VACUUM STORAGE AND METHOD FOR MANUFACTURING A VACUUM STORAGE

Description

[0001] The invention relates to a vacuum storage device for storing hot water, comprising the features of the preamble of claim 1 and a method for manufacturing a vacuum storage device according to claim 8.

[0002] Vacuum storage tanks, such as hot water storage tanks, are used to generate and store hot water, primarily in households. When hot water is drawn from the storage tank, cold water automatically flows into it and is then reheated. Vacuum storage tanks are available in various sizes and storage capacities. Depending on the size and intended use, the installation and setup of the vacuum storage tank also vary. For example, some hot water storage tanks are designed to be wall-mounted.

[0003] These wall-mounted water heaters typically have a cold water inlet, a hot water outlet, a heating element, a temperature sensor, an impressed current anode or MgO anode, and a safety temperature sensor in their lower section, all leading into the interior of the tank. A disadvantage of this design is that these components and their openings each create a heat transfer path from the inside of the tank to the outside. Particularly in the case of vacuum-insulated water heaters, there is a high need for continuous optimization to reduce heat transfer from the tank to the outside.

[0004] German patent application DE 102016012922 A1 discloses a hot water storage tank that has already been optimized to address the aforementioned problem. In this design, the tank's opening acts as a heat sink and consists of an inner and outer ring with a gap between them. The heat sink can be composed of various curves and bends.

[0005] EP 3 315 872 A2 relates to a hot water storage tank with an inner tank and an outer tank surrounding the inner tank. A cavity filled with an insulating medium is provided between the inner and outer tanks. The openings of the inner and outer tanks are connected by a connecting piece forming a side wall, which projects below the bottom of the outer tank and to which a flange-like threaded ring is attached. The bottom of the outer tank is made from a single piece.

[0006] EP 3 995 772 A1 relates to a method for manufacturing a vacuum storage tank for hot water, wherein insulating material is introduced into an intermediate space between an inner and an outer tank of the vacuum storage tank via a pipe element, and the intermediate space is then evacuated. After filling and evacuating the intermediate space, the pipe element is compressed at a pinch point and, while the compression is maintained, cut off at a shear point and sealed fluid-tight.

[0007] EP 3 705 804 A1 shows a hot water storage tank with a storage vessel for holding a fluid and a flanged connection for closing an opening on the storage vessel. The flanged connection has a connection flange connected to the storage vessel, a mounting flange that can be coupled to the connection flange, and a sealing element arranged between the connection flange and the mounting flange for closing the opening. The sealing element is sealed against the connection flange by means of a sealing element and at least one spacer and is galvanically decoupled from the connection flange or mounting flange.

[0008] DE 10 2016 012 921 A1 relates to a heating flange device for a hot water storage tank which has a storage tank with an opening, wherein the heating flange device has a heating element, a cold water inlet, a hot water return and a temperature sensor.

[0009] Therefore, the object of the invention is to provide a hot water storage tank with improved thermal insulation and reduced heat loss. At the same time, manufacturing costs should be kept low, thereby minimizing and optimizing the manufacturing process and the associated number of components and welds.

[0010] This problem is solved by a vacuum storage device having the features of claim 1 and by the method for manufacturing a vacuum storage device having the features of claim 8. Advantageous embodiments of the invention are specified in the dependent claims.

[0011] For hot water storage tanks, it is crucial that the temperature of the water inside can be maintained for as long as possible without reheating. To achieve this, excellent insulation is required all around the tank. A vacuum tank containing a water reservoir is used for this purpose. The gap between the outer and inner tanks is evacuated and filled with a special insulating powder, typically containing pyrogenic silica. The insulation thickness is determined based on the required technical parameters. Insulation with insulating powder is not possible in the lower section of the hot water storage tank. This section contains an opening through which a heating element is inserted, as well as the connections for the water tank's inlet and outlet, and potentially other components.

[0012] Therefore, materials with low thermal conductivity are used in the lower section of the hot water storage tank. The base can consist of one or more components and / or different materials. In the manufacturing process of the hot water storage tank, a storage tank is first produced in the conventional manner, preferably from structural steel. An enamel coating is then applied to the surfaces of the inner tank.

[0013] According to the invention, a vacuum storage device is used, consisting of an inner container and an outer container surrounding the inner container. A gap exists between the inner and outer containers, serving as an insulating layer or for holding insulating material. According to the invention, the bottom of the outer container is formed in two parts, consisting of an inner and an outer ring. The bottom of the outer container is made of steel, preferably stainless steel. A connecting flange projects from the outer container and accommodates a closure element. The connecting flange is made of steel, preferably structural steel, and is welded to the inner container. The closure element is fixed to the upper part of the connecting flange by means of an annular mounting flange and screws.The sealing body can be seen as a unit with the hot water outlet, the cold water inlet, the heating element, an impressed current anode, a temperature sensor and a safety temperature sensor.

[0014] Furthermore, according to the invention, a method for manufacturing a vacuum storage device is provided, in which the vacuum storage device according to the invention has an inner container and an outer container, wherein an insulating unit for receiving an insulating material is provided between the inner container and the outer container.

[0015] The manufacturing process comprises the following steps: First, the connecting flange is welded to the first part of the base of the outer container, or to the inner ring. In the next step, the base of the inner container is welded to the connecting flange. To complete the inner container, the cylindrical shell section and a lid section are welded to the base section. Finally, an enamel coating is applied to the inner container. Herein lies the advantage of the invention, namely that the base of the outer container is designed in two parts.

[0016] Fixing the inner ring of the outer container's base to the inner container's connection flange and then enameling it prevents the enamel from chipping during subsequent fixing. If the outer container's base were welded to the connection flange only after the enamel had been applied, this would lead to chipping or damage to the enamel. This method ensures a complete and intact enamel coating on the inner container.

[0017] In the next step, the inner container is joined and welded to the outer container. This involves welding the second part of the outer container's base, or outer ring, to the first part of the base, or inner ring. On the other side, the outer ring is fixed to the outer container's housing. Finally, the insulation material is filled into the insulating unit between the inner and outer containers and compacted. The insulating unit is then evacuated and sealed.

[0018] The inner container preferably has a wall thickness of up to 3 mm. More preferably, it has a wall thickness of approximately 1.0 to approximately 2.5 mm.

[0019] Preferably, the hot water storage tank has a capacity of up to 300 liters, particularly preferably between approximately 5 and approximately 150 liters.

[0020] The material thickness of the connecting flange is preferably between 0.5 mm and 5 mm, but preferably between 1.5 mm and 2.5 mm.

[0021] Advantages and embodiments of the invention are explained in more detail below with reference to the drawings: Figures: Fig. 1 a perspective view of a vacuum storage tank Fig. 2 a sectional view of a vacuum storage tank Fig. 3 A cross-sectional view of a vacuum storage tank with a focus on the connection flange. Fig. 4 a sectional view of a connection flange Fig. 5 a perspective view of an inner container

[0022] In Fig. 1 is the vacuum storage unit according to the invention 10 The image shows the outer container. 200, which includes an inner container. In the upper part of the outer container 200 is the ground 210, which is designed in two parts and is divided by an inner ring 210aand through an outer ring 210b It consists of rings welded together. The connecting flange protrudes from the inner container out of the outer container. 200 removes and takes the locking body 300 on.

[0023] The closure body 300 is achieved through the ring-shaped mounting flange 310 at the upper part of the connection flange 110 The locking body is fixed with at least four, and in the preferred embodiment with at least six, screws. 300 is as a unit comprising at least the hot water drain 330, the cold water inlet 320, the heating element 340, A forced current anode, a temperature sensor, and a safety temperature sensor can be seen. Via the filling pipe 240 The insulating material is placed between the inner container and the outer container. 200 It was filled and the insulation unit evacuated.

[0024] In Fig. 2is the vacuum storage unit according to the invention 10 as seen in a cross-sectional view. The outer container 200 surrounds the inner container 100. Between the outer container 200 and the inner container 100 There is an insulating unit 201, which is filled with insulating material and in which a vacuum exists. The inner container 100 is made from a lid part 120, a coat part 130 and a base part 140 trained. On the inner container 100, in particular on the bottom part 140, is the connection flange 110 welded on. The floor 210 of the outer container 200 is designed in two parts, the inner ring 210a is on the connection flange 110 welded on, the outer ring 210b is on the case 230 and on the inner ring 210a welded on.

[0025] In Fig. 3 is the connection flange 110shown in a detailed view. The connection flange 110 consists of a pipe section 111 and a flanged part to which the annular mounting flange secures the closure body. On the inner container 100 is the connection flange 110 fixed by a welding process. In the preferred embodiment according to the invention, the connecting flange consists of 110 made of structural steel. The pipe section 111 is from the insulation unit 201 surrounded. The flange part protrudes from the outer container. 200 out and between the ground 210 An air gap is formed between the base and the flange. 210 It is designed in two parts and consists of an inner ring 210a and an outer ring 210b. The inner ring 210a is attached to the connecting flange via a welding process 110 fixed, the outer ring 210b is attached to the inner ring 210aand on the case 230 of the outer container 200 welded.

[0026] The connection flange according to the invention 110 will be in Fig. 4 The section of pipe is shown in the cross-sectional view. 111 and the flange part 112 shown. Between the flange part 112 and the inner ring 210a An air gap is formed. The inner ring 210a In the preferred version, it is made of stainless steel. The inner ring is joined using a welding process. 210a at the connection flange 110 attached. In the opening 113 A locking element is inserted.

[0027] Fig. 5 shows a view of the inner container 100. The inner container 100 consists of a base part 140, a coat part 130 and a lid part 120. On the lid part 120 is the connection flange 110welded on and attached to the connecting flange 110 the inner ring 210a. The inner container 100 In its preferred version, it consists of structural steel. The steel surfaces are enamelled for corrosion protection. Reference symbol list

[0028] 10 Vacuum storage 100 Inner container 110 Connection flange 111 Pipe section 112 Flange part 113 opening 120 Lid part 130 Coat part 140 bottom part 200 Outer container 201 Insulation unit 210 Floor 210a Inner ring 210b Outer ring 220 Lid 230 Housing 240 Filling pipe 300 Closure body 310 Ring-shaped mounting flange 320 Cold water inlet 330 Hot water drain 340 heating element 350 plate

Claims

1. Vacuum storage tank (10) for storing hot water, with - an inner cylinder (100) made of steel for holding water, - an outer cylinder (200) which surrounds the inner cylinder (100) and has a base (210) in a lower region, - an insulation unit (201) between the inner cylinder (100) and the outer cylinder (200), - a connecting flange (110) connected to the inner cylinder (100) for accommodating and securing a closure body (300), wherein the connecting flange (110) is formed in one piece from steel and has a pipe section (111) with a flange part (112) and the base (210) of the outer cylinder (200) is made of stainless steel and is attached to the connecting flange (110), characterised in that the base (210) of the outer cylinder (200) is formed in two pieces and consists of an inner ring (210a) and an outer ring (210b).

2. Vacuum storage tank (10) according to claim 1, characterised in that the connecting flange (110) is made of structural steel and has a greater material thickness than the inner cylinder (100), the material thickness of the connecting flange (110) is between 0.5 mm and 5 mm, but in particular between 1.5 mm and 2.5 mm.

3. Vacuum storage tank (10) according to claim 1 or 2, characterised in that the outer ring (210b) is attached to the inner ring (210a) and to the casing (230) of the outer cylinder (200).

4. Vacuum storage tank (10) according to claims 1 to 3, characterised in that an air gap is formed between the flange part (112) of the connecting flange (110) and the base (210).

5. Vacuum storage tank (10) according to claims 1 to 4, characterised in that a closure body (300) is accommodated on the outer flange (110), wherein the closure body (300) consists of at least one plate (350), one or more heating elements (340), a cold water inlet (320) and a hot water outlet (330) and closes the inner cylinder (100) tightly.

6. Vacuum storage tank (10) according to claim 5, characterised in that an annular fixing flange (310) secures the closure body (300) to the connecting flange (110).

7. Vacuum storage tank (10) according to claim 7, characterised in that the annular fixing flange (310) is made of galvanised steel.

8. A method of manufacturing a vacuum storage tank (10) for storing hot water, comprising the following steps: a) Welding the connecting flange (110) to the inner ring (210a); b) Welding the base part (140) of the inner cylinder (100) to the connecting flange (110); c) Welding the cover part (120), the cylindrical shell part (130) and the base part (140) of the inner cylinder (100); d) Application of enamel to the inner cylinder (100); e) Joining the inner cylinder (100) to the outer cylinder (200), welding the inner ring (210a) to the outer ring (210b), as well as the base (210) to the casing (230) and the cover (220) to the casing (230); f) Filling the insulation unit (201) with the insulation material between the inner cylinder (100) and the outer cylinder (200) and compacting the insulation material in the insulation unit (201); and g) Evacuating and sealing the insulation unit (201).

9. Method of manufacturing a vacuum storage tank (10) according to claim 8, characterised in that pyrogenic silicic acid is used as the insulation material of the insulation unit (201).

10. A method of manufacturing a vacuum storage tank (10) according to claim 8, characterised in that the connecting flange (110) accommodates a closure body (300), wherein the closure body (300) is a unit comprising at least: a plate (350), one or more heating elements (340), a cold water inlet (320) and a hot water outlet (330).