EP3268704A1

EP3268704A1 - Control device and water tank for watering of cattle and horses

Info

Publication number: EP3268704A1
Application number: EP15884809.3A
Authority: EP
Inventors: Hjalmar Fries
Original assignee: Thermobar AB
Current assignee: Thermobar AB
Priority date: 2015-03-10
Filing date: 2015-03-10
Publication date: 2018-01-17
Also published as: EP3268704A4; WO2016144221A1

Abstract

There is provided a control device (100) for a water tank for watering of animals, and a corresponding water tank, which has few parts within the reach of the animals, is sturdy, and is reliable in spite of litter in the water and in harsh outdoor conditions. A water level indicator (110) is arranged for providing an indication if a current water level in the water tank is below a predetermined level LP. The control device is arranged for actuating a supply means (120) for supplying water (20) into the water tank based on the indication. The water level indicator comprises a temperature sensitive element (111) arranged at the predetermined level. The indication is based on the temperature sensitive element detecting a temperature difference caused by a difference in heat transfer as a current water level is below or reaches the predetermined level.

Description

CONTROL DEVICE AND WATER TANK

FOR WATERING OF CATTLE AND HORSES

TECHNICAL FIELD

The present invention relates to the field of water tanks for watering of animals like cattle and horses, and more particularly to a control device, and a corresponding water tank, which provides controlled refilling of water if the water level decreases below a predetermined level.

BACKGROUND OF THE INVENTION

Today a water tank for watering of cattle and horses is preferably provided with automatic refilling of water. A common known manner to control the water level in the water tank is to utilize floating bodies to determine a current water level in the tank, and to activate refilling of water when the current water level is below a preferred level.

US. Patent No. 3,636,312 discloses a control device for a water tank which comprises a water level indicator based on a floating body. The water level indicator controls a valve and a water supply to maintain the preferred water level in the tank. Separate thermostat controlled first and second heaters are arranged to heat the valve and the water in the tank to prevent freezing. For the water level indicator to function, the floating body relies on being in fluid contact with the water of the water tank. Due to the movability of the floating body, the shown solution is sometimes not very reliable due to litter like grass and the like, which may be brought into the water by the animals. The floating body and valve parts of the control device are

troublesome to keep clean from coatings caused by impurities in the water, and if any of the movable parts of the solution gets stuck due to litter, or if the water freezes, overflow or no refilling of water at all may occur. A further problem when utilizing openly arranged floating bodies or other detectors, valve members etc., is that the animals tend to bite in any accessible parts which may cause damage to the equipment. Accordingly, there is a need for at least a complementary solution for water level control in water tanks that resolves these existing issues, and which is relatively simple, economical and reliable. The complementary solution should also be able to cope with litter in the water, and be sturdy enough to endure watering of big animals, as well as to endure outdoor conditions.

SUMMARY OF THE INVENTION

In view of the above identified problems, an object of the present invention is to at least provide an improved control device for a water tank for watering of animals, and a corresponding water tank. It would further be advantageous to provide a control device with as few parts as possible within the reach of the animals, which is sturdy, has a decreased sensitivity to litter in the water, and which is reliable under outdoor conditions.

According to a first aspect of the invention, there is provided a control device for a water tank comprising water level indicator arranged for providing an indication if a current water level in the water tank is below a

predetermined level. The control device is arranged for actuating a supply means for supplying water into the water tank based on the indication. The water level indicator comprises a temperature sensitive element which when mounted is arranged in the water tank at the predetermined level. The indication is based on the temperature sensitive element detecting a temperature difference caused by a difference in heat transfer between a filled state of the water tank, when water reaches the predetermined level (i.e. reaches the same level of the water tank as where the temperature sensitive element is mounted) and an under filled state when the water in the tank is below the predetermined level. Thereby a controlled refilling of water in the water tank is provided. The control device utilizes the principle that heat transfer is more rapid at the temperature sensitive element when the temperature sensitive element is in direct or close (thermal) contact with water in the water tank, as compared to when being in thermal contact with air. By utilizing a temperature sensitive element, advantageously no moving parts are used for detecting the current water level in the water tank.

According to an embodiment of the device, it further comprises an elongated cooling body which is horizontally arranged, and at which the temperature sensitive element is arranged. The elongated shape of the cooling body and the horizontal arrangement, advantageously provide a high difference in heat transfer, i.e. cooling ability of the cooling body, when the water level in the water tank changes between the filled state: when the water level reaches the cooling body, i.e. is above or at the predetermined level, and the under filled state: when the water level is below the predetermined level. The heat transfer between a solid body, preferably with high thermal conductivity like a metal, and water, is higher than between the same solid body and air.

According to an embodiment of the device, the cooling body is a sheet metal plate or a foil, made of a metal of high thermal conductivity, like

Aluminum, Copper, Brass, a Bronze Alloy, etc., which is advantageous as these options all provide a rugged solution for the water level indicator.

According to an embodiment of the device, the cooling body is arranged extending along the wall of the water tank, which is advantageous.

According to an embodiment of the control device, the extension of the elongated cooling body is selected to cover 5 - 30 % of the circumference measurement of the tank.A typical thickness is selected to be approximately 0,5 mm, but should not be limited thereto.

According to an embodiment of the device, the temperature sensitive element is a thermostat. Advantageously, the thermostat may be arranged for selectively actuating the supply means, which is advantageous. The actuation of the supply means can be done directly or over a relay, and with a preselected and optionally adjustable hysteresis, where the thermostat is set to turn off at e.g. below a deactivation temperature of 50°C and turn on at an activation temperature of 60°C (hysteresis of 10 °C). Values of the activation temperature, deactivation temperature, hysteresis are preferably selected depending on the surrounding temperature or expected surrounding temperature, temperature of the supplied water etc.

According to an embodiment of the device, a first heating element is arranged for heating the cooling body. In an exemplifying embodiment, the heating element is a resistor arranged at a first end of the elongated cooling body such that electrical heating of the cooling body is provided. As long as the water level in the water tank is above or at the predetermined level, the water contributes to cooling down the cooling body. When the animals drink the water, and the current water level drops below the cooling body, the heat transfer from the cooling body is decreased, and the temperature sensitive element detects a difference in temperature as compared to when the water is cooling the cooling element. At a detected predetermined temperature difference (or when the activation temperature is reached when using a thermostat) the supply means are actuated to refill water into the water tank.

As the first heating element is positioned at the predetermined level, the first heating element primarily heats the surface of the water in the water tank. This is advantageous to maintain levels of different temperatures of the water in the water tank which promotes that hay and litter stays at the surface. Particularly some horses tend to litter up their water tanks and the keepers have to lift up the litter by hand or with a strainer to limit

contamination of the water, which is thus easier if the litter stays at the surface. Further, in cold weather the heating of the water by means of the first heating element prevents the (surface) water in the water tank from freezing. The heat contribution from the first heating element is however only a fraction compared to the heat loss caused by evaporation from the surface. The amount of heat transferred from the first heating element into the water, alternatively via the wall of the water tank, is drastically decreased as the animals drink the water (or the water evaporates) and the water level is below the water level indicator.

According to an embodiment of the invention, the heating element is a thermistor. The thermistor may be either of Negative Temperature Coefficient (NTC) type or of Positive Temperature Coefficient (PTC) type. The NTC thermistor is one whose zero-power resistance decreases with an increase in temperature and the PTC thermistor is one in which the zero-power resistance increases with an increase in temperature. According to an embodiment of the invention, the PTC element is utilized to quicker reach the actuating temperature on the temperature sensing element, e.g. a thermostat or a NTC element. The NTC thermistor is used to sense the presence or absence of the water by using the difference in heat transfer (heat dissipation constants) between a liquid and a gas. In this embodiment, the temperature sensitive element is advantageously utilized as the heating element. When the water level is below the temperature sensitive element, the cooling effects is decreased, and the NTC thermistor resistance is thereby decresed. The function of the NTC element can thus be used to activate the supply means, e.g. control a valve.

According to an embodiment of the control device, the cooling body and the heating element are integrated in a heating foil, preferably of elongated shape, which is advantagous.

According to an embodiment of the device, the first heating element and the temperature sensitive element are separated a predetermined distance ΔΧ. A temperature gradient is formed in the elongated cooling body (the temperature of the heating element varies in the cooling body long direction, such that the temperature is higher at the heating element and then drops at an increasing distance from the heating element). By selecting a

predetermined distance ΔΧ between the heating element and the temperature sensitive element, advantageously a detection time of the temperature sensitive element identifying a temperature difference can be controlled.

According to an embodiment of the device, the first heating element and the temperature sensitive element are arranged to be adjustably positioned relative to each other. Thereby, a detection time of the water level indicator can be adjusted in a simple manner, e.g. to compensate for extremely cold weather which may hinder the temperature sensitive element, e.g. a thermostat, from reaching a set activation temperature, or warm water temperatures, which results in decreased cooling of the temperature sensitive element/cooling body. The possibility for such compensations is

advantageous to prevent unwanted activation of the thermostat which may result in overfilling of the water level in the water tank.

According to an embodiment of the device, the first heating element is deactivated during actuation of the supply means. This advantageously speeds up the cooling of the cooling body to a (deactivation) temperature below the activation temperature for refilling of water, which prevents overfilling of water.

The water level indicator system is above described with a fixed heat power supply element (the first heating element) and fixed temperature actuating element (the temperature sensitive element) with a preselected relative distance. Alternativly, either the position of the heat supply element or the temperature actuating element/system can be made adjustable.

Further, as alternative adjustability of the system, either the power of the heat supply element or the set temperature of the temperature actuating element/system can be made adjustable.

According to an embodiment of the device, the water level indicator is arranged on an outer side of a side wall of the water tank, which is

advantageous to separate it from the animals, and the water.

Advantageously, this position also prevents litter and coatings from

compromising the water level indicator. The cooling body is arranged as a thermally conductive element which is preferably attached to the side wall of the water tank by means of welding, a bolted joint, or gluing optionally with thermally conductive glue. The cooling body may also be integrated/mounted in the side wall of a water tank, which advantageously increases heat transfer between the cooling body and the water in the water tank.

According to an embodiment of the device, it further comprises a separate housing arranged for being mounted inside the water tank, which is

advantageous when applying the control device to an existent water tank. The housing may be attached to the water tank by means of clamping the housing from above at a side wall of the water tank. According to a second aspect of the invention, there is provided a water tank comprising a device according to the present inventive concept.

According to an embodiment of the water tank, it is arranged having a double side wall. At least the temperature sensitive element may be arranged at the outer side of the inner side wall, which is advantageous to protect it from the animals, weather conditions and so on.

According to an embodiment of the invention, the conduit means for providing water from a water supply is advantageously arranged separated from the water tank, e.g. by a conduit means being arranged above the water tank. This is advantageous from a hygienical view, as the water inlet is thus separated from the water surface of the water tank any reverse flow of the water, which may occur at occasional vacuum in the water system, is prevented. This is commanded in municipal water systems in for instance Sweden.

According to an embodiment of the water tank, it further comprises a second heater element for heating water in the tank. The second heater element may be arranged e.g. at a side or a bottom of the water tank, which is advantageous when the water tank is utilized in extremely cold climates, and the water needs to be kept from freezing at the bottom of the water tank.

Further objective of, features of, and advantages with, the present invention will become apparent when studying the following detailed disclosure, the drawings and the appended claims. Those skilled in the art realize that different features of the present invention can be combined to create embodiments other than those described in the following.

DESCRIPTION OF THE DRAWINGS

The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention, with reference to the appended drawings, where the same reference numerals will be used for similar elements, wherein: Figs. 1 a and 1 b are schematic cross sectional side views of an embodiment of a water tank and a control device according to the present invention;

Figs. 2a - 2c schematically illustrate cut open front and side views, respectively, of cooling bodies with temperature sensitive elements of different embodiments of a control device according to the present invention;

Figs. 3a and 3b are schematic illustrations of a couple of different water level indicators according to embodiments of the present invention; and Figs. 4a and 4b are schematic illustrations of a water tank according to different embodiments of the present invention.

All the figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate the invention, wherein other parts may be omitted or merely suggested. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

For sake of simplicity constructional details have been left out in the following description, which may be considered basic knowledge of the skilled person, and which do not contribute to describing the essence of the inventive concept.

In an exemplifying embodiment of the present inventive concept which is described with reference now to Fig. 1 a, an embodiment of a water tank 1 0 for watering of for instance horses or cattle according to the present invention is shown. The water tank 1 0 has double side walls with an inner side wall 1 1 and an outer sidewall 1 2, which together with a bottom 14 are arranged to contain water 20. The water tank 10 is here of an open type. It should be noted however, that the present inventive concept is applicable also in other types of tanks, e.g. closed tanks with tapping points.

A control device generally indicated with 1 00 is arranged to control the water level of water 20 in the water tank 1 0. Water is provided from a water supply (not shown) via conduit 1 08 which is controlled by means of a valve 1 20, which is actuated (opened) by the control device 1 00 when a water level of the water tank 10 is below a predetermined level Lp. Here the low level is indicated with LB. An outlet 109, a hose or a pipe, is arranged on an output side of the valve 120, and is preferably arranged above the water tank as illustrated schematically in Fig. 1 a. The outlet hose or outlet pipe may however be arranged in the side wall 1 1 of the water tank 10.

To continue with reference to Fig. 1 a, the control device 100 further comprises a water level indicator 1 10 arranged for indicating when the water level in the water tank is below the predetermined level L_P. When receiving an indication from the water level indicator 1 10 that the water level is below the predetermined level, a control unit 1 15 of the control device actuates the valve 120. The water level indicator 1 10 comprises a temperature sensitive element 1 1 1 which is mounted in the water tank 10, at a height which corresponds to the predetermined level Lp.

In operation, starting from an empty water tank 1 0, the temperature sensitive element 1 1 1 , which according to an embodiment of the invention is a thermostat, detects a temperature above an activation temperature of the thermostat which then opens the valve 120 allowing water to flow into the water tank through the outlet 109. Finally, the water 20 in the water tank 10 reaches a filled state, i.e. a water level reaching the predetermined level L_P or (slightly) above, which level is indicated L_A in Fig. 1 a. The water 20 now provides an increase in heat transfer from the thermostat 1 1 1 and cools down the thermostat below the activation temperature such that the thermostat deactivates the valve 120 which closes and stops the water flow into the water tank 10.

In an exemplifying embodiment of the inventive concept, as illustrated in Fig. 2a, the temperature sensitive element 1 1 1 is mounted on a cooling body 1 12, e.g. a piece of sheet metal with good thermal conductivity, like Aluminum, Copper or similar. The cooling body 1 12 is here an elongated body which is arranged with its long side in a horizontal orientation.

According to embodiments of the control device, the cooling body 1 12 and/or the temperature sensitive element 1 1 1 is mounted at an outer side of the side wall 1 1 of the water tank, see Fig. 1 b, or at an inner side of the side wall 1 1 , as illustrated in Fig. 2b, or integrated in the side wall 1 1 , see Fig. 2c. Alternatively, the temperature sensitive element 1 1 1 is mounted directly on the inner side or outer side of the side wall 1 1 which is especially

advantageous if the wall 1 1 is made of metal, or at a side wall of a housing 300 of the control device, as illustrated in Fig. 4a.

As previously described, the water supply is governed by e.g. a valve or similar switch which is able to control the water supply via the conduit 108, and is actuated via a control unit 1 1 5 based on readings from the temperature sensitive element 1 1 1 , or which is actuated by the temperature sensistive element itself when it is a thermostat.

Referring again to Fig. 2a, according to an embodiment of the control device, a first heating element 1 13 is arranged at the height corresponding to the predetermined level Lp to heat the cooling element 1 12 and the surface water of the water 20 in the water tank 1 0. The first heating element 1 1 3 is distanced/separated a predetermined distance ΔΧ from the temperature sensitive element 1 1 1 . The selected distance ΔΧ between the first heating element 1 1 3 and the temperature sensitive element 1 1 1 , is utilised to select/control a preferred detection time for the temperature sensitive element 1 1 1 to detect a temperature increase when the water level in the water tank 20 decreases below the predetermined (preferred) water level Lp, i.e. to level L_B. A smaller distance ΔΧ decreases the detection time, and a larger distance ΔΧ increases the detection time.

In an embodiment of the water level indicator 31 0 as shown in Fig. 3a, the first heating element 1 1 3 is distanced/separated a predetermined distance ΔΧ from the temperature sensitive element 1 1 1 . However, here the distance ΔΧ between the temperature sensitive element 1 1 1 and the first heating element 1 1 3 is made variable. A sliding arrangement 1 30 including a protruding portion (not visible) connected to the temperature sensitive element 1 1 1 is received and allowed to slide along a trace 1 31 arranged in the metal cooling body 1 1 2. Other arrangements to provide variable distance ΔΧ between the temperature sensitive element 1 1 2 and the heating element are possible, e.g. as illustrated in Fig. 3b, where protruding periferal portions (not visible) of the temperature sensistive element 1 1 1 is arranged to slide along flanges 1 32 formed by folding the long sides of e.g. a sheet metal forming the cooling body 1 1 2.

Referring now to the embodiment described with reference to Fig. 2a and Fig. 1 a, the first heating element 1 1 3 is a resistor of a preselected power, e.g. P= 5 W, which is arranged at a first end portion of the cooling body 1 1 2, and the temperature sensitive element 1 1 1 , which is a thermostat also mounted on the cooling body 1 1 2, is separated a distance ΔΧ = 20 mm there from. The cooling body 1 1 2 is elongated and horizontally arranged at a height of the wall 1 1 1 corresponding to the predetermined level.

In operation, starting from an empty water tank 1 0, the first heating element 1 13, the resistor, is powered and heats the cooling body 1 1 2. The thermostat (temperature sensitive element 1 1 1 ) then detects a temperature above a preselected activation temperature of 60°C and opens the valve 1 20 allowing water to flow into the water tank 20 through the outlet 1 09. Finally, the water 20 in the water tank 1 0 reaches level LA above the predetermined level Lp and the water 20 thereby provides an increase in heat transfer from the cooling body 1 1 2 and cools it down, such that the thermostat detects a (deactivation) temperature below the activation temperature. The valve 1 20 is closed and the water flow into the water tank is stopped at the predetermined level. When animals drink the water, the water level in the water tank 20 again decreases below the predetermined level. The cooling effect of the water is then removed from the cooling body, and the thermostat detects a difference in temperature. When the detected temperature reaches the activation temperature of the thermostat, the valve opens, and the water level in the water tank is refilled until the water level is again at or just above the predetermined level.

Consider the water tank and control device as illustrated in Fig. 1 a and Fig. 2a at an outdoor temperature of 1 0 °C and the water temperature

(incoming water in the tank) is 20 °C. In this examplifying embodiment, the cooling body is 40 mm long, the heating element is 3 W, and the activation temperature of the thermostat is selected to be 60 °C. At these conditions, the water level in the water tank will vary approximately 10 cm between min and max levels.

According to an embodiment of the control device, the first heating element is deactivated, e.g. by means of a controllable relay, during filling of water into the water tank 20, thereby speeding up the temperature decrease of the cooling body.

A water tank according to the present inventive concept comprises a control device as described herein. The water tank is advantageously provided with double side walls, as shown in Fig. 1 . Optionally, isolating layers are arranged in the space 13 between the double side walls to decrease influence of the outdoor temperature on the function of the control device, and on the water temperature of the water in the water tank. When applying double side walls, at least part of the control device, e.g. the temperature sensitive element may be arranged in the space 13 between the double walls.

To continue, heat provided by means of the first heating element 1 13 can further be utilized to warm up water in stables or outdoors arrangements where freezing of the water in the water tank may occur. In case of severely cold weather, the power effect of the first heating element may thus be increased to prevent freezing. However, since heating is provided at the height corresponding to the predetermined level, the method may be combined with a conventional heating of the water at the bottom/side wall of the water tank, see a second heater element 43 for heating the water in a water tank 40 in Fig. 4a, such that the water is kept ice free even when the water level in the water tank is low, and the heating effect of the first heating element is limited.

At extremely cold/windy weather, the air may cool down the cooling body in the same amount as the water. According to an embodiment of a water tank 50 according to the present invention, as illustrated in Fig. 4b, it further comprises an isolating element 41 which is arranged at the temperature sensitive element 1 1 . Here, the isolating element is fastened to the inner wall of the water tank 50 opposite to the temperature sensitive element. The isolating element 41 is preferably made of a foam material or sponge plastics having open cells in a hydrophobic material. When the water level is low the isolating element 41 will be filled with isolating air and when the water level is high, water will penetrate and cool the temperature sensitive element by conductivity.

Referring again to Fig. 4a, according to an embodiment of the control device 100, it is enclosed in a housing 300 which is adapted to be submerged into the water. The housing 300 is preferably mounted to the side wall 1 1 of a water tank. According to an embodiment of the control device, it is detachably arranged, e.g. by means of clamping, at the side wall 1 1 of the water tank 40.

The person skilled in the art realizes that the present invention by no means is limited to the embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, embodiments of the invention may be based on a heating element and a temperature sensor system that can be adjusted and controlled in a control device away from the tank but electrically connected.

Claims

1 . A control device (100) for a water tank (10) comprising:

a water level indicator (1 10) arranged for providing an indication if a current water level in the water tank is below a predetermined level Lp, wherein said control device is arranged for actuating a supply means

(120) for supplying water (20) into the water tank based on said indication; c h a r a c t e r i z e d by:

said water level indicator comprising a temperature sensitive element (1 1 1 ) arranged at said predetermined level, wherein said indication is based on said temperature sensitive element detecting a temperature difference caused by a difference in heat transfer as a current water level is below or reaches said predetermined level.

2. A device according to claim 1 , further comprising a cooling body (1 12) which is elongated and horizontally arranged, and at which said

temperature sensitive element (1 1 1 ) is arranged.

3. A device according to claim 2, wherein said cooling body is a sheet metal plate, or a foil.

4. A device according to any of claim 2 - 3, wherein said cooling body (1 12) is arranged extending along the wall of the water tank.

5. A device according to any preceding claim, wherein said temperature sensitive element (1 1 1 ) is a thermostat.

6. A device according to any preceding claim, wherein said temperature sensitive element is a thermistor.

7. A device according to any of claim 2 to claim 6, further comprising a first heating element (1 13) arranged for heating said cooling body (1 12).

8. A device according to claim 7, wherein said first heating element (1 13) and said temperature sensitive element (1 1 1 ) are separated a

predetermined distance ΔΧ.

9. A device according to claim 8, wherein said first heating element (1 13) and said temperature sensitive element (1 1 1 ) are arranged adjustably positioned relative to each other.

10. A device according to any of claim 2 to claim 9, wherein said first heating element (1 13) is deactivated during actuation of said supply means (120).

1 1 . A device according to any preceding claim, wherein said water level indicator (1 10) is arranged on an outer side of a side wall (1 1 ) of said water tank (10).

12. A device according to any preceding claim, further comprising a separate housing (300) arranged for being mounted inside said water tank (10).

13. A live stock water tank comprising a device according to any preceding claim.

14. A water tank according to claim 13, wherein said water tank (10) is arranged having a double side wall (13), wherein at least said temperature sensitive element (1 1 1 ) is arranged at the outer side of an inner side wall 1 1 of said double side wall.

15. A water tank according to claim 13 or 14, further comprising a second heater element (43) for heating said water.