NO20161164A1

NO20161164A1 - Combined jacket ejector and centre ejector pump

Info

Publication number: NO20161164A1
Application number: NO20161164A
Authority: NO
Inventors: Vidar Tregde
Original assignee: Fjord Flow As
Priority date: 2016-07-13
Filing date: 2016-07-13
Publication date: 2018-01-15
Also published as: NO342478B1; NO20171155A1; WO2018012987A1

Abstract

An ejectorpump (1) comprising: - a primary pipe (2) for a first motive fluid; - an inlet tube (3) for a pumped fluid; - a pump house (4) housing a centre nozzle (22) in fluid communication with the primary pipe (2); - a jacket (5) surrounding the pump house (4); - an annular nozzle (52) around the pump house, the annular nozzle (52) is in fluid communication with the jacket (5); and - an outlet pipe (6) downstream of the pump house (4) comprising a mixing zone (60), and the inlet tube (3) comprises a first inlet pipe (31) with a first end portion (310) and a second inlet pipe (32) with a first end portion (320), the first inlet pipe (31) and second inlet pipe (32) form a Y-junction (34) at their first end portions (310, 320) upstream of the pump house (4); and the primary pipe (2) is introduced into the inlet tube (3) at the root (36) of the Y-junction (34).An ejector pump (1) comprising: - a primary pipe (2) for a first motive fluid; an inlet tube (3) for a pumped fluid; - a pump house (4) housing a center nozzle (22) in fluid communication with the primary pipe (2); - a jacket (5) surrounding the pump house (4); - an annular nozzle (52) around the pump housing, the annular nozzle (52) being in fluid communication with the jacket (5); and - an outlet pipe (6) downstream of the pump house (4) comprising a mixing zone (60), and the inlet tube (3) comprising a first inlet pipe (31) with a first end portion (310) and a second inlet pipe (32) with a first end portion (320), the first inlet pipe (31) and second inlet pipe (32) form a Y-junction (34) at their first end portions (310, 320) upstream of the pump house (4); and the primary pipe (2) is introduced into the inlet tube (3) at the root (36) of the Y-junction (34).

Description

COMBINED JACKET EJECTOR AND CENTRE EJECTOR PUMP

This invention relates to an ejector pump. The invention concerns an ejector pump with a central nozzle and an annular nozzle. The central nozzle is fed a motive fluid from a primary pipe and the annular nozzle is fed the motive fluid from a separate feeding pipe. In particular, the invention concerns an ejector pump where a pumped fluid is supplied through two inlet pipes and the primary pipe is introduced into a pump house between the inlet pipes. The ejector pump is in particular suitable for pumping living organisms, such as fish, in a gentle way.

An ejector pump, also known as a jet pump is known for displacing a fluid in a tube. A high pressure primary fluid, also termed a working fluid or a motive fluid, is directed through a nozzle and ejects a secondary fluid having a lower pressure through the pump. The secondary fluid is also termed the pumped fluid or the ejected fluid.

An ejector pump has a simple structure and performance is reliable with low maintenance costs. The ejector pump may be of two basic designs. The ejector pump of a first design may have a central ejector. A primary pipe for the high pressure primary fluid is positioned within a secondary pipe for the secondary fluid. The nozzle discharges the primary fluid at the centre of a pump pipe in an axially direction. The primary fluid entrains the secondary fluid. An annulus is formed between the primary pipe and the secondary pipe. The ejector pump of a second design may have an annular nozzle. The nozzle may be a continuous ring shaped nozzle at the circumference of a pump pipe. As an alternative, several discrete nozzles are positioned at the circumference of the pump pipe. The high pressure primary fluid is fed to the annular nozzle through a jacket surrounding the pump pipe. The annular nozzle may discharge the primary fluid at an angle to the longitudinal direction of the pump pipe and the primary fluid entrains the secondary fluid.

An ejector pump is suitable for pumping liquids with solid particles therein, since there is no impeller blade that may be damaged by the particles, and the particles will not

P27641NO00 description and claims, priority document

be destroyed by the pump. The particles may be delicate such as living species, e.g. fish and crustaceans.

An ejector pump of the annular type is more suitable for pumping fish and other living organisms compared to an ejector pump of the centre type. This is due to that introduction of the primary pipe into the secondary pipe, typically by an elbow conjunction, creates an obstacle in the fluid path and fish or other organisms may bump into the primary pipe. Such collisions are harmful to the organisms. In addition, an annular ejector pump may be constructed with the same open diameter through the pump as upstream and downstream to the pump. The annulus in an ejector pump of the centre type creates a restriction in the flow path. The width or gap of the annulus is a limitation to the possible size of particles in the secondary fluid. Although fish has some elasticity and may pass through the annulus without plugging the annulus, even if the fish basically is too big, this will be harmful to the fish. If the particles in the secondary fluid are not elastic or compressible, such as gravel or stones, an ejector pump of the centre type may be clogged by such material. Due to the bridging effect, this may occur even if the particles on an individual basis are small enough for passing the gap size of the annulus.

It has turned out that the fluid flow may not be streamlined down stream of the nozzle or nozzles in an annular ejector pump. The fluid flow at the centre tends to recirculate and flow towards the ejector pump creating a backwater area. This backwater area is harmful to fish as a first part of the body may be trapped in a downstream directed fluid flow and the second part may be trapped in an upstream directed fluid flow.

Patent document NO301440 discloses a fish pump of the annular ejector pump type. Patent document NO325581 discloses a fish pump of the annular ejector pump type as well. The primary fluid is directed through a first annular nozzle. In an alternative embodiment a second annular nozzle is located downstream of the first annular nozzle.

Patent document US3694107 discloses an ejector pump where the primary fluid may be a high pressure steam and the secondary fluid may be a low pressure steam or vapour. The primary fluid is split and fed to a centre ejector and an annular ejector. The ejector pump is thus a combined centre ejector pump and annular ejector pump. The disclosed pump is suitable for pumping gases but not suitable for pumping liquids comprising soft, elastic or solid particles.

Patent document US2013/0323089 discloses a combined centre ejector pump and annular ejector pump. The disclosed pump is suitable for pumping a gas as a second

P27641NO00 description and claims, priority document

fluid. The disclosed pump is suitable for pumping gases or a mixture of gas and liquid, but not suitable for pumping liquids comprising soft, elastic or solid particles.

The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

The object is achieved through features, which are specified in the description below and in the claims that follow.

The inventor has found that an ejector pump that combines the centre type with the annular type, may create a streamlined or steady fluid flow downstream of the centre nozzle and the annular nozzle in a mixing zone. The output from the centre nozzle at the centre of the pump pipe counteracts the backwater created by the annular nozzle. The inventor has further found that by using two inlet pipes, the primary pipe may be introduced into the pump pipe without risk for the particles in the pumped fluid to collide with the primary pipe. Thereby the invention provides an ejector pump with a smooth passage and the pump is gentle to living organisms in the pumped fluid. The pump is also suitable for pumping fluids with inert particles as sand, gravel and small stones as well as for pumping dead organisms.

In a first aspect the invention relates more particularly to an ejector pump comprising: - a primary pipe for a first motive fluid;

- an inlet tube for a pumped fluid;

- a pump house housing a centre nozzle in fluid communication with the primary pipe; - a jacket surrounding the pump house;

- an annular nozzle around the pump house, the annular nozzle is in fluid communication with the jacket; and

- an outlet pipe downstream of the pump house comprising a mixing zone,

and the inlet tube comprises a first inlet pipe with a first end portion and a second inlet pipe with a first end portion, the first inlet pipe and second inlet pipe form a Y-junction at their first end portions upstream of the pump house; and the primary pipe is introduced into the inlet tube at the root of the Y-junction.

A bulkhead may be positioned between the first inlet pipe’s first end portion and the second inlet pipe’s first end portion, and from the root of the Y-junction and may extend to the pump house; and the primary pipe may be fastened to the bulkhead.

A first pump may be in fluid communication with the primary pipe. A second pump may be in fluid communication with the jacket through a feeding pipe.

P27641NO00 description and claims, priority document

In the following is described examples of preferred embodiments illustrated in the accompanying drawings, wherein:

Fig. 1 shows a side view of an ejector pump according to the invention;

Fig. 2 shows in the same scale as figure 1, a cross section along line II-II in figure 1;

Fig. 3 shows in the same scale as figure 1, a cross section along line III-III in figure 1;

Fig. 4 shows in the same scale as figure 1, a cross section along line IV-IV in figure 1; and

Fig. 5 shows in the same scale as figure 1, a cross section along line V-V in figure 4.

In the drawings, the reference numeral 1 indicates an ejector pump according to the invention. The injector pump 1 comprises a primary pipe 2 for a first motive fluid, an inlet tube 3 for a pumped fluid, a pump house 4 surrounded by a jacket 5 and an outlet tube 6. A mixing zone 60 is formed downstream of the pump house 4 within the outlet tube 6.

The inlet tube 3 is positioned upstream to the pump house 4, and the inlet tube 3 comprises a first inlet pipe 31 and a second inlet pipe 32. The first inlet pipe 31 has a first end portion 310. The second inlet pipe 32 has a first end portion 320. The two inlet pipes 31, 32 are joined in their respective first end portions 310, 320 and form a Y-junction 34 upstream to the pump house 4. The Y-junction comprises a root 36 where the two inlet pipes 31, 32 are joined together in a fluid tight manner. The inlet pipes 31, 32 may comprise a metal such as steel, or a composite reinforced plastics (CRP). The inlet pipes 31, 32 may be welded together.

The Y-junction 34 terminates in the pump house 4. The pump house 4 is tube formed. The pump house 4 has a rim 41 opposite the Y-junction 34. The jacket 5 surrounds the pump house 4 and forms an annulus 51 between the jacket 5 and the pump house 4. The annulus 51 narrows towards the rim 41. An annular ring-shaped nozzle 52 is formed between the rim 41 and the jacket 5. A feeding pipe 54 for a second motive fluid is connected to the jacket 5.

P27641NO00 description and claims, priority document

The outlet tube 6 positioned downstream to the pump house 4, is fluid tight connected to the jacket 5 at the annular nozzle 52. The outlet tube 6 forms a mixing zone 60 immediately downstream of the pump house 4 and the annular nozzle 52.

Spacers (not shown) are provided between the pump house 4 and jacket 5 to align the jacket 5 with the pump house 4. The spacers divide the annular ring-shaped nozzle 52 into sectors (not shown). The width of the spacers in the circumferential direction may be designed to optimize the flow rate through the annular ring-shaped nozzle 52 based on water pressure, flow rate and radial distance between the pump house 4 and the jacket 5.

In an alternative embodiment, the annular nozzle 52 may comprise a number of distinct nozzle tips (not shown) spaced regularly around the inner circumference of the outlet tube 6. The nozzle tips direct the fluid flow parallel to a longitudinal axis 69 of the outlet tube 6.

The primary pipe 2 enters the inlet tube 3 at the root 36 and co-axially to the longitudinal axis 69 of the outlet tube 6. The primary pipe 2 is coaxial with the pump house 4. At its free end portion 21, the primary pipe 2 is terminated in a centre nozzle 22 at the rim 41. The centre nozzle 22 may have one orifice (not shown) or several orifices in an orifice plate (not shown).

A first pump 81 is in fluid communication with a reservoir (not shown) for the first motive fluid. The first pump 81 feeds pressurized first motive fluid into the primary pipe 2. The pressurized first motive fluid flows into the outlet tube 6 at the centre of the outlet tube 6 along the longitudinal axis 69 of the outlet tube 6.

A second pump 82 is in fluid communication with a reservoir (not shown) for the second motive fluid. The second pump 82 feeds pressurized second motive fluid into the feeding pipe 54. The pressurized second motive fluid flows into the annulus 51, out of the annulus 51 through the annular nozzle 52 and into the mixing zone 60 at the circumference of the outlet tube 6. The pressurized second motive fluid is discharged from the annular nozzle 52 in a direction towards the direction of the longitudinal axis 69 of the outlet tube 6. The first motive fluid and the second motive fluid may be the same motive fluid from the same reservoir.

In one embodiment the first pump 81 and the second pump 82 may be the same pump, and the first motive fluid and the second motive fluid is the same motive fluid. In this embodiment a manifold (not shown) is positioned downstream of the pump 81,

P27641NO00 description and claims, priority document

82 and the primary pipe 2 and the feeding pipe 54 is fed pressurized fluid from the manifold.

The Y-junction 34 may in one embodiment be provided with an internal, central bulkhead 7 as shown in figures 4 and 5. The bulkhead 7 separates the pumped fluid in the first inlet pipe 31 and second inlet pipe 32 until the two streams of pumped fluid meet in the pump house 4. The bulkhead 7 is joined to the internal surface of Y-junction from the root 36 as shown in figure 5. At the opposite end the bulkhead 7 terminates in an edge 71 downstream of the pump house 4, see figure 5.

In one embodiment shown in figure 5, the primary pipe 2 is fastened to the bulkhead 7 and protrudes freely from the edge 71 through the pump house 4. In an alternative embodiment (not shown) the primary pipe 2 protrudes freely from the root 36 through the pump house 4.

The ejector pump 1 according to the invention is in particular suitable for pumping of living organisms such as fish. Water, fresh water or sea water with fish is fed into or sucked into the inlet (not shown) of the first inlet pipe 31 and the inlet (not shown) of the second inlet pipe 32. The flow path is smooth through the inlet pipe 31, 32, the Y-junction 34, the pump house 4, the mixing zone 60 and further trough the outlet tube 6. There are no obstacles in the flow path that may harm the fish, as all the internal walls are smooth. There is no backwater area downstream of the annual nozzle 52 due to that the centre nozzle 22 provides additional motive fluid.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

P27641NO00 description and claims, priority document

Claims

C l a i m s

1. An ejector pump (1) comprising:

- a primary pipe (2) for a first motive fluid;

- an inlet tube (3) for a pumped fluid;

- a pump house (4) housing a centre nozzle (22) in fluid communication with the primary pipe (2);

- a jacket (5) surrounding the pump house (4);

- an annular nozzle (52) around the pump house, the annular nozzle (52) is in fluid communication with the jacket (5); and

- an outlet pipe (6) downstream of the pump house (4) comprising a mixing zone (60),

c h a r a c t e r i s e d i n that the inlet tube (3) comprises a first inlet pipe (31) with a first end portion (310) and a second inlet pipe (32) with a first end portion (320), the first inlet pipe (31) and second inlet pipe (32) form a Y-junction (34) at their first end portions (310, 320) upstream of the pump house (4); and the primary pipe (2) is introduced into the inlet tube (3) at the root (36) of the Y-junction (34).

2. An ejector pump (1) according to claim 1, where a bulkhead (7) is positioned between the first inlet pipe’s (31) first end portion (310) and the second inlet pipe’s (32) first end portion (320), and from the root (36) of the Y-junction (34) and extending to the pump house (4); and that the primary pipe (2) is fastened to the bulkhead (7).

3. The ejector pump (1) according to any of the preceding claims, wherein a first pump (81) is in fluid communication with the primary pipe (2).

4. The ejector pump (1) according to any of the preceding claims, wherein a second pump (82) is in fluid communication with the (5) through a feeding pipe (54).

P27641NO00 description and claims, priority document