JPH0745967B2 - Backflow prevention device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backflow prevention device for 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 hot water heater with bath reheating is provided with a space at a water injection port and a drainage port so that sewage (bath water) does not flow back into city water, and is constantly connected to 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 is a side sectional view of a conventional backflow prevention device. FIG. 2 is a system diagram of a water heater with a bath heating kettle incorporating this backflow prevention device. Reference numeral 1 is a hot water supply heat exchanger, which is connected to city water via an inlet pipe 6 and is branched on the way by an outlet pipe 7, one of which is led to a kitchen, a bathroom, a bathroom, etc., and connected to a hot water tap 9. The other is via the solenoid valve 8 and the hopper 10 and the bath kettle heat exchanger 2
, And is further communicated with the bathtub 4 and the circulation pipe 3.

In FIG. 3, 7 is an outlet pipe of the hot water heat exchanger 1 and 8
Is a solenoid valve, 10 is a hopper, 11 is a hopper drainage port, 12 is a communication pipe connecting the hopper 10 to the bath kettle heat exchanger 2, and 13 is an overflow port open to the atmosphere. Reference numeral 21 denotes a flat plate-shaped guide plate, which is provided so as to divide the inside of the hopper 10 into upper and lower parts and has an opening 22. The opening 22 faces the pouring port 14 opened and closed by the solenoid valve 8 and has a diameter slightly larger than the pouring port 14. The guide plate 21 is provided above the upper end of the overflow port 13. The operation of the backflow prevention device configured as described above will be described below.

First, the pouring water dropped into the bathtub 4 is heated by the hot water supply heat exchanger 1, guided through the outlet pipe 7 to the hopper 10 through the pouring port 14 by opening the solenoid valve 8, and through the communication pipe 12 to the bath. It is conducted from the circulation pipe 3 through the kettle heat exchanger 2.
This is not a problem during normal operation, but when the communication pipe becomes clogged with hot water, etc., or when the hot water adheres to the inner wall of the communication pipe 12 and the passage diameter becomes smaller than it was originally, The amount of pouring water from the sprue 14 cannot be completely discharged, and the pouring amount is discharged from the overflow port 13. At this time, if the diameter of the overflow port 13 is determined so that the water surface in the hopper 10 does not reach the opening 22 of the guide plate 21, even if the city water side becomes a negative pressure, the city water side will get dirty water (tub The indoor bath does not flow backwards.

Problems to be Solved by the Invention However, in the above-mentioned configuration, air is sucked from the overflow port 13 due to the ejecting action due to the speed of falling water from the pouring port 14 and the opening 22 of the guide plate 21, and the discharge of the hopper 10 is performed. A mixture of air and hot water is discharged from the outlet 11. The surface of the bathtub 4 is low and the outlet of the hopper 10
When there is a sufficient difference with 11, it is possible to allow the above-mentioned air to be allowed to flow into the bathtub 4 while being mixed with the falling water kinetic energy during pouring. However, the level of the hot water in the bathtub 4 is high, the drop with the discharge port 11 of the hopper 10 is small, and the drop with the hot water surface of the communication pipe 12 is also small, and the hot water mixed with the air is the communication pipe 12 Even if the water flows in with the falling water kinetic energy, the falling water kinetic energy is attenuated by the buoyancy of the air in the middle of the communication pipe 12, and at the same time, an air pool is generated to try to rise in the communication pipe 12 The hot water does not flow smoothly. Therefore, there is a problem that the poured hot water flows out from the overflow port 13. That is, the overflow port 13 for acting in the case of an abnormal pouring
However, even when air is sucked during normal pouring, the action thereof occurs, and the hot water is wasted and smooth pouring cannot be performed.

In view of the above problems, the present invention provides a function of preventing the reverse flow of sewage by rimging the hopper's original city water supply side at atmospheric pressure, and at the same time overflows from the overflow port even when the water level of the liquid pouring tank is high. It is intended to provide a backflow prevention device.

Means for Solving the Problems In order to solve the above-mentioned problems, the backflow prevention device of the present invention has a water injection port, a water discharge port in the upper and lower parts, respectively, in a hopper provided with an overflow port in the side wall, to the water injection port. A cylindrical nozzle having a diameter larger than the water injection port and having a small hole in the lower part is provided so as to face each other, and a space is provided around the nozzle, and a cylindrical guide cylinder is provided. It is set above the upper end, the lower end is below the lower end of the overflow port, and it is set so as to be the start part of the pre-drawing to the drain port of the hopper. It is provided with a configuration in which an extended portion that hangs from the surface on which it is provided is provided.

Effect The present invention has the above-described configuration, in which the hot water flowing out from the water injection port is received by the cylindrical nozzle, and a part of it is directly dropped from the small hole at the bottom into the water discharge port, but most of the amount of the water is the water pressure from the water injection port. The kinetic energy is extinguished, causing it to overflow from the upper end of the cylindrical nozzle, and to drop it into the drain port by spontaneous falling from the space.
When the amount of outflow from the water injection port further increases, it overflows from the upper end of the guide cylinder, drops through the gap between the guide cylinder and the extension along the outer circumference of the guide cylinder, and drops into the drain port. Has the hot water flowing out from the water inlet
The falling velocity of water pressure is reduced by the action of the cylindrical nozzle, the guide tube, the extension and each space, and the air suction due to the eject action does not occur. Will be dropped into.

Embodiment A backflow prevention device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a side cross section of a backflow prevention device in an embodiment of the present invention. FIG. 2 is a system diagram of a water heater with a bath heating kettle incorporating this backflow prevention device. In FIG. 1, 10 is a cylindrical and funnel-shaped hopper, which is provided with a drainage port 11 at the bottom, an overflow port 13 at the side wall, a water injection port 14 at the top, and a solenoid valve for opening and closing the water injection port 14 at the top. 8 is attached to the hopper 10. Inside the hopper 10, the water injection port
A cylindrical nozzle 15 having a diameter larger than that of the water injection port 14 having a small hole 16 at the bottom is provided at 14 and a space 18 is provided at the outer periphery of the cylindrical nozzle 15 to provide a cylindrical guide cylinder 17. The upper end of the guide cylinder 17 is above the upper end of the overflow port 13, and the lower end is below the lower end of the overflow port 13 and the hopper 10
It is formed so as to be the starting portion of the pre-drawing to the funnel-shaped drainage port 11. Reference numeral 19 denotes an extended portion, which extends from the lower surface of the valve body 21 of the solenoid valve 8 and is flush with the water injection port 14 on the outer periphery of the guide cylinder.
An outer circumference 17 and a gap 20 are provided.

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 is heated by the hot water supply heat exchanger 1 through the inlet pipe 6, guided to the outlet pipe 7, branched off along the way, and used as needed by the hot water tap 9 of the kitchen, washbasin, shower, etc. . On the other hand, the branched hot water is guided to the bath heat exchanger 2 through the hopper 10 and the communication pipe 12 by opening and closing the solenoid valve 8, and is supplied to the bathtub 4 from the circulation pipe 3. At this time, in the hopper 10, the solenoid valve 8 is opened to drop the water from the water injection port 14 into the cylindrical nozzle 15 at the flow velocity to which the original pressure of city water is applied. At this time, since the periphery of the water injection port 14 is open to the atmosphere through the overflow port 13, air is sucked by the ejector action due to the rate of water falling from the water injection port 14, and water and air are mixed to enter the cylindrical nozzle 15. To fall. Then, a part is discharged from the small hole 16 at the bottom, but most is accumulated in the cylindrical nozzle 15 where air and water are separated, and the cylindrical nozzle
It overflows from the upper end of 15 and falls naturally from space 18. Normally, the water separated by this action is used as the hopper.
It is possible to allow water to fall from the outlet 10 through the outlet 11 into the communication pipe 12. However, when the source pressure of the city water is high, the amount of pouring water from the pouring port 14 increases, so the discharge from the space 18 and the small hole 16 is insufficient, and it overflows from the upper end of the guide cylinder 17 and from the gap 20 to the guide cylinder 19 The water is allowed to fall naturally along the outer circumference.

As described above, according to the present embodiment, by providing the cylindrical nozzle 15 so as to face the water injection port 14, the ambient air is sucked at the rate of falling water from the water injection port 14, and the mixture with water is a cylindrical nozzle. By receiving at 15, it is possible to eliminate the falling velocity and perform air separation. Further, by providing the guide cylinder 17 and the extension portion 19, even if the amount of pouring water from the pouring port 14 due to an increase in the source pressure of the city water supply is increased, as in the above, the falling velocity is canceled and air separation is performed to perform natural separation. Since the water can be discharged from the hopper 10 when it falls, it can be smoothly circulated in the communication pipe 12.

Further, since the overflow port 13 is always opened to the atmospheric pressure, even if the city water supply side has a negative pressure, the water below the hopper 10 will never flow back from the water injection port 14 to the city water supply side. Furthermore, since the extension portion 19 is integrated with the water injection port 14 and the valve body 21,
Since water pressure is not applied to the joint portion 22 of the valve body 21 and the hopper 10, the need for a water seal is almost eliminated, and at the same time, the extension portion 19 covers the circumference of the guide cylinder 17,
The overflow water at the time of dropping can be flowed to the outer circumference of the guide cylinder 17. Therefore, due to the scattering, the water does not splash from the overflow port 13 to the outside, and the amount of spontaneously falling water is small.
The amount mixed into 12 can be suppressed.

As described above, the present invention provides the nozzle facing the water injection port,
A space is provided around the outer periphery of the nozzle, and a guide cylinder is provided. The guide cylinder has its upper end above the upper end of the overflow port, and the following is below the lower end of the overflow port and the funnel-shaped pre-throttle start portion of the hopper. By providing a gap on the outer periphery of the guide cylinder and providing an extension portion above the upper end of the overflow port and on the outer periphery of the same surface of the water injection port, the extension port is always open to the atmosphere to the water injection port. Therefore, even if the city water side becomes negative pressure, the sewage in the injection tank will not flow back. Also, even if the liquid level drops in the pouring tank when the fluid is dropped, and the difference in the drop with the discharge port of the hopper becomes small, the lower end of the guide cylinder is above the tip drawing start part of the hopper. Since the lower end of the water does not overflow and the amount of drainage in the void of the extension portion increases and the number of splashed water drops that naturally falls does not increase, the amount of suction of air attached to the scattered water drops does not increase.

[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, FIG. 2 is a system diagram of a water heater with a bath heating kettle incorporating the backflow prevention device of the present invention, and FIG. It is a sectional side view of the conventional backflow prevention device. 10 …… Hopper, 11 …… Drainage port, 12 …… Communication pipe, 13
…… Overflow port, 14 …… Water injection port, 15 …… Nozzle, 16 …… Small hole, 17 …… Guide tube, 18 …… Space, 19 …… Extended part, 20…
… Gap, 21 …… Ben body.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Wataru Sugimoto Wataru Sugimoto 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) Bibliography 60-25854 (JP, U)

Claims (1)

[Claims] 1. A cylindrical hopper having a water inlet in the upper portion, a water outlet in the lower portion, and an overflow outlet in the side wall, and a hopper having a diameter larger than that of the water inlet provided in the hopper so as to face the water inlet. A nozzle having a small hole in the lower portion and a guide cylinder provided with a space around the nozzle are provided, and the upper end of the guide cylinder is located above the upper end of the overflow port and the lower end is located below the lower part of the overflow port. It is set downward, and it is set so as to be the starting point of the pre-drawing to the drainage port of the hopper, and the extended portion that hangs down from the surface where the water injection port is provided through a gap on the outer periphery of the upper end of the guide cylinder. A backflow prevention device characterized by being provided with.