GB2562806A

GB2562806A - Cooling device

Info

Publication number: GB2562806A
Application number: GB1709130.7A
Authority: GB
Inventors: Millard Cole Jeffrey
Original assignee: AES Engineering Ltd
Current assignee: AES Engineering Ltd
Priority date: 2017-05-24
Filing date: 2017-06-08
Publication date: 2018-11-28
Anticipated expiration: 2037-06-08
Also published as: GB2562806B; GB201709130D0

Abstract

A cooling device (1, Fig.1) comprises a frame 3 within which is mounted tubing (13, Fig. 2) through which a liquid may be passed. The tubing is arranged in a coil around a longitudinal axis. A fan 29 is located within the frame and arranged for rotation about the longitudinal axis. A motor (33, Fig.2) is mounted on the frame and in driving connection with the fan, the fan and motor being independently supported by the frame. The fan may be coupled to a shaft 21 which may be supported by bearings 23, 25 mounted on the frame. The shaft may be coupled to the motor by an Oldham coupling 30 which isolates the motor bearings from the radial loads on the shaft. The tubing may be supported by bulkhead fittings (15, 17, Fig.2) located on the frame and may have radially extending cooling fins (19, Fig.4). A bell housing 35 may be located between the motor and the frame. The device may be connected to at least one similar device. The devices may be arranged one on top of another and may be arranged such that fluid flow through them is in series or parallel.

Description

(56) Documents Cited:

GB 2362208 A

US 4108240 A1

US 20040149422 A1

F28D1/02 (2006.01)

F28F9/013 (2006.01)

GB 1551112 A US 2379932 A1 (71) Applicant(s):

AES Engineering Ltd (Incorporated in the United Kingdom)

Global Technology Centre, Bradmarsh Business Park, Mill Close, ROTHERHAM, South Yorkshire, S60 1BZ, United Kingdom (72) Inventor(s):

Jeffrey Millard Cole (74) Agent and/or Address for Service:

AESSEAL pic

Global Technology Centre, Mill Close, Bradmarsh Business Park, ROTHERHAM, S60 1BZ, United Kingdom (54) Title of the Invention: Cooling device

Abstract Title: Cooling device for liquids (57) A cooling device (1, Fig. 1) comprises a frame 3 within which is mounted tubing (13, Fig. 2) through which a liquid may be passed. The tubing is arranged in a coil around a longitudinal axis. A fan 29 is located within the frame and arranged for rotation about the longitudinal axis. A motor (33, Fig.2) is mounted on the frame and in driving connection with the fan, the fan and motor being independently supported by the frame. The fan may be coupled to a shaft 21 which may be supported by bearings 23, 25 mounted on the frame. The shaft may be coupled to the motor by an Oldham coupling 30 which isolates the motor bearings from the radial loads on the shaft. The tubing may be supported by bulkhead fittings (15, 17, Fig.2) located on the frame and may have radially extending cooling fins (19, Fig.4). A bell housing 35 may be located between the motor and the frame. The device may be connected to at least one similar device. The devices may be arranged one on top of another and may be arranged such that fluid flow through them is in series or parallel.

(58) Field of Search:

INT CL B21D, F28D, F28F

Other: WPI, EPODOC, Patent Fulltext

Figure 3

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 7D

Cooling Device

Field of Invention

The invention relates to cooling devices which may be used in various applications in which liquids are required to be cooled, an example being the cooling of liquids used in connection with mechanical seals.

Background to the Invention

Liquid to air cooling devices are known which comprise a length of finned tube coiled about a centrifugal fan which is driven by a motor. The tube is wound so that the longitudinal axis of the coil is co-axial with that of the centrifugal fan, the cooling fins extending radially with respect to this longitudinal axis. Liquid to be cooled is fed through the coil and heat is transferred by conduction from the warm liquid to the lower temperature cooling fins. Cool air is driven across the cooling fins by the fan and heat is transferred by convection from the cooling fins to the moving air.

It is also known to provide such cooling devices which can be stacked, one on top of another, with a minimum of modification. In this way, multiple coolers, all driven by a single motor, may be installed in the same space as a single cooler when additional heat transfer capacity is required.

The cooling coil in the or each cooler is supported by vertical bars and horizontal plates. As a result, the coil ends tend to recoil or spread apart, a side effect of the manufacturing process. The tube ends are not supported and the recoil makes difficult the installation of the cooling device in a seal support system.

The motor is mounted on a support such that the motor shaft extends through the support towards the centre of the cooling coil where it is coupled directly to the fan and fan shaft.

The weight (and moment when operating) of the fan and fan shaft create axial and radial loads in excess of those for which the motor and its bearing are designed. As a result, motor bearings overheat and the motors fail prematurely.

Statements of the Invention

According to the present invention, there is provided a cooling device comprising a frame within which is mounted tubing through which a liquid may be passed, the tubing being arranged in a coil around a longitudinal axis, a fan located within the frame and arranged for rotation about an axis which is coaxial with that of the tubing, a motor mounted on the frame and in driving connection with the fan, the fan and motor being independently supported by the frame.

Preferably, the fan is coupled to a shaft and the shaft is supported by bearings mounted on the frame.

Preferably, the shaft is coupled to the motor by a coupling which isolates the motor bearings from the radial loads on the shaft. An example of such a coupling is an Oldham coupling.

Preferably, the tubing is supported by bulkhead fittings located on the frame.

Preferably, the tubing is provided with radially extending cooling fins.

Preferably, a bell housing is located between the motor and the frame.

A device of the invention may be used singly or connected to at least one similar device depending on the extent of cooling required. The devices may be arranged one on top of another and such that the fluid flow through them is in series or in parallel.

Known coolers are limited to vertical stacking due to the method of coupling the fans to the motor. The weight of the fans on an extended shaft horizontally mounted would otherwise cause the motor bearings to fail even faster. In the case of the present invention, the fan shaft and motor may be supported in a way that also allows for “horizontal stacking” where vertical space is limited but lateral space is abundant such that motor life is unaffected.

A cooling device having two stacked coolers can be used in a “series” or “parallel” flow arrangement. The series arrangement doubles the effective cooling area but is normally only used in forced circulation systems as there is an increase in resistance to fluid flow. The parallel arrangement also doubles the effective cooling area but it cuts the flow rate through the cooler in half which reduces the resistance to flow. When used with mechanical seals, the parallel arrangement is suitable where the flow is seal induced. A parallel arrangement is difficult, if not impossible, to achieve with existing cooling devices. Care must be taken to ensure that the flow paths are identical after the flow is split between the two coolers. The present invention renders more readily achievable a parallel arrangement.

Brief Description of the Drawings

The accompanying drawings are as follows:

Figure 1 is a side elevation of a first embodiment of a cooling device of the invention;

Figure 2 is a perspective view of the cooling device of Figure 1;

Figure 3 is a longitudinal section of the cooling device of Figure 1;

Figure 4 is a top plan view, with motor removed, of the device of Figure 1; and

Figure 5 is a perspective view of a second embodiment of a cooling device of the invention.

Detailed Description of the Invention

The invention will now be described, by way of examples only, with reference to the accompanying drawings.

Referring to Figures 1 to 4 of the accompanying drawings, a cooling device 1 of the present invention is for cooling liquids, for instance, cooling the barrier fluid which is circulated through a mechanical seal. The device includes a frame 3 comprising a top plate 5, a bottom plate 7 and interconnecting plates 5 and 7, integral struts 9 and 11. Each of plates 5 and 7 is of D-shape and has a large, centrally located hole.

Arranged between plates 5 and 7 is a length of tubing 13 which is coiled around a vertical axis which extends through the centres of the holes in plates 5 and 7. At each of its ends, tubing 13 is secured to a respective bulkhead tube fitting 15, 17 which extends through a respective strut 9, 11. Tube fittings 15, 17 may, in use, be connected to further tubing serving to feed liquid to and from the tubing 13, warm liquid entering the tubing at fittingl 7 and cooler liquid leaving the tubing at fitting 15. This flow may be reversed with flow in at fitting 17 and flow out at fitting 17.

Tubing 13 is surrounded, along the entirety of its length, apart from short end portions, with an arrangement of radially extending fins 19, the fin elements being either discrete or each being part of a single coiled structure. The fins, in effect, extend the external surface of the tubing 13 thereby enhancing the heat transfer ability of the tubing 13.

Arranged coaxially within tubing 13 is a shaft 21 which is mounted in lower bearing 23 in bottom plate 7 and in upper bearing 25 in top plate 5. Mounted on shaft 21 within legs 27 is centrifugal fan 29.

Shaft 21extends for a short distance above the upper surface of top plate 5, terminating in Oldham Coupling Set which isolates fan shaft 21 from motor shaft 31. Motor shaft 31 extends downwardly from motor 33 mounted on bell housing 35, the latter allowing easy maintenance and being capable of accepting various motors.

In operation, heat is transferred by conduction from the warm liquid in tubing 13 to the lower temperature cooling fins 19. Rotation of centrifugal fan 29 causes cool air to be blown radially outwardly, as indicated by the arrows in Figure 4. The cool air is driven across the cooling fins 19 by the fan 29 and heat is transferred by convection to the moving air.

The fan 29 and shaft 21 are supported independently of the motor 33. The fan 29 is directly coupled to the shaft 21 and the shaft is supported axially and radially by the bearings in the frame 3. The Oldham Coupling 30 has three discs, one 37 coupled to the input (shaft 21), one 39 coupled to the output (shaft 31), and a middle disc 41 that is joined to the first two by tongue and groove connections. The tongue and groove on one side is perpendicular to the tongue and groove on the other. The middle disc 41 rotates around its centre at the same speed as the input and output shafts. Its centre traces a circular orbit, twice per rotation, around the midpoint between input and output shafts. The coupling is compact and allows for small degrees of axis and angular misalignment.

Accordingly, the operational radial loads of the fan and shaft are carried by the shaft bearings 23, 25 which are supported by the cooler frame at plates 5 and 7 and the radial loads are isolated from the motor bearings by the coupling.

In an arrangement in which the fan and its shaft are coupled directly to the motor shaft, the weight (and moment when operating) of the fan and shaft create axial and radial loads in excess of the motor and motor bearings’ design. As a result, motors fail prematurely in the field due to overheated motor bearings.

In an arrangement in which the tubing is supported by vertical bars and horizontal plates, the tubing tends to recoil or spread apart, a side effect of the process of manufacturing the coiled tubing. The tube ends are not supported and the recoil makes installation of the cooler in a seal support system difficult. In the above described embodiment of the invention, bulkhead tube fittings are used to locate and, in conjunction with the frame, support the coil. Such an arrangement eliminates recoil and eases installation.

The above described cooling device can, with a minimum of modification, be part of a multiple tubing arrangement with one or more devices stacked one on top of another An arrangement with two stacked devices is shown in Figure 5 of the accompanying drawings.

In this way, multiple coolers, all driven by a single motor, can be installed in the same space as a single cooler where additional heat transfer capacity is required.

A multiple cooler arrangement, such as that shown in Figure 5, can be used in a “series” or “parallel” flow configuration. A series arrangement doubles the effective cooling but is only for use in forced circulation systems as there is an increase in the resistance to fluid flow. A parallel arrangement also doubles the effective cooling area but it cuts the flow rate through the cooler in half which reduces resistance to flow. The parallel arrangement is suitable for systems in which the flow is self-induced. In both types, the footprint is minimised and installation is simple.

Claims

1. A cooling device comprising a frame within which is mounted tubing through which a liquid may be passed, the tubing being arranged in a coil around a longitudinal axis, a fan located within the frame and arranged for rotation about an axis which is coaxial with that of the tubing, a motor mounted on the frame and in driving connection with the fan, the fan and motor being independently supported by the frame.

2. A device according to Claim 1, wherein the fan is coupled to a shaft and the shaft is supported by bearings mounted on the frame.

3. A device according to Claim 2, wherein the shaft is coupled to the motor by a coupling which isolates the motor bearings from the radial loads on the shaft.

4. A device according to Claim 3, wherein the coupling is an Oldham coupling.

5. A device according to any of the preceding claims, wherein the tubing is supported by bulkhead fittings located on the frame.

6. A device according to any of the preceding claims, wherein the tubing is provided with radially extending cooling fins.

7. A device according to any of the preceding claims, wherein a bell housing is located between the motor and the frame.

8. A device according to any of the preceding claims, wherein the device is connected to at least one similar device.

9. A device according to Claim 6 or Claim 7, wherein the coils are arranged such that liquid flow through them is in parallel.

Intellectual

Property

Office

Application No: GB1709130.7 Examiner: Ms Janet Kohler

9. A device according to Claim 8, wherein the devices are arranged one on top of another.

10. A device according to Claim 8 or Claim 9, wherein the devices are arranged such that fluid flow through them is in series.

11. A device according to Claim 8 or Claim 9, wherein the devices are arranged such that fluid flow through them is in parallel.

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Amendments to the claims have been filed as follows

Claims

1. A device for cooling liquid passing there through a device comprising a frame within which is mounted tubing for accommodating said liquid and arranged in a coil, a fan located within the frame and arranged for rotation about an axis which is coaxial with 5 that of the tubing, a motor mounted on the frame and in driving connection with the fan, the fan and motor being independently supported by the frame, the fan being coupled to a shaft and the shaft being supported by bearings mounted on the frame, and the shaft being coupled to the motor by a coupling which isolates the motor bearings from radial loads on the shaft.

10 2 A device according to Claim 1, wherein the coupling is an Oldham coupling.

3. A device according to Claim 1 or Claim 2, wherein the tubing is supported by bulkhead fittings located on the frame.

4. A device according to any of the preceding claims, wherein the tubing is provided with radially extending cooling fins.

15 5. A device according to any of the preceding claims, wherein a bell housing is located between the motor and the frame.

6. A device according to any of the tubing is arranged in at least two coils. 9.

7. A device according to Claim 6, wherein the coilss are arranged one on top of another.

8. A device according to Claim 6 or Claim 7, wherein the coils are arranged such that

20 liquid flow through them is in series.