GB2400900A

GB2400900A - Tubular liquid heater

Info

Publication number: GB2400900A
Application number: GB0309210A
Authority: GB
Inventors: Jian Wen Zhang
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-04-23
Filing date: 2003-04-23
Publication date: 2004-10-27
Anticipated expiration: 2023-04-23
Also published as: GB0309210D0; GB2400900B

Abstract

The heater includes a number of superimposed metal heat absorber tubes 10 enclosed in a housing 80. Heat-generating elements 20, which may be positive temperature coefficient (PTC) ceramic sheets, are located between two adjoining heat absorbers. Metal electrodes 30 are installed on both sides of each heat-generating element. An insulating material 40 separates the electrodes from the heat absorbers. Each heat absorber tube is connected to its neighbour by a pipe connector 50 which may be located in an axial (Figure 2B) or radial (Figure 3) position. One or more wiring terminals 60 are provided for connection to a power supply. The heater has an inlet 11 and outlet 12 for liquid to flow through the internal cavity of the connected heat absorber tubes.

Description

1 2400900 Document 914895

TUBULAR LIQUID HEATER

Field of The Invention

The present invention relates to a liquid heater for use in such liquid heating equipment as an electric boiler or an electric shower heater. Particularly, but not exclusively the invention relates to an energysaving tubular liquid heater.

Background of the Invention

Currently, there are mainly two types of liquid heaters. One is the gas heater, which feature low thermal conversion rate and when in use may produce harmful gases to pollute the environment. They may also cause inflammable, explosive accidents or even personal injuries due to gas leakage. The other is the electric heater. Electric heaters are made with conventional heat-generating materials, and thus lead to such problems as low thermal conversion rate and low safety factor. To solve these problems, Chinese Patents ZL00228829.X and ZL01209363.7 respectively disclose a "Tubular Electric Liquid Heater" and a "Tubular Liquid Heater", both of which use semiconductor heat-generating materials and metal heat absorbers with built-in square-wave tubes and straight tubes, and thus have a smaller size, higher heat efficiency, faster temperature rise and a higher safety factor than electrical or gas heaters. Therefore, they somewhat solve the above problems. However, these heaters are still associated with defects, such as inconvenience in connector processing and installation, and incomplete structure in wiring terminals. The existence of such defects precludes the said inventions from achieving optimal results in processing and application.

Summary of the Invention

Therefore, the present invention seeks to provide a tubular liquid heater that can further improve the structure of liquid heaters, make it easier to process and use, and achieve optimal results in terms of heat efficiency, temperature rise and safety for use.

A tubular liquid heater according to present invention comprises multiple superimposed metal heat absorbers which are located in the housing. Heatgenerating elements are located between two adjoining heat absorbers and metal electrodes are located on both sides of each heat absorber. The insulating material is used to separate the metal electrode from the heat absorber. The said metal heat absorbers are made with bar-type flatbed hollow tubes and the internal cavity of each heat absorber forms a directthrough pipe, both ends of which are connected with adjoining heat absorbers by a pipe connector, enabling the cavities of all heat absorbers to form an interlinked pipe. The said pipe connector may be axially or radially connected with the ends of two adjoining heat absorbers, and one or more wiring terminals are provided outside the heater for connecting separately with each pair of metal electrodes and power supply. There is an liquid inlet and an liquid outlet on both ends of the pipe.

The radially connected pipe connector may have two short pipes which are fixed outside both ends of closed-end heat absorbers and extended into them; fixed at the corresponding position of adjoining heat absorbers are two short pipes which are closely coupled with the said short pipes. A sealing ring is furnished between each two adjoining short pipes.

The U-shape axially connected pipe connector is closely coupled on two ends of two adjoining open-end heat absorbers and a sealing ring is furnished between the pipe connector and heat absorber. l

The heat-generating element may be a PTC (positive temperature coefficient) ceramic heating sheet.

The insulating material may be silicone rubber sheet, mica sheet, ceramic sheet or polyurethane (PU) film.

By modifying the structure of the tubular liquid heater, embodiments of the present invention effectively solve the defects existing in current technologies, making it easier to process, assemble and operate. Pipe connectors used to connect each heat absorber may be installed both axially and radially, which effectively improves the processes of production and processing, and makes it easier and faster to assemble. The wiring terminals used to connect heating electrodes and power supply can be installed at any position on the housing, which makes it further easier to process and assemble. Embodiments of the present invention not only maintain the excellent features of tubular liquid heaters such as high heat efficiency, quick temperature rise and safety for use, but also effectively improves production and processing conditions, making it easier to implement and conduct batch production, and minimizing production cost. In addition, embodiments of the present invention feature small size, compact structure, quick heating, insulation between water and electricity, no electrical leakage and safe operation.

Brief descriptions of the Drawings

Fig. I shows a sectional view of the radially connected structure of the heat absorber according to a first embodiment of the present invention, of which, Fig. I A shows the breakdown view of components and Fig. I B shows the assembled status.

Fig. 2 shows a sectional view of the axially connected structure of the heat absorber according to a first embodiment of the present invention, of which, Fig. 2A shows the breakdown view of components and Fig. 2B shows the assembled status.

Fig. 3 shows the Fig. SB A-A sectional view of the radially connected general structure of the heat absorber according to the first embodiment of the present invention.

Fig. 4 shows the B-B sectional view of Fig. 5A.

Fig. 5 shows the dimensional plan view of the tubular liquid heater according to the first embodiment of the present invention, of which, Fig. 5A shows the front view and Fig. 5B shows the top view.

Detailed description of the Invention

Embodiment I As shown in Fig. I and Fig. 3, a tubular liquid heater according to a first embodiment of the present invention comprises multiple superimposed metal heat absorbers 10. The said metal heat absorbers 10 are ultrathin bar-type flatbed hollow tubes and the internal cavity of each heat absorber forms a straight-through pipe, inside which reinforcing ribs 13 can be added (See Fig.4). The cross section of the pipe may be rectangular, circular or triangular. Both ends of each heat absorber 10 are connected to adjoining heat absorbers 10 via a pipe connector 50.

The pipe connector 50 in the first embodiment adopts radial setup (as shown in Fig. 1). Both ends of each heat absorber 10 are sealed and holes are punched on pipe walls of symmetrical sides close to the ends. Two short pipes 51 and 52, an internal pipe and an external pipe, are welded into the holes and extended into a heat absorber 10. Welded at the corresponding position of adjoining heat absorbers are short pipes 53 and 54 which are closely coupled with the said short pipes 51 and 52. A sealing ring 55 is furnished between two adjoining short pipes and closely couples corresponding short pipes of adjoining heat absorbers such that the pipe connector 50 connects the internal cavities of all heat absorbers into an interlinked pipe with a liquid inlet 11 and a liquid outlet 12 on both ends. In this way, liquid enters the heat absorbers through the inlet and gets out through the outlet after being heated by multiple heat absorbers 10. Also as shown in Fig. 1 and Fig.3, heat-generating elements 20 are located between two adjoining heat absorbers. The said heat-generating elements may comprise positive temperature coefficient (PTC) ceramic heat-generating sheets and depending on actual needs, multiple PTC heat-generating sheets may be installed between two adjoining heat absorbers with proper spacing to form a combination of heat-generating elements. Metal electrodes 30 are furnished on both sides of each heat-generating element, and one or more wiring terminals 60 are provided at the edges of the electrodes to link power supply. If there is only one wiring terminal, each electrode will be connected with the said wiring terminal via conducting wire. The wiring terminal is separated from the heat absorbers by an insulator 70, and metal electrodes 30 are separated from the heat absorbers by insulating material 40. The said insulating material may be such high- conductivity thermostable material as silicone rubber sheet, mica sheet, ceramic sheet or polyurethane (PU) film. PU film is employed in the first embodiment. The semiconductor heat-generating sheets furnished with electrodes and insulating materials are closely affixed to the external walls of the two adjoining heat absorbers, transmitting the heat given out to the liquid in the heat absorbers. Also as shown in Fig. 4, the multiple superimposed metal heat absorbers 10 are installed inside the metal housing 80 and fixed with bolts 81. The integrated structure according to the first embodiment of the present invention after assembling and connecting is as shown in Fig.35.

Embodiment 2 Fig. 2 shows a second embodiment of the present invention. The basic structure of Embodiment 2 is as shown in Embodiment 1. The difference is that the heat absorbers hereof adopt axially connected structure (as shown) in fig.2. Both ends of the heat absorbers are open and are furnished with end sleeves 14 with greater cross section than the heat absorbers.

The pipe connector 50 that connects heat absorbers is "U" shape and the dimensional size of its two straight pipes corresponds to the size of the heat absorbers' end sleeves, pressing the two straight pipes tightly into the heat absorbers' end sleeves 14. In this way, the internal cavities of all heat absorbers are connected into an interlinked pipe. A sealing ring 56 is furnished between the pipe connector 50 and heat absorber 10.

Claims

Claims: 1. A tubular liquid heater comprising multiple superimposed metal

heat absorbers 10, wherein the superimposed metal heat absorbers are enclosed in a housing, heat-generating elements are furnished between each two adjoining heat absorbers, and metal electrodes are installed on both sides of each heat-generating element, the metal electrodes are separated from heat absorbers by an insulating material, the said metal heat absorbers are bar-type flatbed hollow tubes, the internal cavity of each heat absorber forms a direct-through pipe, the two ends of which are connected with adjoining heat absorbers via a pipe connector such that the internal cavities of all heat absorbers are connected into an interlinked pipe, the said pipe connector may be axially or radially connected with the ends of two adjoining heat absorbers, and one or more wiring terminals are provided outside the heater for connecting separately with each pair of metal electrodes and power supply, there is a liquid inlet and a liquid outlet on both ends of the pipe.
2. A tubular liquid heater according to Claim 1, wherein the pipe connector is connected radially and has short pipes and which are fixed outside both ends of closed-end heat absorbers and extended into them; fixed at the corresponding position of adjoining heat absorbers are short pipes and which are closely coupled with the said short pipes and a sealing ring is furnished between each two adjoining short pipes.
3. A tubular liquid heater according to Claim 1, wherein the pipe connector is U-shape and axially connected, wherein said pipe connector is closely coupled on two ends of two adjoining open-end heat absorbers and a sealing ring is furnished between the pipe connector and heat absorber.
4. A tubular liquid heater according to Claim 1, wherein the said heatgenerating element comprises PTC (positive temperature coefficient) ceramic heat-generating sheets.
5. A tubular liquid heater according to Claim 1, wherein the said insulating material 4 comprises one of: silicone rubber sheet, mica sheet, ceramic sheet or polyurethane (PU) film.
6. A tubular liquid heater comprising: a plurality of superimposed metal heat absorbers, wherein the said superimposed metal heat absorbers are enclosed in a housing; a plurality of heat-generating elements, wherein each said heat-generating element is located between two adjoining heat absorbers; a plurality of metal electrodes, wherein said metal electrode is installed on both sides of each heat-generating element and the said metal electrodes are separated from the said heat absorbers by an insulating material; and at least one wiring terminal provided outside the heater for connecting separately with a pair of metal electrodes and a power supply; wherein each said metal heat absorber comprises a hollow tube with a pipe member with an internal cavity; the internal cavity of each pipe member communicating with adjoining heat absorbers via a pipe connector such that the internal cavities of all the heat absorbers are connected into an interlinked pipe; and the said pipe connector being axially or radially connected to the ends of two adjoining heat absorbers.