WO2004057944A1

WO2004057944A1 - Turf storing apparatus

Info

Publication number: WO2004057944A1
Application number: PCT/GB2003/005627
Authority: WO
Inventors: Paul Andrew Dawson
Original assignee: Rolawn (Turf Growers) Limited
Priority date: 2002-12-24
Filing date: 2003-12-22
Publication date: 2004-07-15
Also published as: GB2411097A; GB0229923D0; GB2411097B; AU2003295150A1; GB0513386D0

Abstract

Rolls of turf (10) are placed in each of six layers on a standard wooden pallet (12). Two smaller layers are placed on top of those six layers. A cover (14) is then placed over the rolls (10) down to the level of the pallet (12). An opening (16) in the cover (14) at an upper side of the rolls incorporates a fan (18), which is driven to draw air up through the rolls and out of the openings (16) in the top of the cover (14).

Description

TURF STORING APPARATUS

This invention relates to turf storing apparatus and to a method of storing turf.

Turf, also known as sod, is a highly perishable product, which once harvested is typically rolled up for storage or transport. Turf is typically stacked onto a pallet. Once rolled up, heat is locked into the turf. Within the roll the turf itself is still growing and respiring. This in itself produces large amounts of heat. In addition, within the soil and the thatch (a layer of organic material between the root structure and the grass itself) there is a large amount of bacterial activity, which also respires and produces heat. In addition, within a roll of turf, there are dead grass clippings produced from mowing the turf prior to harvest. These clippings start to compost producing heat.

The above leads to there being a significant heat build up within each roll, from which heat cannot escape easily because turf is an extremely good insulator. When the turf is stacked onto a pallet, this effectively insulates each roll and heat will build up rapidly from the centre of the pallet. During summer, this heat build up can be so excessive that it can rapidly kill the turf. It can be quite common for turf to be harvested at 25°C and within 24 hours the internal temperature of the pallet maybe 60°C, which will kill the turf. This effect is known as sod heating. The shelf life of turf varies throughout the year ranging from 24 hours in summer to two weeks in winter. It is an object of the present invention to reduce the abovementioned disadvantages. It is a further object of the present invention to extend the shelf life of turf.

According to a first aspect of the present invention, a method of storing turf comprises:

placing a plurality of turf pieces on a support surface, and; - forcing air through or around the turf pieces with ventilation means.

Preferably a plurality of turf pieces are placed on top of each other on the support surface. Preferably, the turf pieces are placed in layers of approximately 8 to 12 turf pieces .

Preferably the turf pieces are folded or rolled turf pieces .

Preferably the turf pieces have an area in the range of about 0.5 to about 1.5 metres squared, preferably about 1 metre squared. Preferably the turf pieces have a width of at least about 45cm, preferably at least about 55cm, most preferably about 60cm wide.

The air may be forced through an interior part of the folded or rolled turf pieces. The air is preferably drawn through the turf pieces.

The ventilation means may include a fan. The ventilation means may be operable to draw air upwards through or around the turf pieces. The ventilation means may be located above, to the side or beneath the turf pieces.

The turf pieces may be located under a cover section, which may be a flexible or rigid cover section. The cover section may extend down to the support surface and may seal around a perimeter thereof. The ventilation means may force air to be drawn upwards through the support surface then through/around the turf pieces and through the ventilation means. The cover section may include openings in one or more sidewalls thereof, through which the ventilation means is operable to draw air. The cover section may be open at a first end thereof. The ventilation means may be located at a second end thereof. The cover section may extend along four to twelve adjacent pallets of turf, although any number of adjacent pallets may be ventilated in this way.

The ventilation means may force air through a number of sets of turf pieces on a plurality of support surfaces. The ventilation means may incorporate a number of ducts to allow air to be forced through/around the sets of turf pieces by a central air forcing section.

The turf pieces may be located within a housing, with the support surface located in the housing. The housing preferably has provision for receiving a plurality of sets of turf pieces, each located on a support surface.

The ventilation means may be arranged to force air substantially sideways through/around the turf pieces. The turf pieces may be placed in abutting relationship with a partition of the housing, which partition preferably has at least one opening therein. Preferably the turf pieces are abutted up to the partition to substantially cover at least one of said openings. The location of the turf pieces against the opening advantageously urges air to be forced through the turf pieces. Preferably the air is forced along a length of the rolled/folded turf pieces.

Preferably, the air is forced from a major section of the compartment in which the turf pieces are located through the partition to a minor section of the compartment.

The ventilation means may include a fan for each of the openings in the partition.

The method of storing may be a method of preserving.

According to a second aspect of the invention turf storing apparatus comprises a turf receiving compartment and ventilation means, in which the ventilation means is operable to force air through/around a plurality of turf pieces located in the turf receiving compartment.

The turf receiving compartment may be a flexible cover, which may have an opening at a lower end thereof. The flexible cover may be arranged to be placed over a plurality of turf pieces. The flexible cover may include a plurality of, preferably lateral, openings. The turf receiving compartment may be open at one end. The turf receiving compartment may have the ventilation means located at one end thereof. The compartment may be a substantially rigid compartment.

The ventilation means may include a fan and may be located at an upper end of the turf receiving compartment. The apparatus may include a frame for supporting the flexible cover.

The apparatus may include refrigeration means for cooling the air to be forced around/through the turf pieces.

The turf receiving compartment may incorporate racking.

The turf receiving compartment may include a partition, preferably having at least one opening therein. The partition may separate major and minor sub-compartments of the turf receiving compartment.

The ventilation means may incorporate a fan behind the or each opening in the partition, in the minor sub- compartment .

All of the features described herein may be combined with any of the above aspects, in any combination.

For better understanding of the invention and to show how the same might be brought into effect, specific embodiments will now be described, by way of example, and with reference to the accompanying drawings, in which: -

Figure 1 is a schematic side view of a first embodiment of turf storing device; Figure 2 is a schematic partially cross sectional view of a second embodiment of turf storing apparatus;

Figure 3a is a schematic front view of a third embodiment of turf storing apparatus;

Figure 3b is a side view of the embodiment of the figure shown in 3a;

Figure 4 is a schematic side view of a fourth embodiment of turf storing device;

Figure 5 is a schematic perspective view of the device in Figure 4; and

Figure 6 is a schematic perspective view of a fifth embodiment of turf storing device.

A number of tests have been carried out in relation to the preservation of shelf life for turf. Cooling gave the best results both in terms of extension of the shelf life and the practicality of the process involved. By using small temperature sensors inserted into rolled turf temperatures were measured within rolls/pallets of turf over a period of time. It has been determined that the shelf life of turf could be extended indefinitely by freezing turf, however this was impractical due to the expensive nature of freezing turf.

Rapidly cooling turf down to 2-3°C gave approximately one to two weeks shelf life, if cooled soon after harvesting. In order to gain the benefits that result from an extension of shelf life, such as in summer turf not being sold within 24 hours having a lengthened shelf life, when otherwise it would have been destroyed. Furthermore, slowing down the sod heating process extends the shelf life of turf and improves the roll-out quality to a customer. An extension of shelf life of the turf gives a greater time between harvesting and the turf being fit for sale, which increases the window of opportunity in which to sell the turf. By having a system of extending the shelf life of turf, more turf can be loaded onto vehicles delivering into turf depots. The turf may not be a result of a specific order, but for sales which arise from time to time. It has been found that an extension of shelf life of one week is adequate to make use of these advantages .

A number of methods have been used which include misting techniques, using the evaporation of water vapour to cool turf in an enclosure. Also, through chilling, using chilled water to wet turf before harvest and also using chilled water to wash the soil off harvested turf being used. Another method is the spreading of ice slurry onto turf before harvest, which ice slurries are then harvested into the roll. Another method is vacuum cooling, which is a technique making use of a mobile vacuum cooler to bring the temperature of turf down from harvest temperature of approximately 25°C to 2°C in approximately 75 minutes. Also, cold storage has been thoroughly investigated using freezer units, insulated trailers for lorries and also portable and fixed cold stores. The quickest method of cooling turf was using a vacuum cooler. However, the cost associated with vacuum cooling makes this method impractical. Cold stores are a more cost efficient method of cooling turf, but it can take a long period of time to cool full pallets and in some cases the sod heating can kill the turf before the pallet has had time to cool. Therefore, different methods for decreasing the cooling time of full pallets of turf placed in cold storage were investigated.

Typically, a number of layers of rolls of turf are built up on a pallet, it has been found that significant storage and longevity advantages are found by preparing turf in rolls which are 24 inches (61cm) wide by 64¹/₂ inches

(164cm) long, rather than the standard 16 inches (41cm) wide and 97 inches (246cm) long. The reason for this is that the wider roll is shorter and so less thick, so the distance to any interior part of the roll from its outer surface is less than the case for the narrower but thicker standard roll mentioned above. Thus, the route for any heat from the roll is shorter for the wider rolls. By its nature, a wider roll has less insulating within the roll and a pallet of 24 inch rolls has more air gaps through the pallet, because there is less turf per layer and therefore more air space.

It was found that the wider rolls heat up more slowly and also, more importantly, cool down more quickly than the existing narrower rolls. It became clear that using the wider rolls, cold stores could be used effectively to cool turf and that cooling rates increased by drawing the cold air through the pallet. The pallet of the narrower existing rolls does not have the same size of gaps through the pallets to allow the air to flow.

A number of trials have been carried out measuring cooling rates with different air flows through pallets. The results were relatively simple, in that more air flow through a pallet results in faster cooling.

Figures 1 and 2 show first and second embodiments of a simple system for drawing air through a covered pallet to remove heat and allow cooler air to pass over the rolls of turf .

In figure 1 ten rolls of turf 10 are placed in each of six layers on a standard wooden pallet 12. Two smaller layers are placed on top of those six layers. A cover 14 is then placed over the rolls 10 down to the level of the pallet 12. An opening 16 in the cover 14 at an upper side of the rolls 10 incorporates a fan 18, which is driven to draw air up through the rolls and out of the opening 16 in the top of the cover 14.

A framework 20 is provided to support the cover 14 and fan 18.

The cover 14 maybe a tarpaulin sheet, or polythene cover or any suitable plastic. Alternatively, the cover maybe rigid. Alternatively, a stretch wrap material could be placed over the rolls 10 as the cover 14.

Whatever cover is used, whether flexible or rigid, the main purpose is simply to cover the rolls to allow air to be drawn through the opening 16 in the cover so that air passes over the rolls 10 to have a cooling effect and to remove heat produced by the rolls of turf 10. The pallet 12a-d has a slatted construction to allow air to pass through the pallet. Figure 2 shows an alternative embodiment using the same method of simply drawing air through or over rolls of turf 10 described in relation to Figure 1. In this embodiment a number of pallets 12a to 12d are used each having six layers of ten rolls 10 per layer stacked thereon. Each set of rolls 10 has a cover 14, which may be the same type of cover as mentioned above in relation to figure 1. An upper opening in each cover is secured to a conduit 22 which leads to a single fan 18 located away from the rolls 10. The fan is used to draw air along the conduit 22 which causes air to be drawn up through the covers 14 over and through the rolls 10 and out of a housing 24 of the fan 18.

The number of covers 14 in the embodiment shown in figure 2 can be varied from between one and as many covers as required. It is simply a matter of the power of the fan 18 being sufficient to draw air through the number of' covers 14 to maintain a satisfactory cooling effect on the rolls of turf 10 under the covers 14.

Figure 3 shows a third embodiment of cooling system for turf.

In figure 3a a cabinet 30 has racking 32 on which pallets 12 can be placed. As before, rolls of turf 10 are placed on the pallets. The cabinet 30 has doors 34 which are closed once pallets 12 bearing the rolls of turf 10 have been placed on the racking 32. The rolls 10 are placed in close abutment with a false wall 36. For each pallet 12 there is an opening 38 in the false wall 36. Behind each opening 38 there is located a fan 40 which is arranged to draw air from the main body of the cabinet 30 through the opening 38 in the first wall 36. Given that the rolls of turf 10 are in close abutment with the opening 38, a sealing effect is provided by the rolls of turf 10. The sealing effect causes air drawn by the fans 40 to be pulled through the rolls of turf 10, rather than simply coming from the main cavity from the cabinet 30.

By locating fans immediately behind the openings 38 very good air flow is achieved through the rolls 10 to cause rapid cooling for the best preservation and storage effects .

A cabinet 30 of the type described and shown in figure 3a and 3b maybe made transportable by using a trailer system.

As well as simply drawing air through the rolls 10 by using the fans 40, cooling can be further enhanced by using a refrigeration plant 42, such as one of the single phase or three phase variety or any other type, to cool air in the cabinet 30 to produce better cooling of the rolls 10.

An alternative arrangement of the cabinet 30 to have a greater number of racking positions for more pallets 12, in which case more openings 38 in the false wall 36 and more fans 40 may be provided. Alternatively, a smaller cabinet 30 could be constructed having only one fan 40 and one racking position for a single pallet 12.

An alternative configuration for the fans 40 to that shown in figures 3a and 3b would be to place the fans at the locations shown at 40a in dashed lines in figure 3. These fans could be arranged to blow out cool air from a refrigeration plant 42, the cool air is pushed into the main cabinet area. Since the doors 34 are closed whilst the system is functioning the air blown into the cabinet 30 by the fans '40a can only return to the smaller compartment via the openings 38 in the false wall 36, which means that the cool air must pass through the rolls 10, which seal against the false wall 36, as mentioned above. Thus, the cool air is forced through the rolls and tends to produce maximum cooling effect. The fans 40a could operate in the opposite sense by sucking air from the main cabinet 30 to cause air to be pulled through the rolls 10 from the openings 38 in the false wall 36, which may pull a supply of cool air supplied from the refrigeration plant 42. It has been found that blowing air into the main compartment is the more efficient direction of action, for fans in the configuration shown at 40a.

The turf rolls may be stacked in other configurations, such as by leaving gaps between some rolls or in the middle of the rolls for extra air circulation.

Figures 4 and 5 show a fourth embodiment of turf storing device 60, in which a flexible cover 62, such as a tarpaulin, is placed over two rows of pallets of turf 64. One end of the cover 62 is open and abuts a fan housing 66, which incorporates a fan (not shown) . The fan draws air through the turf on the pallets of turf 64 and forces it out of the fan housing 66 in the direction of the arrow 68.

Openings 70 in outer faces of the flexible cover 62 allow air into the flexible cover 62, so that it can pass through the turf, into a central channel 74 between the two rows of pallets and onto a grid 76 of the fan housing 66.

The space between allows air warmed in passing through the turf stacks to be pulled out into the fan.

The devices in Figures 4, 5 and 6 (described below) is advantageously used at night for storage when cool ambient air can be drawn into the flexible cover 62 and over/through the turf, which is stacked in rolled form, as described above in relation to earlier embodiments.

Figure 6 shows a variation on the embodiment described above in relation to Figures 4 and 5. As before, flexible covers 62 are placed over rows of turf stacked on pallets

(not shown) . In this version the two flexible covers 62 are open at one end 68 to allow air to enter. At the other end the covers 62 are open to allow abutment up to the fan housing 66. A fan (not shown) draws air through the turf on the pallets of turf. This version of the device has no side openings in the flexible covers 62, because air is drawn from the end 68.

The embodiments shown in Figures 4 to 6 have the advantage of great simplicity, since they require only a fan and a flexible cover. A large number of pallets of turf can be kept cool, particularly overnight, when ambient air is drawn into the covers. The fan housing 66 is easily portable or movable, as are the flexible covers.

Significant advantages are provided with the systems described above, because the shelf life of turf can be significantly prolonged by drawing air, and • also cooled air, through the turf, either whilst it is being stored or whilst it is being transported.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification

(including any accompanying claims, abstract and drawings) , and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMS :

1. A method of storing turf comprises:

- placing a plurality of turf pieces on a support surface, and; forcing air through or around the turf pieces with ventilation means.

2. A method as claimed in claim 1, in which a plurality of turf pieces are placed on top of each other on the support surface in layers of approximately 8 to 12 turf pieces .

3. A method as claimed in either claim 1 or claim 2, in which the turf pieces have an area in the range of about 0.5 to 1.5 m².

4. A method as claimed in any preceding claim, in which the turf pieces have a width of at least about 45 cm.

5. A method as claimed in any preceding claim, in which the air is forced through an interior part of folded or rolled turf pieces .

6. A method as claimed in any preceding claim, in which the turf pieces are located under a cover section.

7. A method as claimed in claim 6, in which the cover section includes openings in one or more side walls thereof.

8. A method as claimed in any preceding claim, in which the ventilation means forces air through a number of sets of turf pieces on a plurality of support surfaces.

9. A method as claimed in any preceding claim, in which the turf pieces are located within a housing, with the support surface located in the housing.

10. A method as claimed in claim 9, in which the turf pieces are placed in abutting relationship with a partition of the housing.

11. Turf storing apparatus comprises a turf receiving compartment and ventilation means, in which the ventilation means is operable to force air through/around a plurality of turf pieces located in the turf receiving compartment .

12. Apparatus as claimed in claim 11, in which the turf receiving compartment is a flexible cover.

13. Apparatus as claimed in either claim 11 or claim 12, which includes refrigeration means for cooling the air to be forced around/through the turf pieces.