FR2533603A1

FR2533603A1 - Method permitting prevention of the formation of icicles on the inner surface of a constructive work

Info

Publication number: FR2533603A1
Application number: FR8216575A
Authority: FR
Inventors: Pierre Mathieu
Original assignee: SEDRIC TP
Current assignee: SEDRIC TP
Priority date: 1982-09-29
Filing date: 1982-09-29
Publication date: 1984-03-30

Abstract

Fitting-out of tunnels and constructive works. The method is characterised in that a chute is formed, enabling flowing water to be channelled through the inner surface and preventing the water from freezing by means of lagging and possible heating with the aid of a polyester sheet in which resistive strips supplied with electrical current at 24 volts are incorporated. Application: to prevent the formation of icicles on the inner surface of constructive works.

Description

La presente invention concerne un système permettant d'éviter la formation de stalactites de glace sous l'intrados des tunnels ou plus généralement de structures couvertes (tabliers de ponts, voltes, etc...), ceci en période hivernale. The present invention relates to a system making it possible to avoid the formation of ice stalactites under the underside of tunnels or more generally of covered structures (bridge decks, volts, etc.), this in winter.

I1 existe au moment où nous écrivons ce texte, différents moyens de lutte contre la formation de ces glaçons qui se classent en quatre sous-groupes
- moyens d'étanchement de l'intrados considéré, par injections de produits appropriés (résines, mousses de polyuréthane, etc...) ; ce procédé présente deux inconvénients : il peut y avoir un inconvénient sur le plan mécanique (mécanique des sols par exemple) à ne pas permettre à l'eau de s'écouler, ceci par modification des caractéristiques de la partie imprégnée d'eau (sol saturé modification de la densité, du coefficient de poussée, etc...) ; il peut y avoir création d'un nouveau passage par l'eau après blocage du premier passage.At the time of writing, there are different ways to fight the formation of these ice cubes, which fall into four subgroups.
- means of sealing the pressure surface under consideration, by injecting appropriate products (resins, polyurethane foams, etc.); this process has two drawbacks: there may be a mechanical drawback (soil mechanics for example) in not allowing water to flow, this by modifying the characteristics of the part impregnated with water (soil saturated change in density, thrust coefficient, etc.); there may be creation of a new water passage after blocking the first passage.

- moyens mécaniques : destruction des stalactites manuellement ou mécaniquement, après formation de celles-ci ; inconvénient : coût en main d'oeuvre, mauvaise fiabilité du fait du temps hétérogène de formation. - mechanical means: destruction of stalactites manually or mechanically, after formation thereof; disadvantage: labor cost, poor reliability due to the heterogeneous training time.

- moyens thermiques : chauffage général de l'intrados de l'ouvrage, soit par rayons infra-rouges, soit par incorporation de résistances électriques ou propulsion d'air chaud dans un revêtement général beton ; ce moyen bien qu'efficace, est très coûteux en énergie. - thermal means: general heating of the lower surface of the structure, either by infrared rays, or by incorporation of electrical resistances or propulsion of hot air in a general concrete coating; this means, although effective, is very costly in energy.

- moyens de protection contre les basses températures qui peuvent être le drainage dans des saignées creusées dans a sous-face à une profondeur dite hors gel, permettant de rejeter l'eau en pied de voûte et calorifugeage general (cintre général en tôle ondulée calorifugée sur lequel tombe et ruisselle l'eau). - means of protection against low temperatures which can be drainage in grooves dug in a soffit at a depth known as frost-free, allowing water to be discharged at the base of the vault and general insulation (general hanger made of corrugated sheet insulated on which falls and runs off the water).

Ce procédé relativement efficace présente deux inconvénients : coût très élevé, et éclatement à la suite d'une chute de température trop importante.This relatively effective process has two drawbacks: very high cost, and bursting after too large a temperature drop.

Par la présente invention, nous avons voulu éliminer les inconvénients inhérents aux procédés existants : en particulier, coût d'installation, coût d'exploitation, fiabilité. By the present invention, we wanted to eliminate the drawbacks inherent in existing processes: in particular, installation cost, operating cost, reliability.

Suivant les caractéristiques de l'invention, on réalise en matière synthétique (résine polyester armée, P.V.C., etc...) une goulotte (1) (figure 1) qui a les caractéristiques suivantes : celle-ci est fixée sur la sous-face de l'ouvrage à traiter, et collecte les eaux arrivant à une température positive. According to the characteristics of the invention, a chute (1) (1) (FIG. 1) is made of synthetic material (reinforced polyester resin, PVC, etc.) which has the following characteristics: it is fixed to the underside of the structure to be treated, and collects water arriving at a positive temperature.

La fixation de cette goulotte se fait par vissage, ceci en écrasant un joint jouant le rôle d'étanchéité thermique et étanchéité aux fluides. Sous cette goulotte est collée une feuille de polyester (2) dans laquelle -sont intégrées des résistances électriques extrèmement fines (rubans résistifs) et reparties sur l'ensemble de la surface. Sous cette feuille est disposée une isolation thermique en forme de U, en polystyrène expansé ou similaire (3). The fixing of this chute is done by screwing, this by crushing a joint playing the role of thermal sealing and fluid tightness. Under this chute is stuck a polyester sheet (2) in which -are integrated extremely fine electrical resistances (resistive tapes) and distributed over the entire surface. Under this sheet is arranged a U-shaped thermal insulation, made of expanded polystyrene or the like (3).

Une seconde goulotte t4) ou carter protège l'ensemble sur le plan mécanique.A second chute t4) or casing protects the assembly mechanically.

L'ensemble (1) + t2) + (3) + (4) est préassemble en usine. Cet ensemble présente un défoncé sur une extrémité permettant de recouvrir une partie de l'ensemble contigu situé en aval, et de favoriser ltecoulement de l'eau dans (1), ceci jusqu'au pied de voûte. The assembly (1) + t2) + (3) + (4) is pre-assembled at the factory. This assembly has a knockout on one end making it possible to cover part of the contiguous assembly situated downstream, and to promote the flow of water in (1), this up to the arch.

Chaque résistance (2) d'un ensemble est connectée à la résistance (2) de l'ensemble contigu aval ou amont dans le cas d'un montage en serie, ou à une alimentation générale dans le cas d'un montage en parallèle. Le rôle de l'ensemble (1) + (2) + (3) + (4) est de maintenir l'eau à une température positive, et de la conduire en pied de votte.Pour cela, un capteur thermique commande la mise sous tension ou l'arrêt de (2) ; (2) étant reliée à une source dSlimentation en électricité (sous une différence de potentiel de 24 V), qui peut être le secteur, un groupe électrogène alimentant une batterie d'accumulateurs au cadmium à démarrage temporisé ou telecom- mandé, ou des cellules solaires. Each resistor (2) of an assembly is connected to the resistor (2) of the contiguous downstream or upstream assembly in the case of a series connection, or to a general supply in the case of a parallel connection. The role of the set (1) + (2) + (3) + (4) is to maintain the water at a positive temperature, and to lead it to the bottom of the tank. For this, a thermal sensor controls the setting on or stopping (2); (2) being connected to a source of electricity supply (at a potential difference of 24 V), which may be the mains, a generator supplying a battery of cadmium accumulators with timed or remote starting, or cells solar.

Claims

t. Method for producing a system intended to prevent the formation of ice stalactites in tunnels, characterized in that the water is allowed to flow along its natural path until it flows through the underside of the work, that it is collected while it is at a positive temperature (Celcius scale), that it is maintained at this temperature, and that it is rejected in an area where the formation of ice is not not dangerous.

2. Method according to claim 1, characterized in that one executes a plastic plastic chute fixed on the lower surface of the structure, into which the collected water flows.

3. Method according to claim 1 to 2, characterized in that one can implement a series of n nestable chutes, to constitute a path with water whose length is equal to n times the length of a chute.

4. Method according to claim 1 to 3, characterized in that it seals by crushing a joint the lateral parts of the chute.

5. Method according to claim 1 to 4, characterized in that a polyester sheet is bonded to the underside of the chute, sandwiching electrical resistances arranged in thin ribbons (lead + tin alloy) at low point of fusion, supplied with electric current according to a potential difference of 24 Volts.

6. Method according to claim g to 5, characterized in that one thermally insulates the chute and the polyester sheet with a suitable material.

7. Method according to claim 1 to 6, characterized in that one implements a second envelope of synthetic plastic, called "casing", mechanically protecting the assembly and fixed on the first chute.

8. Method according to claim 1 to 7, characterized in that the housing is pierced at several points to avoid areas of condensation, inside the thermal insulation.

9. Method according to claim I to 8, characterized in that the temperature is continuously measured by a thermal probe for energizing the installation.

10. Equipment for implementing the method, according to one of claims 1 to 9, characterized in that it comprises at least one chute in the form of parallel or non-parallel generators, constituted by elementary segments in reinforced synthetic plastic.

11. Equipment according to claim 10, characterized in that each chute has along its longitudinal edges of the fixing flanges on the underside of the structure.

12. Equipment according to claim 10 to 11, characterized in that each chute is fixed to the lower surface of the structure by screws, compressing a seal located between the lower surface and the edge of the chute.

13. Equipment according to claim 10 to 12, characterized in that each chute is completed by a polyester sheet bonded to its underside, and in which are incorporated ribbons of a resistive alloy and current conductor.

14. Equipment according to claim 10 to 13, characterized in that each chute is thermally protected by an insulator bonded thereto.

15. Equipment according to claim 10 to 14, characterized in that each chute is protected by a "casing" made of synthetic plastic.

16. Equipment according to claim 10 to 15, characterized in that each casing is perforated.

17. Equipment according to claim 10 to 16, characterized in that each casing has along its longitudinal edges of the fixing flanges on the chute.

18. Material according to claim 10 to 17, characterized in that the trunking + sheet + thermal insulation + casing assembly is pre-assembled in the factory.

19. Equipment according to claim 10 to 18, characterized in that the electrical supply is made under 24 Volts of potential difference.

20.Material according to claim 10 to 19, characterized in that the electrical supply is controlled by a thermal probe.

21. Equipment according to claim 10 to 20, characterized in that the electrical consumption is extremely low (40 W maximum / m2).

22. Equipment according to claim 10 to 21, characterized in that the outside temperature can drop to -30 C (in a tunnel).

23. Equipment according to claim 10 to 22, characterized by the fact that it is supplied with the aid of the E.D.F. network, of a cadmium accumulator battery recharged by a generator set with an automatic start-up thermal engine.