FR2611113A1 - Device for protecting arboricultural plantations from frost during wintry periods - Google Patents

Abstract

The invention relates to an electrical heating device allowing temperature maintenance which ensures the survival of arboricultural plantations during frosty periods. This invention is noteworthy in that, according to Figure 1, it consists: of a regulating cabinet AR, receiving electricity from the mains at the terminal B and including an alarm A1 and a probe S, distribution lines L1, L2, ... Ln supplying the sealed boxes Be and distributing the electrical power to the heating tapes (cords) Cc held in place along the plant by the isothermal jacket E via the distribution element C. The invention finds its main application in the protection of arboricultural plantations, in particular of Actinidia (Kiwi fruit).

Description

 The invention relates to a heating device allowing maintenance at survival temperature, especially in winter of tree plantations. This electric energy-based heating device relates more particularly, because it is in this case that its application seems to have the most interest but not exclusively, the protection of fragile or exotic plantations of the genus "ACTINIDIA".

 Winter temperatures, especially those that are very negative and long lasting, have been found to have harmful effects on certain tree plantations.

 Indeed these very low temperatures freeze the residual sap of the plant, in particular that of the young trunks with fragile bark, putting in danger of destruction of whole plantations and often important in the case of ACTINIDIA.

 We tried to remedy this problem using wraps of hot water pipes, they are unusable for young trunks of variable diameter, the material is bulky and unwieldy, difficult regulation for a large quantity of plants . In addition, water, heat transfer liquid, in the event of even partial breakdown, can become the main reason for destruction of the plantation.

 The invention therefore aims in particular to produce a winter protection device for small or large plantations, based on electrical energy, compact and energy efficient, only the selected part of the frost-resistant plant can be protected.

 This device is easy to make industrially, quick and easy to implement, it can be adapted to the other dimensional characteristics and to the temperatures necessary for the survival of most arboreal species, in particular ACTINIDIA.

 The device according to the invention is characterized by the assembly of elements for distributing electrical energy, in particular in calorific form, known for other uses. These different elements, in this case, form a set of electrical distribution, heating, security, regulation, control, original alarm ensuring reliably the maintenance of the survival temperature of the plantation considered.

In a preferred, but not exclusive, embodiment, the device consists
- on the one hand, a heating electric cord, maintained along the trunk of each plant to be protected
- on the other hand, at least one electrical power supply line, preferably overhead, connected to said heating cords
- on the other hand, finally, an isothermal envelope coating the heating cords and the plants.

 Thus proposing to produce a winter protection device by electric heating, of tree plantations, in particular of ACTINIDIA, of small or great importance, space-saving, calorie-saving, of easy implementation, including safety devices, regulation, control, alarm ensuring reliability, it will be made to include the characteristics highlighted in the description below in respect of the accompanying drawings, the latter being given by way of indication.

 Figure 1 shows in perspective and schematically, the essential elements of a complete installation of the device.

 Figure 2 shows the detail of the control cabinet.

 Figure 3 shows the Ll-L2 ... Ln distribution lines of electrical energy in the plantation.

 Figure 4 shows the heat distribution element.

 Figure 5 shows the envelope of isothermal materials.

The AR control cabinet in wood, metal or plastic materials of regulatory exterior type will in particular receive
- Connection terminal B receiving electrical energy from the mains or from any other source ensuring the necessary electrical power.

- Earth connection
- The Disj differential circuit breaker (s)
- The thematic contactor (s) Ct
- Th thermostat (s) preferably with digital display for better reading
- The set of indicator fuses, serving each starting line F (F1 - F2 ... Fn)
- The equipment of this cabinet can be supplemented by an S sensor used to trigger the start of heating at the selected room temperature and an Al alarm which is triggered in the event of an anomaly (short circuits, power failure .. .). These last two devices can be usefully placed outside the cabinet.

 - The S probe on a witness stand of the plantation to be protected, thus triggering the heating to the actual temperature undergone by the plant.

 - The alarm Al at the workplace or the life of the operator responsible for monitoring the plantation.

The distribution lines Ll-L2 ... Ln are made of commercial electrical conductors with regulatory characteristics for the exterior on which are sealed molded or removable boxes
Each line serves a sector of the plantation and makes it possible to feed all the plants to be protected individually.

 The element D of heat distribution formed by electrical wires and the heating cord can be permanently connected to the waterproof case Be in the case of molded cases or by means of an electrical outlet allowing disconnection.

 The envelope E of the trunks of the plantation, in isothermal materials is in the case which interests us in wrapping paper of type "bag", this envelope is intended to avoid the dispersion of the calories resulting from the heating cord. It will be noted that the probe S is placed here near the trunk to be protected under the isothermal envelope. The temperature at which the heating is switched on and off is therefore taken directly from the plant to be protected, ensuring greater protection reliability.

A planting protection device is then obtained which is simple to set up and operate as described below.
When the drop in temperature threatens the survival of the plantation, the sensor S transmits this temperature to the thermostat Th previously set to the minimum acceptable. Via the contactor Ct, the electrical energy received from the main supply line by terminal B is transmitted to fuses F1 - F2 ... Fn and thereby to distribution lines L1 - L2 ... Ln. The electrical energy via the boxes Be is transmitted to the heat distribution element De. The heating cord Cc then supplied dispenses its heat distributed along the trunk and kept nearby by the heat envelope E.

 As the temperature along the trunk increases, the probe which transmits this continuously causes the contactor to trip again via the thermostat, thus opening the electrical circuit and cutting off the heating to the maximum desired temperature. Each plant is thus effectively protected.

In the event of a breakdown, power cut on the general line, malfunction of the general circuit breaker, short circuit on any of the electrical or heat distribution lines, the alarm Al located in any place of life of the plantation supervisor is triggered, thus warning him of the anomaly and making it possible to urgently take the necessary measures for repair. We will note
1) that troubleshooting is made easier by the rocker fuses with indicator, each of which can be tripped separately
2) that the elements described above can be in indefinite number according to the possibilities of electrical supply, the needs of the plantation to be protected, without this bringing variation in the field which concerns us. In particular, the temperature measurement elements can be single or multiple, as well as the alarm elements which, in the above description are triggered by electrical anomalies but can also be controlled by a thermostat device.

They are then triggered by abnormal ambient temperatures, or by the particular temperature of each plant to be monitored.

 The above device can be used on the one hand for the protection of the entire plant (trunk and branches), the calorific power being adapted to the part to be protected (heated cords doubled when approaching the ground, on the other hand for the departure of the vegetation in the spring by creating a favorable artificial climatic situation.

Claims (3)

 1) Device for protecting arboreal plantations, especially ACTINIDIA, in winter period by electric heating ensuring, by heating, the survival temperature of each plant in the plantation  Device characterized in that it comprises in combination  - on the one hand, an electric heating cord maintained along each plant trunk to be protected  - on the other hand, at least one power supply line, preferably overhead, connected to said heating cords  - on the other hand, a control cabinet to manage the temperature and the heating periods of the cords  - on the other hand, finally, an isothermal envelope coating the heating cords and the plants  2) device according to claim 1 characterized in that, for the control of the general or specific ambient temperature for each plant there is provided one or more thermal probes generally positioned near the plants under the isothermal envelope, or near the planting  3) Device according to claims 1 and 2 characterized in that the control cabinet is equipped with safety devices (circuit breakers, indicator fuses), regulation (thermostat), control (probe, thermostats with digital display), d alarm (buzzer) as well as electric energy arrival and departure terminals