JPS62116855A - Hot-water supplying equipment - Google Patents

Abstract

PURPOSE:To improve corrosion atmosphere, reduce and prevent the generation of leakage due to corrosion and reduce the amount of elution of sacrifice anode by a method wherein a gap between coupling metals is filled with molten metal or softened metal, fluidized plastically by high-temperature pressing, to eliminate a gap formed by the non-molten part of the coupling and connected the coupling sections tightly. CONSTITUTION:The connecting tip ends 11 of upper and lower connecting parts between an inner tube 1, whose upper part is expanded, and an outer tube 2, whose lower part is contracted, are contacted and the other part of the contacting part is formed so as to have a reduced coupling provided with a gap (d) (about half the thickness of connecting plates) capable of holding molten metal while a bonding part 7 is formed so as to have a pear-type bead by employing concentrated arc such as plasma welding or the like. According to this method, the gap of coupling is filed with a molten metal and the inner tube 1 may be connected to the outer tube 2 through the gap (d). Therefore, the generation of an oxygen cell, which is due to the stagnation of hot-water in the gap of coupling part, or the condensation of chloride in the hot-water may be reduced and a gap corrosion, most readily generated in hot-water supplying atmosphere, can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a water heater that uses oil, gas, electricity, or solar heat as a heat source and has a metallic heat exchanger or hot water storage tank.

BACKGROUND OF THE INVENTION A conventional hot water supply device for pans will be explained using a furnace-tube type boiler with reference to FIG.

In Fig. 3, the upper and lower joints of the inner cylinder 1 whose upper part is expanded and the outer cylinder 2 whose lower part is contracted are joined using an edge joint by TIG welding or a lap joint by seam welding. The opening 4 was joined to the upper part of the expanded inner cylinder 1.

The burner 5 passes through a burner insertion tube 6 and faces the inside of the cylinder 1.

In such a furnace-tube type oil boiler, water supplied from the water supply port 3 to the heat exchanger consisting of the inner cylinder 1, the outer cylinder 2, or the burner insertion pipe 6 exchanges heat with the combustion gas from the burner 5 on the wall of the inner cylinder 1. Then, the water becomes hot at 50 to 90°C, and the hot water inlet 4 is heated.
Hot water is supplied from the hot water tank or stored in a heat exchanger. For joining the inner cylinder 1 and the outer cylinder 2, an edge joint by TIG welding or a lap joint by seam welding is used, or a sharp gap 9 several microns wide is formed in the unfused part 8 following the end of the fused part 7. The corrosive environment is deteriorating due to oxygen concentration batteries due to stagnation of hot water and chlorine concentration in hot water.

For this reason, a sacrificial anode 10 made mainly of aluminum is attached to the iron can body by lining it with glass or using stainless steel such as 5US304 or SUS444 as the can body material.

Problems to be Solved by the Invention However, in the configuration shown in FIG. 3, chlorine concentration in the gap between the unfused parts of the welded joint results in strong acidity, which increases the elution of sacrificial anodes such as aluminum. As a result, the life of the sacrificial anode is shortened, and hydrates of the sacrificial anode that have been eluted are deposited at the bottom of the heat exchanger, necessitating frequent cleaning.

The present invention solves such conventional problems, and aims to improve the corrosive environment of heat exchangers and hot water storage tanks, reduce and prevent leakage due to corrosion, and reduce the amount of sacrificial anode eluted.

Means for Solving the Problems In order to solve the above problems, the water heater of the present invention fills the gaps between the joint metals with molten metal or softened metal that has plastically flowed by high temperature pressurization, so that the unfused parts of the joints are The structure is such that the joint portion is joined without forming a gap.

Effects The present invention improves the environment by eliminating gaps several microns wide due to unfused water heating equipment joints with the above-described configuration, reduces elution of sacrificial anodes, and reduces and prevents leakage due to corrosion of water heating equipment. The purpose is to

Embodiment An embodiment in which the present invention is applied to a furnace tube oil boiler is shown in FIGS. 1 and 2.

In Fig. 1, the joint tips 11 of the upper and lower joints of the inner cylinder 1 whose upper part is expanded and the outer cylinder 2 whose lower part is contracted are in contact with each other, and the other side has a gap width d (1/1/2 of the joint plate thickness) that can hold the molten metal. 2), and the fused portion 7 is formed into an oval bead using a concentrated arc such as plasma welding. As a result, the joint gap is filled with molten metal, and the inner tube 1 and the outer tube 2 can be joined through the gap width d.

Therefore, by shortening the edge joint length l, it is possible to reduce oxygen concentration batteries due to hot water boiling in the joint joint gap and chlorine concentration in hot water, thereby reducing crevice corrosion that is most likely to occur in hot water supply environments. be.

Next, another embodiment of the present invention will be described with reference to FIG.

In FIG. 2, the upper and lower joints of the inner cylinder 1 whose upper part is expanded and the outer cylinder 2 whose lower part is contracted are joined by lap joints by seam welding. At this time, by setting the seam welding conditions to a heat input with a larger current than the AWS (American Welding Standard) conditions, the temperature in the vicinity of the fusion zone 7 is increased and softened. The softened metal 11 plastically flows due to the pressure applied by the electrodes and overhangs and fills the overlap joint, thereby eliminating the unfused portion at the tip of the overlap joint and allowing the joints to be joined via the gap distance d.

Therefore, it has the effect of reducing crevice corrosion even in lap joints.

Effects of the Invention As described above, the hot water supply device of the present invention provides the following effects.

(1) By eliminating unfused parts at the joints of heating equipment and increasing the gap width, hot water retention in the gaps is reduced and crevice corrosion, which is most likely to occur in hot water supply environments, is reduced.

(2) By increasing the gap width, the anti-corrosion effect in gaps such as external power supply method and sacrificial anode method is enhanced.

(3) Reduce chlorine concentration in hot water in gaps and reduce sacrificial anode consumption.

[Brief explanation of drawings]

Figures 1a and b are cross-sectional views and vertical cross-sectional views of main parts of a furnace-tube type oil boiler according to the first embodiment of the present invention, Figure 1C is an enlarged view of the joints in the first embodiment, and Figure 2 a and b are cross-sectional views and vertical cross-sectional views of main parts of a furnace tube type oil boiler in another embodiment of the present invention, FIG. 2 C is an enlarged view of a joint in another embodiment, and FIGS. 3 a and b are Main part cross-sectional view and vertical cross-sectional view of a conventional furnace tube type oil boiler, Fig. 3c,
d is an enlarged view of the joints of the edge joint and overlap joint in the conventional example. 0 1. Inner cylinder, 2. Outer cylinder, d. Gap width, 7. Melted part, 11. Softened metal. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
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Claims (3)

[Claims] (1) Water heater equipment with a larger gap width at the tip of the welded joint. (2) The tip of the joint part is in contact with the other end, and the other end has a gap width capable of holding molten metal. The helical joint is joined by filling the molten part of the molten part obtained by blank bead welding with molten metal. hot water equipment. (3) The water heater according to claim 1, in which the resistance welding uses a high current condition, and the softened metal near the molten part flows plastically due to the applied pressure and extends into the lap joint gap.