GB2087538A - Sidewall for ventilated container or goods vehicle - Google Patents

Abstract

A sidewall structure for a container or goods vehicle and in particular for a freight container for shipment of coffee and cocoa has upper and lower ventilator units disposed closely below the top longitudinal member 13 of the wall and closely above the bottom longitudinal member 12 of the wall respectively, and an impervious sheet 28 fitted between the upper and lower ventilator units to close off the cargo space. Each ventilator unit 30 has an inner ventilation slot 36 disposed obliquely upwards relative to an outer ventilation slot 32, the lower end of the inner ventilation slot extending downwardly to constitute a major portion of the internal face of the ventilator unit. A baffle plate 40 positioned within the ventilator unit between the inner and outer ventilation slots at an intermediate position transversely of the ventilator unit so deflects water entering through the external ventilation slot downwardly into a base portion 34 of the ventilator unit from which it drains outwardly, air passages to either face of the baffle plate communicating the inner and outer ventilation slots. Ventilation of the cargo during passage from its port of origin in the tropics to a temperate location takes place by through-flow of air and by a chimney effect. <IMAGE>

Description

SPECIFICATION Sidewall for ventilated goods vehicle The present invention relates to a sidewall structure for a ventilated shipping container or goods vehicle in which adequate ventilation can take place by natural air flow rather than by forced ventilation using fans.

A demand has arisen for ventilated freight containers in particular for the shipment of coffee and cocoa from the countries where they are grown. Cargo is loaded in locations where temperature and humidity are often high, destinations are often at lower temperature, and in transit spells at very low temperature may occur.

Experience has shown the need to provide sufficient ventilation to remove water vapour while at the same time avoiding over-cooling.

An object of the present invention is to provide a container in which the cargo can cool steadily during the transit period using both through air flow and "chimney" effect and avoiding the need for complex and expensive fans and ducts. Existing designs rely primarily upon the "chimney" effect, air flow being created by the heat stored within the cargo, but have not been successful in clearing adequately the condensation from the roof.

Furthermore, the existing designs have not succeeded in maintaining a satisfactory through air flow while at the same time preventing ingress of water in the cargo space.

In one aspect the invention provides a sidewall structure for a shipping container or goods vehicle having upper and lower ventilator units disposed closely below the top longitudinal member of the wall and closely above the bottom longitudinal member of the wall respectively, and an impervious sheet fitted between the upper and lower ventilator units to close off the cargo space, each ventilator unit having an inner ventilation slot disposed obliquely upwards relative to an outer ventilation slot, the lower end of the inner ventilation slot extending downwardly to constitute a major portion of the internal face of the ventilator unit and a baffle plate positioned within the ventilator unit between the inner and outer ventilation slots at an intermediate position transversely of the ventilator unit so as to deflect water entering through the external ventilation slot downwardly into a base portion of the ventilator unit from which it drains outwardly, air passages to either face of the baffle plate communicating the inner and outer ventilator slots.

Other preferred aspects of the invention are defined in the appended claims to which attention is hereby directed.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side view of a container with the ventilators removed; Figure 2 is a front underneath perspective view of the container; Figure 3 is a back top perspective view of the container with its left hand door open; Figure 4 is a diagrammatic view of the container plus load in transverse section showing the major air flows present; Figure 5 is a view in vertical section of a lower ventilator assembly; Figure 6 is a view in vertical section of an upper ventilator assembly; Figure 7 is a fragmentary sectional sidewall view on the line A-A of Figure 1 and looking in the direction of the arrows; and Figure 8 is a fragmentary view in vertical section of the top portion of the lower ventilator assembly and adjoining portions of the sidewall structure.

In Figures 1 to 3, a container frame is defined by upper and lower longitudinal frame members 10-1 3, upper and lower front cross-members 14 and 1 5 and upper and lower rear cross-members 1 6 and 17 with ISO standard corner castings 18.

The major sidewall structure consists of posts 20 secured at regular intervals between the frame members 10 and 11 or 12 and 13 as the case may be, and intermediate longitudinal members 21, 22, 23 and 24 closely spaced from respective longitudinal frame members to define on each sidewall of the container a series of upper ventilator openings 25 and lower ventilator openings 26 extending substantially continuously for the length of the sidewall. The space between the longitudinal members 21 and 22 and 23 and 24 is filled in by a corrugated sheet 28 of waterimpervious material such as steel.

The lower ventilator openings 26 are each fitted with a removable ventilator box whose structure is apparent from Figure 5. The outer face of the ventilator box is defined by a sheet metal upper panel 30 having an inwardly angled lip 31 at its lower end, and by an external grille 32. A downwardly directed base flange 33 of a sheet metal lower pan member 34 is fixed to the lower edge of the grille 32 and has an upwardly directed top flange 35 to which is secured an inner grille panel 36. The top edge 37 of the grille panel 36 is outwardly curved to meet a horizontal rib 38 on the inner face of the panel 30 adjacent the top edge thereof. The outer wall of the ventilator box defined by panel 30 and grille 32 is in spaced parallel relationship to the inner wall defined by grille panel 36 and flange 35 of pan member 34, with the grille 36 obliquely above the grille 32.A baffle plate 40 having a vertically directed centre section 41 and outwardly directed upper and lower lips 42 and 43 is secured within the ventilator box at a position approximately midway between the inner and outer walls of the ventilator box and with its upper lip 42 above the inwardly angled lip 31 of the panel 30. The baffle 40 prevents direct passage of gas or liquid between the grilles 32 and 36 but air can flow above or below the baffle plate 40 as indicated by the arrows. However, in service, water impinging on the grille 32 is stopped by the baffle plate 40 or by the upper flange 35 of the pan member and runs into the pan member 34 and thence back outside the ventilator box. The ventilators therefore do not have to be closed when the container is being subjected to rain or spray and effectively keep water out of the cargo space.The lower ventilators are relatively shallow and do not encroach upon the cargo space since they can be built into the sidewall while remaining within the overall outside dimensions of a standard container. Furthermore, the grills 36 which constitute a major proportion of the inner wall of the ventilator are positioned in the assembled container close to the container floor as is most clearly apparent from Figure 3 so that an air flow can be maintained in the region of the cargo space near to the floor. The inner flange or lip 35 ensures that water trapped by baffle 41 cannot pass into the cargo space but will drain outside. The height of this flange is kept to a practical minimum and its top edge can be positioned well below the top edge of the baffle 41.A further advantage of the ventilator design is that the air flow paths between the grills 32 and 36 are relatively free from obstructions or convolutions and the ventilator therefore offers relatively little resistance to air flow.

The upper ventilator box whose structure is shown in Figure 6 is generally similar to that of the lower ventilator box except that a central horizontal partition member 50 divides the ventilator box into upper and lower compartments 51 and 52. The outer wall of the ventilator box is defined by a plate 53 having an inwardly bevelled lower edge 54, an upper external grille 55 fixed between the plate 53 and an outer downwardly directed flange 56 of the partition 50, and a lower external grille 57 fixed between the flange 56 and a downwardly directed flange 59 of a base pan member 58.The inner face is defined by an upwardly directed inner flange 60 of the pan member 58, a lower internal grille 61 secured between the flange 60 and an upwardly directed inner flange 62 of the partition member, and an upper internal grille 63 fixed between the flange 62 and a horizontal rib 64 on the inner face of the plate 53. In the lower ventilator compartment 52 the inner grille 61 is obliquely above the lower grille 57 and a baffle member 65 whose positioning and arrangement are generally similar to that of the baffle 41 presents relatively little resistance to gas flow while preventing moisture ingress. In the upper ventilator compartment the internal grille 63 is obliquely above the external grille 55 and ingress of moisture is prevented by means of a baffle 66.One possible pattern of air inflow in the compartment 51 is shown by arrows, and a similar flow pattern takes place in the lower compartment 52. Because the upper internal grille 63 is positioned at the top edge of the ventilator, when the ventilator is installed in the container air flow can be maintained close to the roof of the container. Again the top edges of the lips or flanges 60 and 62 are below the top edges of the respective baffle members 65 and 66. The dual ventilator structure shown works in a similar way to the lower ventilator but has the advantage that the maximum grille area is presented but that there is a minimum difference in level between the inner and outer openings.

The pattern of air flow induced in the container is apparent from Figure 4 which shows a container loaded with sacks of coffee or cocoa beans 80.

Under conditions where there is no net air flow transversely of the container, the vvarmth of the cargo induces a chimney effect, air flowing in through the lower ventilators 81 and upwardly through the cargo. Where there is a transverse air current outside the container, there is induced a current of through air between the upper ventilators 82. It has been found that a combination of "chimney effect" ventilation with "through air" ventilation, which is made possible by the low resistance to air flow of the ventilator boxes used, greatly assists in minimizing condensation within the container and hence damp-induced deterioration of the cargo.Where there is a current of "through air" across the roof 83 of the container, the air flow passes close to the lining of the roof, where condensation is prone to occur, and has only a small vertical distance to fall before it enters the grille 63 of the relevant ventilator box on its way to the exterior of the container.

The ventilator boxes have projecting flanges along at least their upper and lower edges as shown, and these flanges are provided with through holes (not shown) for receiving fixing bolts such as huck bolts. Each ventilator box is completely removable for easy replacement in case of damage or for the fitting of blanking plates if ventilation of the container is not required. The sidewall panels and posts may also be made removable for easy replacement in the same way.

Although the ventilator boxes are shown with grille panels, these could if desired be omitted, the ventilator boxes having plain slots instead.

A problem with the lower vents is that their inner grilles are liable to become partly or completely blocked off by the stowed cargo. To some degree this tendency can be reduced by positioning the inner grille at an adequate height above the container floor. A preferred construction in which the adverse effects of inadvertent grille blocking-off are minimised as shown in Figures 7 and 8. The longitudinal member 22 to which the top end of the plate 30 is secured of angle section as shown in Figure 8. The sidewall panel 28 is defined by a series of alternating inwardly facing and outwardly facing corrugations 28a and 28b each of half-hexagonal profile. The portions of the horizontal flange 22a of the longitudinal member 22 underlying the inwardly facing corrugations 28a are formed with through-holed 90 through which air emerging from the top end of the ventilator grille 37 can flow. If the cargo is stowed close to or in contact with the sidewall panel 28, the internally facing channels 28a form channels through which the upward chimney-effect air flow from the lower ventilator boxes can be maintained.

Although the invention has been described with reference to shipping containers it could be applied to analogous goods transport vehicles such as demountable van bodies, and semi-trailer or rigid van bodies.

Claims (9)

1. A sidewall structure for a container or goods vehicle having upper and lower ventilator units disposed closely below the top longitudinal member of the wall and closely above the bottom longitudinal member of the wall respectively, and an impervious sheet fitted between the upper and lower ventilator units to close off the cargo space, each ventilator unit having an inner ventilation slot disposed obliquely upwards relative to an outer ventilation slot, the lower end of the inner ventilation slot extending downwardly to constitute a major portion of the internal face of the ventilator unit, and a baffle plate positioned within the ventilator unit between the inner and outer ventilation slots at an intermediate position transversely of the ventilator unit so as to deflect water entering through the external ventilation slot downwardly into a base portion of the ventilator unit from which it drains outwardly, air passages to either face of the baffle plate communicating the inner and outer ventilator slots.

2. A wall structure as claimed in Claim 1, including posts secured between the upper and lower longitudinal members to define wall sections, upper ventilator boxes secured between the upper longitudinal member and an upper intermediate longitudinal member to which the top end of a respective wall panel of impervious sheet material is secured and lower ventilator boxes secured between a lower intermediate longitudinal member to which the bottom end of the respective wall panel is also secured and the lower longitudinal member.

3. A wall structure according to Claim 2, wherein each upper ventilator box comprises two independent ventilator units disposed one above the other.

4. A wall structure according to any preceding claim, wherein the baffle in each ventilator unit is formed along its top and bottom edge-with an outwardly angled lip.

5. A wall structure as claimed in any preceding claim, wherein bolts fix each ventilator unit in pOsition.

6. A wall structure as claimed in any preceding claim, wherein the external and internal faces of each ventilator unit are substantially in the external and internal planes of the sidewall.

7. A wall structure as claimed in any preceding claim, wherein the impervious sheet is formed with corrugations, and air flow can take place between the top edge of the internal ventilation slot of the lower ventilation units and the inwardly facing corrugations to provide an inward air flow path independent of the major portion of the internal ventilation slot.

8. A wall structure for a goods vehicle substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

New claim filed on 6 May 1980.

New claim:

9. A ventilator box for incorporation into a sidewall of a vehicle, said box including an outer ventilation slot extending substantially the length of an inner wall of the ventilator box at the lower end thereof, an inner ventilation slot extending substantially the length of the inner wall, disposed obliquely upwards with respect to the outer ventilation slot and with its lower edge positioned so that said slot occupies a major portion of the area of the inner surface of the ventilator box, and a baffle plate positioned within the ventilator box between the inner and outer ventilation slots at an intermediate position transversely of the ventilator box so as to deflect water entering the ventilator box through the outer ventilation slot downwardly into a base portion of the ventilator box from which it drains outwardly, air passages to either face of the baffle plate communicating the inner and outer ventilation slots.