DK154462B

DK154462B - APPARATUS FOR AUTOMATIC IRRIGATION OF PLANTS GROWING IN AIR AIR OR ANY GREENHOUSE AND A CONTROLLER FOR USE IN CONNECTION THEREOF

Info

Publication number: DK154462B
Application number: DK1799787AA
Authority: DK
Inventors: Leendert Cornelis Kesting; Cornelis Willem Nieuwkoop
Original assignee: Leendert Cornelis Kesting; Nieuwkoop C W
Priority date: 1977-04-26
Filing date: 1978-04-25
Publication date: 1988-11-21
Also published as: DE2818358A1; NL182274C; NL7704535A; NL182274B; SE433900B; FR2388489A1; DK179978A; DK154462C; SE7804742L; FR2388489B3

Description

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Opfindelsen angår et apparat til automatisk vanding af planter, som gror i fri luft eller i et drivhus, og som omfatter en forbindelsesledning for vandforsyning til et porøst, absorberende substrat, hvor der er anbragt en ventil i denne ledning, som aktiveres ved hjælp af et signal fra 5 en reguleringsenhed, der over en sonde styres af substratets fugtig- hedsindhoid.BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an apparatus for automatically watering plants which grow in the open air or in a greenhouse and which comprises a water supply connection line to a porous, absorbent substrate where a valve is disposed in this line which is actuated by signal from 5 a control unit which is controlled over a probe by the moisture content of the substrate.

Ved et kendt apparat af denne art måles fugtighedsgraden eller fugtighedsindholdet af substratet direkte i substratet, og apparatet bringes automatisk i drift, når fugtighedsgraden er for lav og afbrydes 10 påny, når fugtighedsgraden er steget til en bestemt maksimumværdi.In a known apparatus of this kind, the humidity or moisture content of the substrate is measured directly in the substrate and the apparatus is automatically operated when the humidity level is too low and interrupted again when the humidity level has risen to a certain maximum value.

Når substratet består af kulturjord, pottejord eller spagnum, giver dette apparat rimeligt tilfredsstillende resultater, men variationer i vandets ledningsevne som følge af næringsmidler eller gødningsmidler, som findes i vandet, medfører dog store måleforskel le.When the substrate consists of culture soil, potting soil or spagnum, this apparatus gives reasonably satisfactory results, but variations in the conductivity of the water due to nutrients or fertilizers found in the water, however, result in large measurement differences.

15 For at formindske de risici, som kulturer udsættes for indenfor landbrug og havebrug, er der i de senere år sket en stedse forøget anvendelse af syntetiske substrater, som er sterile, eller som let kan steriliseres.15 In order to reduce the risks that crops are exposed to in agriculture and horticulture, in recent years there has been an ever-increasing use of synthetic substrates that are sterile or that can be easily sterilized.

Blandt forskellige eksempler på syntetiske substrater, som har 20 været foreslået som erstatning for kultur- eller pottejord, har stenuld vist sig i praksis at være et udmærket substrat, som anvendes i stedse større målestok.Among various examples of synthetic substrates, which have been proposed as a substitute for cultural or potting soil, stone wool has in practice proved to be an excellent substrate used on a larger scale.

Det i det foregående omtalte vandingsapparat arbejder imidlertid ikke godt i forbindelse med stenuld. Når et sådant kendt apparat an-25 vendes, indeholder stenuld altid for meget vand, hvorfor der er risiko for forrådnelse.However, the irrigation apparatus mentioned above does not work well in connection with rock wool. When such a known apparatus is used, rock wool always contains too much water, which is why there is a risk of rot.

I stedet for en styring baseret på substratets fugtighedsindhold kan der anvendes et apparat, som styrer vandingen i afhængighed af fugtighedsgraden af bladene, eller der kan anvendes et apparat med 30 en tidsafbryder, som ind- og udkobler vandforsyningen med regelmæssige mellemrum, men det første apparat er mindre favorabelt, navnlig i de tilfælde hvor det drejer sig om planter med et komplet rodsystem, hvor fugtighedsgraden af substratet er væsentligt, fordi fugtighedsgraden af bladene ikke fortæller noget om (ikke står i for-35 hold til) substratets fugtighedsgrad, og det sidste apparat giver kun en meget grov styring.Instead of a control based on the moisture content of the substrate, an apparatus can be used to control the irrigation depending on the moisture content of the leaves, or an apparatus with a timer can be used which switches on and off the water supply at regular intervals, but the first apparatus is less favorable, especially in the case of plants with a complete root system, where the moisture content of the substrate is significant, because the moisture content of the leaves does not tell (in relation to) the moisture content of the substrate, and lastly apparatus provides only a very coarse control.

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Det har nu vist sig, at når en beholder med vand er forbundet med substratet ved hjælp af et fugtighedssugende system med væskeberøring overalt, vil vandhøjden i en sådan beholder variere med substratets fugtighedsindhold og er ikke påvirket af variationer, hvad 5 angår vandets indhold af gødnings- eller næringsmidler.It has now been found that when a container of water is connected to the substrate by means of a moisture-sucking system with liquid touch everywhere, the height of the water in such a container will vary with the moisture content of the substrate and is not affected by variations in the water content of the fertilizer. - or foods.

Ifølge den foreliggende opfindelse anvendes denne erkendelse Åpparatet ifølge opfindelsen er ejendommeligt ved, at sonden er anbragt i en beholder, der over en kanal, som er lukket langs omkredsen, og som er fyldt med et fugtighedssugesystem, og som er forbun-10 det med beholderen under sondens laveste punkt, står i forbindelse med det porøse absorberende substrat. Herved opnås, at vandhøjden i beholderen anvendes til styring af reguleringsenheden over sonden, som ved et bestemt vandniveau i beholderen automatisk sætter vandings-apparatet i gang, og som automatisk afbryder vandingsapparatet ved 15 et andet vandniveau, hvorved der opnås en fugtighedsgrad af substra tet, der ligger indenfor snævre grænser. Endvidere bliver styringen uafhængig af indholdet af gødnings- eller næringsmidler i vandet.According to the present invention, this recognition is used. The apparatus according to the invention is characterized in that the probe is placed in a container which is over a duct which is closed along the circumference and which is filled with a moisture suction system and which is connected to the container. below the lowest point of the probe, is associated with the porous absorbent substrate. Hereby it is obtained that the water height in the container is used to control the regulating unit over the probe, which at a certain water level in the container automatically activates the irrigation apparatus and which automatically switches off the irrigation apparatus at another water level, thereby obtaining a moisture degree of the substrate. that is within narrow limits. Furthermore, the control becomes independent of the content of fertilizers or nutrients in the water.

Sonden kan f.eks. være en mekanisk sonde, som f.eks. en svømmer, eller man kan anvende en pneumatisk virkende sonde, d.v.s.The probe may e.g. be a mechanical probe such as a swimmer, or one can use a pneumatically acting probe, i.e.

20 et organ ved hjælp af hvilket en lille gasstrøm blæses mod væskeover fladen, eller der kan anvendes en elektrisk sonde, f.eks. et organ, som reagerer overfor kapacitetsændringer.20 a means by which a small gas stream is blown against the liquid surface or an electric probe, e.g. a body that responds to capacity changes.

Hensigtsmæssigt består sonden af et sæt elektroder, som giver et elektrisk signal ved et bestemt vandniveau.Conveniently, the probe consists of a set of electrodes which provide an electrical signal at a particular water level.

25 Et sådant elektrodesæt medfører den fordel, at det kun fylder lidt, således at den beholder, hvori elektrodesættet anbringes, også kan have små dimensioner, og et sådant elektrodesæt har endvidere ikke nogen bevægelige dele, således at mekaniske forstyrrelser praktisk talt ikke kan forekomme, og endvidere kan det elektriske kreds-30 løb, som er nødvendigt, være meget enkelt.Such an electrode set has the advantage that it fills only slightly, so that the container in which the electrode set is placed may also have small dimensions, and such an electrode set also has no movable parts, so that mechanical disturbances can practically not occur. and furthermore, the electrical circuit required may be very simple.

Det er vigtigt, at der i apparatet ifølge den foreliggende opfindelse er væskeberøring mellem væsken i beholderen og væsken i substratet via fugtighedssugesystemet. For at sikre dette under alle omstændigheder kan det sted, hvor den med fugtighedssugesystemet 35 fyldte kanal er forbundet med beholderen, hvori sonden er anbragt, fortrinsvis ifølge opfindelsen være anbragt 3-10 cm under substratets underside.It is important that in the apparatus of the present invention there is fluid contact between the liquid in the container and the liquid in the substrate via the moisture suction system. In order to ensure this in any case, the location where the duct filled with the humidifier system 35 is connected to the container in which the probe is located may preferably be located 3-10 cm below the underside of the substrate.

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Når denne højdeforskel er mindre end 3 cm, opstår der let en tilstand, hvor beholderen suges tom ved hjælp af fugtighedssugesystemet.When this height difference is less than 3 cm, a condition easily arises where the container is sucked empty by the humidifier.

Når denne højdeforskel er større end 10 cm, er fugtighedssugesystemets fugtighedssugeevne sædvanligvis ikke tilstrækkelig til at tilvejebringe 5 en væskeforbindelse mellem vandet i beholderen og den væske, som er absorberet i substratet.When this height difference is greater than 10 cm, the humidity suction system's moisture suction is usually not sufficient to provide a fluid connection between the water in the container and the liquid absorbed in the substrate.

Når det sted, hvor kanalen er forbundet med beholderen, ifølge opfindelsen befinder sig 5-7 cm under substratets underside, opnås den bedste arbejdsmåde, og følgelig udformes apparatet fortrinsvis således, 10 at den nævnte højdeforskel er 5-7 cm.When the site where the channel is connected to the container, according to the invention, is 5-7 cm below the underside of the substrate, the best working method is obtained, and consequently the apparatus is preferably designed such that the height difference is 5-7 cm.

Foruden at der i apparatet ifølge den foreliggende opfindelse bør være væskeberøring meilem væsken i beholderen og væsken i substratet ved hjælp af væsken i fugtighedssugesystemet, bør denne væskeberøring fortrinsvis også være en sådan, at hurtig væskeforskydning frem-15 kommer fra substratet via fugtighedssugesystemet og mod væsken i be holderen, idet dette nemlig fremmer den hastighed, hvormed apparatet reagerer overfor variationer i substratets fugtighedsindhold.In addition, in the apparatus of the present invention, there should be fluid contact between the liquid in the container and the liquid in the substrate by means of the liquid in the moisture suction system, this liquid contact should preferably also be such that rapid liquid displacement emerges from the substrate via the moisture suction system and against the liquid. in the container, since this promotes the rate at which the apparatus responds to variations in the moisture content of the substrate.

Med dette formål for øje udformes fugtighedssugesystemet fortrinsvis ifølge opfindelsen således, at det ved substratssiden strækker sig 20 langs en afstand på mindst 5 cm og fortrinsvis mindst 10 cm forbi kana len og langs denne afstand står i berøring med substratet.For this purpose, the moisture suction system is preferably designed according to the invention such that it extends at the substrate side at a distance of at least 5 cm and preferably at least 10 cm past the channel and along this distance contacts the substrate.

Af hensyn til en hurtig væskeforskydning i kanalen har denne endvidere fortrinsvis ifølge opfindelsen en hydraulisk diameter på mindst 5 mm og fortrinsvis mindst 10 mm, hvor den hydrauliske diame-25 ter er defineret ved ligningen: , 4 x tværsnitsareal d =- n befugtet omkreds af tværsnittetFurther, for the sake of rapid fluid displacement in the duct, it preferably has, according to the invention, a hydraulic diameter of at least 5 mm and preferably at least 10 mm, the hydraulic diameter being defined by the equation: 4 x cross-sectional area d = - n wetted perimeter of cross section

For en kanal med cirkulært tværsnit svarer denne diameter til kanalens indvendige diameter.For a circular cross section, this diameter corresponds to the inside diameter of the channel.

30 Fugtighedssugesystemet kan bestå af ethvert materiale, der sand synligvis på grund af kapillarfænomener er i stand til at indsuge fugtighed, og en væge af fugtighedssugende fibermateriale, der i det væsentlige fylder kanalen, har ifølge opfindelsen vist sig meget veleg net. En sådan væge kan f.eks. bestå af bomuld, uld eller glasfibre.The humidity suction system may consist of any material which is likely to absorb moisture due to capillary phenomena, and a wick of moisture-sucking fiber material which substantially fills the duct has been found to be very suitable according to the invention. Such a wick can e.g. consist of cotton, wool or fiberglass.

35 Dette fugtighedssugesystem bør ifølge opfindelsen være omsluttet i sideretningen ved hjælp af kanalens væg for at forhindre, at udtørringsfænomener fremkommer, som ville virke tilbage på vandniveauetThis moisture suction system according to the invention should be enclosed in the lateral direction by means of the wall of the duct to prevent the emergence of drying phenomena which would act at the water level.

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i beholderen.in the container.

Som allerede nævnt i det foregående kan sonden være udformet på forskellige måder, men den består fortrinsvis ifølge opfindelsen af et sæt elektroder, som har en bestemt afstand fra hinanden, og som er 5 indbyrdes isoleret.As already mentioned above, the probe may be formed in various ways, but it is preferably according to the invention a set of electrodes which are spaced apart and which are isolated from each other.

Et sådant elektrodesæt er i og for sig kendt, men i dette tilfælde er elektrodesættet anbragt direkte i et substrat, hvis fugtighedsind-hold skal måles og styres.Such an electrode set is known per se, but in this case the electrode set is placed directly in a substrate whose moisture content is to be measured and controlled.

Ved apparatet ifølge den foreliggende opfindelse består substra-10 tet fortrinsvis af stenuld. Dette er et substratmateriale med særligt favo rable egenskaber, som giver et udmærket resultat i et apparat som beskrevet i det foregående.In the apparatus of the present invention, the substrate preferably consists of rock wool. This is a substrate material with particularly favorable properties which gives an excellent result in an apparatus as described above.

Endvidere angår den foreliggende opfindelse et reguleringsapparat til åbning eller lukning af en ventil i en fordelingsledning for vand-15 tilførsel til et porøst, absorberende substrat, og som omfatter en regu leringsenhed, der ved hjælp af en sonde styres af fugtighedsindholdet i substratet. Ifølge den foreliggende opfindelse er reguleringsapparatet ejendommeligt ved, at sonden er anbragt i en beholder med en kanal, som befinder sig under sondens laveste punkt, og som er fyldt med et 20 fugtighedssugesystem, hvilken kanal endvidere er lukkef langs omkred sen, og som kan forbindes med det porøse, absorberende substrat.Furthermore, the present invention relates to a control apparatus for opening or closing a valve in a water supply distribution line to a porous, absorbent substrate, and comprising a control unit controlled by a probe by the moisture content of the substrate. According to the present invention, the control device is characterized in that the probe is arranged in a container with a channel which is below the lowest point of the probe and which is filled with a humidifier which is further closed along the perimeter and which can be connected. with the porous, absorbent substrate.

Et sådant reguleringsapparat kan indgå i et eksisterende anlæg for vanding af planter ved at forbinde den med fugtighedssugesyste-met fyldte kanal med et porøst absorberende substrat, hvorpå eller 25 hvori planter gror, og ved at anbringe beholderen, hvori sonden er anbragt, fortrinsvis i et sådant niveau, at det punkt, hvor kanalen er forbundet med beholderen, befinder sig 3-10 cm, og fortrinsvis 5-7 cm under substratets underside, og ved at forbinde reguleringsenheden med ventilen i fordelingsledningen.Such a regulating apparatus may form part of an existing plant for watering plants by connecting the moisture-filled duct filled channel with a porous absorbent substrate on which plants grow, and by placing the container in which the probe is placed, preferably in a such a level that the point at which the duct is connected to the container is 3-10 cm, and preferably 5-7 cm below the underside of the substrate, and by connecting the control unit to the valve in the distribution line.

30 Fugtighedssystemet i dette reguleringsapparat strækker sig ifølge opfindelsen fortrinsvis mindst i en længde på 5 cm og mest fordelagtigt mindst 10 cm ud af kanalen, og dette fugtighedsabsor-berende materiale indsættes i substratet på en sådan måde, at det er fuldstændigt i forbindelse med dette, når apparatet anbringes.The moisture system of this control apparatus according to the invention preferably extends at least a length of 5 cm and most advantageously at least 10 cm out of the channel, and this moisture-absorbing material is inserted into the substrate in such a way that it is completely connected therewith. when the appliance is placed.

35 Den kanal, hvori fugtighedssugematerialet findes, har fortrins vis i dette reguleringsapparat ifølge opfindelsen en hydraulisk diameter på mindst 5 mm, og det foretrækkes, at den hydrauliske 5Preferably, the channel in which the humidifier is located in this control apparatus according to the invention has a hydraulic diameter of at least 5 mm, and it is preferred that the hydraulic 5

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diameter er mindst TO mm.diameter is at least TO mm.

Fugtighedssugesystemet består fortrinsvis ifølge opfindelsen af en væge af fugtighedssugende fibermateriale, som i hovedsagen fylder kanalen, og sonden består fortrinsvis ifølge opfindelsen af et sæt elektro-5 der, som har en bestemt afstand fra hinanden, og som er indbyrdes isoleret.The moisture suction system according to the invention preferably consists of a wick of moisture-sucking fiber material which generally fills the duct, and the probe preferably according to the invention consists of a set of electrodes which are a certain distance apart and which are mutually insulated.

Opfindelsen skal herefter forklares nærmere under henvisning til tegningen, som skematisk viser et snit gennem en plade med planter i et drivhus og forsynet med en udføre!sesform for reguleringsapparatet 10 ifølge opfindelsen.The invention will then be explained in more detail with reference to the drawing, which schematically shows a section through a plate of plants in a greenhouse and provided with an embodiment of the control apparatus 10 according to the invention.

På et lag understøtningsmateriale 1 af polystyren er der anbragt en plade 2 af stenuld af en type, som fås på markedet. En sådan stenuldspiade har en længde på 1 m, en bredde på ca. 40 cm og en højde på ca. 10 cm og er langs undersiden, de opretstående langsider 15 og delvis Sangs oversiden dækket med en plastfilm 3. I praksis vii en række plader være anbragt den ene bag den anden i i serie), således at der opnås en totallængde på ca. 20 m. Bredden af det blottede overfladeareal 4 af stenuldspladen er ca. 20 cm. På dette areal 4 er der anbragt potter 5 med kimplanter eller stiklinger med regelmæssige 20 mellemrum. Disse potter består fortrinsvis af et legeme af stenuld, som i sideretningen er omgivet ved hjælp af en plastfilm. Over det blottede overfladeareal 4 findes der sprøjtehoveder 6 til et ydre vandingssystem. Til siden for understøtningsmateriaiet 1 er der anbragt en beholder 7, hvortil der i nærheden af bunden er forbundet et rør 8, 25 som er fyldt med en væge af glasfibre 9, hvilken glasfibervæge rager ud af begge rørets ender. Røret 8 og den udragende ende af glasfibervægen er indsat gennem en åbning, som er tilvejebragt i den piastfilm, som omgiver stenuldspiaden, således at de udragende glasfibre står i berøring med stenulden. Højdeforskellen mellem det sted, hvor 30 røret 8 er forbundet med beholderen 7, og undersiden af stenuldspladen er ca. 6 cm. I beholderen er der anbragt et sæt elektroder 10, som er forbundet med en ikke vist reguleringsenhed af i og for sig kendt art, hvilken reguleringsenhed åbner dier lukker en ventil i vandingssystemet. I beholderen findes der en vandmængde 11, 35 som i afhængighed af vandstanden i beholderen enten står i berøring med den ene elektrode eller med to elektroder, i hvilket sidste tilfælde en elektrisk strøm begynder at strømme, og som afbryderOn a layer of polystyrene support material 1, a sheet 2 of stone wool of a type available on the market is placed. Such a stone wool spade has a length of 1 m, a width of approx. 40 cm and a height of approx. 10 cm and along the underside, the upright long sides 15 and partly the upper side of the cover is covered with a plastic film 3. In practice, a number of plates are arranged one behind the other in series), so that a total length of approx. 20 m. The width of the exposed surface area 4 of the rock wool plate is approx. 20 cm. In this area 4 are placed pots 5 with seedlings or cuttings at regular intervals. These pots preferably consist of a body of stone wool, which is laterally surrounded by a plastic film. Above the exposed surface area 4 there are spray heads 6 for an external irrigation system. To the side of the support material 1 is placed a container 7, to which is connected near the bottom a pipe 8, 25 which is filled with a wall of glass fibers 9, which glass fiber wall protrudes from both ends of the pipe. The tube 8 and the protruding end of the fiberglass wall are inserted through an opening provided in the plaster film surrounding the stone wool spade so that the projecting glass fibers are in contact with the stone wool. The height difference between the place where the tube 8 is connected to the container 7 and the underside of the rock wool plate is approx. 6 cm. In the container is arranged a set of electrodes 10, which are connected to a control unit not shown, known per se, which control unit opens and closes a valve in the irrigation system. In the container there is a quantity of water 11, 35 which, depending on the water level in the container, is either in contact with one electrode or with two electrodes, in which case an electric current starts to flow and which switches off

Claims

An apparatus for automatically watering plants which grow in the open air or in a greenhouse, comprising a water supply distribution line for a porous absorbent substrate (2), wherein a valve is disposed in this line which is activated by means of a signal from a control unit controlled over a probe (10) by the moisture content of the substrate (2), characterized in that the probe (10) is arranged in a container (7) which is closed over a channel (8) which is closed along the circumference, which is filled with a humidifier (9) and which is connected to the container (7) below the lowest point (10) of the probe, communicates with the porous absorbent substrate (2).

Apparatus according to claim 1, characterized in that the place where the duct (8) filled with the humidifier (9) is connected to the container (7) in which the probe (10) is located is 3-10 cm below the underside of the substrate (2).

Apparatus according to claim 2, characterized in that the place where the channel (8) is connected to the container (7) is 5-7 cm below the underside of the substrate (2).

Apparatus according to any one of claims 1-3, characterized in that the moisture suction system (9) extends at the substrate side, at a distance of at least 5 cm, past the channel (8) and along this distance is in contact. with the substrate (2).

Apparatus according to claim 4, characterized in that the humidifier system (9) extends, at a distance of at least 10 cm, past the channel (8) and along this distance contacts the substrate (2). DK 154462 B

Apparatus according to any one of claims 1-5, characterized in that the channel (8) has a hydraulic diameter of at least 5 mm.

Apparatus according to claim 6, characterized in that the channel 5 has a hydraulic diameter of at least 10 mm.

Apparatus according to any one of claims 1-7, characterized in that the humidification system consists of a wick (9) of moisture-sucking fibrous material which essentially fills the duct (8).

Apparatus according to any one of claims 1-8, characterized in that the probe consists of a set of electrodes (10) spaced apart and mutually insulated.

Apparatus according to any one of claims 1-9, characterized in that the porous absorbent substrate is rock wool (2).

Control apparatus for opening or closing a valve in a distribution line for water supply to a porous absorbent substrate (2), comprising a control unit controlled by a probe (10) by the moisture content of the substrate (2), characterized by the probe (10) being arranged in a container (7) having a channel (8) which is below the lowest point of the probe (10) and filled with a humidifier (9), which channel (8) further, it is closed along the circumference and can be connected to the porous absorbent substrate (2).

Control device according to claim 11, characterized in that the moisture suction system (9) extends at the substrate side out of the channel (8) for a length of at least 5 cm.

A regulating apparatus according to claim 12, characterized in that the length is at least 10 cm. 1¾. Control apparatus according to any one of claims 11-13, characterized in that the channel (8) has a hydraulic diameter of at least 5 mm.

Control device according to any one of claims 11-14, characterized in that the channel (8) has a hydraulic diameter of at least 10 mm.

Regulating apparatus according to claim 15, characterized in that the humidifier suction system consists of a wick (9) of a humidifier which mainly fills the duct (8).

Control apparatus according to any one of claims 11-16, characterized in that the probe consists of a set of electrodes (10) spaced apart at a certain distance and mutually insulated.