Water heater with at least two water tanks

Abstract

The water heater, according to the invention, provides simultaneous heating of two or more water tanks (1), connected by coupling elements (4), through which a heating element (2) extends, which heats all water tanks (1).

Description

Description

[0001] The water heater with at least two water tanks is applicable in water heating systems for storing and heating water for industrial and domestic purposes.Prior art

[0002] A flat type water heater described in EP3904780B1 is known from the prior art, comprising two water tanks with cold and hot water pipes mounted thereto, an outer jacket surrounding the water tanks and polyurethane foam insulation between the water tanks and the outer jacket. The water tanks have flanges with technological openings through which a heating element is installed in each of the water tanks. Alternatively, it is possible to have a heating element installed in only one water tank to heat the water in both water tanks, since the volumes of the two water tanks are connected by means of collar-type through coupling elements. In the embodiment with a heating element in each of the tanks, the design is expensive to manufacture due to the use of two heaters in each of the tanks, also there are more components that can malfunction, and it is not efficient enough in terms of electricity consumption of both heaters. In the embodiment with a heater in only one water tank, the disadvantage of the design is that it has a limited ability to reduce the turbulence of the flow of hot and cold water passing through the through coupling elements, which leads to difficult convection of water in the water tank. Another disadvantage is that it has an unfavorable surface for applying a quality protective anticorrosion coating, in this case enamel, due to the flat surface at the base of the coupling collars, which rests on the outer wall of the water tanks, and which creates a shadow area at the base of the collars where it causes accumulation of enamel of large thickness and its subsequent cracking after firing both in wet enameling and in dry electrostatic enameling.Summary of the invention

[0003] The task of the invention is to create water heater with at least two water tanks with increased efficiency and increased life, which is cheaper to manufacture and more economical in operation.

[0004] This task is achieved by creating a water heater comprising at least two water tanks with cold and hot water pipes mounted to them, an outer jacket surrounding the water tanks and polyurethane foam insulation between the water tanks and the outer jacket, wherein at least one water tank has a flange. A heating element is mounted to a technological opening of one water tank. Every two adjacent water tanks are hermetically connected to each other through their side walls by means of at least two through coupling elements located at a distance from each other, wherein the internal volumes of the water tanks are connected through these through openings. The heating element extends from one water tank, through the through openings of one or more coupling elements, and into the other water tanks to provide simultaneous heating of all water tanks by a single heating element, wherein the water tank in which the heating element ends is end water tank.

[0005] In one embodiment of the invention, the through openings of the coupling elements are coaxial, and the technological opening for mounting the heating element in one water tank is coaxial with the through openings of the coupling elements through which the heating element extends into the other water tanks.

[0006] In another embodiment of the invention, the openings of the coupling elements are not coaxial with each other and the technological opening for mounting the heating element is not coaxial with the openings of the coupling elements, and all the openings together are located on a straight line passing obliquely through all water tanks.

[0007] In another embodiment of the invention, the technological opening for mounting the heating element is not coaxial with the through openings of the coupling elements through which the heating element extends, which in the water tank, where the technological opening is located, is bent at an angle allowing the heating element to pass through said through openings. Preferably, the technological opening for mounting the heating element in the water tank in which it is located coincides with an opening on the flange of this water tank. It is possible that the heating element is bent in an arc-shape in all water tanks.

[0008] In one embodiment of the invention, during operation, the water tanks are under pressure.

[0009] In one embodiment of the invention, the water heater comprises three water tanks connected consequently with coupling elements, wherein the heating element extends into all three water tanks through two coupling elements with coaxial through openings.

[0010] In a preferred embodiment of the invention, the water heater is vertical water heater and the heating element extends into all water tanks through coaxial through openings of the coupling elements located in the lowest position of the water tanks.

[0011] In a preferred embodiment of the invention, the heating element extends into the end water tank to at least half of its diameter, wherein in order to provide substantially equal power to the sections of the heating element in all water tanks, the section of the heating element in the end water tank is bent.

[0012] In a preferred embodiment of the invention, through openings are drilled in the side walls of the water tanks, and the material around the through openings of the corresponding side wall of a water tank is shaped as a collar projecting above the side wall of the water tank and around the through opening, which constitutes the corresponding coupling element of the water tank.

[0013] Preferably, the coupling elements are two tubular elements, respectively one male on one water tank and one female on the other water tank, which two tubular elements are connected in an assembly one inside the other and they are fixed to each other by a welding seam.

[0014] In one embodiment of the invention, the water heater is a flat water heater.

[0015] The water heater, according to the invention, has increased water heating efficiency, provides uniform distribution with low flow rate of cold water, and reduced defectiveness of the product. The water heater has lower production cost due to the fewer components used, while maintaining high heating efficiency. Also, the water heater is produced using a simplified process compared to the state of the art due to the presence of fewer components.Brief description of the drawings

[0016] Further in the description, the water heater with at least two water tanks is explained with preferred embodiments, given as non-limiting the scope of the invention examples, with reference to the attached figures, where: Figure 1 is side view of a preferred embodiment of the invention with two water tanks adapted for vertical installation, and coaxially located technological opening and through openings of the coupling elements of the water tanks. Figure 2 is longitudinal sectional view along line C-C of the embodiment of Figure 1. Figure 3 is axonometric view of the embodiment of Figure 1. Figure 4 is side view of a preferred embodiment of the invention with three water tanks adapted for vertical installation, and coaxially located technological opening and through openings of the coupling elements of the water tanks. Figure 5 is longitudinal sectional view along line D-D of the embodiment of Figure 4. Figure 6 is axonometric view of the embodiment of Figure 4. Figure 7 is longitudinal sectional view of a preferred embodiment of the invention with two water tanks adapted for horizontal installation, and coaxially located technological opening and through openings of the coupling elements of the water tanks. Figure 8 is longitudinal sectional view of a preferred embodiment of the invention with three water tanks adapted for horizontal installation and coaxially located technological opening and through openings of the coupling elements of the water tanks. Figure 9 is partial view in longitudinal section of a preferred embodiment of the invention with two vertical water tanks in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements, and wherein the technological opening is formed on the water tank to which the inlet pipe for cold water is mounted. Figure 10 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements, and wherein the technological opening is formed on the water tank to which the inlet pipe for cold water is mounted. Figure 11 is partial view in longitudinal section of a preferred embodiment of the invention with two vertical water tanks, in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements, and wherein the technological opening is formed on the water tank to which the outlet pipe for hot water is mounted. Figure 12 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements, and wherein the technological opening is formed on the water tank to which the outlet pipe for hot water is mounted. Figure 13 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is not coaxial with the through openings of the coupling elements, and the through openings are not coaxial with each other, but together with the technological opening they form a straight line, which passes obliquely through all water tanks through which the heating element passes, and wherein the technological opening is formed on the water tank to which the outlet pipe for hot water is mounted. Figure 14 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is not coaxial with the through openings of the coupling elements, and the through openings are not coaxial with each other, but together with the technological opening they form a straight line, which passes obliquely through all water tanks through which the heating element passes, and wherein the technological opening is formed on the water tank to which the inlet pipe for cold water is mounted. Figure 15 is longitudinal sectional view of a preferred embodiment of the invention with two water tanks adapted for horizontal installation, in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements. Figure 16 is longitudinal section of a preferred embodiment of the invention with vertically oriented two water tanks showing an exemplary movement of the water flows in water tanks. Figure 17 is longitudinal section of a preferred embodiment of the invention with horizontally oriented two water tanks showing an exemplary movement of the water flows in water tanks. Figure 18 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is not coaxial with the through openings of the coupling elements, and the through openings are coaxial with each other, and the heating element is arc-shaped. Exemplary embodiment and application of the invention

[0017] In this description, the terms "bottom" and "top" refer to the arrangement of the elements of the water heater in its usual operating position.

[0018] The water heater according to the invention provides good stratification with simultaneous heating of two or more water tanks 1, connected as communicating vessels by coupling elements 4, by one heating element 2 extending in all water tanks 1. Since the heating element 2 extends in all water tanks 1, it is longer than a heating element from the prior art, which provides lower surface loading and longer life of the heating element 2.

[0019] The water heater, as shown in the figures, comprises two or more water tanks 1, for example three, four or more, with cold and hot water pipes 5, 6 mounted thereto, an outer jacket (not shown in the figures) surrounding the water tanks 1 and insulation from polyurethane foam between the water tanks 1 and the outer jacket.

[0020] The inlet pipes 5 for cold water and the outlet pipes 6 for hot water can be more than one, connected to different water tanks 1, they can also be of different shape and geometry, and their place of connection to water tanks 1 can vary along the entire geometry of water tanks 1 and it can be at different locations.

[0021] One or more of the water tanks 1, and in one embodiment of the invention, all water tanks 1, have a flange.

[0022] One of the water tanks 1, which is the first water tank 1, has a technological opening 3 through which the heating element 2 is installed.

[0023] Each two adjacent water tanks 1 are hermetically connected to each other through their side walls by means of at least two through coupling elements 4, located at a distance from each other, and the internal volumes of the water tanks 1 are connected through their through openings. The heating element 2 extends from one water tank 1, through the through openings of the coupling elements 4, and into the other water tanks 1 to ensure simultaneous heating of all water tanks 1 by one heating element 2, wherein the water tank 1 in which the heating element 2 ends is an end water tank 1.

[0024] The coupling elements 4 can be located along the entire length of the water tanks 1 and their number can be different, the minimum being two. It is preferable if the coupling elements 4 are at both ends of the water tanks 1 at a large distance from each other. This embodiment provides the following benefits: Maximum quick and easy heating of the volume of water in the water tanks 1; Maximum exchange of water between the two water tanks 1.

[0025] In the embodiments with more than two water tanks 1, the through openings of the coupling elements 4 can be coaxial with each other (Figures 5, 8, 10), or alternatively not coaxial, but hierarchically located between two end points of the two end water tanks 1, being located on a straight line passing obliquely to the extension of water tanks 1, as shown in figures 13 and 14.

[0026] The technological opening 3 for installation of the heating element 2 in one water tank 1 can be coaxial with one or more of the through openings of the coupling elements 4 of the other water tanks 1, through which the heating element 2 extends, as shown in Figures 1, 2, 3, 4, 5, 6, 7, 8 and 12, in which embodiment the technological opening 3 is made on the side wall of the first water tank 1. Alternatively, the technological opening 3 may not be coaxial with the through openings of the coupling elements 4, as shown in Figures 9, 10, 11, 15, 16 and 17, for example, it can be arranged perpendicularly, in which case in the first water tank 1 the heating element 2 is bent at an angle (in the embodiment shown in figures - at an angle of about 90°) so that it passes through the through openings of the coupling elements 4. When the axes of the technological opening 3 and coupling elements 4 are not coaxial, the axes can be diverged, for example, by an angle greater than 46 degrees, for example 90 degrees, other values are also possible. In this embodiment, it is possible for the heating element 2 to be arcuately curved in all water tanks 1 (Fig. 18). For example, the ends of the arc can point to the bottoms of the two end water tanks 1 in an embodiment of vertically located water tanks 1. Alternatively, it is also possible that the technological opening 3 is not coaxial with the through openings of the coupling elements 4, in which embodiment the technological opening 3 is made on the side wall of the first water tank 1, and extends through the through openings of the coupling elements 4, which are also not coaxial with each other, but are located on a straight line passing obliquely to the extension of the water tanks 2, as shown in Figures 13 and 14.

[0027] It is possible that the technological opening 3 for mounting the heating element 2 in the first water tank 1 is located on the flange of this water tank 1.

[0028] The technological opening 3 for the heating element 2 can be located both on the water tank 1, on which the inlet pipe for cold water 5 is installed, and on the water tank 1, on which the outlet pipe for hot water 6 is installed (Figures 11 and 13).

[0029] The water tanks 1 can be of various types, including those that are under pressure during operation.

[0030] The clear section of the water tanks 1 can be of different shapes, for example, it can be rectangular or square shape with rounded corners, superellipse, rounded rectangle, oval, circle, rectangle and two semicircles, curved square, curved rectangle or polygon. Different shapes require different thicknesses of the metal and possibly additional reinforcements.

[0031] The heating element 2 can be oriented in different ways. It is advantageous, in the case of vertical water heaters, that the heating element 2 is located as low as possible in the water tank 1 and passes through corresponding coupling element 4, also located as low as possible in the water tanks 1. It is also advantageous that it extends at least to half of the diameter of the end water tank 1.

[0032] Preferably, the heating element 2 heats all water tanks 1 with the same power, that is, all its sections in the different water tanks provide equal heating. It is possible that the section of the heating element in the end water tank is bent to provide substantially equal power to the sections of the heater in all water tanks. Alternatively, it is possible for the heating element to have sections, which heat with different power.

[0033] The shape of the heating element can be different as long as it provides the necessary heating of water tanks.

[0034] Different types of heaters 2 can be used, for example dry, ceramic or immersion heating elements.

[0035] The heating element 2 can have several power levels, which are controlled by an external regulator.

[0036] The coupling elements 4 can be shaped in different ways, for example: by welding corresponding finished coupling elements 4 to the outer walls of the water tanks 1 around a corresponding opening; by drilling through openings in the side walls of the water tanks 1, the material around the through openings of the corresponding side wall of a water tank 1 is bent outward from the water tank 1, and it is formed as a collar projecting above the side wall of the water tank 1 and around the through opening, which forms the corresponding coupling element 4 of the water tank 1; by bending a strip in the form of a collar and welding both ends of the strip to obtain a round element which is welded to the outer walls of the water tanks 1 around a corresponding opening; by flattening a tube to the desired shape of the coupling elements 4, after which the element is welded to the outer walls of the water tanks 1 around a corresponding opening.

[0037] In all of said embodiments, the shape of the coupling elements 4 favors application of a protective anticorrosion coating, since no shadow areas are formed at the base of the coupling elements 4, where they are connected to the water tanks 1, and where enamel could accumulate when applying protective anticorrosion coating leading to possible cracks there.

[0038] In an alternative embodiment of the invention, it is possible that the coupling elements have coupling collars and they are welded on the outer walls of the water tanks. In this embodiment, however, a shadow area is formed at the base of the collars, where enamel can accumulate leading to possible cracks.

[0039] The coupling elements 4 are two tubular elements and can be connected to each other in different ways, for example: if they are made as one male on one water tank 1 and one female on the other water tank 1, that is, they have a different but close diameter, the two tubular elements are connected in an assembly one within the other and fixed to each other by a welding seam; if they are of same diameter, they are connected by a welding seam, for example by butt weld or resistance weld.

[0040] The water heater according to the invention can be a flat water heater or another type of water heater. It can also be vertical as shown in Figures 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14 and 16 or horizontal water heater as shown in Figures 7, 8, 15 and 17.

[0041] In a preferred embodiment of the invention, the water in the water tanks 1 enters through an inlet pipe 5 mounted to one of the water tanks 1. Then, because of the coupling elements 4, the water enters the other water tanks 1. Because the heating element 2 passes through each water tank 1, the water in the water tanks 1 is simultaneously heated, and thus the already heated liquid is taken out through an outlet pipe 6 of another of the water tanks 1. Alternatively, it is possible for the water to enter the water tanks 1 through inlet pipes 5 mounted to more than one of the water tanks 1, for example, each water tank 1 can have one inlet pipe 5. It is also possible for the heated liquid to be taken out through more than one outlet pipe 6 from the water tanks 1, for example, each water tank 1 can have one outlet pipe 6.

[0042] The reference numbers of the technical features are included in the claims solely for the purpose of increasing the comprehensibility of the claims and, therefore, these reference numbers do not have any limiting effect on the interpretation of the elements indicated by these reference numbers.

Examples

Embodiment Construction

[0001]The water heater with at least two water tanks is applicable in water heating systems for storing and heating water for industrial and domestic purposes.

Prior art

[0002]A flat type water heater described in EP3904780B1 is known from the prior art, comprising two water tanks with cold and hot water pipes mounted thereto, an outer jacket surrounding the water tanks and polyurethane foam insulation between the water tanks and the outer jacket. The water tanks have flanges with technological openings through which a heating element is installed in each of the water tanks. Alternatively, it is possible to have a heating element installed in only one water tank to heat the water in both water tanks, since the volumes of the two water tanks are connected by means of collar-type through coupling elements. In the embodiment with a heating element in each of the tanks, the design is expensive to manufacture due to the use of two heaters in each of the tanks, also there are more componen...

Description

[0001] The water heater with at least two water tanks is applicable in water heating systems for storing and heating water for industrial and domestic purposes.Prior art

[0002] A flat type water heater described in EP3904780B1 is known from the prior art, comprising two water tanks with cold and hot water pipes mounted thereto, an outer jacket surrounding the water tanks and polyurethane foam insulation between the water tanks and the outer jacket. The water tanks have flanges with technological openings through which a heating element is installed in each of the water tanks. Alternatively, it is possible to have a heating element installed in only one water tank to heat the water in both water tanks, since the volumes of the two water tanks are connected by means of collar-type through coupling elements. In the embodiment with a heating element in each of the tanks, the design is expensive to manufacture due to the use of two heaters in each of the tanks, also there are more components that can malfunction, and it is not efficient enough in terms of electricity consumption of both heaters. In the embodiment with a heater in only one water tank, the disadvantage of the design is that it has a limited ability to reduce the turbulence of the flow of hot and cold water passing through the through coupling elements, which leads to difficult convection of water in the water tank. Another disadvantage is that it has an unfavorable surface for applying a quality protective anticorrosion coating, in this case enamel, due to the flat surface at the base of the coupling collars, which rests on the outer wall of the water tanks, and which creates a shadow area at the base of the collars where it causes accumulation of enamel of large thickness and its subsequent cracking after firing both in wet enameling and in dry electrostatic enameling.Summary of the invention

[0003] The task of the invention is to create water heater with at least two water tanks with increased efficiency and increased life, which is cheaper to manufacture and more economical in operation.

[0004] This task is achieved by creating a water heater comprising at least two water tanks with cold and hot water pipes mounted to them, an outer jacket surrounding the water tanks and polyurethane foam insulation between the water tanks and the outer jacket, wherein at least one water tank has a flange. A heating element is mounted to a technological opening of one water tank. Every two adjacent water tanks are hermetically connected to each other through their side walls by means of at least two through coupling elements located at a distance from each other, wherein the internal volumes of the water tanks are connected through these through openings. The heating element extends from one water tank, through the through openings of one or more coupling elements, and into the other water tanks to provide simultaneous heating of all water tanks by a single heating element, wherein the water tank in which the heating element ends is end water tank.

[0005] In one embodiment of the invention, the through openings of the coupling elements are coaxial, and the technological opening for mounting the heating element in one water tank is coaxial with the through openings of the coupling elements through which the heating element extends into the other water tanks.

[0006] In another embodiment of the invention, the openings of the coupling elements are not coaxial with each other and the technological opening for mounting the heating element is not coaxial with the openings of the coupling elements, and all the openings together are located on a straight line passing obliquely through all water tanks.

[0007] In another embodiment of the invention, the technological opening for mounting the heating element is not coaxial with the through openings of the coupling elements through which the heating element extends, which in the water tank, where the technological opening is located, is bent at an angle allowing the heating element to pass through said through openings. Preferably, the technological opening for mounting the heating element in the water tank in which it is located coincides with an opening on the flange of this water tank. It is possible that the heating element is bent in an arc-shape in all water tanks.

[0008] In one embodiment of the invention, during operation, the water tanks are under pressure.

[0009] In one embodiment of the invention, the water heater comprises three water tanks connected consequently with coupling elements, wherein the heating element extends into all three water tanks through two coupling elements with coaxial through openings.

[0010] In a preferred embodiment of the invention, the water heater is vertical water heater and the heating element extends into all water tanks through coaxial through openings of the coupling elements located in the lowest position of the water tanks.

[0011] In a preferred embodiment of the invention, the heating element extends into the end water tank to at least half of its diameter, wherein in order to provide substantially equal power to the sections of the heating element in all water tanks, the section of the heating element in the end water tank is bent.

[0012] In a preferred embodiment of the invention, through openings are drilled in the side walls of the water tanks, and the material around the through openings of the corresponding side wall of a water tank is shaped as a collar projecting above the side wall of the water tank and around the through opening, which constitutes the corresponding coupling element of the water tank.

[0013] Preferably, the coupling elements are two tubular elements, respectively one male on one water tank and one female on the other water tank, which two tubular elements are connected in an assembly one inside the other and they are fixed to each other by a welding seam.

[0014] In one embodiment of the invention, the water heater is a flat water heater.

[0015] The water heater, according to the invention, has increased water heating efficiency, provides uniform distribution with low flow rate of cold water, and reduced defectiveness of the product. The water heater has lower production cost due to the fewer components used, while maintaining high heating efficiency. Also, the water heater is produced using a simplified process compared to the state of the art due to the presence of fewer components.Brief description of the drawings

[0016] Further in the description, the water heater with at least two water tanks is explained with preferred embodiments, given as non-limiting the scope of the invention examples, with reference to the attached figures, where: Figure 1 is side view of a preferred embodiment of the invention with two water tanks adapted for vertical installation, and coaxially located technological opening and through openings of the coupling elements of the water tanks. Figure 2 is longitudinal sectional view along line C-C of the embodiment of Figure 1. Figure 3 is axonometric view of the embodiment of Figure 1. Figure 4 is side view of a preferred embodiment of the invention with three water tanks adapted for vertical installation, and coaxially located technological opening and through openings of the coupling elements of the water tanks. Figure 5 is longitudinal sectional view along line D-D of the embodiment of Figure 4. Figure 6 is axonometric view of the embodiment of Figure 4. Figure 7 is longitudinal sectional view of a preferred embodiment of the invention with two water tanks adapted for horizontal installation, and coaxially located technological opening and through openings of the coupling elements of the water tanks. Figure 8 is longitudinal sectional view of a preferred embodiment of the invention with three water tanks adapted for horizontal installation and coaxially located technological opening and through openings of the coupling elements of the water tanks. Figure 9 is partial view in longitudinal section of a preferred embodiment of the invention with two vertical water tanks in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements, and wherein the technological opening is formed on the water tank to which the inlet pipe for cold water is mounted. Figure 10 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements, and wherein the technological opening is formed on the water tank to which the inlet pipe for cold water is mounted. Figure 11 is partial view in longitudinal section of a preferred embodiment of the invention with two vertical water tanks, in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements, and wherein the technological opening is formed on the water tank to which the outlet pipe for hot water is mounted. Figure 12 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements, and wherein the technological opening is formed on the water tank to which the outlet pipe for hot water is mounted. Figure 13 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is not coaxial with the through openings of the coupling elements, and the through openings are not coaxial with each other, but together with the technological opening they form a straight line, which passes obliquely through all water tanks through which the heating element passes, and wherein the technological opening is formed on the water tank to which the outlet pipe for hot water is mounted. Figure 14 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is not coaxial with the through openings of the coupling elements, and the through openings are not coaxial with each other, but together with the technological opening they form a straight line, which passes obliquely through all water tanks through which the heating element passes, and wherein the technological opening is formed on the water tank to which the inlet pipe for cold water is mounted. Figure 15 is longitudinal sectional view of a preferred embodiment of the invention with two water tanks adapted for horizontal installation, in which the technological opening for the heating element is perpendicular to the through openings of the coupling elements. Figure 16 is longitudinal section of a preferred embodiment of the invention with vertically oriented two water tanks showing an exemplary movement of the water flows in water tanks. Figure 17 is longitudinal section of a preferred embodiment of the invention with horizontally oriented two water tanks showing an exemplary movement of the water flows in water tanks. Figure 18 is partial view in longitudinal section of a preferred embodiment of the invention with three vertical water tanks, in which the technological opening for the heating element is not coaxial with the through openings of the coupling elements, and the through openings are coaxial with each other, and the heating element is arc-shaped. Exemplary embodiment and application of the invention

[0017] In this description, the terms "bottom" and "top" refer to the arrangement of the elements of the water heater in its usual operating position.

[0018] The water heater according to the invention provides good stratification with simultaneous heating of two or more water tanks 1, connected as communicating vessels by coupling elements 4, by one heating element 2 extending in all water tanks 1. Since the heating element 2 extends in all water tanks 1, it is longer than a heating element from the prior art, which provides lower surface loading and longer life of the heating element 2.

[0019] The water heater, as shown in the figures, comprises two or more water tanks 1, for example three, four or more, with cold and hot water pipes 5, 6 mounted thereto, an outer jacket (not shown in the figures) surrounding the water tanks 1 and insulation from polyurethane foam between the water tanks 1 and the outer jacket.

[0020] The inlet pipes 5 for cold water and the outlet pipes 6 for hot water can be more than one, connected to different water tanks 1, they can also be of different shape and geometry, and their place of connection to water tanks 1 can vary along the entire geometry of water tanks 1 and it can be at different locations.

[0021] One or more of the water tanks 1, and in one embodiment of the invention, all water tanks 1, have a flange.

[0022] One of the water tanks 1, which is the first water tank 1, has a technological opening 3 through which the heating element 2 is installed.

[0023] Each two adjacent water tanks 1 are hermetically connected to each other through their side walls by means of at least two through coupling elements 4, located at a distance from each other, and the internal volumes of the water tanks 1 are connected through their through openings. The heating element 2 extends from one water tank 1, through the through openings of the coupling elements 4, and into the other water tanks 1 to ensure simultaneous heating of all water tanks 1 by one heating element 2, wherein the water tank 1 in which the heating element 2 ends is an end water tank 1.

[0024] The coupling elements 4 can be located along the entire length of the water tanks 1 and their number can be different, the minimum being two. It is preferable if the coupling elements 4 are at both ends of the water tanks 1 at a large distance from each other. This embodiment provides the following benefits: Maximum quick and easy heating of the volume of water in the water tanks 1; Maximum exchange of water between the two water tanks 1.

[0025] In the embodiments with more than two water tanks 1, the through openings of the coupling elements 4 can be coaxial with each other (Figures 5, 8, 10), or alternatively not coaxial, but hierarchically located between two end points of the two end water tanks 1, being located on a straight line passing obliquely to the extension of water tanks 1, as shown in figures 13 and 14.

[0026] The technological opening 3 for installation of the heating element 2 in one water tank 1 can be coaxial with one or more of the through openings of the coupling elements 4 of the other water tanks 1, through which the heating element 2 extends, as shown in Figures 1, 2, 3, 4, 5, 6, 7, 8 and 12, in which embodiment the technological opening 3 is made on the side wall of the first water tank 1. Alternatively, the technological opening 3 may not be coaxial with the through openings of the coupling elements 4, as shown in Figures 9, 10, 11, 15, 16 and 17, for example, it can be arranged perpendicularly, in which case in the first water tank 1 the heating element 2 is bent at an angle (in the embodiment shown in figures - at an angle of about 90°) so that it passes through the through openings of the coupling elements 4. When the axes of the technological opening 3 and coupling elements 4 are not coaxial, the axes can be diverged, for example, by an angle greater than 46 degrees, for example 90 degrees, other values are also possible. In this embodiment, it is possible for the heating element 2 to be arcuately curved in all water tanks 1 (Fig. 18). For example, the ends of the arc can point to the bottoms of the two end water tanks 1 in an embodiment of vertically located water tanks 1. Alternatively, it is also possible that the technological opening 3 is not coaxial with the through openings of the coupling elements 4, in which embodiment the technological opening 3 is made on the side wall of the first water tank 1, and extends through the through openings of the coupling elements 4, which are also not coaxial with each other, but are located on a straight line passing obliquely to the extension of the water tanks 2, as shown in Figures 13 and 14.

[0027] It is possible that the technological opening 3 for mounting the heating element 2 in the first water tank 1 is located on the flange of this water tank 1.

[0028] The technological opening 3 for the heating element 2 can be located both on the water tank 1, on which the inlet pipe for cold water 5 is installed, and on the water tank 1, on which the outlet pipe for hot water 6 is installed (Figures 11 and 13).

[0029] The water tanks 1 can be of various types, including those that are under pressure during operation.

[0030] The clear section of the water tanks 1 can be of different shapes, for example, it can be rectangular or square shape with rounded corners, superellipse, rounded rectangle, oval, circle, rectangle and two semicircles, curved square, curved rectangle or polygon. Different shapes require different thicknesses of the metal and possibly additional reinforcements.

[0031] The heating element 2 can be oriented in different ways. It is advantageous, in the case of vertical water heaters, that the heating element 2 is located as low as possible in the water tank 1 and passes through corresponding coupling element 4, also located as low as possible in the water tanks 1. It is also advantageous that it extends at least to half of the diameter of the end water tank 1.

[0032] Preferably, the heating element 2 heats all water tanks 1 with the same power, that is, all its sections in the different water tanks provide equal heating. It is possible that the section of the heating element in the end water tank is bent to provide substantially equal power to the sections of the heater in all water tanks. Alternatively, it is possible for the heating element to have sections, which heat with different power.

[0033] The shape of the heating element can be different as long as it provides the necessary heating of water tanks.

[0034] Different types of heaters 2 can be used, for example dry, ceramic or immersion heating elements.

[0035] The heating element 2 can have several power levels, which are controlled by an external regulator.

[0036] The coupling elements 4 can be shaped in different ways, for example: by welding corresponding finished coupling elements 4 to the outer walls of the water tanks 1 around a corresponding opening; by drilling through openings in the side walls of the water tanks 1, the material around the through openings of the corresponding side wall of a water tank 1 is bent outward from the water tank 1, and it is formed as a collar projecting above the side wall of the water tank 1 and around the through opening, which forms the corresponding coupling element 4 of the water tank 1; by bending a strip in the form of a collar and welding both ends of the strip to obtain a round element which is welded to the outer walls of the water tanks 1 around a corresponding opening; by flattening a tube to the desired shape of the coupling elements 4, after which the element is welded to the outer walls of the water tanks 1 around a corresponding opening.

[0037] In all of said embodiments, the shape of the coupling elements 4 favors application of a protective anticorrosion coating, since no shadow areas are formed at the base of the coupling elements 4, where they are connected to the water tanks 1, and where enamel could accumulate when applying protective anticorrosion coating leading to possible cracks there.

[0038] In an alternative embodiment of the invention, it is possible that the coupling elements have coupling collars and they are welded on the outer walls of the water tanks. In this embodiment, however, a shadow area is formed at the base of the collars, where enamel can accumulate leading to possible cracks.

[0039] The coupling elements 4 are two tubular elements and can be connected to each other in different ways, for example: if they are made as one male on one water tank 1 and one female on the other water tank 1, that is, they have a different but close diameter, the two tubular elements are connected in an assembly one within the other and fixed to each other by a welding seam; if they are of same diameter, they are connected by a welding seam, for example by butt weld or resistance weld.

[0040] The water heater according to the invention can be a flat water heater or another type of water heater. It can also be vertical as shown in Figures 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 13, 14 and 16 or horizontal water heater as shown in Figures 7, 8, 15 and 17.

[0041] In a preferred embodiment of the invention, the water in the water tanks 1 enters through an inlet pipe 5 mounted to one of the water tanks 1. Then, because of the coupling elements 4, the water enters the other water tanks 1. Because the heating element 2 passes through each water tank 1, the water in the water tanks 1 is simultaneously heated, and thus the already heated liquid is taken out through an outlet pipe 6 of another of the water tanks 1. Alternatively, it is possible for the water to enter the water tanks 1 through inlet pipes 5 mounted to more than one of the water tanks 1, for example, each water tank 1 can have one inlet pipe 5. It is also possible for the heated liquid to be taken out through more than one outlet pipe 6 from the water tanks 1, for example, each water tank 1 can have one outlet pipe 6.

[0042] The reference numbers of the technical features are included in the claims solely for the purpose of increasing the comprehensibility of the claims and, therefore, these reference numbers do not have any limiting effect on the interpretation of the elements indicated by these reference numbers.

Examples

Embodiment Construction

[0001]The water heater with at least two water tanks is applicable in water heating systems for storing and heating water for industrial and domestic purposes.

Prior art

[0002]A flat type water heater described in EP3904780B1 is known from the prior art, comprising two water tanks with cold and hot water pipes mounted thereto, an outer jacket surrounding the water tanks and polyurethane foam insulation between the water tanks and the outer jacket. The water tanks have flanges with technological openings through which a heating element is installed in each of the water tanks. Alternatively, it is possible to have a heating element installed in only one water tank to heat the water in both water tanks, since the volumes of the two water tanks are connected by means of collar-type through coupling elements. In the embodiment with a heating element in each of the tanks, the design is expensive to manufacture due to the use of two heaters in each of the tanks, also there are more componen...

Claims

1. Water heater comprising at least two water tanks (1) with cold and hot water inlet and outlet pipes (5, 6) mounted to them, an outer jacket surrounding the water tanks (1) and polyurethane foam insulation between the water tanks (1) and the outer jacket, wherein at least one water tank (1) has a flange, wherein a heating element (2) is mounted to a technological opening (3) of one water tank (1), wherein every two adjacent water tanks (1) are hermetically connected to each other through their side walls by means of at least two through coupling elements (4) located at a distance from each other, the internal volumes of the water tanks (1) are connected through these through openings, characterized in that the heating element (2) extends from one water tank (1), through through openings of one or more coupling elements (4), also into the other water tanks (1) to provide simultaneous heating of all water tanks (1) by a single heating element (2), wherein the water tank (1) in which the heating element (2) ends is an end water tank (1).

2. Water heater according to claim 1, characterized in that the through openings of the coupling elements (4) are coaxial, and the technological opening (3) for mounting the heating element (2) in one water tank (1) is coaxial with the through openings of the coupling elements (4), through which the heating element (2) extends into the other water tanks (1).

3. Water heater according to claim 1, characterized in that the technological opening (3) for mounting the heating element (2) is not coaxial with the through openings of the coupling elements (4) through which the heating element (2) extends, which heating element (2) is bent at an angle in the water tank (1), where the technological opening (3) is located, said angle allowing the heating element (2) to pass through said through openings.

4. Water heater according to claim 3, characterized in that the technological opening (3) for mounting the heating element (2) in the water tank (1) in which it is located, coincides with an opening in the flange of this water tank (1).

5. Water heater according to claims 3 and 4, characterized in that the heating element (2) is curved arcuately in all water tanks (1).

6. Water heater according to claim 1, characterized in that the openings of the coupling elements (4) are not coaxial with each other and the technological opening (3) for mounting the heating element (2) is not coaxial with the openings of the coupling elements (4), and all the openings through which the heating element (2) passes are located on a straight line passing obliquely through all the water tanks (1).

7. Water heater according to any of the preceding claims, characterized in that during operation, the water tanks (1) are under pressure.

8. Water heater according to any of the preceding claims, <b>characterized in that it comprises three water tanks (1) connected consequently with coupling elements (4), wherein the heating element (2) extends into all three water tanks (1) through two coupling elements (4) with coaxial through openings.

9. Water heater according to any of the preceding claims, characterized in that the water heater is vertical water heater and the heating element (2) extends into all water tanks (1) through coaxial through openings of the coupling elements (4) located in the lowest position of the water tanks (1).

10. Water heater according to any of the preceding claims, characterized in that the heating element (2) extends into the end water tank (1) to at least half of its diameter, wherein in order to provide substantially equal power to the sections of the heating element (2) in all water tanks (1), the section of the heating element (2) in the end water tank (1) is bent.

11. Water heater according to any of the preceding claims, characterized in that through openings are drilled in the side walls of the water tanks (1), and the material around the through openings of the corresponding side wall of one water tank (1) is shaped as a collar projecting above the side wall of the water tank (1) and around the through opening, which constitutes the corresponding coupling element (4) of the water tank (1).

12. Water heater according to any of the preceding claims, characterized in that the coupling elements (4) are two tubular elements, respectively one male on one water tank (1) and one female on the other water tank (1), which two tubular elements are connected in an assembly one inside the other and they are fixed to each other by a welding seam.

13. Water heater according to any of the preceding claims, characterized in that it is a flat water heater.

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