JPH0735923B2 - Backflow prevention device for water heater with bath reheating oven - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backflow prevention device that is a device for dropping hot water heated by a water heater into a bathtub through a heat exchange circuit of the bath kettle in a water heater with a bath heating kettle. Is.

2. Description of the Related Art In general, a backflow prevention device in a water heater with a bath reheating oven has a space at the water inlet and drainage port so that there is no risk of backflow of sewage (bath water) into city water, and it is in continuous communication with the atmosphere. The city water and bath water are cut off. An example of the above-described conventional backflow prevention device will be described below with reference to the drawings. FIG. 3 shows a side cross-sectional view of a conventional backflow prevention device, and FIG. 4 is a system diagram of a hot water supply device with a bath reheating oven incorporating the backflow prevention device. Reference numeral 4 is a main body of a water heater with a bath heating kettle, which contains a hot water heat exchanger 6 and a bath heating heat exchanger 5. Reference numeral 7 denotes a water supply inlet, which is branched at the outlet of the hot water heat exchanger 6 and one of the water supply heat exchanger 6 is led to a kitchen / washroom or the like and connected to a hot water tap 8. The other side is connected to the bath-fired heat exchanger 5 via a solenoid valve 9 and a hopper 10. Further, the bathtub 1 and the bath reheating heat exchanger 5 are connected in the middle of the circulation return pipe 3 and the circulation outward pipe 2 via a circulation pump 12. Reference numeral 13 is a diaphragm-type water level sensor, which is connected to the bath-fired heat exchanger 5 via a pipe 14.

In FIG. 3, 23 is an outlet pipe of the hot water supply heat exchanger 6, and 9
Is a solenoid valve for opening and closing the valve body 9a. 10 is a hopper, 11 is an overflow port and is open to the atmosphere. Reference numeral 21 is a cylindrical water splash prevention plate, 20 is a funnel-shaped guide tube, and 22 is a connection pipe, which connects the hopper 10 and the bath reheating heat exchanger 5.

The operation of the backflow prevention device configured as described above will be described below.

First, the pouring water poured into the bathtub 1 is heated by the hot water supply heat exchanger 6, is guided to the hopper 10 by opening the valve body 9a of the solenoid valve 9, passes through the inside of the guide cylinder 20, and connects to the bath. It is poured into the bathtub 1 through the circulation return pipe 3 via the reheating heat exchanger 5. The water level 15 in the bathtub 1 is the circulation pump 12
Circulation pump 12
, The water in the bathtub 1 is sucked from the circulation return pipe 3, and the water is added from the hopper 10 via the bath reheating heat exchanger 5 together with the pouring water dropped from the hopper 10 and the bath 1 via the circulation forward pipe 2. A circulation circuit for returning to the bathtub is formed, and the water is poured into the bathtub 1 for pouring. The pouring water level to the bathtub 1 is set in advance, and the circulating pump 12 and the solenoid valve 9 are stopped by detecting with the water level sensor 13. As a result, a desired amount of water can be poured into the bathtub 1. This is not a problem during normal operation, but when the connection pipe 22 is clogged with scale or the scale inside the connection pipe 22 becomes smaller than the initial diameter, the amount of pouring water into the hopper 10 is discharged. It will not be exhausted and will be discharged from the overflow port 11. At this time, if the diameter of the overflow port 11 is set so that the water surface in the hopper 10 does not reach the valve body 9a in the solenoid valve 9, even if the city water side becomes a negative pressure, the city water side will be polluted. (Hot water in the bathtub) never flows backwards.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above configuration, when the valve body 9a is opened and water falls into the guide cylinder 20, air is sucked from the overflow port 11 due to the ejecting action, and the connection pipe from the hopper 10 is generated. A mixture of air and hot water is dropped into the bath reheating heat exchanger 5 through 22. The bath surface is low and good while the circulation pump 12 is not operating. However, when the level of the hot water in the bathtub 1 rises and the operation of the circulation pump 12 is started, the air accumulates in the circulation pump 12 and becomes an empty operation, damaging the mechanical seal of the circulation pump 12 and causing water leakage.
Further, air is accumulated in the bath reheating heat exchanger 5, and the air passes through the connection pipe 22 to pass from the hopper 10 to the overflow port 11 or to pass from the circulation return pipe 2 to the bathtub 1. At this time, there is a problem that the pressure fluctuation in the bath reheating heat exchanger 5 occurs, and the water level sensor 13 malfunctions due to this pressure fluctuation.

In view of the above problems, the present invention has a function to prevent backflow of sewage by rimming the city water supply side of the hopper at atmospheric pressure, and even when the water level of the liquid tank is high, air is poured into the liquid from the hopper. Prevents mixture and even if air enters the bath reheating heat exchanger, it smoothly escapes and prevents air from entering the circulation pump. Further, the present invention provides a backflow prevention device in which pressure fluctuations in the bath reheating heat exchanger do not occur.

Means for Solving the Problems In order to solve the above problems, the backflow prevention device of the present invention has a water injection port on the upper wall, an overflow port on the side wall, and a drain port extending from the lower wall to the inside. A hollow pipe is placed with a gap inside the drain port, the upper end is opened above the overflow port upper end, and the lower end is opened at the upper part inside the pipe connected from the drain port to the bath reheating heat exchanger. In addition, the upper end of the air vent pipe extending inward from the lower wall is opened near the overflow port, and the lower end is connected to the upper part of the bath-fired heat exchanger with a pipe to form a hopper, which is poured into the hopper. A tubular body having a small hole is provided in the lower part so as to face the water outlet, and a space is provided around the outer periphery of the tubular body to provide a guide tube.

Effect The present invention has the above-mentioned configuration, in which the hot water flowing out from the water injection port is received by the cylindrical body, and a part of the water is discharged into the hopper through the small hole at the bottom. Extinguish the kinetic energy and let it overflow from the top of the cylinder,
It is discharged into the hopper from the space with the guide cylinder by natural falling water. At this time, due to the ejecting action due to the water falling from the water injection port, air is sucked from the overflow port and the air mixed water is accumulated in the hopper. When this air-mixed water flows into the drainage port protruding from the lower wall of the hopper, air is separated because the flow velocity of the air-mixed water is slow and the open air surface is wide. Thus
The hot water separated from the air passes through the connection pipe from the drain port, enters the bath-fired heat exchanger, and is dropped into the bathtub. If the flow rate from the water inlet increases due to changes in the water pressure of the city water supply, the air separation in the hopper is completely lost, and the hot water mixed with air enters the bath-fired heat exchanger. At this time, an air pool is created in the connection pipe between the hopper drainage port and the bath reheating heat exchanger. This air is released into the hopper with a hollow tube provided inside the drainage port. further,
Even with this, the air flowing into the bath reheating heat exchanger can be prevented from entering the circulation pump by letting the air flowing into the bath reheating heat exchanger pass through the pipe connected to the top of the bath reheating heat exchanger to escape the upper part inside the hopper. It is possible to reduce the pressure fluctuation in the heating heat exchanger, and to improve the detection accuracy of the water level sensor.

Example Hereinafter, a backflow prevention device according to an example of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view of a backflow prevention device according to an embodiment of the present invention. FIG. 2 is a system diagram of a water heater with a bath reboiler that incorporates this backflow prevention device. In FIG. 1, 10 is a hopper which has an overflow port 11 on the side wall and a water injection port 24 on the upper side, and a small hole 20a on the lower side facing the water injection port 24.
A cylinder 20 having the above is provided, and a space is provided around the outer circumference of the cylinder 20 to provide a guide cylinder 21. Reference numeral 9 is a solenoid valve for opening and closing the water injection port 24, 9a is a valve body of the solenoid valve, and 23 is a solenoid valve inlet. Reference numeral 25 denotes a cylindrical drain port, which extends upward from the bottom of the hopper 10 and has an opening 25a. Reference numeral 22 denotes a connection pipe connected to the drain port 25. The drain port 25 is a bath-fired heat exchanger 5
Is in communication with. Reference numeral 26 is a hollow pipe, which penetrates the inside of the drainage port 25, the upper end of which is opened above the upper end of the overflow port 11 and the lower end of which is opened above the connection pipe 22. An air vent pipe 27 extends upward from the bottom of the hopper 10 and is opened at the height of the overflow port 11 in view of the inside of the hopper 10. Reference numeral 28 denotes an air vent connecting pipe connected to the air vent pipe 27, which communicates the air vent pipe 27 with the upper portion of the bath reheating heat exchanger 5. 16 is an air solenoid valve on the side wall of the hopper 10 and the overflow port
It is mounted with an open end above 11. 29 is an air suction pipe, which communicates from the air solenoid valve 16 to the purification unit 30.

In FIG. 2, reference numeral 1 is a bathtub, which is a circulation return pipe 3 from the side wall, communicates with the bath reheating heat exchanger 5, and a purification unit 30 is attached to the side wall of the bathtub 1. The purification unit 30 is provided with a nozzle 31. A jet port having a space 36 in front of the nozzle 31
An air suction pipe 29 is connected to the rear space of the nozzle 31. On the other hand, from the space 36, the passage 37 and the filter 33
A passage 37 is extended above the bathtub 1 through the above, and an intake pipe 34 is slidably provided at the upper end of the passage 37 so as to be vertically movable.
Reference numeral 4 is a main body of a water heater with a bath reheating oven, which has a hot water supply heat exchanger 6 and a bath reheating heat exchanger 5 inside. Reference numeral 7 is a city water supply connection port, which is connected to the hot water supply heat exchanger 6 and branched at the outlet of the hot water supply heat exchanger 6, one of which is led to a kitchen / washroom or the like and connected to a hot water tap 8. The other is guided to the hopper 10 via the solenoid valve 9 and connected to the reheating heat exchanger 5. A circulation pump 12 connects the suction side to the refueling heat exchanger 5 and the discharge side to the nozzle 31 of the purification unit 30 via the circulation forward pipe 2. Reference numeral 13 is a water level sensor, which is connected to the additional heat exchanger 5 by a pressure guiding pipe 14.

The operation of the backflow prevention device configured as described above will be described below with reference to FIGS. 1 and 2.

The water supplied from the city water supply connection port 7 is heated by the hot water supply heat exchanger 6, is branched on the way, and is used as needed by the hot water supply tap 8 for kitchens, washbasins, and the like. On the other hand, the branched hot water is guided to the hopper 10 by opening and closing the solenoid valve 9, enters the reheating heat exchanger 5 through the connection pipe 22, and is supplied to the bathtub 1 through the circulation return pipe 3. When hot water accumulates in the bathtub 1 and the water level rises, the hot water enters the pressure guiding pipe 14 of the water level sensor 13,
By shutting off from atmospheric pressure, the internal pressure of the air in the pressure guiding pipe 14 rises.
The preset pressure, that is, the water level in the bathtub 1 filled with water in the circulation pump 12 is detected to be higher than that, and the circulation pump 12 is operated. By the operation of the circulation pump 12, the hot water dropped from the hopper 10 through the connection pipe 22 and the hot water in the bathtub 1 sucked through the circulation return pipe 3 are combined, and the hot water coming through the bath reheating heat exchanger 5 is combined, It is sent to the bathtub 1 through the circulation going pipe 2 and the nozzle 31 and the jet port 32. Furthermore, when the water level sensor 13 continues to drop into the bathtub 1 and the water level in the bathtub 1 reaches the set water level, the solenoid valve 9 is closed, the circulation pump 12 is stopped, and the water drops into the bathtub 1. To complete. When the hot water in the bathtub 1 is used by bathing and the water level drops, the solenoid valve 9 and the circulation pump 12 are restarted by the detection of the water level sensor 13, and the water drops to the original water level and stops. Although not shown in the figure, a thermistor is attached to the bath heating heat exchanger 5 to detect the temperature of the hot water, and the bath heating burner (not shown) is burned and the circulation pump 12 is operated, whereby the hot water in the bath 1 is heated. The temperature can be kept constant.

The circulation pump 12
By operating the air solenoid valve 16 and the air solenoid valve 16, the circulation pump 12 sucks the bath water from the bath 1 through the circulation return pipe 3 and the bath reheating heat exchanger 5, and the circulation outward pipe 2 and the nozzle.
31, the water is discharged from the jet port 32 into the bathtub 1, and the bath water is circulated. When this circulating flow is discharged from the nozzle 31 and enters the ejection port 32, an attracting action occurs in the space 36 due to the eject action, and the hopper 10 is passed through the air connection pipe 29 and the air solenoid valve 16.
The atmosphere inside is sucked, the circulating flow and air are jetted into the bathtub 1 from the jet port 32, and bubbles are jetted, so that the bather can enjoy the bubble bath. Also, by operating only the circulation pump 12 in the separately installed controller,
In the same manner as the above, a circulating flow of bath water is created, and attraction of the space 36 starts suction of bath water from the suction port 35 through the purifying passage 37 and the filter 33. Due to the flow in the purification passage 37, the purification pipe
The internal pressure of 34 becomes lower than the water pressure in the bathtub 1, and the purification pipe 34
The buoyancy is generated by the pressure difference between the inside and the outside of the bath, and it floats up to near the water surface of the bathtub 15 and sucks the upper water of the bath water.
Suck hair, scale 15a, etc. floating on the surface of the bathtub 1,
It is passed through the filter 33 and has a function of returning to the bathtub 1 from the ejection port 32 to purify bathtub water.

The operation of the hopper 10 of the water heater 4 with a reheating boiler having such a function will be described with reference to FIG.

The hot water heated by the hot water supply heat exchanger 6 is guided to the inlet 23 of the solenoid valve 9 and dropped from the water inlet 24 by opening the valve body 9a. At this time, the surroundings of the water injection port 24 are open to the atmosphere through the overflow port 11, so the air is sucked by the ejector action due to the falling speed of the water injection port 24, and the water and air are mixed and fall into the cylinder 20. To do. Then, a part is discharged from the small hole 20a, but most is collected in the cylinder 20, where air and water are separated, overflows from the upper end of the cylinder 20, and naturally falls from the gap with the guide cylinder 21.

However, when the source pressure of the city water supply is high, the amount dropped from the water injection port 24 increases, and the above cannot be covered, and hot water mixed with air accumulates at the bottom of the hopper 10.
When this air-mixed hot water flows into the upper opening 25a of the drain port 25 projecting upward from the bottom of the hopper 10, the flow velocity of the air-mixed hot water becomes slow, and since the atmosphere open area is wide, air separation is possible. Done. The hot water thus air-separated enters the bath-fired heat exchanger 5 through the connection pipe 22, and is dropped into the bathtub 1 through the circulation pump 12. Further, if the drop amount from the water injection port 24 increases due to the change of the city water supply source pressure, the air is not completely separated by the above action, and the air-mixed hot water flows from the drain port 25. At this time, since air is trapped in the connecting pipe 22, the air in the connecting pipe 22 is escaped to the upper part in the hopper by the hollow pipe 26.
This action prevents the hot water that has risen in the connection pipe 22 from the drain outlet 25 and escapes into the hopper 10 and the hot water that has accumulated in the hopper 10 from naturally falling through the drain outlet 25. Is.

Furthermore, some air bubbles still flow into the bath reheating heat exchanger 5, so that the air vent pipe 28 connected to the upper part of the bath reheating heat exchanger 5 allows the air to escape to the upper part of the hopper 10 by the air vent pipe 27. Is.

As described above, according to the present embodiment, by providing the cylinder 20 and the guide cylinder 21 facing the water injection port 24, the primary air separation of the air-mixed hot water is performed by the air suction by the ejector action when the water is dropped from the water injection port 24. To do. Secondary air separation is performed by a drain port 25 extending upward from the bottom of the hopper 1, and a hollow pipe 26 penetrating the drain port 25 escapes the air that has entered the connection pipe 22 and further heat-exchanges the bath. By connecting the air vent pipe 28 connected to the upper part of the vessel 5 to the air vent pipe 27 extending above the bottom of the hopper 10, the bath reheating heat exchanger 5
The bubbles that have flowed into the can be escaped. As a result, the air suction of the circulation pump 12 is eliminated, and the water leakage accident due to the mechanical seal damage of the circulation pump 12 can be prevented. Also,
Since there is no pressure fluctuation in the bath reheating heat exchanger 5,
The malfunction of the water level sensor 13 also disappears.

EFFECTS OF THE INVENTION As described above, according to the present invention, a guide cylinder is provided inside the hopper so as to face the water injection port of the hopper, with a gap between the cylinder and the outer periphery thereof, and the guide cylinder extends upward from the bottom of the hopper to discharge the water. Provide a hollow pipe that penetrates with a gap inside this drain port, and further provide an air vent pipe extending upward from the bottom of the hopper to the inside of the hopper, connecting the drain port and the bath reheating heat exchanger. By communicating with the pipe and connecting the air vent pipe and the upper part of the bath reheating heat exchanger with an air vent pipe, it is possible to prevent air from entering the bath reheating heat exchanger and it is easy to mix even if it happens. It can be released to the hopper, thus preventing air from entering the circulation pump, preventing damage to the mechanical seal of the circulation pump, and preventing water leakage accidents. In addition, since there is no air mixing in the bath reheating heat exchanger, there is no fluctuation in the internal pressure of the bath reheating heat exchanger.For example, in the water level sensor that detects the internal pressure, the detection accuracy is high, and the set water level is high. It can be dropped into the street tub. Furthermore, since the water injection port to the hopper is always open to the atmosphere by the overflow port, the backflow prevention device does not backflow the bath water even if the city water supply side has a negative pressure due to water cutoff. .

[Brief description of drawings]

FIG. 1 is a side sectional view of a backflow prevention device according to a first embodiment of the present invention, and FIG. 2 is a system configuration diagram of a water heater with a bath reheating oven incorporating the backflow prevention device of the present invention, FIG. FIG. 4 is a side cross-sectional view of a conventional backflow prevention device, and FIG. 4 is a system configuration diagram of a hot water heater with a bath-fired kettle incorporating the conventional backflow prevention device. 5 …… Bath reheating heat exchanger, 10 …… Hopper, 11 ……
Overflow port, 20 …… Cylinder (cylindrical), 21 …… Guide tube, 22 ……
Connection pipe, 24 ... water injection port, 25 ... drainage port, 26 ... hollow pipe, 27 ... air vent pipe, 28 ... air vent pipe.

Claims (1)

[Claims] 1. A hopper having a water injection port on the upper wall, an overflow port on the side wall, a drain port projecting inward from the bottom wall, and a drain port inside the hopper, with a gap between them. Is open above the overflow port into the hopper at the upper end, and the lower end is a hollow pipe opened above the connection pipe that connects to the bath reheating heat exchanger from the drain port, and extends upward from the bottom wall of the hopper. An air vent pipe that is installed and has its upper end opened near the overflow port,
An air vent pipe that is connected to this air vent pipe and communicates with the upper part of the bath reheating heat exchanger, a tubular body that is provided inside the hopper so as to face the water injection port, and has a small hole at the bottom, and a space around the outer periphery of this tubular body. A backflow prevention device for a water heater with a bath reheating boiler equipped with a guide tube provided.