water heater

Abstract

To provide a water heater with superior cleaning performance that allows for cleaning at the desired timing and completely removes all dirt from inside the tank. [Solution] A water heater 1 that heats water to produce and store hot water, comprising: a vertical tank 2 for storing hot water; a transducer 3 provided on the outside of the bottom surface of the tank 2 for transmitting ultrasonic vibrations to the hot water when cleaning the tank 2; and a drain port 21 provided on the bottom surface of the tank 2 for discharging dirt scraped off inside the tank 2 by the ultrasonic vibrations.

Description

Technical Field

[0001] The present invention relates to a water heater having a function of discharging dirt such as hot water sludge and sand accumulated in the tank of the water heater.

Background Art

[0002] Conventionally, a storage water tank type water heater that heats tap water with an electric heater or the like and stores it in a tank has been used in electrified homes and the like. Such a water heater generally has an electric heater provided at the bottom of the tank, and heats and stores the tap water supplied into the tank to a predetermined temperature. For this reason, a usage method is generally adopted in which hot water is boiled at night when the electricity charge is low and stored in the tank, and the hot water in the tank is used during the day.

[0003] By the way, since the storage water tank type water heater heats and stores tap water, there is a problem that dirt such as hot water sludge and sand derived from the components contained in the tap water precipitates at the bottom of the tank (particularly, the bottom surface), and the sanitary condition deteriorates. Therefore, it is recommended to discharge the dirt accumulated in the tank about once a month.

[0004] For example, Patent Document 1 describes a storage water tank, in which a heater plate is provided on the bottom plate of the storage water tank body, and the heater plate is vibrated by bubbles generated when the hot water boils, and the scale (dirt) deposited on the bottom surface of the tank is discharged from the drain port by the vibration and the inclination of the bottom surface.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, sufficient scraping power is required to drain the dirt that has settled over a wide area at the bottom of the tank. If the scraping power is insufficient, the dirt may remain at the bottom of the tank. In the hot water storage tank of Patent Document 1, a heating plate is installed on the inclined bottom of the tank to generate bubbles at the bottom of the tank, but the vibrations caused by the bubbles generated when the water boils are not sufficient to scrape off the dirt. In addition, the timing for scraping off the dirt is limited to when the water is boiling, and it is not possible to adjust the timing of cleaning.

[0007] Therefore, the present invention aims to solve the above-mentioned problems and provide a water heater with excellent cleaning performance that can be cleaned at a desired timing and can completely remove dirt from inside the tank. [Means for solving the problem]

[0008] To solve the above problems, the invention of claim 1 is a water heater for heating water to produce and store hot water, characterized by comprising: a vertical tank for storing the hot water; a transducer provided on the outside of the bottom surface of the tank for transmitting ultrasonic vibrations to the hot water when cleaning the tank; and a drain port provided on the bottom surface for discharging dirt from inside the tank scraped off by the ultrasonic vibrations.

[0009] The invention of claim 2 is characterized in that, in the water heater described in claim 1, the tank is provided with a funnel-shaped projection that protrudes downward in approximately the center of the bottom surface, the drain port is provided in approximately the center of the projection, and the vibrators are provided in a plurality in proportion to the size of the tank and are provided on both sides of the projection.

[0010] The invention of claim 3 is characterized in that, in the water heater according to claim 1 or 2, the bottom surface further comprises a water inlet for supplying water to the tank, the water inlet is connected to a water supply pipe equipped with a water inlet valve for controlling the water supply, the drain outlet is connected to a drain pipe equipped with a drain valve for controlling drainage, and the drain valve and the water inlet valve are interlocked such that the water inlet valve closes when the drain valve is opened.

[0011] The invention of claim 4 is a water heater according to any one of claims 1 to 3, wherein the cleaning of the tank comprises a first process of activating the transducer to scrape and collect dirt inside the tank by ultrasonic vibration, and a second process of discharging the collected dirt from the drain port, and is equipped with a control means for automatically adjusting the timing of the first process and the timing of the second process so that the time interval of the first process is shorter than the time interval of the second process. [Effects of the Invention]

[0012] According to the invention described in claim 1, a transducer is provided on the bottom surface of the water heater tank, and the tank is cleaned by activating the transducer, so the tank can be cleaned at a desired timing. Furthermore, when the transducer transmits ultrasonic vibrations to the hot water in the tank, the large impact force when the bubbles generated by the ultrasonic vibrations burst mechanically scrapes off the dirt, so all the dirt in the tank can be scraped off, improving the cleaning performance.

[0013] According to the invention described in claim 2, a funnel-shaped projection is provided that protrudes downward approximately in the center of the bottom surface of the tank, making it possible to easily discharge the dirt scraped off and collected in this area from the drain. Furthermore, it is possible to temporarily store the scraped-off and collected dirt in this funnel-shaped projection until the time of discharge. This makes it possible to set separately the timing of the process of activating the transducer to scrape and collect the dirt in the tank using ultrasonic vibrations, and the timing of the process of discharging the collected dirt from the drain.

[0014] According to the invention described in claim 3, when the drain valve is opened, the water supply valve closes in conjunction, eliminating the need for complicated operations during drainage and making it possible to easily drain water from the tank.

[0015] According to the invention described in claim 4, the timing of the first process, in which the transducer is activated to scrape and collect dirt inside the tank using ultrasonic vibrations, and the timing of the second process, in which the collected dirt is discharged from the drain, can be automatically controlled. This makes it possible to regularly clean the tank, which is often forgotten, and to maintain the hygienic condition of the water heater at all times. Furthermore, since the time interval for the first process is automatically adjusted to be shorter than the time interval for the second process, the number of times the second process, which has a complicated processing step, is performed is reduced, making it possible to clean the tank efficiently. [Brief explanation of the drawing]

[0016] [Figure 1] This is a front view showing a water heater according to Embodiment 1 of the present invention. [Figure 2] These are a plan view (a) and a front view (b) showing the lower part of a water heater according to Embodiment 2 of this invention. [Figure 3] Figure 2 shows specific examples of water supply valves and drain valves that can be used in the water heater shown in Figure 2. [Figure 4] This is a front view showing a water heater according to Embodiment 3 of the present invention. [Figure 5] Figure 4 is a flowchart showing the processing procedure for ultrasonic cleaning in a water heater. [Modes for carrying out the invention]

[0017] The present invention will be described below based on the illustrated embodiments.

[0018] (Embodiment 1) FIG. 1 is a front view showing the water heater 1 according to this embodiment. This water heater 1 is a vertical storage tank type electric water heater, which is a device for heating tap water by a heating device (for example, a heater) and storing it in a tank. The water heater 1 includes a tank 2, a vibrator 3, a water supply pipe 4, and a drain pipe 5, and is housed in an exterior body 6 for protecting the tank. In addition, the water heater 1 further includes a heating device for heating tap water, a hot water supply pipe for taking out the boiled hot water, a relief valve for adjusting the pressure in the tank 2 (not shown), and various devices generally provided in a storage tank type electric water heater, etc.

[0019] The tank 2 is a hot water storage tank for storing the hot water obtained by heating the tap water supplied from the water supply pipe 4. In this embodiment, it is formed in a vertical substantially cylindrical shape.

[0020] A drain port 21 for draining the hot water in the tank 2 is provided on the bottom surface of the tank 2. In this embodiment, the drain port 21 is provided at substantially the center of a funnel-shaped convex portion 23 also formed on the bottom surface of the tank 2, and is used as an outlet for discharging the dirt in the tank 2 collected in the convex portion 23 to the outside. A drain pipe 5 provided with a drain valve 51 for controlling drainage is connected to this drain port 21.

[0021] In addition, a water inlet 22 for supplying tap water into the tank 2 is provided on the bottom surface of the tank 2. In this embodiment, the water inlet 22 is provided above the funnel-shaped convex portion 23 on the bottom surface of the tank 2, but the installation position is not limited to this, and it may be provided on the side surface of the tank 2, for example. A water supply pipe 4 provided with a water supply valve 41 for controlling water supply is connected to this water inlet 22.

[0022] A funnel-shaped projection 23 is provided approximately in the center of the bottom surface of the tank 2, protruding downwards. In this embodiment, the opening diameter of this projection 23 is about 1 / 3 to 1 / 4 of the diameter of the bottom surface of the tank 2, and it is formed in a funnel shape with an inclination angle of about 60°. Therefore, when draining, the dirt from the tank 2 that is scraped off and collected in this part quickly falls down the steeply inclined surface to the drain port 21 and is easily discharged from the drain port 21.

[0023] The funnel-shaped protrusion 23 is used as a temporary storage place for the dirt scraped off and collected during the cleaning of the tank 2 until it is time to drain it. In other words, the dirt scraped off and collected during the cleaning of the tank 2 can be stored in the protrusion 23, so it does not have to be immediately discharged from the drain port 21. Therefore, the cleaning of the tank 2 can be divided into two processes (steps): the process of activating the transducer 3 to scrape off and collect the dirt inside the tank 2 using ultrasonic vibrations (first process), and the process of discharging the collected dirt from the drain port 21 (second process), and each process (step) can be performed at the desired timing.

[0024] The transducer 3 is located on the outside of the bottom surface of the tank 2 and is activated when cleaning the tank 2 to transmit ultrasonic vibrations to the hot water inside the tank 2. Multiple transducers 3 may be provided depending on the size of the tank 2. In that case, it is preferable to arrange the multiple transducers 3 so that the ultrasonic vibrations are transmitted evenly to the hot water inside the tank 2. In this embodiment, two transducers 3 are provided on each side of the funnel-shaped protrusion 23 on the bottom surface of the tank 2, at approximately equal intervals. It is also possible to provide one transducer 3 on each side of the protrusion 23.

[0025] The technique of cleaning the hot water in the tank 2 using ultrasonic waves generated from the transducer 3 (hereinafter also referred to as ultrasonic cleaning) is a well-known technique, so a detailed explanation will be omitted here, but an overview is given below.

[0026] The transducer 3 converts the electrical signal from the oscillator (not shown) into vibrations, generating ultrasonic waves, which are then transmitted to the hot water in tank 2. These ultrasonic vibrations cause alternating pressure waves of varying density in the hot water of tank 2, forming countless tiny bubbles. During low-density pressure waves, these bubbles expand, creating cavities (cavitation), and during high-density pressure waves, these cavities (cavitation) are compressed, causing the bubbles to burst. This expansion-compression-bursting cycle for the bubbles repeats approximately 40,000 times per second or more. The large impact force generated when the cavities (cavitation) are compressed and the bubbles burst is used to mechanically scrape away dirt from tank 2.

[0027] The type of oscillator 3 is not particularly limited, and any type can be used. Specifically, oscillator 3 includes an "electrostrictive type" that expands and contracts when an electric field is applied, and a "magnetostrictive type" that expands and contracts when a magnetic field is applied. In this embodiment, an "electrostrictive type" BL oscillator (bolt-clamped Langevin type oscillator) is used.

[0028] Next, the ultrasonic cleaning process of the tank 2 in the above embodiment will be described.

[0029] First, the first process is performed. Specifically, the transducer 3 is activated, and ultrasonic vibrations are transmitted from the transducer 3 to the hot water in the tank 2 for a predetermined time. As a result, countless bubbles are generated in the hot water in the tank 2, and the impact force when the cavities (cavitation) formed in the bubbles burst scrapes off dirt floating in the hot water, as well as dirt attached to or settled on the sides or bottom of the tank 2. The scraped-off dirt is collected and settles in the funnel-shaped protrusion 23 formed on the bottom of the tank 2.

[0030] Next, the second process is performed. Specifically, the water supply valve 41 is closed to stop the water supply from the water supply pipe 4 to the tank 2, the relief valve (not shown) is opened, and then the drain valve 51 is opened to drain a predetermined amount of hot water from the tank 2 through the drain port 21. As a result, the settled dirt is discharged to the outside through the drain port 21 and the drain pipe 5 along with the hot water. After the drainage is complete, the drain valve 51 is closed and the water supply valve 41 is opened to return the water heater 1 to normal operation.

[0031] As described above, according to this embodiment of the water heater 1, a transducer 3 is provided on the bottom surface of the tank 2 of the water heater 1, and the tank 2 is cleaned by activating the transducer 3, so the tank 2 can be cleaned at a desired timing. Furthermore, when the transducer 3 transmits ultrasonic vibrations to the hot water in the tank 2, the large impact force when the bubbles generated by the ultrasonic vibrations burst mechanically scrapes off the dirt, so all the dirt in the tank 2 can be scraped off, improving the cleaning performance.

[0032] Furthermore, since a funnel-shaped protrusion 23 is provided that projects downwards approximately in the center of the bottom surface of the tank 2, the dirt scraped off and collected in this area can be easily discharged from the drain port 21. In addition, the dirt scraped off and collected can be temporarily stored in the protrusion 23 until the time of discharge. This makes it possible to set separately the timing of the process of activating the transducer 3 to scrape off and collect the dirt in the tank 2 using ultrasonic vibrations, and the timing of the process of discharging the collected dirt from the drain port 21.

[0033] (Embodiment 2) Figures 2 and 3 show this second embodiment, which differs in configuration from the first embodiment in that the water supply valve 41 and the drain valve 51 are interlocked. Components similar to those in the first embodiment are denoted by the same reference numerals, and their explanation is omitted.

[0034] In Embodiment 1, when discharging dirt, the water supply valve 41 is closed to stop the water supply from the water supply pipe 4 to the tank 2, and the drain valve 51 is opened to drain a predetermined amount of hot water from the tank 2, and these operations are performed separately. However, such valve opening and closing operations tend to be troublesome and complicated, and may result in the ultrasonic cleaning process not being performed at all. In addition, if the operations are performed separately, there is a risk of errors such as forgetting to close the water supply valve 41 when draining.

[0035] Therefore, in this embodiment, by linking the water supply valve 41a and the drain valve 51a, the complicated operation required for drainage is eliminated, and a water heater 1 is provided that allows for easy drainage from the tank 2.

[0036] Figure 2 shows a plan view (a) and a front view (b) of the lower part of the water heater 1 according to this embodiment. As shown in Figure 2, the water supply valve 41a and the drain valve 51a are connected by an operating lever 7 so as to be interlocked, and by operating (rotating) the operating lever 7, it is possible to switch between a state in which the water supply valve 41a is open and the drain valve 51a is closed, and a state in which the water supply valve 41a is closed and the drain valve 51a is open.

[0037] Figure 3 shows a specific example of a water supply valve 41a and a drain valve 51a that can be used in the water heater 1 according to this embodiment. In this example, the two valves 41a and 51a are positioned vertically so that the axis of rotation of the disc-shaped, rotary water supply valve 41a and the axis of rotation of the disc-shaped, rotary drain valve 51a are aligned in a straight line, and are connected by an operating lever 7. When draining the hot water from the tank 2, the operating lever 7 is rotated clockwise or counterclockwise to switch the water supply valve 41a to a closed state and the drain valve 51a to an open state as shown in Figure 3. After the drainage process is complete, the operating lever 7 is rotated in the reverse direction to switch the water supply valve 41a to an open state and the drain valve 51a to a closed state (not shown), allowing the water heater 1 to return to normal operation.

[0038] As described above, with the water heater 1 according to this embodiment, when the drain valve 51a is opened, the water supply valve 41a closes in conjunction, eliminating the need for complicated operations during drainage and making it possible to easily drain water from the tank.

[0039] (Embodiment 3) Figures 4 and 5 show this third embodiment, which differs from the first embodiment in that it includes a remote control (control means) 8 for automatically controlling ultrasonic cleaning inside the tank 2. Components similar to those in the first embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0040] In Embodiment 1, ultrasonic cleaning of tank 2 is performed at a desired timing, which can easily be overlooked. Moreover, if one attempts to perform the two processes (the first process and the second process) included in the ultrasonic cleaning of tank 2 at desired timings, managing (planning and executing) the schedules of these two processes (steps) becomes complicated and troublesome.

[0041] Therefore, in this embodiment, the calendar function and timer function of the remote control 8 are used to automatically control the ultrasonic cleaning of the tank 2, thereby providing a water heater 1 that can perform ultrasonic cleaning of the tank 2, which is often forgotten, on a regular basis.

[0042] Figure 4 is a front view of the water heater 1 according to this embodiment. As shown in Figure 4, the water heater 1 is connected to a remote control 8 for communication. The remote control 8 is a device that can remotely operate the water heater 1, and is configured so that the ultrasonic cleaning of the tank 2 can be controlled by operating the remote control 8. For this reason, the water heater 1 and the remote control 8 are equipped with a transmit / receive function (not shown) for sending and receiving operation signals. Furthermore, the remote control 8 has a calendar function to check the date and a timer function to check the time so that the ultrasonic cleaning can be controlled.

[0043] The specific details of the automatic control provided by Remote Control 8 are explained below.

[0044] As described in Embodiment 1, the ultrasonic cleaning of the tank 2 is divided into two processes (steps): a first process in which the transducer 3 is activated to scrape and collect dirt inside the tank 2 using ultrasonic vibrations, and a second process in which the collected dirt is discharged from the drain port 21. Both the first and second processes are preferably performed during times when the use of the water heater 1 is expected to be relatively low, for example, between 2 PM and 3 PM. However, while the first process is desirable to be performed frequently in order to maintain good sanitary conditions inside the tank 2, the second process requires closing the water supply valve 41 to temporarily stop the normal use of the water heater 1, and also requires discharging (discarding) a predetermined amount of hot water from the tank 2. Therefore, performing the second process too frequently would interfere with the use of the water heater 1.

[0045] Therefore, the remote control 8 automatically adjusts the timing of the first processing and the timing of the second processing so that the time interval for the first processing is shorter than the time interval for the second processing. In this embodiment, the time interval for the first processing is set to once a day, and the time interval for the second processing is set to once a month. Specifically, the remote control 8 uses its calendar function to set the execution day for the first processing to once a day and the execution day for the second processing to once a month, and uses its timer function to set the execution times for the first and second processing to predetermined times (for example, between 2 PM and 3 PM).

[0046] Upon receiving an operation signal from the remote control 8 configured in this way, the water heater 1 operates as shown in the flowchart in Figure 5.

[0047] First, if it is the start date and time for the first treatment (Yes in step S1), the water heater 1 performs the first treatment (step S2). Specifically, the transducer 3 is activated and transmits ultrasonic vibrations to the hot water in the tank 2. This scrapes off dirt adhering to or settled on the sides or bottom of the tank 2, and the scraped-off dirt is collected and settled in the funnel-shaped protrusion 23 formed on the bottom of the tank 2.

[0048] If the start date and time for the second process has passed since the completion of the first process (Yes in step S3), the second process is executed (step S5). Specifically, the water supply valve 41 is closed to stop the water supply from the water supply pipe 4 to the tank 2, the relief valve (not shown) opens, and then the drain valve 51 opens to drain a predetermined amount of hot water from the tank 2. As a result, the settled dirt is discharged to the outside through the drain outlet 21 and the drain pipe 5 along with the hot water. After the drainage is complete, the drain valve 51 closes and the water supply valve 41 opens, returning the water heater 1 to normal operation. Note that the water supply valve 41a and drain valve 51a of Embodiment 2 may be applied to the water supply valve 41a and drain valve 51a, and they may be operated together by the operating lever 7. After the completion of the second process, the ultrasonic cleaning process of the tank 2 is terminated.

[0049] On the other hand, if the start date and time of the second process is not yet reached after the completion of the first process (No in step S3), the ultrasonic cleaning process of tank 2 is terminated.

[0050] Furthermore, if it is not the start date and time of the first process (No in step S1), but it is the start date and time of the second process (Yes in step S4), the second process is executed. After the second process is completed, the ultrasonic cleaning process of tank 2 is terminated.

[0051] Furthermore, if it is not the start date and time of the first process (No in step S1) and it is also not the start date and time of the second process (No in step S4), the process returns to step S1.

[0052] As described above, the water heater 1 according to this embodiment allows for automatic control of the timing of the first process, in which the transducer 3 is activated to scrape and collect dirt inside the tank 2 using ultrasonic vibrations, and the timing of the second process, in which the collected dirt is discharged from the drain port 21. This makes it possible to regularly clean the tank 2, which is often forgotten, and to maintain the hygienic condition of the water heater 1 at all times. Furthermore, since the time interval for the first process is automatically adjusted to be shorter than the time interval for the second process, the number of times the second process, which has a complicated processing step, is performed is reduced, making it possible to clean the tank 2 efficiently.

[0053] Although embodiments of this invention have been described in detail above, the specific configuration is not limited to these embodiments, and any design changes, etc., that do not depart from the gist of this invention are also included. For example, regarding the configuration for linking the water supply valve 41a and the drain valve 51a, in the above embodiment, the two valves 41a and 51a are positioned vertically so that the rotation axis of the water supply valve 41a and the rotation axis of the drain valve 51a are aligned in a straight line, and they are linked together by the operating lever 7. However, the two valves 41a and 51a may also be positioned vertically so that the rotation axis of the water supply valve 41a and the rotation axis of the drain valve 51a are parallel, and they are linked together by aligning the gears attached to each rotation axis. [Explanation of Symbols]

[0054] 1 water heater 2 tanks 21 Drain 22 Water inlet 23 Convex part 3. Oscillator 4 Water supply pipe 41 Water supply valve 5 Drain pipe 51 Drain valve 6. Exterior 7. Operating lever 8. Remote control (control means)

Claims

1. A water heater that heats water to produce and store hot water, A vertical tank for storing the aforementioned hot water, A transducer is provided on the outside of the bottom surface of the tank and transmits ultrasonic vibrations to the hot water when cleaning the tank, The bottom surface is provided with a drain port for discharging the dirt inside the tank that has been scraped off by the ultrasonic vibrations, A water heater characterized by the following features.

2. The tank is provided with a funnel-shaped protrusion projecting downwards at approximately the center of its bottom surface. The drain port is provided approximately in the center of the protrusion. The vibrators are provided in multiple quantities according to the size of the tank and are located on both sides of the protrusion. The water heater according to feature 1.

3. The bottom surface is further provided with a water inlet for supplying water to the tank, The water inlet is connected to a water supply pipe equipped with a water supply valve for controlling the water supply. The drain outlet is connected to a drain pipe equipped with a drain valve for controlling drainage. The drain valve and the water supply valve are linked so that when the drain valve is opened, the water supply valve closes. The water heater according to claim 1 or 2.

4. The cleaning of the tank comprises a first process of activating the transducer to scrape and collect dirt inside the tank using ultrasonic vibrations, and a second process of discharging the collected dirt from the drain port. The system includes a control means for automatically adjusting the timing of the first processing and the timing of the second processing so that the time interval for the first processing is shorter than the time interval for the second processing. A water heater according to any one of claims 1 to 3.

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