FR2502896A1 - Water manifold system for radiant heating of greenhouses etc. - using flexible hose for ease of installation or alteration - Google Patents

Abstract

The blanket is laid on the floor of a hothouse in which vegetables are grown in rows. Between adjacent rows a continuous strip, comprising e.g. three parallel flexible plastic water tubes, extends from a hot-water inlet collector to a cold-water outlet collector on the same side of the hothouse. The three parallel tubes are held together by narrow intermediate strips which may be formed with them in a single extrusion operation. The collectors are composed of rigid tubular sections alternating with flexible tubular sections and are connected respectively to a hot-water supply and a cold-water drain. The collectors with their flexible sections are adaptable to uneven flooring or ground and easily transportable from site to site.

Description

 The present invention relates to a radiant heating mat at low temperature for the intensive cultivation of plants.

 For the heating of greenhouses, it is already known to use a heat exchanger in the form of a continuous strip, made of extruded plastic, consisting of tubes parallel to each other, intended for the circulation of heating water and connected between them by narrow tabs. This strip of constant width, for example twelve centimeters, is supplied in rolls and can be cut to the desired length. It is placed on the ground, in the intervals between the parallel rows where the plants are grown and it is gRaFralemeat arranged in a loop so that its two ends are located on the same side and connected respectively to a hot water inlet manifold and a chilled water outlet manifold. These manifolds, which are made of plastic or copper, are arranged transversely to the parallel strips of tubes.

 Up to now, long collectors have been used (1 meter or more in rigid material, these collectors being connected to each other by glued or screwed connection sleeves. The junction of the tubes of the various bands with the collectors is carried out by the 'through holes that are drilled in these manifolds and in which the ends of the individual tubes are engaged.

 The use of such long and rigid collectors leads to several drawbacks. Firstly the positions and the density of the parallel tube strips are fixed once and for all. This results in an obvious lack of flexibility in use, both immediately and subsequently. Furthermore, because the collectors are rigid, they adapt poorly to the relief of the ground and they constitute an annoying dam at the end of the greenhouse. Finally the cost of their assembly is very high because it is a traditional piping and this assembly requires a qualified workforce.

 The present invention aims to remedy these various drawbacks by providing collectors of very simple design and allowing great flexibility of use.

For this purpose, this radiant heating mat with low temperature for intensive cultivation of plants, comprising several strips of parallel flexible plastic tubes connected to each other by intermediate tabs, and two transverse hot water collectors and cold water outlet to which the two ends of each tube strip are respectively connected, is characterized in that each transverse collector consists of tubular sections of rigid material each carrying fittings on which
the ends of the parallel tubes of each strip are threaded, and of flexible pipe sections connecting the rigid sections together.

The heating mat according to the invention offers the advantage that the collectors can be produced on site and very easily adapted to the width and spacing of the rows along which the plants are grown. In addition, assembling the manifolds can be carried out very easily, by an unskilled labor force, since it suffices in fact to cut the sections of pipe to the desired length.
flexible and assemble them with the rigid sections carrying the fittings. Furthermore, the fact that these rigid sections have a relatively small length and that they are connected to one another by longer long sections, these flexible sections follow the profile of the ground and the collectors do not constitute an annoying protruding dam with respect to the ground. After a specific use, the collectors can be dismantled in elementary sections and be reused for another application, with the parallel tube strips also recovered.

An embodiment of the present invention will be described below, by way of non-limiting example, with reference to the appended drawing in which:
Figure 1 is a partial-thematic plan view of a radiant heating mat used for heating a greenhouse in which takes place an intensive cultivation of plants.

 Figure 2 is a plan view, partially in horizontal section, of a rigid section of a manifold carrying fittings on which are fitted the ends of the parallel tubes of a strip.

 Figure 3 is an elevational view of a collector.

 The radiant heating mat shown in Figure 1 is applied to the floor of a greenhouse in which intensive cultivation of plants arranged in rows 1 is practiced. In the intervals between these rows l are arranged continuous strips 2 each made of 'a number of parallel tubes 3 (three in number) in the example illustrated. These tubes are interconnected by narrow intermediate tabs 4. The entire continuous strip 2 is advantageously made in one piece by extrusion of a plastic material.

 The ends of the tubes 3 of the strips 2 are respectively connected to a hot water inlet manifold 5, itself connected to a hot water inlet pipe 6, and to a cold water outlet manifold 7 itself connected to a cold water return pipe 8. The hot water 5 and cold water return 7 collectors extend transversely to the strips 2 and are located at the same end of the greenhouse, one close to the other as it appears in Figure 1. As a result, the tubes 3 of each band 2 form loops: in other words the tubes 3 of a band 2 extend from the hot water inlet manifold 5 in an interval between rows 1 then they pass in the next interval to return to the end of the greenhouse where the cold water return manifold 7 is located. The intermediate tabs 4 are removed at the ends where the loops of the tubes are formed to allow easy bending of the latter.

 According to the invention, each of the collectors 5 and 7 is made of several individual sections connected to each other, namely rigid tubular sections 9 and sections of connecting pipes made of flexible material 10. Each rigid tubular section 9 carries on its surface lateral, fittings 11 on which are fitted the end parts of the tubes 3, by elastic deformation of the latter. Additional clamping members may or may not be provided to firmly hold the tubes 3 on the connectors 11. In the particular case described by way of example, each rigid section has three connectors 11 on which the ends of the three tubes 3 come to rest. band 2.

 Each connecting section 10 is made of a flexible plastic pipe which can thus follow the unevenness of the ground as can be seen in FIG. 3. The internal diameter of each flexible connecting section 10 is equal to or slightly less than the external diameter of the rigid section 9, so as to be able to engage closely on the latter, with or without the provision of an additional clamping member such as a collar.

 The connecting sections 10 are cut to the desired length from a roll of flexible plastic pipe and it can be seen from the above that the assembly of the assembly of one of the collectors 5 and 7 is carried out very easily since it suffices to effectively cut the sections 10 to the desired length and to connect them by interlocking to the rigid sections 9 which have a predetermined length.

 After use, the entire mat can be recovered very easily because the collectors 5 and 7 are very easy to disassemble.

The strips 2 of parallel tubes 3 can also be recovered to be reused in other places.

Claims (1)

CLAIM 1. Low temperature radiant heating mat for indoor cultivation  sive of plants, comprising several strips of parallel tubes  flexible plastic material interconnected by inter tabs  and two transverse hot water inlet manifolds and  cold water outlet to which the  two ends of each strip of tubes, characterized in that each  transverse collector (5,7) consists of tubular sections in  rigid material (9) carrying each of the fittings on which are  threaded the ends of the parallel tubes (3) of each strip (2),  and flexible pipe sections (10) connecting the  rigid sections (9).