EP2697513A1

EP2697513A1 - Pressure boosting system

Info

Publication number: EP2697513A1
Application number: EP12714305.5A
Authority: EP
Inventors: Abdul-Sattar HASSAN
Original assignee: Grundfos Management AS
Current assignee: Grundfos Management AS
Priority date: 2011-04-12
Filing date: 2012-04-10
Publication date: 2014-02-19
Anticipated expiration: 2032-04-10
Also published as: WO2012140012A1; EP2511528A1; CN103477072B; CN103477072A; EP2697513B1

Abstract

The present invention relates to a pressure boosting system (2) comprising: two or more pumps (4) each having an inlet (6) connected to an inlet manifold (30) and an outlet (8) connected to an outlet manifold (28). The line that connects an inlet (6) and its corresponding connection at the inlet manifold (30) defines an inlet line (λ1, λ2, λ3, λ4) and the line that connects an outlet (8) and its corresponding connection at the outlet manifold (28) defines an outlet line (ω1, ω2, ω3, ω4). At least two of the inlet lines (λ1, λ2, λ3, λ4) are angled relative to each other, wherein the at least two of the inlet lines (λ1, λ2, λ3, λ4) are non-parallel to each other, and/or at least two of the outlet lines (ω1, ω2, ω3, ω4) are angled relative to each other, wherein the at least two of the outlet lines (ω1, ω2, ω3, ω4) are non-parallel to each other. By this arrangement, the pressure boosting system can be very compact.

Description

A pressure boosting system is a multi-pump system that is used to pressurise fluids. Pressure boosting systems are used in various applications. Normally, pressure boosting systems comprise a plurality of pumps (typically two, three or four pumps) that are connected to a common pipe system. In the prior art pressure boosting systems, the inlet pipes of the pumps are connected to an inlet manifold having a flange that is configured to be directly connected to a main inlet pipe. In the same manner, the outlet pipes of the pumps are connected to an outlet manifold having a flange that is configured to be directly connected to a main outlet pipe. The manifolds typically have a tubular elongated geometry and the pumps are arranged along the longitudinal axis of the manifolds.

In the prior pressure boosting system, the inlet manifold and the outlet manifold extend parallel to one another and are individually spaced from one another. The weight of the manifolds is often exposed to the pump sleeves and accordingly, the pumps are often exposed to high mechanical stress, especially at the pump sleeve where the inlet pipes or outlet pipes are connected to the pump. Due to the mechanical stress caused by the manifolds and valves during transportation or operation, the pipe connection of pump sleeve is often subject to damages. Leakages may result from the above mentioned stress. To overcome the mechanical stress, it is possible to support the manifolds by a mechanical support structure. This introduces higher costs and me- chanical restrictions regarding service of the pressure boosting system. Moreover, replacement and service of pumps requires that all pumps are disconnected. This procedure is time-consuming and introduces the risk of failure to the system. In addition to the above, the prior art pressure boosting systems require a rather huge clearance area all around the system in order to carry out inspection and service of the booster system. The manifolds of a pressure boosting system constitute a manifold system, and a manifold system is required in all pressure boosting systems.

In the prior art pressure boosting systems stagnant water is present at the blind end of the manifold even when fluid is pumped through the manifold. This stagnant water will give rise to bacteria growth. Therefore, it is an object of the present invention to provide a pressure boost- ing system in which stagnant water can be avoided or minimised.

It is also an object of the present invention to provide a pressure boosting system that subjects the pump sleeves to less mechanical stress . It is also an object of the present invention to provide a pressure boosting system that avoids the requirement to disconnect all pumps during replacement and service of a pump.

Furthermore, it is an object of the present invention to provide a pres- sure boosting system that requires less clearance area in order to carry out inspection and service of the pumps of the pressure boosting system.

This object can be achieved by a pressure boosting system having the features defined in claim 1 . Preferred embodiments are disclosed in the dependent claims, the following description and the drawings. The pressure boosting system according to the invention comprises two or more pumps each having an inlet connected to an inlet manifold and an outlet connected to an outlet manifold, wherein the line that connects an inlet and its corresponding connection at the inlet mani- fold defines an inlet line, and wherein the line that connects an outlet and its corresponding connection at the outlet manifold defines an outlet line. At least two of the inlet lines are angled relative to each other, wherein the at least two of the inlet lines are non-parallel to each other and/or that at least two of the outlet lines are angled relative to each other, wherein the at least two of the outlet lines are non-parallel to each other.

By the above arrangement, it is achieved that the pressure boosting system can be very compact. It is also achieved that the pump sleeve is subjected to less mechanical stress compared to prior art pressure boosting systems.

Moreover, the inventive pressure boosting system allows for replacement and service of a pump being carried out without disconnecting all pumps.

The pressure boosting system requires less clearance area in order to carry out inspection and service of the pressure booster system compared to prior art pressure boosting systems.

The term "angled relative to each other" means that the lines are non- parallel. The angle between adjacent pumps may be fixed so that the pumps are uniformly distributed. However, it is also possible to arrange the pumps with different angles between different sets of adjacent pumps. Advantageously, all inlet lines are angled relative to each other and/or all outlet lines are angled relative to each other. In this way, it is possible to make the pressure boosting system very compact. It may be beneficial that each pump has a longitudinal axis and the longitudinal axes of the pumps are angled relative to each other. This makes it possible to arrange the pumps in a formation such that the pumps can be connected to centrally arranged manifolds. In this way, a very compact pressure boosting system can be achieved.

It may be an advantage that the outlet of each pump is connected to an outlet pipe comprising a basically straight outlet pipe member and that the inlet of each pump is connected to an inlet pipe comprising a basically straight inlet pipe member.

Hereby, a compact pressure boosting system can be achieved. Moreover, the distance between the outlets of the pumps and the main outlet as well as the distance between the inlets of the pumps and the main inlet can be minimised.

Advantageously, the longitudinal axis of each pump extends basically parallel to the corresponding inlet line and/or to the corresponding outlet line of the pump. Such a construction may be an advantage because standard components may be used and because this embodi- ment is very compact.

It may be beneficial that the inlet pipes of the pumps are directed basically towards a first common axis and the outlet pipes of the pumps are directed basically towards a second axis. In this manner, it is possi- ble to provide a very compact pressure boosting system, and there is very good access to the pumps (e.g. for service/maintenance of the pumps, for connection or disconnection of the pumps, etc.). I† also is possible†o arrange the axes such that the first axis and the second axis are parallel to each other, or even coinciding. It is possible that the pumps are arranged along an arced or curved line, preferably on a section of a circle. By this, a very compact and robust pressure boosting system can be made.

It is advantageous if all straight outlet pipe members are of one first length and all straight inlet pipe members are of one second length. In this embodiment, the pumps may be arranged on the section of a circle. Hereby, it is achieved that the pressure boosting system can be made very compact and that a great part of the pipe structures may be used for both, the inlet pipe members and the outlet pipe members.

When the inlet pipes of the pumps are directed basically towards a first common axis and the outlet pipes of the pumps are directed basically towards a second axis, it may be advantageous if the longitudinal axes of the pumps extend basically perpendicular to the first axis and/or to the second axis. Hereby, it is possible to use 90 degrees connections between the outlet pipe members and a main outlet piping extending along the first and second axes. In the same way, it is possible to use 90 degrees connections between the inlet pipe members and a main inlet piping extending along the first and second axes.

Advantageously, each straight outlet pipe member and/or each straight inlet pipe member extends basically parallel to the longitudinal axis of the corresponding pump. Hereby, it is possible to provide a direct and short distance connection between the pumps and the main inlet and between the pumps and the main outlets. Accordingly, a very compact and robust pressure boosting system can be achieved. I† may be advantageous if af least some of the straight outlet pipe members and/or at least some of the straight inlet pipe members comprise a valve or are connected to a valve. This may be of great importance during pump replacement or service of the pumps.

It may be beneficial if all straight outlet pipe members and all straight inlet pipe members comprise or are connected to a valve. Hereby, it is achieved that all pumps can be easily disconnected by using the valves.

Advantageously, the inlet pipes are arranged in a first plane and the outlet pipes are arranged in a second plane extending basically parallel to the first plane. Accordingly, this embodiment makes it possible to provide a very compact pressure boosting system. Moreover, this embodiment may be beneficial due to the fact that all pumps may be arranged at a common pump level, that all inlets may be arranged at a common inlet level, that all outlets may be arranged at a common outlet level, and that all outlet pipe members and all inlet pipe members may be arranged parallel.

It is possible that the inlet pipes and outlet pipes are connected to a manifold system that comprises: a basically cylindrical inlet manifold having a longitudinal axis and being arranged adjacent to a basically cylindrical outlet manifold having a longitudinal axis; wherein the inlet manifold comprises a connection to the main inlet and a number of connections for the inlet pipes of the pumps, and wherein the outlet manifold comprises a connection to the main outlet and a number of connections for the outlet pipes of the pumps. This embodiment allows for a very compact and service-friendly connection of the pumps to the main inlet and to the main outlet.

It is possible that the longitudinal axis of the inlet manifold of the mani- fold system and the longitudinal axis of the outlet manifold of the manifold system are parallel to each other, and are basically arranged in a vertical direction.

Advantageously, the pumps are arranged on a base plate. This em- bodiment makes it possible to preassemble the pressure boosting system, and to ensure that the pressure boosting system is fixed firmly.

Hereby, it is achieved that the inlet manifold and the outlet manifold of the manifold system can be arranged in a manner such that the mani- fold system is very compact. Moreover, it is possible to use an inlet manifold having the same geometry as the outlet manifold and vice versa.

Even though both the outlet manifold and the inlet manifold have a basically cylindrical structure, the shape and/or diameter of the outlet manifold and the inlet manifold may differ.

It is possible to provide a pressure boosting system having a manifold system comprising an outlet manifold and an inlet manifold with basically the same geometry.

Advantageously, a valve is provided between the manifold system and each pump inlet and between the manifold system and each pump outlet. It may be advantageous if the pumps are multistage pumps. Multistage pumps are widely used in pressure boosting systems, and they are ca- pable of generating the required pressure and flow. The multistage pumps may be arranged horizontally.

It may be beneficial if each manifold comprises a number of connec- tion pipes provided at the cylindrical periphery of the manifold and the connection pipes extend radially, preferably perpendicular, to the longitudinal axis of the manifolds.

Advantageously, the inlet pipes of the pumps extend basically horizon- tally from the pumps to the inlet manifold and the outlet pipes of the pumps comprise a bent section connecting the outlets to the straight outlet pipe members. The straight outlet pipe members extend basically horizontally to the outlet manifold, and the outlet manifold of the manifold system is arranged above and adjacent to the inlet manifold of the manifold system, and the outlet manifold of the manifold system and the inlet manifold of the manifold system are separated from each other.

Accordingly, it is possible to provide a very compact and robust pres- sure boosting system.

The pressure boosting system according to the invention may comprise a manifold system that comprises a manifold having: - a manifold space configured to receive a fluid; a main connection pipe configured to connect the manifold space to a main pipe; and

a number of connection pipes each configured to connect the manifold space to a pump.

At least some connection pipes of the manifold are angled relative to each other. In this way the manifold system can be arranged centrally relative to the pumps of the pressure boosting system and thus, the pressure boosting system can be very compact. It is also achieved that the pump sleeve is subjected to less mechanical stress compared to the prior art pressure boosting systems.

Moreover, the manifold system makes it possible to build a pressure boosting system that allows for replacement and service of a pump without disconnecting all pumps.

When the manifold system is used, the pressure boosting system requires less clearance area in order to carry out inspection and service of the pressure booster system compared to prior art pressure boosting sys- terns.

All the connection pipes of the manifold may be angled relative to each other. This way of arranging the connection pipes makes it possible to simplify the way of producing the manifold system, and makes it possible to build a very compact pressure boosting system.

The manifold may be cylindrical and the connection pipes may be arranged at the outer periphery of the cylindrical manifold. Hereby, a robust manifold may be produced in an easy manner.

It is possible to arrange the connection pipes so that they extend basically perpendicular to the longitudinal axis of the manifold.

Preferably, the manifold and the connection pipes are arranged in a star connection wherein the manifold is the centre of the star. I† is possible †o provide a pressure boosting system in which a diaphragm tank is arranged on the outlet manifold, or alternatively the diaphragm may be built into the outlet manifold. Hereby, a pressure can be maintained in the outlet manifold when the last pump in opera- tion is switched off. Hereby, pressure energy can be stored in the outlet manifold, and a fluid can be pressurised even when there is no pump activity.

Furthermore, it is possible to configure the manifold system such that the longitudinal axes of the connection pipes span a first plane that is basically perpendicular to the longitudinal axis of the manifold and such that the main connection pipe extends basically parallel to the first plane. This configuration will take up less space than prior art manifold systems, and allows for easily connecting pumps of a similar type to the manifold system.

The manifold system may comprise an inlet manifold having a longitudinal axis and being arranged adjacent to an outlet manifold having a longitudinal axis and furthermore, the axes of the inlet manifold and the outlet manifold are basically parallel to each other. It is advantageous to use a manifold system according to this configuration because both the inlet manifold and the outlet manifold make it possible to achieve a very compact pressure boosting system. It is possible to arrange the inlet manifold and the outlet manifold in several configurations. By way of example, the inlet manifold and the outlet manifold may be individually spaced from each other. However, it is also possible to weld the inlet manifold and the outlet manifold or connect the inlet manifold and the outlet manifold together by me- chanic means. The inlet manifold and the outlet manifold may, for instance, be arranged on top of each other or in a side-by-side configuration. I† is possible that the inlet manifold and the outlet manifold are arranged adjacent to each other and that the longitudinal axes of the inlet manifold and the outlet manifold are basically parallel to each other. Hereby, a compact manifold system can be achieved.

It is possible that the inlet manifold and the outlet manifold are integrally built in one unit. Still, the two manifolds may be produced separately. Building the manifolds in one and the same unit may be achieved in several ways. By way of example, two manifolds may be welded together or fixed to each other by mechanical means. For example, it would be possible to produce the manifold by one or more moulding processes. The connection pipes of the inlet manifold may be evenly distributed so that the angle between the longitudinal axes of all adjacent connection pipes are basically the same and/or the connection pipes of the outlet manifold may be evenly distributed so that the angle between the longitudinal axes of all adjacent connection pipes is basically the same. In this way, it is possible to distribute the pumps evenly around the inlet manifold and the outlet manifold and to provide a very compact pressure boosting system.

It is possible to provide a pressure boosting system comprising a mani- fold system according to any of the described manifold systems.

The inlet manifold and the outlet manifold may have the same diameter. Accordingly, it is possible to produce the inlet manifold and the outlet manifold in the same way by using the same production tools.

The connection pipes of the inlet manifold may be arranged in a manner such that the longitudinal axes of the connection pipes of the inlet manifold span a second plane fhaf is basically perpendicular†o the longitudinal axis of the inlet manifold, and the main connection pipe may extend basically parallel to the first plane, and the connection pipes of the outlet manifold may be arranged in a manner such that the longitudinal axes of the connection pipes of the outlet manifold span a third plane that is basically perpendicular to the longitudinal axis of the outlet manifold, and wherein the main connection pipe extends basically parallel to the second plane, and wherein the second plane and the third plane are basically parallel to each other.

Hereby, a very compact and robust pressure boosting system can be made. Moreover, this embodiment may be beneficial due to the fact that all pumps may be arranged on a common pump level, that all inlets may be arranged on a common inlet level, that all outlets may be arranged on a common outlet level, and that all outlet pipe members and all inlet pipe members may be arranged in parallel.

The inlet pipes of the pumps may extend basically horizontally from the pumps to the inlet manifold, and the outlet pipes of the pumps may comprise a bent section connecting the outlets with the straight outlet pipe members. The straight outlet pipe members may extend basically horizontally from the pumps to the outlet manifold, and the outlet manifold may be arranged above and adjacent to the inlet manifold, and the outlet manifold and the inlet manifold may be hermetically sepa- rated from each other.

The present invention will become apparent from the following detailed description and the accompanying drawings which are given by way of illustration only, and thus, they are not limiting for the present inven- tion, wherein: Fig. 1 shows a top view of one pressure boosting system according to an embodiment of the invention;

Fig. 2 shows a bottom view of one pressure boosting system shown in Fig. 1 without base plate;

Fig. 3 shows a perspective side view of a pressure boosting system shown in Fig. 1 ;

Fig. 4 shows a front view of a manifold system according to another embodiment of the invention;

Fig. 5 shows a perspective view of the manifold system shown in

Fig. 4;

Fig. 6 shows a top view of the manifold system shown in Fig. 4 and Fig. 5;

Fig. 7 shows a cross sectional view of a manifold system according to another embodiment of the invention; and

Fig. 8 shows various embodiments of the manifold systems according to the invention.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, an indication of preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be become apparent to those skilled in the art from this detailed description. Referring now in detail to the drawings for the purpose of illustrating preferred embodiments of the present invention, elements of a pressure boosting system comprising a manifold system 26 according to an embodiment of the present invention are illustrated in Fig. 1 . The pressure boosting system 2 comprises four pumps 4 arranged along a section of a circle C. The pumps 4 have longitudinal axes Xi , X₂, X3 X4 which are rotational axes of the rotor and which are angled relative to each other. The angle ai between the pump having a longitudinal axis Xi and the pump having a longitudinal axis X2 is similar to the angle a₂ be- tween the pump having the longitudinal axis X₂ and the pump having the longitudinal axis X3. In fact, the angle 0,3 between the pump having the longitudinal axis X3 and the pump having the longitudinal axis X4 is similar to both, the angle ai and the angle a₂. It would, however, be possible to arrange the pumps 4 differently with the pumps 4 still being arranged along a section of a circle. This may be done by choosing the angle ai differently from the angle a₂ and 0,3.

The pumps 4 are connected to a manifold system 26 comprising an outlet manifold 28 and an inlet manifold 30 (shown in Fig. 3). The outlet manifold 28 is connected to a main outlet pipe 10. The outlet manifold 28 is connected to the outlets 8 of the pumps 4 via a pipe system 22. Since Fig. 1 shows a top view of the pumps 4, only the pump outlet 8 can be seen. The input manifold 30 (as can be seen in Fig. 2 and 3) comprises a main connection pipe 48 that is provided with a flange 44. This flange 44 is bearing against flange 44' of the main outlet pipe 12. Preferably, the flanges 44 and 44' may be mechanically attached to each other with a sealing in between. The output manifold 28 comprises a main connection pipe 46 that has a flange 42 bearing against a flange 42' of a main outlet pipe 10. For each pump 4, an outlet line κπ , 02, 03, and KM, respectively, connecting the pump outlets 8 to the corresponding connection at the outlet manifold 28 is indicated. The angles βι, β₂ and β3 between the outlet lines κπ and 02, κ>₂ and 03, and 03 and KM, respectively, are indi- cated. It can be seen that even though all outlet lines κπ, 02, 033, and KM are angled relative to each other, the angles βι, βζ and β3 between the outlet lines are equal.

Fig. 2 illustrates a bottom view of the pressure boosting system 2 basical- ly similar to the one shown in Fig. 1 . The four pumps 4 are shown from the bottom side and thus, the inlet pipes 20 can be seen. The inlet lines λι, λ2, λ3, λ₄ connecting the pumps inlet 6 and their corresponding connection at the inlet manifold 30 are indicated. The angles ai, 0,2, and 0,3 between the inlet lines λι and λ₂, λ₂ and λ3, and λ3 and λ₄, respectively, are shown. All inlet lines λι, λ₂, λ3 and λ₄ are angled relative to each other, however all of the angles ai, a₂, and 0,3 between the inlet lines are equal.

Fig. 3 illustrates a perspective view of the pressure boosting system 2 basically similar to the one shown in Fig. 1 . The four pumps 4 of the pressure boosting system 2 comprise inlet pipes 20 connecting the inlet manifold 30 of the manifold system 26 and outlet pipes 18 connecting the outlet manifold 28 of the manifold system 26. The outlet manifold 28 of the manifold system 26 is connected to a main outlet pipe 10 and the inlet manifold 30 of the manifold system 26 is connected to a main inlet pipe 12. The inlet pipes 20 of all pumps 4 comprise a straight inlet pipe member 16 and the outlet pipes 18 of all pumps comprise a straight outlet pipe member 14. A non-return valve 62 is provided between each pump outlet 8 and the outlet manifold 28. During opera- tion of the pressure boosting system 2, one or more pumps 4 can be turned on. The non-return valves 62 make sure that no fluid can enter the pump outlet 8 of a pump that has been switched off. The fluid fhaf is pressurised by the pressure boosting system 2 enters the inlet manifold 30 through the main connection pipe 48 via the main inlet pipe 12, and the inlet manifold 30 distributes the fluid to the pumps 4 via the inlet pipes 20. The fluid enters a pump 4 through the inlet 6 and leaves the pump 4 through the outlet 8 from where it is pumped through the outlet pipe 18 and enters the outlet manifold 28 of the manifold system 26 that is connected to a main outlet pipe 10. Each pump 4 has an inlet 6 and an outlet 8. The inlets 6 are provided at the axial extremity of the pumps 4 facing the manifold system 26. Each inlet 6 is connected to an inlet pipe 20 that is further connected to a connection pipe 36 of the inlet manifold 30 of the manifold system 26. The outlets 8 of the pumps 4 are provided at the radial surface of the pump sleeve and a bent section 34 is connected to each outlet 8. The bent section 34 is further connected to an outlet pipe 18 that is connected to a connection pipe 38 of the outlet manifold 28 of the manifold system 26 through the main pipe connection 46. A valve 24 is arranged in each straight inlet pipe member 16 and straight outlet pipe member 14. When a pump is removed, installed, or exposed to service, the valve 24 may be closed so that there is no access of fluid into the pump. The valves may be of any suitable type. Both the straight outlet pipe member 14 and the straight inlet pipe member 16 of each pump 4 extend parallel to the rotational axis of the pump Xi , X₂, X3, X4. Both the inlet manifold 30 and the outlet manifold 28 of the manifold system 26 have a cylindrical geometry and the longitudinal (cylinder) axis B of the inlet manifold 30 as well as the longitudinal (cylinder) axis A of the outlet manifold 28 of the manifold system 26 ex- tend basically perpendicular to the straight outlet pipe members 14, the straight inlet pipe members 1 6, the axes of the pump Xi , X2, X3, X4, the inlet lines λι , λ₂, λ3, λ4 and the outlet lines KM , 02, C03 and 04. In fact, the longitudinal axis B of the inlet manifold 30 and the longitudinal axis A of the outlet manifold 28 of the manifold system 26 are basically parallel to one another. The pressure boosting system 2 is fastened to a base plate 32 by a number of screws. The base plate 32 is configured to be arranged in a 90 degree corner; however it may be possible to arrange the pressure boosting system 2 on a base plate 32 having another shape or geometry. By way of example, it is possible to arrange five to eight pumps on a 180 degree section of a circle.

The manifold system 26 has an inlet manifold 30 and an outlet manifold 28, and the bottom part of the outlet manifold 28 is mechanically and hermetically separated from the top part of the inlet manifold 30. The outlet manifold 28 is arranged on the top of the inlet manifold 30 and the two manifolds 28, 30 are separated from each other by a flexible thin intermediate plate 40. It would, however, be possible to attach the outlet manifold 28 and the inlet manifold 30 to each other by welding or any other suitable kind of attachment. The outlet manifold 28 and the inlet manifold 30 may also be individually separated and displaced from one another.

Fig. 4 illustrates a perspective view of the manifold system 26 according to the invention. The manifold system 26 consists of an outlet manifold 28 arranged on top of an inlet manifold 30. Both manifolds 28, 30 are cylindrical, and connection pipes 36, 38 are arranged on the cylindrical periphery thereof. The outlet manifold 28 comprises a main connection pipe 46 having a flange 42 that is configured to be connected to a main outlet pipe. The connection pipes 46, 48 (see Fig. 5 for connection pipe 48) are provided with sensor inlets 60 that are configured to receive a sensor. For example, a pressure sensor (not shown in the figures) may be inserted into the sensor inlet. In the same manner, the inlet manifold 30 comprises a main connection pipe 48 having a flange 44 that is configured to be connected to a main inlet pipe (this is indicated in Fig. 5) . Fig. 5 illustrates a perspective view of the ma nifold system 26 shown in Fig. 4.

In Fig. 6, a top view of a manifold system 26 according to the embodiment shown in Fig. 4 and Fig. 5. It can be seen that the connection pipes 36, 38 (see Fig. 5 for connection pipe 36) of the inlet manifold 30 (see Fig. 5) and of the outlet ma nifold 28, respectively, are arranged on the same side of the respective manifold system 26. It can a lso be seen that the main connection pipes 46, 48 are angled at 90 degrees relative to each other. It is possible to arrange the main connection pipes 46, 48 in another way. For example, the main connection pipes 46, 48 may be arra nged parallel to one another.

Fig. 7 illustrates a cross sectional view of an outlet manifold 28 according to an embodiment of the invention. The ma nifold 28 has a manifold space 58 configured to receive a fluid. The main connection pipe 46 connects the manifold space 58 to a main pipe (not shown) . Further, the connection pipes 38 connect the manifold space 58 to a pump 4 (see Fig. 3) . A diaphragm tank 50 is built into the outlet manifold 28 so that pressure may be maintained in the outlet manifold 28 even with the pumps not being active. In the top of the dia phragm ta nk 50 a n air screw 56 is arranged. Through this screw 56 pressurised air 52 can be filled into the diaphragm ta nk 50. The diaphragm tank 50 will cha nge its geometry according to the pressure conditions on both sides of it, and it is adapted to tra nsfer pressure forces between the air side of the dia- phragm 54 and the fluid side of the diaphragm 54. The outlet manifold 28 comprises a main connection pipe 46 with a flange 42 and four connection pipes 38 as well as a sensor inlet 60. The diaphragm tank 50 is also known as an expansion tank or an expansion vessel that typically is used in domestic hot water systems and closed water heating systems. The diaphragm tank 50 may be divided into two by a rubber diaphragm 54 or a diaphragm of another suitable material. As the fluid pressure increases, the diaphragm moves compressing the air on its fluid-free side.

Fig. 8 illustrates four different embodiments of the manifold systems 26 according to the invention. It can be seen that the manifold connections 46, 48 can be oriented in different ways. Fig. 8 a) shows an embodiment according to which the manifold connection 46 of the outlet manifold 28 extends vertically while the manifold connection 48 of the inlet manifold 30 extends horizontally. In Fig. 8 b), both the manifold connection 46 of the outlet manifold 28 and the manifold connection 48 of the inlet manifold 30 extend vertically. In Fig. 8 c), the manifold connection 46 of the outlet manifold 28 extends horizontally while the manifold connection 48 of the inlet manifold 30 extends vertically. In Fig. 8 d), a diaphragm tank is integrated in the outlet manifold 28, and both the manifold connection 46 of the outlet manifold 28 and the manifold connection 48 of the inlet manifold 30 extend horizontally.

List of reference numerals

2 - Pressure boosting system

4 - Pump

6 - Inlet

8 - Outlet

10 - Main outlet pipe

1 2 - Main inlet pipe

1 4 - Straight outlet pipe member 1 6 - Straight inlet pipe member

1 8 - Outlet pipe

20 - Inlet pipe

22 - Pipe system

24 - Valve

26 - Manifold system

28 - Outlet manifold

30 - Inlet manifold

32 - Base plate

34 - Bent section

A - Axis

B - Axis

Xi , X2, X3, X4, - Axes of the pumps

36, 38 - Connection pipes

40 - Intermediate plate

ω ι , on, 03, ecu - Outlet lines

λι , λ2, λ3, λ4 - Inlet lines

42, 44, 42', 44' - Flanges

46, 48 - Main connection pipes

50 - Dia phragm tank

52 - Pressurised air

54 - Flexible dia phragm

56 - Air screw Manifold space Sensor inlet Section of a circle Non-return valve

Claims

A pressure boosting system (2) comprising: two or more pumps (4) each having: an inlet (6) connected to an inlet manifold (30), and an outlet (8) connected to an outlet manifold (28); wherein the line connecting the inlet (6) and its corresponding connection at the inlet manifold (30) defines an inlet line (λι, λ₂, λ3, λ4), and wherein the line connecting the outlet (8) and its corresponding connection at the outlet manifold (28) defines an outlet line (KM , K>2, K>3, KM) , characterised in that at least two of the inlet lines (λι, λ₂, λ3, λ4) are angled relative to each other, wherein the at least two of the inlet lines (λι, λ₂, λ3, λ4) are non-parallel to each other, and/or that at least two of the outlet lines (KM , K>₂, K>3, KM) are angled relative to each other, wherein the at least two of the outlet lines (KM , K>₂, K>3, KM) are non-parallel to each other.

Pressure boosting system (2) according to claim 1 characterised in that all inlet lines (λι, λ₂, λ3, λ4) are angled relative to each other and/or that all outlet lines (κπ, κ>₂, κ>3, KM) are angled relative to each other. Pressure boosting system (2) according to claim 1 or claim 2 characterised in that each pump (4) has a longitudinal axis (Xi, X₂, X3, X4) and that the longitudinal axes (Xi, X2, X3, X4) of the pumps (4) are angled relative to each other.

Pressure boosting system (2) according to any one of the preceding claims characterised in that the outlet (8) of each pump (4) is connected to an outlet pipe ( 18) comprising a basically straight outlet pipe member ( 14), and that the inlet (6) of each pump (4) is connected to an inlet pipe (20) comprising a basically straight inlet pipe member ( 16).

Pressure boosting system (2) according to claim 3 or 4 characterised in that the longitudinal axis (Xi, X2, X3, X4) of each pump (4) extends basically parallel to the corresponding inlet line (λι, λ₂, λ3, λ4) and/or to the corresponding outlet line (KM, co₂, C03, KM) of the pump (4).

Pressure boosting system (2) according to claim 4 or 5 characterised in that the inlet pipes (20) of the pumps (4) are directed basically towards a first common axis, and that the outlet pipes ( 18) of the pumps (4) are directed basically towards a second axis.

7. Pressure boosting system (2) according to a ny one of the preceding claims characterised in that the pumps (4) are arra nged along an arced line, preferably on a section of a circle.

Pressure boosting system (2) according to claim 3 characterised in that the longitudina l axes (XI , X2, X3, X4) of the pumps (4) extend basica lly perpendicular to a first axis and/or to a second axis.

Pressure boosting system (2) according to any one of claims 4-8 characterised in that each straight outlet pipe member ( 14) and/or each straight in let pipe member ( 1 6) extends basica lly parallel to the longitudina l axis (Xi, X₂, X3, X4) of the corresponding pump (4) .

Pressure boosting system (2) according to any one of claims 4-9 characterised in that the in let pipes (20) are arra nged in a first plane and that the outlet pipes ( 18) are arra nged in a second plane extending basica lly parallel to the first plane.

1 1 . Pressure boosting system (2) according to any one of claims 4-10 characterised in that the inlet pipes (20) and outlet pipes ( 18) are connected to a manifold system (26) that comprises: a basically cylindrical inlet ma nifold (30) having a longitudinal axis (B) , and being arranged adjacent to a basica lly cylindrical outlet manifold (28), the basica lly cylindrical outlet ma nifold (28) having a longitudinal axis (A); wherein the inlet manifold (30) comprises a connection to the main inlet ( 12) and a number of connections (36) for the inlet pipes (20) of the pumps (4), and wherein the outlet manifold (28) comprises a connection to the main outlet ( 10) and a number of connections (38) for the outlet pipes ( 18) of the pumps (4).

2. Pressure boosting system (2) according to claim 1 1 , characterised in that the longitudinal axis (B) of the inlet manifold (30) of the manifold system (26) and the longitudinal axis (A) of the outlet manifold (28) of the manifold system (26) are parallel to each other, and are arranged basically in a vertical direction.

3. Pressure boosting system (2) according to claim 1 1 or claim 12 characterised in that each manifold comprises a number of connection pipes (36, 38) provided at the cylindrical periphery of the manifold, and that the connection pipes extend radially, preferably perpendicular to the longitudinal axis of the manifolds (A, B).

14. Pressure boosting system (2) according to any one of the preceding claims 4-13 characterised in that

the inlet pipes (20) of the pumps (4) extend basically horizontally from the pumps (4) to the inlet manifold (30);

the outlet pipes ( 18) of the pumps (4) comprise a bent section (34) connecting the outlets (8) to the straight outlet pipe members ( 14);

the straight outlet pipe members (14) extend basically horizontally with respect to the outlet manifold (28);

the outlet manifold (28) of the manifold system (26) is arranged above and adjacent to the inlet manifold (30) of the manifold system (26); and the outlet manifold (28) of the manifold system (26) and the inlet manifold (30) of the manifold system (26) are separated from each other.

Pressure boosting system (2) according to any one of the preceding claims characterised in that a diaphragm tank (50) is arranged on the outlet manifold (28), or in that a diaphragm is build into the outlet manifold (28) .