Electrode boiler

Abstract

The present invention relates to an electrode boiler comprising a vessel (5) containing water; a plurality of electrodes (7), each electrode comprising a first upper end connected to an electrical power supply and a second lower end immersed in the water; and means for controlling the water level in the vessel. The means comprise a circulation pump (2) and a throttle valve (14), the circulation pump supplying water to the vessel (5) through a supply line (16). Additionally, the boiler comprises an arc chute (15) located below the second lower end of each electrode (7), the arc chute comprising a receptacle made of electrically insulating material, wherein an upper rim of the receptacle is positioned level with or just above the second lower end of the associated electrode (7).

Description

Technical Field

[0001] The present invention relates to an electrode boiler for providing hot water or hot steam and a method for operating the electrode boiler. Background Technology

[0002] Electrode boilers consist of multiple electrodes immersed in a water bath, each corresponding to a single electrode. Heat is generated by conducting AC current between the electrodes or conducting current to the opposing electrode using water as a conductor. The boilers are designed for low-voltage (230-690 V) or high-voltage (1-36 kV) power supplies and have a thermal power output of approximately 0-100 MW. Electrode boilers offer numerous advantages, such as near 100% efficiency, easily controllable output range, and rapid start-up.

[0003] The boiler output can be controlled by the water level covering the electrodes to a greater or lesser extent. The output can be shut off by switching on or by lowering the water level to a point where the electrodes are inaccessible. Each method has its advantages. Switches are subject to wear because they must handle large currents. Lowering the water level below the electrodes completely eliminates the need for switching on or off the boiler. However, when water is drained and reaches below the electrode tip, an electric arc may occur. This arc can travel directly to the other electrode or through the boiler's metal components. This could result in a complete short circuit.

[0004] GB 472,479 provides a steam-generating electrode boiler in which the bottom of the electrode terminates at an "arc deflection boiler". When the water level in the boiler drum drops below the electrode, the boiler ensures that the electrode tip remains surrounded by water to prevent current interruption and arc formation. Summary of the Invention

[0005] The purpose of this invention is to provide an electrode boiler that can be shut down by lowering the water level without generating an electric arc that would cause a short circuit in the power supply.

[0006] This is achieved in the boiler defined in the embodiments. Specifically, the electrode boiler of the present invention includes a container for holding water; a plurality of electrodes, each electrode including a first upper end connected to a power source and a second lower end immersed in water; and means for controlling the water level in the container. The means includes a circulation pump and a throttling valve, the circulation pump being used to supply water to the container via a supply line. Furthermore, the supply line is connected to an arc extinguisher located below the second lower end of each electrode, the arc extinguisher including a receiver made of an electrically insulating material, wherein the upper edge of the sidewall is positioned flush with or only above the second lower end of the associated electrode.

[0007] Operate the electrode boiler using the method described in the embodiments. In particular, when shutting down the boiler by lowering the water level inside the vessel, the presence of the insulating arc extinguisher will effectively prevent the formation of an electric arc. Attached Figure Description

[0008] Referring to the accompanying drawings, the advantages of the present invention will become clear from the following detailed description, in which:

[0009] Figure 1 This is a general overview of the boiler facility, showing its main components.

[0010] Figure 2 Details of the boiler according to the present invention are shown. Detailed Implementation

[0011] This invention relates to an electrode boiler, and the embodiments of the invention described in the following paragraphs are intended for supplying hot water. Figure 1 As shown, boiler 1 is connected to circulating pump 2 and heat exchanger 3 in a closed water loop. The pump continuously circulates water through the boiler, where it is heated. The heat generated is removed in heat exchanger 3, and the currently cooler water is then returned to the boiler for reheating. In a corresponding embodiment for generating steam, the heat exchanger is omitted, and the steam is delivered directly to the piping network.

[0012] The boiler includes a boiler drum 4. Inside the boiler drum 4, an inner container 5 is mounted on an electrically insulating support. Multiple electrodes 7 are suspended from the top of the drum on conductive rods passing through insulating sleeves. The rods are connected to an AC power source via conductors 10.

[0013] In addition, the boiler system includes: a three-way throttle valve 6 that controls the flow rate in a closed water circuit, which includes a circulation pump 2 and a supply line 16 for supplying water to the inner container 5; a level safety gauge 8 and a level control system 9; a pressure safety valve 11; a throttle valve 14 for discharging water from the inner container 5; a treated water inlet 12 and a sewage outlet line 13.

[0014] The inner container 5 holds water at a predetermined level. The water level is controlled by a throttle valve 14 based on readings from a level gauge. Boiler production can be controlled by changing the water level. Water is supplied through a supply line 16, which branches into multiple smaller pipes entering the bottom of the inner container 5.

[0015] Figure 2This is an illustrative representation of the invention. An arc-extinguishing device 15 is mounted below each electrode 7. Each arc-extinguishing device includes a receiver made of an electrically insulating material, such as ceramic (e.g., porcelain), glass, or PFTE. The arc-extinguishing device may be positioned at the bottom of the inner container 5. The arc-extinguishing device is mounted to ensure that the top edge of the receiver is positioned flush with or preferably slightly above the lower end of the associated electrode 7. An opening is provided in the bottom of each arc-extinguishing device, which connects the receiver to the water supply line 16.

[0016] When production is expected to cease, the water in the inner container 5 is discharged via the throttle valve 14. The water outside the arc-extinguisher 15 is completely drained, while the water inside the arc-extinguisher remains level with the upper edge of the receiving seat and in contact with the electrode 7. Then, the circulating pump 2, supplying water through the supply line 16, stops, causing the water level inside the arc-extinguisher 15 to drop. At some point, the water will lose contact with the electrode 7. This is the moment when an electric arc may occur. However, the presence of the arc-extinguisher means that the arc must climb the insulating barrier to reach the other electrode or the surrounding metal part of the boiler drum 4. This effectively prevents the formation of an electric arc.

Claims

1. An electrode boiler, the electrode boiler comprising a vessel (5) containing water; a plurality of electrodes (7), each electrode comprising a first upper end connected to an electrical power source and a second lower end immersed in the water; and means for controlling the water level in the vessel (5), wherein, The device comprises a circulation pump (2) for supplying water to the tank (5) through a supply line (16), characterized in that the supply line (16) is connected to an arc chute (15) located below the second lower end of each electrode (7), the arc chute (15) comprising a receptacle made of electrically insulating material having a bottom wall and a side wall, wherein the upper edge of the side wall is positioned level with or just above the second lower end of the associated electrode (7).

2. A method of operating the electrode boiler of claim 1, wherein, The production of the electrode boiler is started and stopped by controlling the water level outside and inside the arc chute (15).

3. The method of claim 2, wherein, The production is stopped by first draining the water from the tank (5) and then draining the water from the arc chute (15).

Images