Means for preventing the formation of ice, particularly on roads

Claim 2

Means for preventing the formation of ice on an external outwardly facing surface endangered by frost, such as the surface of a road, path, staircase, balcony or roof, characterized in that the surface is a solar heat receiving surface which is in heat conductive communication with storage bodies which receive and store solar heat wherein said bodies comprise essentially a storage mass capable of forming ion crystals and wherein the storage mass has a melting point slightly above the freezing point of water.

Claim 3

Means for preventing the formation of ice according to claim 1, characterized in that storage bodies (2,20,34,65) are arranged in cavities beneath the outward facing surface.

Claim 4

Means for preventing the formation of ice according to claim 1, characterized in that the storage bodies (65) are arranged in containers (64) which are thermally insulated against the exterior, and in that heat exchangers (61) are provided beneath the outward facing surface (60) on the surfacing, which communicate with a heat exchanger (63) which is arranged in the storage body (65), the heat transfer between the two heat exchangers taking place through a flowable heat medium, e.g. a vapor or a liquid.

Claim 5

Means for preventing the formation of ice according to claim 3, characterized in that the heat medium consists of a material which is present in vapor form as well as in the form of a condensate (67) at the melting point of the storage mass (3).

Claim 6

Means for preventing the formation of ice according to claim 1, characterized in that the melting point of the storage mass (3) in the storage bodies (2, 20, 34, 65) lies between 1* and 10* C.

Claim 7

Means for preventing the formation of ice according to claim 1, characterized in that the storage mass (3) is a hydrate of an alkalimetal salt or double salt.

Claim 8

Means for preventing the formation of ice according to claim 1, characterized in that the storage bodies consist essentially of the storage mass and substances which do not participate in the change of state and thicken up the melt.

Claim 9

Means for preventing the formation of ice according to claim 1, characterized in that the storage mass is accommodated in geometrically arranged cavities formed between two foils (31 and 33).

Claim 10

Means for preventing the formation of ice according to claim 8, characterized in that the cavities are made up of two bulges (56 and 57), whose depth (58) is greater than the radius (59).

Claim 11

Means for preventing the formation of ice on roads according to claim 8, characterized in that the foundation (38) of the road is connected to the road surfacing (30) by tensioned elements (35) which protrude through openings (39) in the foil (32).

Claim 12

Means for preventing the formation of ice according to claim 3, characterized in that vapor is used as the heat medium, which is collected in a tank (66) after condensation and from there conducted to the heat exchangers (61,63) by a conveying device (70).

Claim 13

Means for preventing the formation of ice according to claim 11, characterized in that the condensate (67) is conveyed by conveying means into the heat exchanger (61) and in that at the lowest point of this heat exchanger a condensate-bypass (74) conducts a small portion of the condensate formed into the condensate tank (66), while the other portion of the condensate is conducted into the condensate tank via the heat exchanger (63).

Claim 14

Means for preventing the formation of ice according to claim 1, characterized in that the storage bodies (34, 20, 42) are in good heat conductive communication with a heating means (22, 40).

Claim 15

A method of de-icing a road by means for preventing the formation of ice according to claim 11, characterized in that the conveying device (70) is switched on in a temperature range adjacent the temperature of crystallization of the storage mass and exceeding the latter by a predetermined amount, and switched off again when this range is exceeded, in that when the ambient temperature drops and is expected to drop below the freezing point and when simultaneously the road is wet, it is switched on and again switched off when the freezing point is exceeded or when the road has dried up, and in that in the case of a supercooled road it is switched on in dependance on meteorological indications, e.g. barometric drop and again switched off after the road has dried up.

Claim 16

Means for preventing the formation of ice according to claim 1 having in addition crystals (a) of a structure which is isotypic and/or epitaxic with respect to the storage mass, (b) are insoluble in the melted storage mass, (c) have a melting point above any operating temperature of the surface area, and (d) are uniformly distributed in the storage mass.

Claim 17

Means for preventing the formation of ice according to claim 13 wherein said heating means comprises an electric power supply, and having in addition means for switching on said power supply when an outer portion of the storage body drops to a temperature which is slightly above the temperature of crystallization of the storage mass in the storage body and switches off said electrical supply when the temperature of the storage mass exceeds the temperature of crystallization.

Claim 18

A means for preventing the formation of ice according to claim 1 having in addition a first heat exchanger in heat conductive communication with said surface, a second heat exchanger in heat conductive communication with said first heat exchanger and located in said storage body, a flowable heat medium connecting said exchangers, interruption means for interrupting the circulation of said heat medium, and a control means for operating said interruption means upon the presence of meteorological conditions conducive to the formation of black ice.