GB2068900A - Ventilated cargo containers - Google Patents

Abstract

A cargo container has permanently open large upper ventilators (2) at the upper side of the sidewalls so as to provide a ventilation area of preferably at least 0.645 sq. metres for a standard 6.1 metre long container. The ventilation area may be increased by providing lower ventilators (3) at the lower side of the sidewalls, either through apertures in preferably corrugated the sidewalls or else in a lower rail. The ventilation path in the upper and lower ventilators is tortuous and perforated plates or grills (6) are provided in the ventilation paths to act as water defectors. <IMAGE>

Description

SPECIFICATION Ventilated containers The present invention relates to road, rail, ship or airbourne cargo containers.

With worldwide growth in containerised cargo traffic, the use of ventilated containers for such commodities as coffee and cocoa beans is well established. Because of their very high moisture content and the climatic extremes the journey may impose, the beans and indeed other perishables are particularly susceptible to condensation which, if allowed to fall back onto the cargo in the container, causes mildew and destruction or deterioration of the cargo.

In order to overcome this problem, known containers have been designed with manually operated flap ventilators and several of these are normally located on the vertical sides of the container. When the container is loaded into a ship's cell the ventilators are usually fully-opened. When the container is standing on the dockside, the ventilators are normally half-opened. On deck or on road or rail vehicles, the ventilators are normally shut. This arrangement works satisfactorily if the various adjustments are correctly carried out. However, it does depend very much on a knowledgeable operator going round each container and carrying out the correct procedure and this is easier said than done when dealing with closely stacked tiers of containers.

It will also be appreciated that the reason for having to close the ventilators on deck or during road or rail transport is to prevent spray or rain driving through the ventilators.

Whilst it is known from Patent Specification No. 1 ,575,230 to provide permanently open ventilators at the upper and lower end of the vertical sidewalls of a container, the ventilators provided are very small in comparison with the size of a standard container. Such slight ventilation is only effective when this known container is in motion during road or rail transport and would not be effective during the majority of the time when the container is being used, that is when it is static in a hold or in a storage park at a dockside or transit depot.

A cargo container according to the invention is provided with permanently open substantially large ventilators at least at or toward the upper end of one or more vertical sidewalls of the container, each ventilator having deflectors therein so arranged and con structed that substantial ventilating air may pass through the container whilst in a stowed or stored condition and that air passing through the ventilator follows a tortuous path.

Preferably the upper ventilators of a standard l.S.O. 20 feet (6.1 metres) long container constructed according to the invention provide at least 1000 sq. ins. (0.645 sq.

metres) of ventilation area and in one embodiment of the invention 1 500 sq. ins. of ventilation area (0.968 sq. metres) are provided by upper side ventilators.

Preferably the deflectors are formed with an inner and an outer baffle plate, the plates being separated horizontally and staggered vertically. The inner and outer plate can be formed as a single member with an interconnecting portion. The air vents are preferably arranged above or below the inner or outer baffle and may be guarded by a grill or perforated screen.

Structural strength of the container is provided by the container framework and is not substantially affected by the upper ventilation area. The horizontal beams are unpierced by ventilation apertures unlike the construction shown in Patent No. 1,575,230 so that the top weight of the container is reduced when compared with that ot Patent No. 1,575,230 and in which very heavy apertured top beams are evident.

In known containers, flap ventilators, of necessity, are usually about 4 ins. (10 cm) deep and therefore trespass within the cargo space. In a container in accordance with the invention, multiple tiers of vents are used all of which are contained within the depth of the side wall corrugations. Loss of useful cargo capacity is thus avoided. This feature is particularly valuable when the containers are used for general cargo on outward bound voyages.

In order to increase the ventilation in the container a further open ventilator may be provided on the sidewalls of the container at or toward the lower end of one or more sidewalls, the further ventilator being so arranged and constructed that air passing through the further ventilator follows a tortuous path. The lower ventilator preferably has a ventilation area of approximately 1/9 of that of the upper ventilator.

In a preferred embodiment, the or each further open ventilator is formed within corrugations of the container with a plate portion sloping downwards outwardly and a baffle sloping downwards inwardly, the further ventilator openings each being guarded with a grill or perforated screen.

Alternatively in another embodiment the lower ventilator which need be only 1/9 of the area of the upper ventilator may be provided by an apertured lower side rail, the apertures being suitably protected by a baffle plate and an apertured cover member. The area of such a lower ventilator need only be about 100 sq. ins (645 sq. cm) on each side of the container.

The tortuous arrangement of the baffles enables air to pass into and out of the container whilst rain or spray are prevented from entry. Furthermore, air movement through the open ventilators both at the top and bottom of the walls is induced by small differential pres sures due to temperature variations inside and outside the container. This ensures the cargo is kept in as favourable a state as possible without using more complex arrangements.

Embodiments of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a part sectional perspective view of part of a container according to a first embodiment of the invention, Figure 2 is a cross-sectional side view of the vertical container wall of Fig. 1, Figure 3 is a partly cut-away perspective view of the container of Fig. 1, Figure 4 is a similar view to Fig. 1 of a second embodiment of the invention, and Figure 5 is a similar view to Fig. 1 of a third embodiment of the invention.

The cargo container shown generally at 1 in the drawings has upper open ventilators 2 on the sides 4 and further or lower open ventilators 3 also on the sides 4. The sides 4 are mostly corrugated and the lower ventilators are formed between the corrugations. Each upper ventilator 2 has three vents 5 provided with guards formed from perforated plates 6 which are "Z" shaped to guard both the exterior vents 5 and interior vents 7. Whilst the guards in Fig. 1 are shown as perforated screens, meshed grills can be used. Howeve;, the perforated grills have been found to act efficiently as water deflectors without impeding air flow.

Upper baffle plates 8, intermediate baffle plate 9 and lower baffle plates 10 are formed and positioned so that the exterior vents 5 and exterior vents 7 are staggered vertically to provide tortuous paths 1 2 for air entering or leaving the container through the vents. The intermediate plates 9 are formed as a single member with an inner vertical baffle portion 13, a horizontal inter-connecting portion 14 and an outer vertical baffle portion 1 5. The portion 14 is dimensioned so that the inner portion 1 3 is substantially in the plane of the inner wall skin, and the outer portion 1 5 is substantially in the plane of the outer wall skin.

At the bottom of the sidewalls the further ventilators 3 are formed by means of plate portions 20 and baffle plates 21 and perforated grilled vents 22 and 23. The vents 22 and 23 are staggered vertically in a similar way to the upper ventilators to prevent the centry of spray or rain. The plate portion 20 is downwards and outwardly sloping and the baffle plate 21 is downwards and inwardly sloping leaving an air passage 25 between its inner extremity and the inner wall skin 26.

Entry or exit of air through the lower ventilators is by means of a tortuous passage indicated by arrow 27.

The upper parts of the end doors 30 are provided with ventilators 31 constructed in an similar fashion to the lower ventilators 3.

In the embodiment shown in Fig. 4 the upper ventilator 2 is the same as that of Fig.

1 and need not be further described. The lower ventilator shown generally at 3' is however different to that shown at 3 in Fig. 1 and is provided by means of apertures 40 in the upper part of a horizontal rail 41 mounted to the outer extremities of transverse members 42. The apertures are covered by a cover member or plate 43 suitably apertured on the side at 44 and at the bottom 45. A baffle plate or grill 46 between the rail 41 and cover palte 43 provides suitable protection from rain or spray entering the container through the apertures 40.The ventilation area provided by the lower ventilator 3' is effectively about 90 sq. ins. (580 sq. cm.) on each side of a standard 20 foot (6.1 metre) container whilst' the upper ventilator 2 of the same size as that shown in Fig. 1 is about 750 to 880 sq. ins (8.48-0.52 sq. metres) so that the ratio of areas of the lower ventilator to the upper ventilator is about 1:9, but the total lower area should be not more than 20% of the total ventilation area.

In the embodiment shown in Fig. 5 the lower ventilator is the same as that of Fig. 4 and need not be further described. The upper ventilator shown generally at 2' is however different to that shown at 2 in Figs. 1 and 4 and is provided by means of two exterior vents 50 provided with guards formed from perforated planar plates 53. Each exterior vent has a corresponding interior vent 51 also guarded by a perforated planar plate 5a,. In place of the 'Z' shaped guards Pj of Fig. 1, each vent pair 50/51 has an interior unperforated deflector plate 55 mounted between the interior and exterior vents so as to provide a tortuous ventilation path above and below the deflector plate. The deflector plates 55 are mounted to end and intermediate upright members similar to those shown at 56 and 57 in Fig. 3 at the end of each ventilator section.

The upper ventilation area of this embodiment is similar to that of the embodiments in Figs.

1 and 4. The modified deflector arrangement however is easier and more economic to manufacture than the 'Z' shaped deflectors.

Claims (19)

1. A cargo container having permanently open substantially large ventilators at least at or toward the upper end of one or more vertical sidewalls of the container, each ventilator having deflectors therein so that substantial ventilating air may pass through the container whilst in a stowed or stored condition and that air passing through the ventilator follows a tortuous path.

2. A container as claimed in Claim 1 wherein in standard 6.1 metre container the total effective ventilation area d the ventilators at or toward the upper end of the sidewalls is at least 0.645 sq. metres.

3. A container as claimed in Claim 2 wherein each sidewall has an effective ventilation area of substantially 0.48 to 0.52 sq.

metres.

4. A container as claimed in Claim 2 wherein each sidewall has an effective ventilation area of 0.3225 to 0.645 sq. metres.

5. A container as claimed in any one of Claims 1 to 4 wherein a ventilator is provided at or toward the lower end of one or more vertical sidewalls of the container.

6. A container as claimed in Claim 5 wherein the lower ventilation area is between an eighth and a tenth of the upper ventilation area or more more than 20% of total ventilation area.

7. A container as claimed in Claim 5 wherein the effective lower ventilation area of each sidewall is substantially 580 sq. cm.

8. A container as claimed in any one of Claims 1 to 7 wherein each deflector is formed as a plate between inner and outer vertically and horizontally staggered inner and outer ventilator vents.

9. A container as claimed in any one of Claims 1 to 7 wherein the deflectors are formed with an inner and an outer baffle plate, the plates being separated horizontally and staggered vertically.

10. A container as claimed in Claim 9 wherein the inner and outer plate are formed as a single member with an interconnecting portion.

11. A container as claimed in any one of Claims 5 to 7 wherein the lower ventilator is formed between corrugations of the sidewall, the air passing through the lower ventilator following a tortuous path.

1 2. A container as claimed in Claim 11 wherein the lower ventilator is formed with two plates one sloping downwards outwardly and the other sloping downwards inwardly.

1 3. A container as claimed in Claim 11 or 1 2 wherein the lower ventilator is guarded with a grill or perforated screen.

14. A container as claimed in any one of Claims 5 to 7 wherein the lower ventilator is provided by apertures in a bottom rail of the container.

1 5. A container as claimed in Claim 1 4 wherein the apertures in the bottom rail are covered by an apertured plate, the apertures in the apertured plate being so arranged that air passing through the lower ventilator follows a tortuous path.

1 6. A container as claimed in Claim 1 5 wherein a grill or perforated screen is provided between the apertured plate and rail in the ventilation path.

1 7. A cargo container substantially as described with reference to Figs. 1 to 3 of the accompanying drawings.

1 8. A cargo container substantially as described with reference to Fig. 4 of the accompanying drawings.

19. A cargo container substantially as described with reference to Fig. 5 of the accompanying drawings.