US3792966A

US3792966A - Heating shuttering panels

Info

Publication number: US3792966A
Application number: US00298590A
Authority: US
Inventors: A Kleiber
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-12-13
Filing date: 1972-10-18
Publication date: 1974-02-19
Anticipated expiration: 1991-02-19
Also published as: DE2161707A1; FR2166983A5; JPS4866614A; GB1387896A; CH557728A

Abstract

The specification describes a method of heating hollow shuttering panels for use in casting concrete and similar hardenable materials in which method hot air is used and is arranged to flow through the panel directly in contact with the internal surface of one or more of the sides of the panel. In a rectangular panel described by way of example the interior of the panel is divided, by partitions extending between the sides of the panel, to provide two manifolds extending along opposite edges of the panel and ducts extending between and communicating at their ends with the two manifolds. Hot air from a heating means is passed into one of the manifolds, through the ducts to the other manifold and thence back to the heating means for reheating and recirculation.

Description

United States Patent 1 Kleiber HEATING SHUTTERING PANELS [76] Inventor: Armin Kleiber, Mozarstr. 5,

Karlsruhe, Germany [22] Filed: Oct. 18, 1972 [21] Appl. N0.: 298,590

[30] Foreign Application Priority Data Dec. 13, 1971 Germany P 21 61 707.2

[52] US. Cl 432/223, 165/86, 432/9 [51] Int. Cl F28f 5/00 [58] Field of Search 165/81; 432/178, 223, 9

5/1972 MitchelletaL. l/1919 Brand [451 Feb. 19, 1974 Primary Examiner-John J. Camby Attorney, Agent, or Firm-Wenderoth, Lind & Ponack [57] ABSTRACT The specification describes a method of heating hollow shuttering panels for use in casting concrete and similar hardenable materials in which method hot air is used and is arranged to flow through the panel directly in contact with the internal surface of one or more of the sides of the panel. In a rectangular panel described by way of example the interior of the panel is divided, by partitions extending between the sides of the panel, to provide two manifolds extending along opposite edges of the panel and ducts extending between and communicating at their ends with the two manifolds. Hot air from a heating means is passed into one of the manifolds, through the ducts to the other manifold and thence back to the heating means for reheating and recirculation.

4 Claims, 3 Drawing Figures PAIENIEDHEB 1 91914 amazon 4 HEATING SHUTTERING PANELS BACKGROUND OF THE INVENTION The invention relates to a method of heating shuttering panels having cavities into which a heating medium is introduced, and to heated shuttering apparatus.

In the production of planar structural elements from concrete or other hardenable materials that are charged into forming means in a casting process, use is made of shuttering panels which may be designed to be heated in order to accelerate the setting process. Shuttering panels of this kind are used singly, forexample in the horizontal position on tilting tables, or are used in the vertical position when made up into a set, which can either be stationary or transportable. The known heating systems comprise pipe arrangements which are inserted in the shuttering panels and secured by various means. These pipe systems carry steam or hot oil, and high-pressure flexible connections have to be provided between the heating means and the shuttering panels. A system of this kind, employing pipe arrangements is very expensive and carries serious disadvantages as regards the production of the shuttering panels and the carrying out of repairs. Since the pipes are caused to oscillate by the vibrators connected to the shuttering panels, breakage of the pipes occurs relatively frequently, so that such arrangements have only a short service life. A further disadvantage of the known pipe systems resides in the fact that heat is dissipated mainly at the surfaces of the pipes, so that the sheeting of the shuttering panels has to perform the function of distributing the heat across the area of the panels. This results in uneven distribution of heat and can, for example, lead to charring of the concrete in zones near the pipes if supervision is not carried out properly and heat is allowed to build up.

SUMMARY OF THE INVENTION The object of the invention is to provide a method of heating shuttering panels which avoids the use of pipe systems likely to cause trouble and which results in substantially uniform heating of the surface of the shuttering. Accordingly the invention provides, in one aspect a method of heating a hollow shuttering panel comprising passing hot air, constituting the heating medium, from a heating means directly over the internal surface of at least one side of the panel. The hollow interior of the shuttering panels may be open or subdivided, and the inflowing hot air heats the entire forming face or faces of the shuttering panel in a substantially uniform manner, and the likelihood of cracks developing as a result of the movements imparted by the vibrator is greatly reduced. The pressure of the hot air used is conveniently just below or slightly above normal pressure and less than 3 atmos., so that high-pressure connections between the heating means and the shuttering panel are not required. The heating means can simply take the form of an air heater with a fan unit, and heat losses are reduced by re-circulation of the heating medium.

In another aspect the invention provides shuttering apparatus comprising a hollow shuttering panel comprising at least one side which has an external surface providing a moulding surface and which has an internal surface and having an inlet union and an outlet union, the panel providing within it a fluid flow path extending from the inlet union to the outlet union, at least part of which path is defined by the internal surface of the one side, and air heating means connected to supply hot air to the flow path through the inlet union and to receive the air back again from the outlet union for reheating.

In one preferred arrangement, the inlet union and the outlet union are fitted at opposite ends of one edge of the shuttering panel, and the heating means can be disposed adjacent such edge of the panel. An arrangement of this kind offers advantages in the overall installation of production plants, particularly when use is made of shuttering panels that are transportable along a production line.

It is also advantageous where a plurality of panels are put together to form a shuttering set, to provide all the shuttering panels with inlet and outlet unions for connection to respective complementary inlet and outlet unions on the heating means, the heating means being located at one end of the panels so that all the shuttering panels can be connected simultaneously to the heating means.

The shuttering panels can be arranged for movement relative to the stationary heating means over the floor, e.g., on rails or with the aid of bogeys fitted with rollers or spherical runners. This arrangement is preferred for production lines in which the individual shuttering panels are first made up into a set, using panels that have come from a pretreatment line, and then passed as a set from the casting station to a heating station in which the heating means is connected to the shuttering panels. For other applications it may be advantageous for the heating device to be displaceable relative to shuttering panels which are stationary, at least at the heating station, so that the individual shuttering panels or sets of shuttering panels can be successively connected to the heating means. In this way, considerable savings in the cost of the heating means can be achieved.

For the purpose of improving the distribution of flow of the hot air with a view to achieving uniform heating of the shuttering surface, it may also be advantageous to provide guide elements in the interior of the shuttering panel for directing the current of heating medium in the required manner. Such guide elements can take various forms; for example they may be guide strips, perforated metal sheets, wire mesh and the like. In one advantageous arrangement, there are provided, as guide elements or in addition to the guide elements already present, partitions containing openings of differing cross-sections such that the openings adjacent the inlet and outlet unions are of smaller cross-section than those more remote from the unions. In this way, the pressure-drop occurring during the movement of the hot air can be taken into account for the purpose of producing a uniform heating effect. It may also be advantageous to provide, in addition to the partitions, walls which divide up the interior of the shuttering panel. This further increases the evenness of the heating.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 3 shows a shuttering panel, with parts thereof cut away, for use in an apparatus as shown in FIGS. 1 and 2.

DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 and 2 illustrate a transportable set of shuttering panels 1, which can be moved on bogeys 2 and 3 travelling on rails 4 and 5 in a production line.

Each of the shuttering panels 1 has an inlet union 6 and an outlet union 7 on the same end edge for supplying and returning the heating medium. The inlet and outlet unions 6 and 7 of each shuttering panel 1 are connected by resilient intermediate members in the form of flexible metal pipes 8 and 9, to the complementary unions l0 and 11 ofa heating means 12. This heat-' ing means 12 consists of an electrical, gas-fired or oilfired heat-producing unit of which the hot air can be caused to circulate over a closed path through the hollow interior of the shuttering panels 1. The unions 10 and 11 on the heating means 12 are disposed in parallel with each other between suitable ports or manifolds l3 and 14.

The travel of the air inside a hollow shuttering panel is illustrated diagrammatically in FIG. 1 by means of flow-lines. The air is caused to flow in the direction of these lines with the aid of guide elements, the form of which will be explained by reference to FIG. 3.

FIG. 3 shows a shuttering panel 1, parts of which are cut away to show the construction, having fitted internally thereof two partitions l7 and 18 forming passages 15 and 16 for the hot air. The lower hot-air passage 15 communicates with the inlet union 6, and the upper hot-air passage 16 communicates with the outlet union 7 of the shuttering panel 1. Each of the partitions 17 and 18 contains a row of openings 19 and 20 respectively, the cross-sectional areas of which increase with increasing distance from the inlet and outlet unions 6 and 7 respectively. In this way, the pressure-drop in the hot-air passage 15 and 16 can be taken into account for the purpose of achieving uniform distribution of the heating medium. The interior of the shuttering panel is divided into a plurality of ducts by means of vertical separating walls 21 located between the partitions l7 and 18. An opening 19, 20 in each of the partitions is provided opposite the ducts so that the manifolds l5, 16 formed by the partitions communicate with each other via the vertical ducts.

The shuttering panels 1 are produced as box-like hollow bodies and preferably are made of metallic materials having good thermal conductivity. To prevent heatlosses, appropriate lagging can be provided at the edges of the sides of the shuttering panels 1 and/or on the pipes connecting the panels to the heating means.

It may also be advantageous not to form the two hotair manifolds 15 and 16 by means of partitions l7 and 18 as illustrated, but to use lengths of tubing of rectangular cross-section. These would then also each contain a row of openings 19 and 20. Instead of a single opening providing access to each associated duct in the shuttering panel, a plurality of openings could be provided, in which case the total cross-sectional area of the openings associated with each chamber must increase from one set of openings to the next in a direction away from the inlet and outlet unions.

I claim:

1. In an apparatus for manufacturing planar structural elements from concrete or other hardenable materials with hollow shuttering boards which are singly movable in a production line and which may be connected together to build up a multicompartment mold the improvement wherein:

said shuttering boards each comprising a closed body having a heating space and having an inlet union and an outlet union at the same side edge of said shuttering board in connection with said heating space; and

a heating air generator having connections, said inlet and outlet unions being fittable with said connections of said heating air generator to build up a closed heating air circuit for each of the hollow shuttering boards.

2. Apparatus according to claim 1, in which said heating air generator is movable with respect to said shuttering boards.

3. Apparatus according to claim 1, further comprising guiding elements positioned in said heating space of each of said hollow shuttering boards.

4. Apparatus according to claim 3, wherein each of said guiding elements comprises distributing channels positioned at opposite sides within each of said hollow shuttering boards, and a plurality of parallel ducts extending from one distributing channel to the other, said distributing channels being in connection with said inlet and outlet unions and having apertures each communicating with the parts of said heating space formed by said parallel ducts, the area of said apertures in each of said channels progressively increasing from duct to duct in a direction away from said inlet and outlet unions.

Claims

1. In an apparatus for manufacturing planar structural elements from concrete or other hardenable materials with hollow shuttering boards which are singly movable in a production line and which may be connected together to build up a multicompartment mold the improvement wherein: said shuttering boards each comprising a closed body having a heating space and having an inlet union and an outlet union at the same side edge of said shuttering board in connection with said heating space; and a heating air generator having connections, said inlet and outlet unions being fittable with said connections of said heating air generator to build up a closed heating air circuit for each of the hollow shuttering boards.