EXTERNAL IMMERSION DEVICE FOR REMOVAL OF LIMESCALE AND SEDIMENT FROM ELECTRIC WATER HEATING TANKS

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to an external immersion device for removal of limescale and sediment from electric water heating tanks.

Water heating tanks in which the heating is done by means of an electric heating element are highly common. These tanks usually have a cylindrical shape. A water heating tank disposes so that the cylinder's symmetry axis is approximately perpendicular to the horizon is usually referred to as a standing tank, such as tank 100 shown in Figure 1. A standing tank is usually equipped with a flange 4 disposed at the bottom of the tank, through which various accessories are installed into the tank, such as an electric heating element 6, a thermostat 7, and sometimes also a magnesium rod serving as an anode (not shown in the illustration). Tank 100 has walls 12 and openings, an opening 9 for entry of cold water at its lower part and an opening 10a for pouring hot water at its upper part. An additional alternative for pouring hot water is through opening 10b, which is disposed at the bottom end of a perpendicular pipe draining hot water from the upper part of tank 100.

When the tank is integrated in a solar-powered system, it will have additional openings. Tank 100 will also usually be equipped with a safety valve, not shown in the illustration. In order to decrease the time interval from activation of the electric heating element until it is possible to pour hot water, the tank can also be equipped with an accelerator 1, a device for accelerating the heating of a limited amount of water. This device includes accelerator sleeve 5, which is usually cylindrical, surrounding heating element 6 and thermostat 7, and its bottom part has at least one opening 8 for entry of water, and its top part has at least one opening 11 for pouring hot water into the space of the tank.

There are also tanks 100 as described, in which the thermostat 7 is outside of the accelerator sleeve 5. The accelerator sleeve 5 is usually composed of plastic material and forms a space for heating water, which is small in comparison with the volume of the entire tank 100, with a smaller diameter at its upper part, which is formed as a tubule, with an opening 11 at its upper part, adjacent to the upper part of the tank 100.

The purpose of accelerator 1 is to accelerate the heating of the water, by leading the water that is being heating in close proximity to the heating element 6 directly to the upper part of the tank 100, thus preventing them from being mixed with colder water during their upward motion. This creates a layer of hotter water near the water exit, enabling faster access to hot water.

During the activation of heating element 6, the water that comes into contact with it and into its close proximity is heated, creating a thermosyphonic flow of hot water upwards and pumping and flowing of colder water into the lower part of accelerator 1. The difference between the water temperatures at the entrance point into accelerator 1 and its exit point is referred to as δT. When the water is being heated, if there is no pumping of hot water from the tank, the layer of hot water at the top of the tank gradually becomes thicker while δT remains approximately constant, and the temperature of the water coming out of accelerator 1 through opening 11, also remains approximately constant.

Once the bottom of the layer of hot water reaches opening 8, the temperature of the water coming out of accelerator 1 through opening 11 starts to rise, and the temperature of the water at the upper part of the tank 100 starts to rise as well.

The functioning of a water heating tank with an accelerating device of this sort is disrupted after some time seeing as the space surrounding the heating element 6 accumulates limescale and sediment 20 settles in the space within accelerator sleeve 5, causing a severe disruption of the water flow within the sleeve 5, disruption of the function of the thermostat

7, and damaging the electrical heating element 6.

Common solutions for prevention or reduction of the disruption described above include adding openings in the accelerator sleeve 5 and even omitting the lower part of the accelerator sleeve 5, so that the limescale and sediment can be dispersed in the bottom part of the tank 100. These solutions hamper the efficiency of the accelerated water heating.

This solution causes accumulation of limescale and sediment 20 on the bottom of tank 100.

SUMMARY OF THE INVENTION According to the present invention there is provided an immersion device, for removal of limescale and sediment from electric water heating tank having a bottom, the immersion device including: (a) an immersion device wall having a longitudinal cylindrical shape,

having a first end and a second end; (b) an immersion device bottom, disposed at the second end of the immersion device wall; and (c) an immersion device connector, disposed at the first end of the immersion device wall, wherein the immersion device connector has a sediment draining opening. According to further features in preferred embodiments of the present invention the immersion device connector is a flange.

According to further features in preferred embodiments of the present invention the immersion device bottom includes: (i) an opening equipped with a closure.

According to further features in preferred embodiments of the present invention the closure is selected from a group consisting of a lid, a faucet, and a tap.

According to further features in preferred embodiments of the present invention the immersion device is mounted below the electric water heating tank on the electric water heating tank bottom, wherein the electric water heating tank bottom has an opening, wherein the electric water heating tank bottom opening and the immersion device bottom opening are so aligned as to enable draining of limescale and sediment through both of them.

According to further features in preferred embodiments of the present invention the immersion device further including: (d) a funnel disposed at the immersion device connector inside the electric water heating tank.

According to another embodiment of the invention the system there is provided an integrated accelerator and immersion device, for improved accelerated heating of a limited amount of water, and for removal of limescale and sediment from electric water heating tank having a bottom, the integrated accelerator and immersion device including: (a) a cylindrical sleeve having a diameter, a lower end, and an upper end; (b) an cylindrical accelerator emission tubule having a diameter disposed at the upper end of the sleeve, wherein the accelerator emission tubule diameter is smaller than the sleeve diameter; and (c) a sediment draining opening, equipped with a closure, disposed close to the lower end of the sleeve.

According to further features in preferred embodiments of the present invention the accelerator emission tubule includes at least one tubule joint.

According to further features in preferred embodiments of the present invention the closure is selected from a group consisting of a lid, a faucet, and a tap.

According to further features in preferred embodiments of the present invention the integrated accelerator and immersion device further including: (d) an accelerator suction pipe

having an accelerator water suction opening, located outside of the integrated accelerator and immersion device, and an accelerator water entry opening, located inside of the integrated accelerator and immersion device.

According to further features in preferred embodiments of the present invention the integrated accelerator and immersion device further including: (e) a bottom, disposed at the lower end of the sleeve; (f) a thermostat disposed at the integrated accelerator and immersion device bottom, inside the integrated accelerator and immersion device bottom; and (g) an electrical heating element disposed at the integrated accelerator and immersion device bottom, inside the integrated accelerator and immersion device bottom. According to further features in preferred embodiments of the present invention the electrical heating element has an active segment, and a passive segment.

According to further features in preferred embodiments of the present invention the integrated accelerator and immersion device further including: (h) a flow regulation opening disposed at the sleeve. According to further features in preferred embodiments of the present invention the integrated accelerator and immersion device further including: (i) a closure disposed at the flow regulation opening.

According to further features in preferred embodiments of the present invention the closure of the flow regulation opening has a hole for regulating the flow of water through the flow regulation opening.

According to further features in preferred embodiments of the present invention the integrated accelerator and immersion device further including: (j) an immersion device flange, disposed at the sleeve, the flange having an immersion device flange opening.

According to further features in preferred embodiments of the present invention the integrated accelerator and immersion device is mounted on the bottom of the electric water heating tank, wherein the electrical heating element active segment is located above the bottom of the electric water heating tank, and the sediment draining opening is located below the bottom of the electric water heating tank, and the sediment draining opening, wherein the electric water heating tank has an internal height dimension and wherein the accelerator water suction opening is disposed at a height above the bottom of the electric water heating tank, of at least X percent of the internal height dimension, wherein X is selected from a group consisting of sixty, seventy, eighty and ninety.

According to further features in preferred embodiments of the present invention the integrated accelerator and immersion device is mounted on the bottom of the electric water heating tank, wherein the electrical heating element active segment is located above the bottom of the electric water heating tank, and the sediment draining opening is located below the bottom of the electric water heating tank, and the sediment draining opening, wherein the electric water heating tank has an internal volume and wherein the accelerator water suction opening is disposed at a height above the bottom of the electric water heating tank, wherein the volume for containing water above the accelerator water suction opening within the electric water tank can contain no more than Y liters, wherein Y is selected from a group consisting often, twenty, thirty, forty and fifty.

According to further features in preferred embodiments of the present invention, the thermostat is disposed within said accelerator suction pipe.

According to further features in preferred embodiments of the present invention the integrated accelerator and immersion device further including: (d) an accelerator suction tubule having an accelerator water suction opening, located outside of the integrated accelerator and immersion device, and an accelerator water entry opening, located inside of the integrated accelerator and immersion device; (e) a bottom, disposed at the lower end of the sleeve; (f) a thermostat disposed at the integrated accelerator and immersion device bottom, inside the integrated accelerator and immersion device bottom; (g)an electrical heating element disposed at the integrated accelerator and immersion device bottom, inside the integrated accelerator and immersion device bottom, wherein the electrical heating element has an active segment, and a passive segment; (h) a flow regulation opening disposed at the sleeve; (i) a closure disposed at the flow regulation opening, wherein the closure of the flow regulation opening has a hole for regulating the flow of water through the flow regulation opening: and (j) an immersion device flange, disposed at the sleeve, the flange having an immersion device flange opening, wherein the integrated accelerator and immersion device is mounted on the bottom of the electric water heating tank, wherein the electrical heating element active segment is located above the bottom of the electric water heating tank, and the sediment draining opening is located below the bottom of the electric water heating tank, and the sediment draining opening.

According to the present invention there is provided a method of operating an integrated accelerator and immersion device including the steps of: (a) providing an

integrated accelerator and immersion device including: (i) a cylindrical sleeve having a diameter, a lower end, and an upper end; (ii) a cylindrical accelerator emission tubule having a diameter disposed at the upper end of the sleeve, wherein the accelerator emission tubule diameter is smaller than the sleeve diameter; (iii) a sediment draining opening, equipped with a closure, disposed close to the lower end of the sleeve; (iv) an accelerator suction pipe having an accelerator water suction opening, located outside of the integrated accelerator and immersion device, and an accelerator water entry opening, located inside of the integrated accelerator and immersion device; (v) a bottom, disposed at the lower end of the sleeve; (vi) a thermostat disposed at bottom of the integrated accelerator and immersion device, inside the integrated accelerator and immersion device bottom; (vii) an electrical heating element disposed at bottom of the integrated accelerator and immersion device, inside the integrated accelerator and immersion device bottom, wherein the electrical heating element has an active segment, and a passive segment; (viii) a flow regulation opening disposed in the sleeve; and (ix) an immersion device flange, disposed in the sleeve, the flange having an immersion device flange opening, wherein the integrated accelerator and immersion device is mounted on the bottom of the electric water heating tank; (b) disposing a closure at the flow regulation opening, wherein the closure of the flow regulation opening has a hole for regulating the flow of water through the flow regulation opening; (c) mounting the integrated accelerator and immersion device on the bottom of the electric water heating tank, so that the electrical heating element active segment is located above the bottom of the electric water heating tank, and the sediment draining opening is located below the bottom of the electric water heating tank, and the sediment draining opening; (d) opening the closure of the sediment draining opening; and (e) removing sediment from the inside of the integrated accelerator and immersion device. Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein:

Figure 1 of the prior art is a schematic illustration of a longitudinal cross section of a standing water heating tank.

Figure 2 is a schematic illustration of a longitudinal cross section of a standing water heating tank equipped with an external immersion device for removal of limescale and sediment, according to the present invention.

Figure 3 is a schematic illustration of a longitudinal section of a standing water heating tank equipped with an external immersion device for removal of limescale and sediment, according to the present invention, in which an accelerator sleeve is disposed at a large distance from the bottom of the tank. Figure 4 is a schematic illustration of a longitudinal cross section of a standing water heating tank equipped with an integrated accelerator and immersion device for removal of limescale and sediment, according to the present invention.

Figure 5 is a schematic illustration of a longitudinal cross section of another configuration of a standing water heating tank equipped with an integrated accelerator and immersion device for removal of limescale and sediment, according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The principles and operation of an external immersion device for removal of limescale and sediment from electric water heating tanks according to the present invention may be better understood with reference to the drawings and the accompanying description.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, dimensions, methods, and examples provided herein are illustrative only and are not intended to be limiting.

The following list is a legend of the numbering of the application illustrations: 100 standing water heating tank

200 immersion device

300 integrated accelerator and immersion device

1 accelerator

2 immersion device flange opening

3 sediment draining opening

4 immersion device flange

5 accelerator sleeve

6 electrical heating element

7 thermostat

8 accelerator water entry opening

9 tank cold water entry opening

10a tank hot water exit opening

10b additional tank hot water exit opening

11 accelerator hot water exit opening

12 tank walls

13 runnel

14 immersion device walls

15 immersion device bottom

16 accelerator emission tubule

18 accelerator water suction pipe

19 accelerator water suction opening

20 limescale and sediment

21 limescale and sediment storage cavity

22 immersion device flange opening

23 the electrical heating element active segment

24 the electrical heating element passive segment

25 flow regulation opening

26 closure

27 base rod

28 magnesium anode rod

29 tubule joint

30 accelerator water suction pipe joint

Referring now to the drawings, Figure 2 is a schematic illustration of a longitudinal cross section of a standing water heating tank 100 equipped, with an external immersion device 200 for removal of limescale and sediment 20, according to the present invention.

Under the bottom of the tank 100 and outside of it, the immersion device 200 is connected to flange 4. The limescale and sediment 20 goes through opening 2, which is in flange 4, into immersion device 200, and thus does not accumulate within the accelerator sleeve 5 and therefore, undesired accumulation of sediment 20 in the aforementioned space does not disrupt the flow. The movement of sediment 20 can be driven by the force of gravity and by the force of the cold water flowing into the inner space of accelerator sleeve 5.

The removal of limescale and sediment 20 from tank 100 can be improved by shaping the bottom part of accelerator sleeve 5 and opening.2 as a spout or any other suitable shape of inclines.

There are several possibilities for removing the sediment 20 accumulated in the immersion device 200, such as removal via opening 3 which can be equipped with a faucet, lid, or any other suitable means. An additional option is removal of the immersion device

200 from the tank 100, emptying the sediment 20 from it, and returning it to place, or installing a new immersion device 200 in its place.

Removal and installation of the immersion device 200 can be with any suitable means known to any expert of ordinary knowledge in the art, such as using a gasket and suitable screwing.

Figure 3 is a schematic illustration of a longitudinal section of a standing water heating tank 100 equipped with an external immersion device 200 for removal of limescale and sediment 20, according to the present invention, in which accelerator sleeve 5 is disposed at a large distance from the bottom of the tank, namely at a large distance from flange 4, or in which accelerator sleeve 5 has large openings 8. Such a tank 100 enables dispersion of limescale and sediment 20 on the bottom of the tank. According to an additional embodiment according to the present invention, a funnel 13 is disposed at the bottom of the tank. The walls of the funnel 13 have suitable inclines to lead the limescale and sediment into immersion device 200 through the opening 2 in flange 4.

Immersion device 200 can also be installed in a tank that does not have a device for accelerating the heating of water, enabling efficient removal of limescale and sediment 20 through funnel 13 in this configuration as well.

Figure 4 is a schematic illustration of a longitudinal cross section of a standing water heating tank 100, equipped with an integrated accelerator and immersion device 300, for removal of limescale and sediment, according to the present invention, hi addition to the efficient removal of limescale and sediment, this device also enables faster acceleration of the heating of the water in comparison with standard accelerators. The operation principle of the improved accelerator includes suction of water into the lower part of the integrated accelerator and immersion device 300 from a pooling area, and creation of a hot water layer in the upper part of the standing water heating tank 100, resulting in the heating of a smaller amount of water in comparison with the quantity usually heated in standard accelerators, thus shortening the time interval necessary for achieving a specific desired temperature of hot water near the exit opening.

The illustration shows the components of the integrated accelerator and immersion device 300 and its assembly within the standing water heating tank 100.

Integrated accelerator and immersion device 300 is a long cylinder with an accelerator sleeve 5, usually disposed within and along the symmetry axis of tank 100, which also has an elongated cylindrical shape, and protruding from the bottom part of the tank 100. The upper part of integrated accelerator and immersion device 300 has a smaller diameter and serves as an emission tubule 16 for hot water from the accelerator, through the accelerator hot water exit opening 11. Tubule 16 can be made of tubule joints 29 which can be connected to each other to enable adapting its length to the height of the tank in which it is assembled. Sediment draining opening 3 is disposed at the bottom the accelerator sleeve 5. The opening 3 is usually closed by means of closure 26, which can be any suitable closure such as a tap, lid, or cap, and can be opened and closed repeatedly, for the purpose of cleaning and removing the limescale and sediment. A pipe 18 for suction of water into the accelerator enters the integrated accelerator and immersion device 300. The pipe 18 can be straight, as shown in the illustration, or curved, and includes an opening 19 for suction of water into the accelerator, which is disposed at the upper part of the tank 100, where the hot water layer is formed, while accelerator water entry opening 8 is disposed at a suitable height near the bottom of tank 100 (the geometrical relations noted in the present patent application, such as "near" and the like, are with regard to a typical size of tank 100).

Straight accelerator suction pipes 18 can be provided with various lengths to suit various sizes of tanks 100, and a pipe 18 can even be selected to dispose both of its openings at specific heights within a tank 100 of a specific size, affecting the thickness of the layer of hot water which is formed, and the heating performance. This also applies to curved pipes 18. Accelerator suction pipes 18 can include accelerator water suction pipe joints 30, which can be connected to each other to enable adapting its length to the height of the tank in which it is assembled.

Alongside the accelerator sleeve 5, a flow regulation opening 25, equipped with a closure (not shown in the illustration), can be disposed. This opening 25 serves as an option enabling rotation between the layers of water, balancing the dispersal of heat energy in the lower layers. In the case of choosing to have maximal heat energy at the upper part of tank 100, opening 25 will be closed or completely inexistent, so that the suction of the water into

the accelerator will be performed only from the upper part of tank 100. The suction of water from the lower level will increase as the size of the opening 25 is increased, also by means of increasing the closure's opening size.

The thermostat 7, and the electrical heating element 6, can be connected to the bottom of the integrated accelerator and immersion device 300, as shown in the illustration, however in this case, in order to conserve energy, the electrical heating element 6 will include two segments, a lower segment 24 which is electrically passive and an upper segment 23 which is electrically active and serves as the heating component.

The integrated accelerator and immersion device 300 can be connected to the standing water heating tank 100 with screws and immersion device flange 4, in the center of which is immersion device flange opening 22.

The standing water heating tank 100 and the integrated accelerator and immersion device 300 can obviously be equipped with suitable seals to prevent water leakage.

Figure 5 is a schematic illustration of a longitudinal cross section of another configuration of a standing water heating tank 100 equipped with an integrated accelerator and immersion device 300 for removal of limescale and sediment, according to the present invention. In this possible configuration, thermostat 7 is disposed within accelerator water suction pipe 12, and tank 100 is also equipped with an magnesium anode rod 28, as is commonly used in tanks, in order to prevent corrosion of the tank 100, however in the configuration shown in this illustration, magnesium anode rod 28 is disposed at the end of base rod 27, which goes through the accelerator sleeve 5. Base rod 27, carrying magnesium anode rod 28, can also be disposed outside of the accelerator sleeve 5, parallel to it, within tank 100.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claim.

Several examples of possible variations: ^■ The magnesium anode rod can be disposed in a different position within the tank, without the base rod. ^■ The base rod can be welded or screwed to immersion device flange.

^■ External thermal isolation can be added to the lower part of the integrated accelerator and immersion device, which protrudes underneath the tank.

^■ The accelerator sleeve can also be composed of metal, and can be connected to an immersion device composed of another material, such as a plastic. Its shape can be chosen from a variety of spatial shapes.

^■ The tank, equipped with the improved accelerator, can also be used without the immersion device, however this is only recommended when the water supplied to the tank has a low concentration of limescale and sediment.

^■ The accelerator emission tubule and the accelerator water suction pipe can have a telescopic structure, for adaptation to varying water suction and emission heights.

The diameter of the accelerator emission tubule does not necessarily need to differ from that of the accelerator sleeve.

^■ The electrical heating element active segment can cover segments of varying lengths of the total length of the electrical heating element and various areas on it, and can even cover the entire length of the electrical heating element.