DE102005022214A1 - A method of undersoil heating for agricultural purposes, especially asparagus cultivation, has Flexible electric resistance heating wires beneath the rows of plants - Google Patents

Abstract

The plants are laid in rows (4) of raised earth below which heating wires (5.6) are laid and supplied with low voltage from a transformer (3) with multiple outlets (3.n) and a generator or mains supply (2). The formation of the wire heaters may take different patterns.

Description

TECHNICAL AREA

The The invention relates to an electric heater for Erdbodenerwärmung for outdoor crops, in particular for asparagus crops.

Field crops, especially vegetable crops and here especially asparagus crops thrive only in certain climates Seasons. The harvest of the grown asparagus in Germany takes place between the end of April and the middle of June. Early asparagus harvests can be determined by certain measures such as covering the asparagus bars with heat radiation reach absorbent films. This is a external heat input from the atmosphere, these films capture heat by good the heat radiation favor absorbent properties and hinder the heat emission due to radiation and simultaneously a stay of heat in the ground to a limited extent. Another preference the asparagus harvest in the winter months is characterized by the above activities not possible, since the available standing external heat input for one sufficient soil warming not enough.

asparagus consumption in the winter months and in the spring in Germany therefore regularly requires the import of foreign Asparagus, being its quality and taste usually does not match the usual German quality.

The Prices for German asparagus are to be achieved at the beginning of the harvest season the highest and in normal weather conditions, i. at continuous warm weather continuously, with the end of the harvest season the Supply decreases in quantity and the prices for As a rule, the lower supply is not significant again rise, because the asparagus quality decreases significantly.

each Week to save the asparagus harvest from the previously possible Harvest start could be brought forward, meant the achievement of prices at the highest level. The possibilities, which allow the asparagus harvest to start as early as possible briefly described above and largely exhausted. Floor heating systems by means of piping systems, the transport of a heat transfer medium such as Water, air or exhaust gases are too expensive and expensive, so whose use has not yet been considered.

It Object of the invention, a simple and inexpensive heating to the earth warming for field crops, especially for Asparagus crops, with the start of harvest far outstripping the previous climate-induced harvest beginning can be brought forward.

SUMMARY OF THE INVENTION

These The task is performed by an electric heater for heating the ground for outdoor crops solved with the features of claim 1. Advantageous embodiments the proposed electric heater according to the invention are the subject the dependent claims.

Of the inventive idea It is in the soil below the deepest root area To embed the culture heating elements, which consist of a wire-shaped electrical Consist of ladders that are flexible and two-dimensional one by one covering the culture to be heated determined limited level. The electric heater works as resistance heating and gives the heat released in the electrical conductor directly into the soil from. The part before the measures according to the invention for Erdbodenerwärmung exists especially in that the release of the in the electrical conductor generated heat is very easily controllable and that the heat in the crucial root area of the cultures where growth is generated becomes. The laying of the flexible wire-shaped electrical conductor is relatively simple and does not interfere with the culture, especially the asparagus culture, dar.

According to one advantageous embodiment is the limited plane to be heated is designed as an elongated surface, wherein the occupancy of such geometrically designed area with the electrical according to the invention Heating very easy is. As a result, for example, an optimal adaptation of this electrical Heating of asparagus crops possible, which are known in the form of so-called. Bars designed.

A first embodiment the electrical according to the invention Heating to earth heating for outdoor crops provides that the wire-shaped electrical conductors in a single meandering first heating loop covering the limited level. In this first embodiment then only two electrical connections are required and the arrangement of the wire-shaped electrical conductor has no way on the way between these two terminals Branches up.

For very elongated to be heated surfaces it is advantageous if, as this is a second embodiment provides, the wire-shaped electrical conductors in meandering Heating loops covering the limited level, with the heating loops each divided into more than one section. That's it advantageous, as provides a further embodiment of the invention, when the individual sections of the heating coils are each parallel are connected to a supply line.

The individual areas of meandering Heating loops are in accordance with a further embodiment designed such that the respective wire-shaped conductor the second heating loop substantially in the direction of the length of limited level runs. Another embodiment according to the invention looks in this regard before that the respective wire-shaped Head of the third heating coils essentially in the direction of Width of the limited level runs.

A very cost effective design of the wire-like Ladder is given when, as proposed, made of copper wire.

The Laying the wire-shaped Ladder in the soil to be heated is designed according to another advantageous embodiment then particularly simple when the wire-shaped conductor on a carrier is applied. This carrier is either as rot-resistant fabric or as rot-resistant Slide executed. If in the last embodiment the foil is heat insulating Features that ensures that the over the wire-shaped conductor released heat essentially penetrates into the soil above the film and a heat dissipation prevented in the bottom areas located below the film becomes.

BRIEF DESCRIPTION OF THE DRAWINGS

embodiments the proposed electric heater for ground heating for outdoor crops according to the invention are shown in the figures of the drawing and are below described. Show it

1 a schematic representation of a first embodiment of the electric heater for ground heating for field crops according to the invention, wherein the wire-shaped electrical conductor covers the limited plane in a single meandering first heating loop;

2 a schematic representation of a section through a field crop, in the present case by an asparagus beam, according to a in 1 with CD marked cutting course;

3 a schematic representation of an electric heater for Erdbodenerwärmung for outdoor crops in a second embodiment, wherein the wire-shaped electrical conductor covers the limited plane in several meandering heating loops and the wire-shaped conductor extends substantially in the direction of the length of the limited plane and

4 in a schematic representation of an electric heater for Erdbodenerwärmung for outdoor crops in a third embodiment, wherein the wire-shaped electrical conductor covers the limited plane in several meandering heating loops and the wire-shaped conductor extends substantially in the width of the limited plane.

DETAILED DESCRIPTION

The proposed invention is exemplified by an asparagus culture 4 with several asparagus beams arranged parallel to each other 4.1 to 4-n ( 1 ) explained. Below a root area W ( 2 ) the asparagus beams 4.1 to 4-n in the soil A is a heating element in the form of a wire-shaped electrical conductor 5 arranged. This wire-shaped conductor 5 is heated by resistance heating so far that the heat released the adjacent soil A and thus the root area W of the asparagus culture 4 heated in the manner required for growth. The respective asparagus beams 4.1 to 4-n is formed as a limited plane E in the form of an elongated surface whose width B is much smaller than its length L ( 1 ).

The wire-shaped electrical conductor 5 is in a single meandering first heating loop 6 arranged completely covering the limited plane E. The ends of the wire-shaped electrical conductor 5 are equipped with a first and a second terminal A1, A2, in turn, a connection with a first and second terminal 3.1 . 3.2 a transformer 3 exhibit. In the same way, the first heating loop 6 in the second asparagus bar 4.2 with a third or fourth connection terminal 3.3 . 3.4 of the transformer 3 connected. More asparagus beams 4.3 to 4-n are each in the same way with a first heating loop 6 provided and each to the transformer 3 connected (terminals 3.5 to 3.n ).

The transformer 3 On the primary side, for example, it is supplied with a 400/230 V three-phase voltage and on the secondary side it has a low voltage below 42 V AC. The Power and voltage supply of the transformer 3 via a current / voltage source 2 , which may be, for example, a Hochspannungsstrafo that of a landline overhead power line via a supply line 2a is supplied. The current / voltage source 2 but can also be designed in the form of a generator, which is driven for example via a small wind turbine. The current / voltage source 2 , the transformer 3 and the associated distribution devices and terminals A1, A2 are in a weatherproof power supply device 1 summarized.

Current and voltage on the electrical conductor 5 be dimensioned in conjunction with its resistance so that a sufficient heat development is ensured without that preferably designed as a copper wire electrical conductor 5 Inadmissibly heated and destroyed. As the electrical conductor 5 is flexible, it can be easily deployed into the soil A in the two-dimensional bounded plane E.

3 shows the configuration of the wire-shaped electrical conductor 5 in several meandering second heating loops 7 , these second heating loops 7 through the separately supplied sections 7.1 to 7.n be formed. The respective wire-shaped conductors are 5 the individual sections 7.1 to 7.n the second heating loop 7 arranged substantially in the direction of the length L of the be bounded plane E and each parallel to a supply line 9 connected.

In a third embodiment ( 4 ) becomes the limited plane E through the wire-shaped electrical conductor 5 in the form of several meandering third heating loops 8th covered, the third heating coils 8th each in the sections 8.1 to 8.n. are divided. Each of these individual sections 8.1 to 8.n. is again in parallel to a supply line 9 connected and the respective wire-shaped conductor 5 in the individual areas 8.1 to 8.n. the third heating loop 8th is substantially in the direction of the width B of the limited plane E.

The embodiments of the invention according to the 3 and 4 offers advantages in spreading in the soil A, if the individual sections 7.1 to 7.n respectively. 8.1 to 8.n. on a carrier 10 are applied ( 4 ). This carrier 10 is rolled in the soil A, for example, and the respective two ends of the meandering on the support 10 applied wire-shaped conductor 5 then be with the utility 9 connected (first clamping connections A1.1 to A1.n, second clamping connection A2.1 to A2.n). In this case, the carrier 10 from a rot-resistant fabric 10a or from a rot-resistant film 10b consist.

If the film 10b , as suggested, has heat-insulating properties, migration through the wire-shaped conductor will 5 released heat into the soil A below the wire-shaped conductor 5 largely prevented, so that the heat dissipated predominantly in the overlying root area W of the crops 4 arrives.

1

Power supply means

2

Current / voltage source (e.g., high voltage transformer,

Generator; secondary 400 / 230V)

2a

supply

3

transformer (secondary: ≤ 42V ~)

3.1

first terminal

3.2

second terminal

3.3

third terminal

3.4

fourth terminal

4

Culture; asparagus Culture

4.1

first Culture; first asparagus

4.2

second Culture; second asparagus beam

4.I.

Ith Culture; i-th asparagus beams

4-n

nth Culture; nth asparagus beams

5

heating element; wire-shaped electrical conductor

6

first heating loop

7

second heating coils

7.1

first Section of the second heating loops

7.2

second Section of the second heating loops

7.i

i-th Section of the second heating loops

7.n

nth Section of the second heating loops

8th

third heating coils

8.1

first Section of the third heating loops

8.2

second Section of the third heating loops

8.i

i-th Section of the third heating loops

8.n.

nth Section of the third heating loops

9

supply line

10

carrier

10a

tissue

10b

foil

A

soil

A1

first connection

A1.1

to

A1.n

first clamp connection

A2

second connection

A2.1

to

A2.n

second clamp connection

B

width

e

limited level

L

length

W

root area

Claims (12)

Electric heating for ground heating for outdoor crops, in particular for asparagus crops, which works as resistance heating and in the Heating elements • from a wire-shaped electrical conductor ( 5 ), • flexible, • two-dimensional, a culture to be heated ( 4 ) cover the determinate limited level (E) and • into the soil (A) below the deepest root area (W) of the culture ( 4 ) are embedded. Electric heater according to claim 1, characterized that the limited plane (E) is formed as an elongated surface whose width (B) is much smaller than its length (L) is. Electric heater according to claim 1 or 2, characterized in that the wire-shaped electrical conductor ( 5 ) in a single meandering first heating loop ( 6 ) covers the limited plane (E). Electric heater according to claim 1 or 2, characterized in that the wire-shaped electrical conductor ( 5 ) in meandering heating loops ( 7 ; 8th ) covering the limited plane (E), the heating loops ( 7 ; 8th ) each in more than one section ( 7.1 . 7.2 , ..., 7.i , ..., 7.n ; 8.1 . 8.2 , ..., 8.i , ..., 8.n. ) are divided. Electric heater according to claim 4, characterized in that the individual sections ( 7.1 . 7.2 , ..., 7.i , ..., 7.n ; 8.1 . 8.2 , ..., 8.i , ..., 8.n. ) of the heating loops ( 7 ; 8th ) in parallel to a supply line ( 9 ) are connected. Electric heater according to claim 4 or 5, characterized in that the respective wire-shaped conductor ( 5 ) of the second heating loops ( 7 ; 7.1 . 7.2 , ..., 7.i , ..., 7.n ) extends substantially in the direction of the length (L) of the limited plane (E). Electric heater according to claim 4 or 5, characterized in that the respective wire-shaped conductor ( 5 ) of the third heating loops ( 8th ; 8.1 . 8.2 , ..., 8.i , ..., 8.n. ) extends substantially in the direction of the width (B) of the limited plane (E). Electric heater according to one of claims 1 to 7, characterized in that the wire-shaped conductor ( 5 ) is a copper wire. Electric heater according to one of claims 1 to 8, characterized in that the wire-shaped conductor ( 5 ) on a support ( 10 ) is applied. Electric heater according to claim 9, characterized in that the carrier ( 10 ) a rot-resistant fabric ( 10a ). Electric heater according to claim 9, characterized in that the carrier ( 10 ) is a rot-resistant film ( 10b ). Electric heater according to claim 11, characterized in that the film ( 10b ) is heat-insulating.