NL8800294A - IR retro-reflecting screen - is polyethylene film placed film placed pref. over cold body e.g. deep freeze, cold room, ice-skating track, etc. - Google Patents

Abstract

The retro reflecting screen is supplied and placed at a distance from a cold body which can be a deep-freeze or frozen food stuff and in which case, the screen is placed above it. The cold body may also be a skating track. The screen can form the ceiling and/or the walls of a cold space, completely or partially covered to reflect the heat emitted from people back to them. The screen is completely composed of polyethylene film.

Description

sf I

NO 34 884 1 * -

Short designation: Application of a retro-reflective screen.

The invention relates to the use of a retro-reflective screen.

Retro reflectors reflect incident light or incident radiation in a direction opposite and parallel to the incident direction. They consist of a large number of cells comprising a number of substantially perpendicular planes. These planes are the reflection planes.

It is known to use retro reflector screens industrially to limit heat losses in the vicinity of heat sources.

For example, a retro-reflecting screen is placed at some distance in front of the door of an oven to return the heat radiating out through the hole in the oven to the oven when the door is opened. This application is described, inter alia, in U.S. Pat. No. 4,082,414.

The invention relates to another application of a retro-reflective screen, namely one in which a cold body is protected from external heat radiation.

According to the invention, a retro-reflective screen is placed at a distance from a cold body in order to prevent heating of that cold body by heat radiation from the environment.

In contrast to the above-mentioned known application in ovens in which heat radiation is reflected back to the object to be insulated, in the application according to the invention heat radiation from the environment of the cold body to be insulated is radiated back to the environment by retro-reflection.

Examples of cold bodies that can be advantageously protected from external heat radiation are open containers for cooled or frozen items and covered ice rinks.

Of course, more applications can be imagined.

When storing refrigerated or frozen products in open trays in shops, it is a major problem that the products in the top of the trays become too hot due to ambient radiation. Using the invention, this problem is solved in a simple manner by arranging a retro-reflecting screen at some distance above the trays and possibly also on one of the sides of the trays.

In the case of a covered ice rink, the most important effect of the retro-reflective screen placed at a distance above the ice rink is that the ice rink is less stressed by heat radiation from the area around the ice rink. However, like the heat radiated from floors, walls and people, an additional advantage is that the skaters and the audience get some of their radiated heat back radiated by retro reflection, making them feel more comfortable.

Building on this idea, the invention also relates to an application in a room uncomfortably cold for persons.

According to the invention, a retro-reflective screen covers the ceiling and / or the walls of that cold space in whole or in part in order to reflect heat radiation emitted by persons in the space to those persons.

The retro reflectors used should be suitable for reflecting infrared radiation. A retro-reflective polyethylene film is preferred. This material is permeable to infrared radiation, that is to say that little of the incident infrared radiation is absorbed. If the smooth side of the film, which has a thickness of, for example, 0.5 mm, faces the radiation source and the retro-reflective surfaces are applied on the other side, the radiation can pass twice the thickness of the material without a a significant percentage of the radiation is absorbed. The retro-reflective films of polyethylene are inexpensive to manufacture in large areas and relatively strong.

The invention will now be explained in more detail with reference to the figures.

Figure 1 shows a number of trays 1 containing 30 cooled or frozen foods. A retro-reflective screen 2 is arranged at a distance above the bins.

Figure 2 shows an ice rink 3 with a skater on it. Above the track is a retro-reflective screen 4.

Figure 3 shows a cooled room in which a person is present. The walls and ceiling are covered with strips of reflective material 5; a stack of goods in the room is also covered with sheets 6 of that material.

Heat radiated by people (infrared radiation) is reflected on the retro-reflective screens to the people .8800294 3 k ·. In Figures 1 and 2, the main effect is that the cooled or frozen goods, respectively, are not heated up or to a much lesser extent by heat radiation from the environment, while in the embodiment according to Figure 3 the effect is not so great that the covered surfaces are not become warm but that the people in the room lose less heat and feel more comfortable.

Variants and changes are of course conceivable within the scope of the invention.

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Claims (5)

The use of a retro-reflective screen, characterized in that the retro-reflective screen is placed at a distance from a cold body in order to prevent heating of that cold body by heat radiation from the environment. 2. Use according to claim 1, characterized in that the cold body is a container for chilled or frozen foods and the retro-reflective screen is arranged above the container. 3. Use according to claim 1, characterized in that the cold body is a covered ice rink. 4. The use of a retro-reflective screen, characterized in that the screen completely or partially covers the ceiling and / or the walls of a cold room in order to reflect heat radiation emitted by persons in the room to those persons. Retro-reflective screen particularly intended for the applications according to any one of the preceding claims, characterized in that the screen consists entirely of a polyethylene film. 8800294