium. Only over the openings is a connection to the boiler room. In the openings of the ring, a pipe is preferably arranged in each case through which the heating medium in the heating chamber to or can be removed from this.

At least one sealing ring can be arranged on the inner circumferential surface of the housing. This sealing ring interacts with the arranged on the respective partition / the respective wall O-ring. The sealing ring projects radially inwards relative to the inner circumferential surface of the housing. This allows easy removal and insertion of the housing insert with the partitions / walls arranged thereon and the O-ring seals arranged in turn from the housing or into the housing in the axial direction. In an advantageous embodiment of the screw pump, each partition can be assigned exactly one sealing ring. If the dividing wall has two walls, then the walls or the seals arranged thereon interact with the same sealing ring on the housing. In principle, it is also conceivable that each wall is associated with exactly one sealing ring.

The housing of the screw pump according to the invention expediently has at least one inlet and at least one outlet for the heating medium, which are each arranged in the region of the heating chamber, for example in the form of corresponding through-holes. Advantageously, the inlet and the outlet are arranged substantially at radially opposite positions on the housing in order to achieve an optimal replacement of the heating medium. But it is also conceivable that the inlet and the outlet are arranged close to each other. If the heating space has a wall or separating element which preferably extends in the longitudinal direction of the screw pump, then the inlet and the outlet are advantageously arranged in front of and behind the separating element. If the heating medium is introduced via at least one pipe into the heating chamber according to the invention or let out again therefrom, then the pipes extend through the inlet and / or outlet of the housing. The pipeline may be immediately adjacent to the wall of the inlet or the outlet. But it is also conceivable that an O-ring, in particular an elastic O-ring, is arranged on the pipe, which adjoins the wall of the inlet or outlet. In addition to a sealing function, the O-ring can also compensate for movements of the housing insert. The heating medium in the boiler room can be liquid or vaporous. As a heating medium, for example, water can be used. This has a very high specific heat capacity. But also the use of superheated steam is possible. Furthermore, thermal oil can be used as the heating medium, in particular a mineral oil or a silicone oil. The heating space provided according to the invention can in principle also be combined with the heating options known from the prior art, such as heating jacket, heating foot or heating coils. The invention is preferred provided boiler room for this purpose by external piping or else by channels in the housing with another heating option.

The invention and the technical environment will be explained in more detail with reference to FIGS. It should be noted that the figures show a particularly preferred embodiment of the invention. However, the invention is not limited to the embodiment shown. In particular, the invention includes, as far as is technically feasible, any combination of the technical features that are listed in the claims or described in the description as being relevant to the invention. Shown are: schematic sectional side view of a double screw pump according to the invention in a first embodiment, schematic sectional side view of a double screw pump according to the invention in a second embodiment, schematic sectional side view of a double screw pump according to the invention in a third embodiment.

Figure 1 shows schematically a sectional side view of a screw pump 10 of the invention (in the embodiment is a double screw pump) in a first embodiment. The screw pump 10 according to the invention comprises a housing 12 which surrounds a delivery chamber. Furthermore, the pump 10 comprises at least one rotor 18 (in the double-screw pump, two counter-rotating rotors are arranged one behind the other in the illustration) with thread-shaped profiling and a housing insert 20, which is arranged in the housing 12 and surrounds the rotor 18. Furthermore, the Pump 10 at least one partition 22, which divides the pumping chamber into a suction chamber 14 and a pressure chamber 16. By means of the rotor 18, a fluid is conveyed axially from the suction chamber 14 into the pressure chamber 16. The partition 22 is double-walled, so that it contains a relative to the suction 14 and pressure chamber 16 sealed boiler room 24. The heating chamber 24 can be acted upon by a heating medium which comes into direct contact with the housing insert 20 in the heating chamber 24 and heats the latter and the fluid therein. The partition wall 22 has a first wall 26 and a second wall 28, wherein the walls 26, 28 are arranged to each other so that the heating chamber 24 is located between them.

In order to ensure the seal between the heating chamber 24 and the suction 14 or pressure chamber 16, at least one seal 32 is arranged on each wall 26, 28 of the partition 22. The seal 32 is disposed on the outer periphery 30 of the respective wall 26, 28. As seals preferably O-rings are used.

At least one sealing ring 40, 40 ', 40 "is arranged on the inner circumferential surface 38 of the housing 12. In the mounted state, the sealing ring 40, 40', 40" preferably acts with the dividing wall 22, at least one wall 26, 28 or a seal 32 together. Preferably, each partition 22 is associated with exactly one sealing ring 40. If the dividing wall 22 has two walls 26, 28, then the walls 26, 28 or the seals 32 arranged thereon interact with the same sealing ring 40. This is shown in Figure 1 on the left side. However, in principle it is also possible for exactly one sealing ring 40 ', 40 "to be associated with each wall 26, 28. This is shown on the right-hand side in FIG.

The housing 12 has leading inlet openings 46 into the suction chamber 14 and an outlet opening 48 leading from the pressure chamber 16 for the fluid to be delivered. The flow direction of the conveying fluid is shown by arrows in the figures. Furthermore, the housing 12 has at least one inlet 42 and at least one outlet 44, which is substantially opposite the inlet 42, for the heating medium, each in the region of the heating chamber 24 are arranged. The flow direction of the heating medium is also indicated in the figures by arrows.

FIG. 2 shows a schematic view of a screw pump 10 according to the invention in a second embodiment. The walls 26, 26 ', 28, 28' are formed substantially disc-shaped. The walls 26, 26 ', 28, 28' of a partition wall 22, 22 'may have the same wall thickness or different wall thicknesses. The wall thicknesses depend on the pressure conditions in the adjacent rooms 14, 16, 24. 2, two seals 32 ', 32 "are arranged on the left wall 26' of the left dividing wall 22 'shown in Figure 2. Between the two seals 32', 32" there is a space 34, in which a pressure sensor 36 is arranged. By this configuration, the tightness between suction 14 / pressure chamber 16 and boiler room 24 can control during operation of the pump. FIG. 3 shows a schematic view of a screw pump 10 according to the invention in a third embodiment. In the inlet 42 and in the opposite outlet 44, a respective pipe 50 is arranged, through which the heating medium flows into and out of the heating chamber 24. In this case, the left-hand pipeline 50 essentially corresponds to the extent of the inlet 40 or of the passage 42. The sealing to the atmosphere takes place completely in the housing 12. However, it is also possible that between the inlet 40 or the outlet 42 and the pipeline 50 an O-ring 56 is arranged, which seals the heating chamber 24 to the atmosphere.

In Figure 3 on the right side, another possibility is shown how the heating chamber 24 can be sealed against the suction 14 and pressure chamber 16. For this purpose, an annular element 52 is arranged on the side facing the housing 12 of the heating chamber 24, which defines the heating chamber radially outward and closes. The connection with the walls of the partition wall 22 is preferably carried out by means of welding. The annular element 52 has at least one inlet and one outlet opening 54 for the heating medium. Only via the openings is a connection to the boiler room 24. In The openings of the annular element 52 each have a pipe 50 is arranged through which the heating medium in the heating chamber 24 to or can be removed from this.

- List of Reference Signs -

Reference list Screw screw pump

casing

suction

pressure chamber

Rotor / conveyor screw

Housing insert / liner

partition wall

boiler room

first wall

second wall

Outer circumference wall

poetry

Space between two seals 36 pressure sensor

38 inner lateral surface housing

40 sealing ring

42 inlet heating medium

44 outlet heating medium

46 inlet opening for Forderfluid

48 outlet for Forderfluid

50 pipeline

52 ring-shaped element

54 opening annular element

56 O-ring piping

- Claims -

Claims

claims

1 . A heatable screw pump (10) having a housing (12) surrounding a delivery space, at least one threaded profiled rotor (18), a housing insert (20) disposed in the housing (12) and surrounding the rotor (18), and at least one partition wall (22) dividing the delivery space into a suction (14) and a pressure space (16), the rotor (18) delivering a fluid axially from the suction (14) into the pressure space (16),

h against the suction (14) and the pressure chamber (16) sealed heating chamber (24), which is acted upon by a heating medium, the heating medium in the heating chamber (24) with the housing insert (20) enters into heat transfer in contact.

2. Screw pump (10) according to claim 1, characterized in that the partition wall (22) bores or channels for

Receiving the heating medium, which form the boiler room (24).

3. screw pump (10) according to claim 1, characterized in that the partition wall (22) with the housing insert (20) is integrally formed, wherein the partition wall (22) is double-walled, comprising a first (26) and a second (28) Wall, and between the two walls (26, 28) of the boiler room (24) is located.

4. screw pump (10) according to the preceding claim, characterized in that on each wall (26, 28), in particular at the respective outer periphery (30) in each case at least one of the inside of the housing (12) adjacent the seal (32), in particular an O- Ring, is arranged, which seals the heating chamber (24) relative to the suction (14) and the pressure chamber (16).

5. screw pump (10) according to the preceding claim, characterized in that on the outer circumference (30) at least one wall (26, 28) two seals (32) are arranged side by side.

6. screw pump (10) according to the preceding claim, characterized in that in the space (34) between the two seals (32), a measuring sensor (36), preferably arranged for pressure measurement.

7. screw pump (10) according to one of the preceding claims, characterized in that on an inner circumferential surface (38) of the housing (12) at least one sealing ring (40) is arranged, with the partition (22), at least one wall (26 , 28) or a seal (32) cooperates.

8. screw pump (10) according to the preceding claim, characterized in that each partition (22) is associated with exactly one sealing ring (40).

9. screw pump (10) according to claim 7, characterized in that each wall (26, 28) is associated with exactly one sealing ring (40).

10. Screw pump (10) according to one of the preceding claims, characterized in that the housing (12) has at least one inlet (42) and at least one outlet (44) for the heating medium, which are each arranged in the region of the heating chamber (24) ,

1 1. Screw pump (10) according to one of the preceding claims, characterized in that the heating medium is superheated steam or thermal oil.

12. Screw pump (10) according to any one of the preceding claims, characterized in that the housing insert (20) and the partition wall (22) with heating chamber (24) or the housing insert (20) and the walls (26, 28) as a casting are made.

13. Screw pump (10) according to one of the preceding

Claims, characterized in that the heating chamber (24) is formed by machining the housing insert (20).

- Summary -