DE19926971A1 - Insulated low temperature transport container for refrigerated produce held at 10 C - Google Patents

Abstract

The container for food products such as ice cream has a volume to hold the product and heat insulating surrounds containing low temperature packets of dry ice or frozen eutectic material which surrounds the product volume completely or almost completely.

Description

Technical field of the invention

The invention relates to improved low temperature containers to keep the contents at a temperature below 10 ° C, even while the ambient temperature is very high.

Background of the Invention

Many perishable food products are used Temperatures below ambient temperature transported / stored / distributed to consumers to either spoil them due to biological processes (as in the case of Milk / fish / meat etc.), or their physical, smell and taste characteristics during the To conserve consumption (non-alcoholic beverages, frozen desserts, ice cream, etc.). container Different types and sizes are used for this purpose used. They are thermally insulated to withstand the heat load of the  reduce stored products. In addition Various means are used to keep the contents of these containers keep cool by removing heat. For example sometimes dry ice is added to the container to this effect to evoke. Alternatively, one can do this use sealed bags / pillows, the coolant included and serve as "coolant batteries". Such Coolant pillows are at sufficiently low temperatures pre-chilled or pre-frozen and together with perishable Food packaged to get them in the desired Keep temperature range. The coolant pads can be loose be filled in. Alternatively, you can use a Holding device stacked along the vertical walls be to accessibility to the stored To improve food products.

Sometimes the coolant solutions are provided in coats that on the vertical walls to store them Food products used insulated containers are attached. The coolant can stay in the solid Coats should be included. In such cases, it can Coolant on-line, continuously or intermittently cooled be attached by keeping small on the containers Operates cooling units. If those with a coat Containers are movable, they can alternatively be used from time to time be brought to a service station to have the Pre-cool / coolant solution in the coats / pillows freeze by temporarily using a central Cooling / cooling unit connects.

In such freezers, the end sale of ice creams general use, the coolant is chosen so that it is using the installed cooling unit can be frozen completely or partially and the provides the necessary cooling effect for the content. Even if it was there are temporary power cuts, or when the cabinet is disconnected from the power supply and to the  If sales are taken on a vehicle, that delivers partially or completely frozen coolants continue the Cooling effect, no electricity available during the unit stands.

However, the container designs described above have one Disadvantage. The stored products cannot be sufficient long periods within the desired temperature range are kept, especially when the ambient temperatures are very high are high if the coolant / cooling surfaces are not Temperatures are kept well below the desired maximum temperature of the stored Food products lie. This makes using one oversized cooling system required and leads to a higher energy consumption. For example, in the case of Ice cream for best results like the product near and below Distribute -18 ° C. The usual starting temperature of ice cream when loading into the container is -20 ° C. It is observed that under aggressive, hot environmental conditions, how to it occurs in tropical countries, the temperature of Ice cream kept in the containers described above despite the presence of cooling bags or cooling jackets quickly rises to over -18 ° C.

BR 9501576 discloses for the storage of frozen Food freezers, below Provision of a eutectic material within the Cupboards to very deep inside the coats or pillows Maintain temperatures. The recommended coolant Temperatures were -27 ° C and below to ice cream above keep at or below -18 ° C for a reasonable period of time. Generally this is an impractical or expensive option in tropical countries where the ambient temperatures are relatively high and even a small drop in Coolant temperature extreme demands on the cooling system especially if the electrical power supply is irregular and is expensive.  

The aim of the present invention is to find a suitable one Provide containers for aggressive Environmental conditions without resorting to excessively deep Cooling surface temperatures its contents over long periods of time can keep at temperatures below 10 ° C.

Another object of the present invention is to make containers provide that without resorting to excessively deep Cooling surface temperatures especially for transport / storage / Sales of ice creams below and near -18 ° C over longer periods Periods in aggressive environmental conditions are suitable.

The applicants have found that thermally insulated containers can be provided in which the temperature of the Content without resorting to excessively deep Cooling surface temperatures for longer periods under one Desired value can be preserved by a continuous or sectioned cooling surface jacket with a adequate containment to the contents of the container is provided. The applicants have found that optimal Results can be achieved by using a cooling surface that provides the inner storage space of the container encloses about 70-100%.

Accordingly, the invention relates to a heat insulated Container to the temperature of the inside cavity to keep stored items below 10 ° C, including a outer insulating sleeve and one between the outer sleeve and the internal cavity provided through or in sections divided cooling surface, which is a large or complete Enclosure of the inner cavity causes.

According to a preferred aspect, the invention relates to a thermally insulated container to control the temperature of the inside To keep cavity objects below 10 ° C, comprising an outer insulating sleeve and one between the  outer shell and the inner cavity provided continuous or sectioned cooling surface that internal Encloses cavity to 70 to 100%.

In a more preferred aspect, the invention relates to one thermally insulated container to control the temperature of the inside To keep cavity objects below 10 ° C, comprising an outer insulating sleeve and one between the outer shell and the inner cavity provided continuous or sectioned cooling surface that internal Encloses cavity to 85 to 100%.

In a preferred aspect, the container is with a inner compartment or container that provides a space between the outer shell and the inner compartment or container limited. If the inner compartment or container is provided, the cooling surface is either in the space between the outer shell and the inner compartment or container or as Interior lining of the compartment or container provided.

The temperature of the cooling surface is preferably in the range of 9 ° C to -45 ° C and especially 9 ° C to -30 ° C.

The cooling surface can take various alternative forms be provided, such as thin, with cooling coils connected thermally conductive (for example metallic) plates or sealed coats filled with a cooling medium / interchangeable pillows etc.

In a preferred embodiment of the invention, the Cooling medium of any suitable composition be such that the medium is near and below the Temperature range in which the content must be preserved, a high heat absorption capacity (heat capacity) of <50 Owns joules / gram. In a more preferred embodiment According to the invention, the cooling medium has a heat capacity of <50 Joules / gram in the temperature range between -18 and -30 ° C.  

In an even more preferred embodiment of the invention the cooling medium has a heat capacity of <120 joules / gram between -18 and -30 ° C. It is further preferred, one To use coolant composition that is food compatible, and with a low Corrosiveness compared to that in the construction of Containers commonly used inexpensive materials. The coolant can be from refrigerant gases, such as R-12, CARE 30, aqueous solutions from Freezing point depressants or low temperature mixtures or eutectic mixtures of salts and water become.

It is preferred that the coolant jacket cover the front of one Heat exchange with the outside of objects to be protected completely encloses. The shape of the container can be one cuboid, cube-shaped, cylindrical or any different shape. All walls are preferred Freezer lined with the coolant jacket so that he as a heat barrier between the stored objects and the outside atmosphere.

The coolant jackets and pillows can be made from a suitable one Made of material that can withstand low temperatures. Examples of suitable materials are low steel Carbon content, stainless steel, galvanized steel sheet, Plastic, polymer or other materials, such as High, medium or low density polyethylene, linear Low density polyethylene, polyvinyl chloride, polycarbonate, Polyester, metal foil, etc. It can be in removable / interchangeable units of variable form, shape and Size packed.

The main and other objects of this invention as well as their advantages will now be described in more detail with reference to the non-limiting ones described below exemplary embodiments of the invention.  

Examples Demonstration under sales conditions

Six sets of test data were for containers of different designs that are for sale Ice cream was used. The container had one Nominal capacity of 150 liters, a height of 0.457 m, a width of 0.508 m and a length of 0.660 m. The lid had dimensions of 0.3 mx 0.5 m. The container was with one 75 mm PU foam insulation (k ∼ 25 mW / m K) insulated. At In all investigations, the ambient temperature was 40 ° C. The relative humidity of the ambient air was 80%. Ice cream was filled in at -20 ° C. The lid of the container was opened for 90 seconds every 10 minutes, and the Temperatures of ice cream cones (cornetto) were in the container noted over a period of 12 hours. The others, for each study specific parameters were as below specified.

example 1

This was a conventional design container with one ∼ Enclosing 62% of the interior storage cavity and one aqueous solution of sodium acetate with sodium benzoate as Main additive as coolant jacket containing coolant four vertical walls. The coolant surface was during the entire investigation was kept at -20 ° C.

Example 2

This was a conventional design container with one ∼ Enclosing 62% of the interior storage cavity and one aqueous solution of sodium acetate with sodium benzoate as Main additive as coolant jacket containing coolant four vertical walls. The cooling surface content was increased by 50% enlarged by adding additional along with the ice cream Coolant pillow in the storage cavity of the container  were filled. Throughout the investigation, the Cooling surfaces of the jacket and the additional pillows at -20 ° C held.

Example 3

This was a conventional design container with one ∼62% of the inner storage cavity enclosing and one aqueous solution of sodium acetate with sodium benzoate as Main additives as coolant jacket containing coolant four vertical walls. The cooling surface content was increased by 100% enlarged by adding additional along with the ice cream Coolant pillow in the storage cavity of the container were filled. Throughout the investigation, the Cooling surfaces of the jacket and the additional pillows at -20 ° C held.

Example 4

This was a container of conventional design with Coolant jackets on four vertical walls covering ∼62% of the enclosed inner storage cavity. The coats contained a eutectic aqueous saline solution as cooling medium. The cooling surface was during the entire investigation Kept at -30 ° C.

Example 5

This was a container of conventional design with Coolant jackets on four vertical walls covering ∼62% of the enclosed inner storage cavity. The coats contained a eutectic aqueous saline solution as cooling medium. The cooling surface was during the entire investigation Kept at -35 ° C.

Example 6

This was a container of modified construction with Coolant jackets on all of the chamber walls and ∼93% of the internal storage cavity  enclosed, being an aqueous solution of Contained sodium acetate with sodium benzoate as the main additive. The coolant surfaces were maintained throughout Examination kept at -20 ° C.

Table 1

Examples 1 to 6 show that containers of improved Construction with coolant jackets that were kept at -20 ° C, however, the contents of the container completely or almost completely enclosed with a view to keeping the Ice cream temperature below -18 ° C in a 12 hour Sales cycle gave the best results. An enlargement of the cooling surface content by up to 100% for a conventional one  designed container by additional, loosely filled Coolant pillow can not only the weight of the coolant but could increase the ice cream temperature in a 12- Do not keep the hourly sales cycle below -18 ° C either. The Choosing a cooling jacket kept at -35 ° C is not practical and would not be economical because of the energy requirement is significantly higher to reach ever lower temperatures.

Demonstration under closed conditions

Six sets of test data were collected for containers from different designs, which are used to store Ice cream was used under closed conditions. In The following examples 7 to 12 became the lid of the containers kept closed during the investigation period and not subjected to opening and closing. The container had one Nominal capacity of 150 liters, a height of 0.457 m, a width of 0.508 m and a length of 0.660 m. The lid had dimensions of 0.3 mx 0.5 m. The container was with one ∼75 mm PU foam insulation (k ∼ 25 mW / m K) insulated. At In all investigations, the ambient temperature was 40 ° C. The relative humidity of the ambient air was 80%. Ice cream was filled in at -20 ° C. The others, for everyone Examination specific parameters were as below specified.

Example 7

This was a container of conventional design with Cooling jackets on the four vertical walls, which account for ∼62% of the enclosed inner storage cavity. The coats contained aqueous salt solution as cooling medium. The Coolant surface area was maintained throughout the investigation kept at -26 ° C. The temperatures of ice cream cones (Cornetto) in the container over a period of 12 Hours noted.  

Example 8

This was a container of conventional design with Coolant jackets on the four vertical walls covering ∼62% of the enclosed inner storage cavity. The coats contained aqueous salt solution as cooling medium. The Coolant surface area was maintained throughout the investigation kept at -27 ° C. The temperatures of ice cream cones (Cornetto) in the container over a period of 12 Hours noted.

Example 9

This was a container of conventional design with Coolant jackets on the four vertical walls covering ∼62% of the enclosed inner storage cavity. The coats contained aqueous salt solution as cooling medium. The Coolant surface area was maintained throughout the investigation kept at -36 ° C. The temperatures of ice cream cones (Cornetto) in the container were over a period of 50 days written down.

Example 10

This was a container of conventional design with Coolant jackets on the four vertical walls covering ∼62% of the enclosed inner storage cavity. The coats contained aqueous salt solution as cooling medium. The Coolant surface area was maintained throughout the investigation kept at -37 ° C. The temperatures of ice cream cones (Cornetto) in the container were over a period of 50 days written down.

Example 11

This was a container of modified construction with Coolant jackets on the inside and 93% on the inside Enclosing storage cavity. The coats contained one aqueous solution of sodium acetate and sodium benzoate as Cooling medium. The coolant surface was maintained throughout  Examination kept at -20 ° C. The temperatures of Ice cream cones (cornetto) in the container were over a period of time of 50 days.

Example 12

This was a container of modified construction with Coolant jackets on the inside and 100% on the inside Enclosing storage cavity. The coats contained one aqueous solution of sodium acetate and sodium benzoate as Cooling medium. The coolant surface was maintained throughout Examination kept at -20 ° C. The temperatures of Ice cream cones (cornetto) in the container were over a period of time of 50 days.

Table II

Examples 7 and 8 show that in a container of conventional design with 62% enclosure of the Storage cavity has a cooling surface temperature of -27 ° C or below is required to pass the ice creams over a  Keep below -18 ° C for 12 hours, even if the Lid remains closed during the 12 hour period.

Accordingly, Examples 9 and 10 show that in one Conventional design containers with 62% containment of the storage cavity has a cooling surface temperature of -37 ° C or below is required to pass the ice creams over a Hold period of 50 days below -18 ° C when the lid remains closed during the 50-day period.

On the other hand, Examples 11 and 12 show that in a container of modified construction, which for a 93% up to 100% enclosure of the storage cavity by the Cooling surface ensures the ice creams over a period of 50 Days below -18 ° C can be kept if the lid remains closed during the 50-day period, although the Cooling surface is kept at -20 ° C, which is far above that in the Examples 7 to 10 required cooling surface temperatures.

This improvement in keeping ice creams in the area desired temperature of -18 ° C, although the cooling surface at is kept at a relatively high temperature of -20 ° C, by ensuring that the cooling surfaces for a 70 to 100% enclosure around the storage cavity for the Worrying ice cream around is remarkable and unexpected.

Claims (6)

1. Thermally insulated container around the temperature of the inside Keep hollow objects below 10 ° C, the Containers an outer insulating sleeve and a continuous or in Sections divided cooling surface comprises, the cooling surface 70-100% containment of the inner cavity. 2. Container according to claim 1, characterized in that the Cooling surface causes an 85-100% enclosure. 3. Container according to claim 1 or 2, characterized in that the temperature of the cooling surface from 9 to -30 ° C, more preferred Is -10 to -20 ° C. 4. Container according to one of claims 1 to 3, characterized characterized that the cooling surface of interchangeable Cooling pad is formed, which is filled with a cooling medium are. 5. Container according to one of claims 1 to 3, characterized characterized that the cooling surface of thin thermally conductive Plates is formed, which are connected to cooling coils. 6. Container according to one of claims 1 to 5, characterized characterized that the container is free from one Electricity supply or other power connection is.