GB2570398A

GB2570398A - Temperature-controlled containers

Info

Publication number: GB2570398A
Application number: GB1820087.3A
Authority: GB
Inventors: Appleton Ian
Original assignee: Kerax Ltd
Current assignee: Kerax Ltd
Priority date: 2017-12-08
Filing date: 2018-12-10
Publication date: 2019-07-24
Also published as: GB201820087D0; GB201720460D0

Abstract

A temperature controlled container 10 (intermediate bulk container) comprises a hollow interior vessel 12 for containing a product to be transported and has a temperature regulation system 26, which comprises a jacket 24 containing a liquid surrounding the interior vessel and one or more elements 26 for heating or cooling the liquid in the jacket. Inclined tubes 30 may extend through the interior vessel and have open ends in fluid communication with the jacket. The tubes may provide cross-bracing for the interior vessel in addition to circulation currents 29. A flow return tube 56 may be located near the top of interior vessel and extend between opposite sides of the jacket. Thermal insulation 44 may surround the jacket and a shell 44 may surround the insulation. An access / filling aperture 46 with a removable lid 48 may be provided at the top of the container. A fill level and temperature sensor may be provided and may be internet connected to allow remote monitoring and control of the temperature and fill level. An exterior support structure comprising a base 54 with fork lift apertures 55 and scaffold assembly 56, 60, 62 may provide protection and permit stacking.

Description

TEMPERATURE-CONTROLLED CONTAINERS

This invention relates to temperature-controlled containers, such as intermediate bulk cargo containers (IBC).

When transporting, storing or processing goods, it is often necessary to maintain those goods at a certain temperature. One example is when waxes, high viscosity liquids or foodstuffs need to be transported at a certain temperature. In particular, it is sometimes desirable to transport waxes or high viscosity liquids in liquid form, which requires them to be heated and then maintained at an elevated temperature, i.e. above the liquid or softening point of the product.

Traditionally, temperature-controlled transport systems are large - of the ISO container size - which is expensive, and uneconomic for small batches. On the other hand, IBC containers, which are much smaller than ISO containers can be used, but they lack the necessary heating and temperature maintenance sophistication that is required, in certain circumstances.

A known temperature-controlled IBC comprises a plastics container in which the product to be transported is contained. One or more immersion heater elements are provided within the base of the container, which are used to heat the contents and thereby maintain them at a desired temperature.

However, and this is particularly the case when transporting waxes and other liquids, which have a very low thermal conductivity, the immersion heaters tend to form a melt pool locally around the elements, but the heat from the elements is not effectively distributed to the bulk of the wax (due to the poor thermal conductivity of the wax), which can lead to pockets of molten wax surrounding the elements, but with the remainder of the wax remaining in a solid state.

Due to poor heat dissipation and localised heating, this can lead to degradation of the product through localised over-heating in the vicinity of the heating elements; as well as the transportation of solid wax in the remainder ofthe container.

This invention aims to provide a solution to one or more of the above problems and/or to provide an improved and/or alternative type of container.

Aspects of the invention are set forth in the appended independent claims. Various preferred and/or optional features of the invention are set forth in the appended dependent claims. According to the invention, there is provided a temperature-controlled container comprising a hollow interior vessel for containing a quantity of a product to be transported and a heating system therefor, the heating system comprising a liquid heating jacket surrounding the hollow interior vessel and one or more heating elements for heating a thermal transfer liquid within the liquid heating jacket.

According to another aspect of the invention, there is provided a temperature-controlled container comprising a hollow interior vessel for containing a quantity of a product to be transported and a cooling system therefor, the cooling system comprising a liquid cooling jacket surrounding the hollow interior vessel and one or more cooling devices for cooling a thermal transfer liquid within the liquid cooling jacket.

The temperature-controlled container may further comprise an insulating jacket around the liquid heating or cooling jacket so as to minimise heat loss and also to help maintain a more homogeneous heating regime within the hollow interior vessel.

Suitably, a support structure is provided around the temperature-controlled container, which can facilitate manual handling and/or assisted (e.g. fork-lift) handling. The support structure, where provided, may comprise a base and a relatively rigid scaffold assembly, which may provide impact protection for the temperature-controlled container, and/or which may enable temperaturecontrolled containers to be stacked one on top of the other.

Preferably, one or more tubes is provided within the hollow interior vessel. The tubes, where provided, suitably extend through the interior of the hollow interior vessel, and have open ends, which are in fluid communication with the liquid heating jacket. The tubes, where provided, can provide fluid communication between opposite sides of the liquid heating jacket surrounding the hollow interior vessel.

Suitably, the tubes are inclined so as to allow convective current circulation of heat transfer fluid within the liquid heating jacket to cause the heat transfer fluid to flow through the pipes. For example, relatively warmer heat transfer fluid will tend to flow up the incline, whereas relatively cooler heat transfer fluid will tend to flow down inside the tubes. In certain cases, there may be a contraflow situation whereby relatively warmer heat transfer fluid flows up and along the top part of each tube, whereas relatively cooler heat transfer fluid flows down and along the lower part of each tube. Because the pipes, where provided, extend through the hollow interior vessel, this configuration allows the heat transfer fluid within the liquid heating jacket to also heat the core of the material being stored within the hollow interior vessel; instead of and/or in addition to wall heating of the hollow interior vessel in the usual way.

Suitably, the tubes are inclined at a shallow angle to the horizontal, say between 2 and 10 degrees to the horizontal. It has been found that an inclination of about 5 degrees provides an optimum effect as too low a tilt angle and the rising, hot fluid will not flow up through the tubes, and too great an angle and the reverse-flow of cooler fluid down the pipes becomes appreciable. Furthermore, by inclining the pipes at about five degrees, this allows some inclination to exist even where the system is not placed on a level surface because some tubes will be more horizontal, but those that are more inclined - due to the tilt angle of the container, will still be below an angle of about 10 degrees in most cases.

Furthermore, the tubes can form struts, which provide cross-bracing and/or reinforcement to the hollow interior vessel by cross-bracing (e.g. opposite) side walls of the internal vessel. This is particularly advantageous because it enables the side walls of the hollow interior vessel to be made from much thinner material than would ordinarily be the case, whilst retaining the requisite strength and rigidity.

A certain amount of side wall strength is required because if material being transported within the hollow interior vessel cools, then it may have a tendency to thermally-contract; and unless the side walls are sufficiently stiff or internally braced, then there is, or can be, a tendency for the side walls of the hollow interior vessel to cave inwardly. By providing cross-bracing tubes, this adverse effect can be avoided or reduced.

The heat transfer fluid is typically water, a water-glycol mixture or, preferably, an oil. Oils are preferred because they have a board operating range, that is to say, the temperature-viscosity profile over an operating temperature range of 25-150C is typically quite flat; because solidification or freezing of oils in that temperature range is unlikely, and because the thermal conductivity of oils is generally acceptable for the desired purpose.

In certain embodiments, the heating elements mentioned previously could be replaced by cooling elements, in which case the temperature-controlled IBC of the invention is designed to maintain the contents at a desired, reduced temperature compared to the ambient air temperature.

A thermostatic control system is preferably provided, which regulates the temperature ofthe heat transfer fluid within the liquid heating/cooling jacket and/or within the hollow interior vessel. One or more temperature sensors, e.g. thermocouples, may be provided within the hollow interior vessel and/or within the liquid heating/cooling jacket to facilitate this. The thermostatic control system may be internet-connected, to permit remote controlled operation of the temperaturecontrolled container. A web-based application may be provided, which interfaces with the thermostatic control system to permit this to happen.

A content monitoring system may also be provided for monitoring the fill level of the hollow interior vessel. This may comprise a pressure sensor or a load cell located at the base thereof, which effectively weighs the content above it, thus giving rise to a fill-level indication. The content monitoring system may be internet-connected, to permit remote controlled monitoring of the filllevel of the temperature-controlled container. A web-based application may be provided, which interfaces with the content monitoring system to permit this to happen.

In certain embodiments of the invention, more than one heating element and/or cooling element is provided. Preferably, two heating elements are provided, which can be wired in series and/or parallel. A selector switch is preferably provided, which enables an operator to switch between having no heating elements connected, one heating element connected, two heating elements connected in parallel, or two heating elements connected in series. This affords the operator a great deal of versatility with regard to heating rate and power consumption. The apparatus is suitably provided with a control panel with a selector switch to enable an operator to select between the various different modes of operation. The control panel, where provided, may also comprise a display area, which can provide a read out of temperatures and/or fill levels, etc. within the hollow interior vessel.

In a preferred embodiment of the invention, the hollow interior vessel can be filled via a filling port located on the top thereof. The filing port is suitably provided towards an intended front of the device, which minimises the amount of reach-over required to fill and/or inspect the contents of the hollow interior vessel. An outlet is also suitably provided, which outlet is located at the bottom of the hollow interior vessel. Again, the outlet is suitably provided on the front of the system. Additionally, the control panel, where provided, is suitably located on the front of the system as well. By placing the fill aperture, outlet and control panel on the front of the device, this means that the device can be placed against a wall or other obstruction - thereby providing single-sided access to all the relevant controls, inlets and outlets.

Any of the foregoing features of the invention could be provided in any combination and/or permutation without departing from the scope of the invention. Advantageous of the invention will be readily apparent to those skilled in the art.

Embodiments of the invention shall now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic cross-sectional view of a temperature-controlled container in accordance with the invention;

Figure 2 is schematic cross-sectional view of the temperature-controlled container of Figure 1 when viewed from II of Figure 1;

Figure 3 is a schematic side view of a pair of stacked temperature-controlled containers, as shown in Figure 1;

Figure 4 is a schematic side view of an alternate embodiment of the invention; and

Figure 5 is a perspective view of two temperature-controlled containers in accordance with the invention placed side by side against a wall.

Referring to the drawings, a temperature-controlled container 10 comprises a hollow interior vessel 12, which is fabricated from welded sheets of stainless steel. The hollow interior vessel 12 has a sloping base wall 14, which has a valley 16 defining a lowest point, from which an outlet spigot 18 extends. The outlet spigot 18 has a valve (not shown) and internally screw-threaded distal end 20 to facilitate connection of the temperature-controlled container 10 to another system (not shown). The hollow interior vessel 12 can be filled with a material to be transported (not shown).

Surrounding the hollow interior vessel 12 is a liquid heating/cooling jacket 24, which is also fabricated from welded sheets of stainless steel. A fill 70 and drain 72 port for the jacket 24 is shown in Figure 2. A set of electrical immersion heater elements 26 are located within the liquid heating/cooling jacket 24 below the sloping base wall 14 of the hollow interior vessel 12. When the electrical immersion heater elements 26 are switched on, they heat a thermal transfer fluid (e.g. oil or water-glycol) within the liquid heating/cooling jacket 24, and this sets up a convective circulation current, as indicated by the dashed arrows 28 shown in Figure 1.

A set of tubes 30 are provided, which extend through the hollow interior vessel 12 and whose open ends 32 are in fluid communication with the interior of the liquid heating/cooling jacket 24. The tubes 30 are staggered laterally and horizontally; and inclined slightly relative to the horizontal, and this permits the convective circulation current 29 to flow through the tubes 30, thus heating the centre part of the hollow interior vessel 12.

Due to the inclination of the tubes 30, a circulation pump within the liquid heating/cooling jacket 24 is not necessarily required.

Liquid-tight welds join the tubes 30 to the liquid heating/cooling jacket 24, thereby preventing leakage of the thermal transfer fluid into the hollow interior vessel 12, and/or the contents of the hollow interior vessel 12 into the liquid heating/cooling jacket 24.

The liquid heating/cooling jacket 24 is surrounded by a thermal insulation layer 40, which is suitably formed from about 70mm-thick expanded polyurethane foam, which serves to completely fill any internal voids and affix and support the liquid heating/cooling jacket 24. In alternative embodiments, the thermal insulation layer 40 can be made from sheet materials, such as sheet PU foam, polystyrene foam, insulation wool material, etc..

A steel shell 44, fabricated from welded sheets of mild steel, surrounds the thermal insulation layer 40.

An access/filIing aperture 46 is provided at the top of the temperature-controlled container 10, which is closed by a removable lid 48, which also comprises stainless steel barrier layer 50 and a thermal insulation layer 52.

The steel shell 44 is supported by a steel base 54, which has fork-lift apertures 55 therein. A set of angle-iron, vertical bumper bar columns 56 protect the corners of the temperature-controlled container 10 from impacts, and also provide weight-bearing strength, so that the temperaturecontrolled containers 10 can be stacked for ease of transportation and/or storage.

The vertical bumper bar columns 56 connect to the top of the temperature-controlled container 10 by corner pieces 60, which have short, vertical angle-iron pieces 62 extending therefrom, which locate with the corners of the base 54 of another temperature-controlled container 10, when they are stacked, as shown in Figure 3.

Referring now to Figure 4 of the drawings, an alternative embodiment of the invention 10 is shown in which there are only two heating elements 26. The heating elements 26 are controlled by a control panel 50, as shown in Figure 5, which has a display area 52 which shows the internal temperatures and fill level of the hollow interior vessel 12, and a selector switch 54, which can be rotated by an operator, or controlled via an online application, to select which of the heating elements 26 is connected and in what configuration.

In the afore-described embodiments, there were two heating elements 26, which were all switched on together. This gave rise to convection current 28 as previously described, with warmer, rising heat transfer fluid flowing up each side of the heating/cooling jacket 24. However, in certain cases, it may be preferred to use just one heating element, for example, for energy-saving reasons, but it only one heating element is switched on, then this leads to an asymmetric convection flow 280, as shown in Figure 4 of the drawings.

As can be seen, when the left-hand heating element 26 is switched on, it will heat the heat transfer fluid surrounding it and this sill tend to rise, by virtue of its interaction with the sloping base wall 14 of the hollow interior vessel 12 of the left-hand side of the jacket 24. Once the heat transfer fluid has reached the top of the jacket 24 it would have nowhere to go, except, in this embodiment, there is a horizontal cross tube 56, which runs across the top of the hollow interior vessel 12. This provides a return flow path 282 for the heat transfer fluid across the top of the hollow interior vessel 12 and back down the opposite side where, as it cools, it can re-join the flow back in the vicinity of the switched-on heating element 26. In the meantime, rising/cooling heat transfer fluid can flow 29 through the tubes 30 in the manner previously described and so the core of the contents of the hollow interior vessel 12 can be relatively homogeneously heated by the heat transfer fluid - even when only one heating element 26 is switched on.

In all of the respects, the temperature-control container 10 of the embodiment shown in Figure 4 is substantially the same as that previously described.

Referring now to Figure 5 of the drawings, it can be seen that the outlets figured, heating elements 26, the control panels 50, and the fill aperture/cover 48 are provided at, or toward, a front side 58 of each temperature-controlled container 10. This configuration enables the apparatus to be placed against a wall surface 60 and beside a like temperature-controlled container 10 but still to have all of its main services and controls available because they are presented at the front 58 of the device in each case.

The invention is not restricted to the details of any of the foregoing description and drawings.

In particular, any dimensions, materials or configurations, whether explicit or implied, are illustrative only, and are not necessarily intended to limit the scope of the invention.

Claims

1. A temperature-controlled container comprising: a hollow interior vessel for containing a quantity of a product to be transported and a temperature regulation system therefor, the temperature regulation system comprising a liquid jacket surrounding the hollow interior vessel and one or more elements for heating or cooling a thermal transfer liquid within the liquid jacket.

2. The temperature-controlled container of claim 1, in which the temperature regulation system comprises either or both of:

a heating system comprising a liquid heating jacket surrounding the hollow interior vessel and one or more heating elements for heating a thermal transfer liquid within the liquid heating jacket; and a cooling system comprising a liquid cooling jacket surrounding the hollow interior vessel and one or more cooling devices for cooling a thermal transfer liquid within the liquid cooling jacket.

3. The temperature-controlled container of claim or claim 2, further comprising one or more tubes within the hollow interior vessel, the tubes extending through the interior of the hollow interior vessel, and having open ends, which are in fluid communication with the liquid jacket.

4. The temperature-controlled container of claim 3, wherein the tubes provide fluid communication between opposite sides of the liquid jacket surrounding the hollow interior vessel.

5. The temperature-controlled container of claim 4 or claim 5, wherein the tubes are inclined relative to the horizontal.

6. The temperature-controlled container of claim 5, wherein the tubes are inclined at between 2 and 10 degrees to the horizontal.

7. The temperature-controlled container of claim 6, wherein the tubes are inclined at substantially 5 degrees to the horizontal.

8. The temperature-controlled container of any of claims 3 to 7, further comprising a flow return tube extending between opposite sides of the liquid jacket, the flow return tube being located at to near to the top of the hollow interior vessel.

9. The temperature-controlled container of any of claims 3 to 8, wherein the tubes are structural and provide cross-bracing and/or reinforcement to the hollow interior vessel, the tubes cross-bracing opposite side walls of the hollow interior vessel.

10. The temperature-controlled container of any preceding claim, further comprising an insulating jacket around the liquid heating jacket, the insulating jacket comprising any one or more of: expanded polyurethane foam; sheets of polyurethane foam; sheets of polystyrene foam; and insulation wool material.

11. The temperature-controlled container of claim 10, further comprising a shell surrounding the thermal insulation layer.

12. The temperature-controlled container of any preceding claim, further comprising an access/filling aperture at the top thereof, which is closed by a removable lid.

13. The temperature-controlled container of any preceding claim, further comprising a support structure around the temperature-controlled container, the support structure comprising a base and a relatively rigid scaffold assembly.

14. The temperature-controlled container of claim 13, wherein base comprises fork-lift apertures.

15. The temperature-controlled container of claim 13 or 14, wherein the relatively rigid scaffold assembly comprises vertical columns, which protect the corners of the temperature-controlled container from impacts, and which also provide weight-bearing strength, to permit like temperature-controlled containers to be stacked.

16. The temperature-controlled container of claim 15, wherein the relatively rigid scaffold assembly comprises corner pieces, which have vertical projections extending therefrom, the vertical projections being configured, in use, to locate with the corners of the base of another like temperature-controlled container, when stacked.

17. The temperature-controlled container of any preceding claim, wherein the heat transfer fluid comprises any one or more of the group comprising: water; a water-glycol mixture; and an oil.

18. The temperature-controlled container of any preceding claim, wherein the temperature regulating system comprises one or more electric elements.

19. The temperature-controlled container of any preceding claim, wherein the temperature regulating system comprises a heat exchanger connected to the evaporator of a refrigeration system.

20. The temperature-controlled container of any preceding claim, further comprising a thermostatic control system, the thermostatic control system comprising a temperature sensor and control means for controlling the element or elements in response to a signal received from the temperature sensor, the temperature sensor being located in any one or more of the group comprising: the hollow interior vessel; within the liquid heating jacket; within the liquid cooling jacket; and within one or more of the tubes.

21. The temperature-controlled container of claim 20, wherein the temperature regulation system comprises more than one element, and wherein the thermostatic control system comprises a selector switch for selectively connecting: the elements in series, the elements in parallel, or for switching the elements off.

22. The temperature-controlled container of any preceding claim, further comprising a content monitoring system, the content monitoring system comprising a pressure sensor or a load cell at the base of the hollow interior vessel.

23. The temperature-controlled container of any preceding claim, wherein either or both of the thermostatic control system and/or the content monitoring system is/are internet-connected.

24. The temperature-controlled container of claim 23, further comprising an internet-connected server, access to which can be gained via an internet-connected user terminal, wherein any one or more of: temperature; a temperature history; a heating or cooling setting; and a fill level can be monitored or controlled via a user interface of the internet-connected user terminal, the internetconnected server being configured to host a web site or a web-based application, with which the internet-connected user terminal can access via a web browser or client app, respectively.

25. The temperature-controlled container of any preceding claim, wherein the hollow interior vessel comprises a sloping base wall, which has a valley defining a lowest point, at which lowest point, an outlet is provided, the outlet comprising an outlet spigot and/or a valve.