Patent Application
20100031692
The present invention is directed to a top-opening freezer having an improved cooling gas flow distribution. Particularly, the present invention is directed to a top-opening freezer including an outer casing, a goods compartment disposed within the outer casing and having a bottom wall, a front wall, a rear wall, two side walls and a top-opening. A first flow path is provided such that cooling gas is guided from an opening at an upper portion of the front wall side of the goods compartment to an opening in an upper portion of the opposite rear wall side of the goods compartment thereby providing a cooling gas curtain across the top opening.
Top-opening freezers are widely used. E.g. in supermarkets, top-opening freezers are used both for deep-freezing consumer products such as food and at the same time displaying these products to customers. In these top-opening freezers having e.g. the form of chests cold air remains in the goods compartment as the goods compartment is only open at its upper side and the cold air being heavier than the air of the surrounding environment is captured within the goods compartment.
In order to reduce the heat entry due to customers grasping into the goods compartment cold air is conventionally directed across the top opening of the goods compartment thereby creating a cooling air curtain. The flow path of the cooling air curtain usually extends from an opening in an upper portion of a front wall in the goods compartment to an upper portion of a rear wall.
However, close to the side walls of the goods compartment, i.e. at the lateral sides of the cooling air curtain, there may be regions which are not sufficiently cooled as there may be turbulences in the cooling gas flow of the gas curtain at these regions where the gas curtain is adjacent to one of the side walls. Furthermore, heat can be transferred via the side walls further increasing the temperatures in these regions.
There may be strict regulations indicating maximum temperature limits which are not allowed to be exceeded within the goods compartment. Due to such regulations regions of elevated temperature at the sides of a top-opening freezer may not be acceptable.
It is therefore an object of the present invention to prevent regions of elevated temperature especially at the sides of the goods department.
The top-opening freezer according to the present invention is characterized by a side wall cooling means cooling at least one of the side walls of the goods compartment and being positioned between a side wall of the goods compartment and the outer casing. A second flow path can be provided such that cooling gas is guided in at least one channel positioned between a side wall of the goods compartment and the outer casing.
In the inventive top-opening freezer, cooling gas can flow in a closed loop. Preferably, the cooling gas is provided by cooled air which can circulate in the closed loop. Thus, losses of cooled air to the environment can be replaced by drawing ambient air into the closed loop. Preferably a cooling gas circulation means such as a fan is provided to circulate the cooling gas. The cooling gas can flow to an entry to the second flow path being proximal to the front wall of the goods department, then flow through the second flow path and then from an exit of the second flow path back to its entry, optionally via the cooling gas circulating means.
There may be one common cooling gas circulating means circulating both the cooling gas in the first flow path and the cooling gas in the second flow path. E.g. a fan can be provided underneath the bottom wall of the goods compartment propelling a common cooling gas flow. Subsequently, this common cooling gas flow is divided into the first flow producing the cooling gas curtain from the front wall to the rear wall of the goods compartment and the second flow flowing through the channel positioned adjacent to the side wall of the goods compartment. Alternatively, two separate cooling circulation means can be provided for the first and the second flow path, respectively.
Preferably a cooling means such as a heat exchanger is provided within the closed loop. Cooling gas for the first and/or second flow path can be cooled by passing it through the cooling means. Preferably, the cooling means is located within the top opening freezer, but can also be provided remotely thereof.
The cooling gas flowing in the second flow path serves for cooling the adjacent side wall. Thereby, the heat entry across the side wall to the goods compartment can be reduced significantly.
According to one embodiment, the channel of the second flow path is defined by one of the respective side walls and the outer casing. In other words, walls defining the channel of the second flow path can be constituted by a side wall and a wall of the outer casing. The cooling gas can enter the space between the side wall and the outer casing proximal to a front wall side, then flow through the space between the side wall and the outer casing and then exit at the opposite rear wall side. No additional tubing needs to be provided between the side walls of the goods department and the outer casing.
Preferably, the second flow path is arranged such that cooling gas flows from a front wall side of the goods compartment across the entire side wall surface to a rear wall side of the goods compartment. Thereby, the side wall can be cooled along its entire length.
According to a further embodiment the channel of the second flow path is positioned laterally adjacent to an upper edge of the side wall of the goods compartment. Thereby, the side wall is especially cooled in a region adjacent to the top-opening where heat losses occur due to turbulences in the cooling gas curtain.
According to a further embodiment the channel of the second flow path includes one or more flow connections to the goods compartment. Through these flow connections cooling gas can flow from the second flow path into the goods compartment thereby providing improved cooling of the goods compartment especially in a region close to the side walls. The flow connections can be provided by holes or cut-outs in the side wall of the goods compartment. These holes or cut-outs can have any geometry allowing a gas flow between the cooling channel and the goods compartment. Optionally, the second flow path is closed at its rear wall side such that the entire gas flow is forced through the flow connections into the goods compartment. By using special geometries for the flow connections or the holes the flow of cooling gas into the goods compartment can be enhanced, thereby providing even better cooling. E.g., the holes or cut-outs can be made larger in regions where additional cooling is especially desired, such as at a region proximal to the rear wall, compared to other regions such that more cooling gas enters at these regions. In order to both cool the space between the side walls of the goods compartment and the outer casing and allow a predetermined cooling gas flow to the goods compartment, the second flow path can be divided into a first continuous flow portion extending from a front wall side of the goods compartment to a rear wall side and a second flow portion having flow connections to the goods compartment. The first flow portion serves for better isolating the goods compartment against the surrounding environment of the top-opening freezer while the second flow portion improves the cooling within the goods compartment within the region close to the side walls. The first and second flow portions can be separated e.g. by a guide vane.
Preferably, the flow connections can be arranged at the filling limit of the goods compartment. That means that the openings for introducing cooling gas from the channel of the second flow path to the goods compartment are approximately arranged in a height of the side wall up to which the goods compartment is to be filled at maximum with goods to be stored therein. By such arrangements, the goods closest to the cooling gas curtain are especially cooled.
Furthermore, the flow connections are preferably arranged at a portion of the side wall proximal to the rear wall. Accordingly, cooling gas can specifically be introduced into the goods compartment in a region downstream of the middle of the first flow path, i.e. the middle of the cooling gas curtain. Thereby, especially the region closer to the opening in the rear wall for returning the cooling gas of the first flow back to cooling gas circulation means, i.e., the region where the cooling gas curtain is warmest and most disturbed, can be additionally cooled.
Further advantages of the present invention will be apparent to those skilled in the art from the following detailed description of preferred embodiments together with the Figures, wherein:
In
The illustrated top-opening freezer 1 further includes a heat exchanger (not shown) positioned within the cooling gas circuit and connected to a cooling unit (not shown) included in a lower part 21 of the top-opening freezer 1.
As can be seen from
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2006/007503 | 7/28/2006 | WO | 00 | 9/28/2009 |
