JPS61278669A - Reverse flow prevention device - Google Patents

Abstract

PURPOSE:To prevent overflow out of an overflow port even when liquid level in a receiving tank is high by arranging a partition plate, with a gap interposed, around a guide cylinder arranged around a nozzle with a space interposed. CONSTITUTION:Facing to a water inlet 14, a cylindrical nozzle 15 is arranged. A guide cylinder 17 is arranged around the nozzle with a space interposed. The guide cylinder is so arranged that the upper rim of the guide cylinder is above the upper rim of an overflow port 13 and the lower rim of the guide cylinder is below the lower rim of the overflow port 13. Further, a partition plate 19 is arranged above the upper rim of the overflow port 13 and around the guide cylinder 17 with a gap interposed so that inside of a hopper 10 is divided into upper and lower sections. With this constitution, smooth liquid flow into a receiving tank is possible even when liquid level in the receiving tank becomes high, without causing flow obstruction due to air trap in a communication pipe 12.

Description

[Detailed description of the invention] Industrial application field original F! A relates to a backflow prevention device for a device in which hot water heated by a hot water heater is dropped into a bathtub through the heat exchange circuit of the bathtub, such as in a water heater with a bath reheating pot.

Conventional technology In general, backflow prevention devices in hot water heaters with bath reheating pots are designed to prevent sewage (bathwater) from flowing back into the city's water supply by providing a space at the water inlet and drain to ensure constant communication with the atmosphere. This is to separate the water supply from the bathtub water.

An example of the above-mentioned conventional backflow prevention device will be described below with reference to the drawings. FIG. 3 shows a side sectional view of a conventional backflow prevention device. FIG. 2 is a system diagram of a water heater with a bath reheating pot incorporating this backflow prevention device. Reference numeral 1 denotes a hot water heat exchanger, which is connected to the city water supply via an inlet pipe 6, branched in the middle by an outlet pipe 7, and one end is led to the kitchen, washroom, bathroom, etc., and connected to a hot water tap 9. The other side is connected to the bathtub heat exchanger 2 via a solenoid valve 8 and a hopper 10, and is further communicated with the bathtub 4 via a circulation pipe 3.

In FIG. 3, 7 is an outlet pipe of the hot water heat exchanger 1;
is a solenoid valve, 10 is a hopper, 11 is a hopper drain port, 1
2 is a communication pipe connecting the hopper 10 to the bath pot heat exchanger 2, and 13 is an overflow port that is open to the atmosphere. Reference numeral 21 denotes a flat guide plate, which is provided to divide the interior of the hopper 10 into upper and lower sections, and has an opening 22. This opening 22 faces the pouring port 14 which is opened and closed by the electromagnetic valve 8, and has a slightly larger diameter than the pouring port 14.

Further, 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, when pouring hot water into the bathtub 4, it is heated by the hot water heat exchanger 1, passes through the outlet pipe 7, and is poured into the pouring port 14 by the solenoid valve 8.
The water is guided to the hopper 10, passes through the communication pipe 12, passes through the bathtub heat exchanger 2, and is carried out through the circulation pipe 3.

This is not a problem during normal operation, but when the communication pipe 12 is clogged with hot water scale, etc., or when hot water scale adheres to the inner wall of the communication pipe 12 and the passage diameter becomes smaller than the original, the hopper 1
The amount of molten metal poured from the pouring port 14 located at the upper part of the molten metal can no longer be completely discharged, and the molten metal is discharged from the overflow port 13. At this time, the water surface inside the hopper is at the opening 22 of the guide plate 21.
By setting an overflow diameter of 130 mm so that the overflow does not reach 130 mm, even if the city water supply side becomes negative pressure, the sewage (hot water in the bathtub) will flow to the city water supply side.
will not flow backwards.

Problems to be Solved by the Invention However, in the above configuration, depending on the speed at which water falls from the pouring spout 14 and the opening 22 of the guide plate 21,
Air suction occurs from the overflow port 13 due to the ejecting action, and a mixture of air and hot water is discharged from the discharge port 11 of the hopper 10. When the hot water level in the bathtub 4 is low and there is a sufficient head difference with the discharge port 11 of the hopper 10, the above-mentioned air can be mixed and flowed into the bathtub 4 by the kinetic energy of falling water during pouring. However, the hot water level in the bathtub 4 has become high, the drop between the outlet 11 of the hopper 10 and the hot water level is small, and the water level between the communicating pipe 12 and the hot water level has also become small, and the hot water mixed with the air flows through the communicating pipe. Note that even if falling water flows into the pipe 12 with kinetic energy, the kinetic energy of falling water is attenuated by the buoyancy of the air in the middle of the communicating pipe 12, and at the same time, air pockets are generated and the water tries to rise inside the communicating pipe 12. The hot water for hot water does not flow smoothly. For this reason, the poured hot water flows through the overflow port 1a.
This has the problem of more leakage. In other words, the overflow port 13, which operates when there is an abnormality in molten metal pouring, has the same effect even when air is sucked during normal molten pouring, resulting in wasted hot water and failure to smoothly pour molten metal.

In view of the above-mentioned problems, the present invention has a function to prevent the backflow of sewage by separating the hopper from the original city water supply side at atmospheric pressure, and at the same time, even when the water level of the liquid injection tank is high, it does not overflow from the overflow port. This provides a backflow prevention device that does not cause any problems.

Means for Solving the Problems In order to solve the above problems, the backflow prevention device of the present invention has a water inlet and a drain in the upper and lower parts, respectively, and a hopper with an overflow port on the side wall, facing the water inlet. A cylindrical nozzle with a small hole at the bottom is provided, and a space is provided around the outer periphery of the nozzle to provide a cylindrical guide tube, the upper end of which is above the upper end of the overflow port, and the lower end of which is located above the overflow port. The hopper is set to be below the lower end of the opening 13, a gap is provided on the outer periphery of the guide cylinder marked with #, and a partition plate is provided above the upper end of the overflow opening 13 to divide the interior of the hopper into upper and lower sections. It is something that

Function: With the above-described configuration, the present invention has a cylindrical nozzle in which hot water flows out from the water inlet, and a portion of the hot water flows directly into the outlet through the small hole at the bottom, but most of the water is absorbed by the water pressure from the water inlet. The kinetic energy of the falling water is eliminated, the water overflows from the top of the cylindrical nozzle, and the water naturally falls from the space into the drain. Furthermore, when the amount of water flowing out from the water inlet increases, the water overflows from the upper end of the guide cylinder, falls through the gap in the guide cylinder male partition plate 19, and falls into the drain port, so that the hot water flowing out from the water inlet have. The falling speed with water pressure applied is determined by the cylindrical nozzle, the guide tube, the partition plate 19, and each space 18.
20 to prevent air suction from occurring due to the ejecting action, hot water with no air mixture is smoothly poured down from the drain port.

EXAMPLE Hereinafter, a backflow prevention device according to an example of the present invention will be described 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 reheating pot incorporating this backflow prevention device. In FIG. 1, it is a 10Iri cylindrical funnel-shaped hopper with a drain port 11 at the bottom, an overflow port 13 at the side wall, and a water inlet 14 at the top, and an electromagnetic valve 8 communicating with the water inlet 14 at the top. is attached to hopper 10. Hopper 1
A cylindrical nozzle 15 having a diameter larger than the water inlet 14 and having a small hole 16 at the bottom facing the water inlet 14 is provided inside the water inlet 14, and a space 18 is provided around the outer periphery of the cylindrical nozzle 16 to form a cylindrical guide tube 17. It is equipped with The upper end of this guide tube 17 is above the upper end of the overflow port 13, and the lower end is located above the overflow port 13.
It is formed so that it is below the lower end of 3. Reference numeral 19 denotes a partition plate which separates the inside of the hopper 10 into upper and lower parts, and also provides a gap 20 with the outer periphery of the guide tube 17.

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

Water supplied from the city water supply passes through an inlet pipe 6, is heated by a hot water heat exchanger 1, is led to an outlet pipe 7, is branched midway, and is used for special purposes by hot water faucets 9 for kitchens, sinks, showers, etc. . On the other hand, the branched hot water is guided to the bath heat exchanger 3 via the hopper 10 and the communication pipe 12 by opening and closing the solenoid valve 8, and is then supplied to the bathtub 4 from the circulation pipe 3. At this time, in the hopper 10, the water inlet 14 is opened by opening the solenoid valve 8.
The water is then dropped into the cylindrical nozzle 15 at a flow rate with the original pressure of the city water supply added. At this time, since the area around the water inlet 14 is open to the atmosphere through the overflow port 13, air suction occurs due to the ejector action depending on the speed of water falling from the water inlet 14.
Water and air are mixed and fall into the cylindrical nozzle 15. A part of the water is discharged from the small hole 16 at the bottom, but most of it collects inside the cylindrical nozzle 15, where air and water are separated, and the water falls naturally from the space 18 over 70 degrees from the upper end of the cylindrical nozzle 15. do. Normally, this action allows the air-separated water to fall from the hopper 10 to the communication pipe 12 through the outlet 11. However, if the source pressure of the city water supply is high, the amount of molten metal poured from the water inlet 14 will increase, so the discharge from the space 18 and the small hole 16 will not be sufficient.
It extends 70- over the upper end of the guide tube 17 and allows water to fall naturally through the gap 20.

As described above, according to this embodiment, by providing the cylindrical nozzle 15 opposite to the water inlet 14, the surrounding air is sucked according to the speed at which water falls from the water inlet 14, and the air mixed with water is transferred to the cylindrical nozzle. 15, it is possible to eliminate the falling water speed and perform air separation. Furthermore, by providing the guide tube 17 and the shikiri plate 19, even if the amount of molten water poured from the water inlet 14 increases due to an increase in the source pressure of the city water supply, the falling water speed is canceled out, air separation is performed, and natural water falls. Since it can be discharged from the homper 10 at
This results in smooth circulation within the communication pipe 12.

Furthermore, since the overflow port 13 is always open to atmospheric pressure, even if the city water supply side becomes negative pressure, water below the hopper 10 will never flow back through the water inlet 14 to the city water side.

Effects of the Invention As described above, the present invention has a cylindrical nozzle 15 facing the water inlet.
A space is provided on the outer periphery of the nozzle to provide a guide tube, the upper end of the guide tube is above the upper end of the overflow port, and the lower end is below the upper end of the overflow port. By creating a gap and installing a partition plate above the top of the overflow port to divide the interior of the hopper into upper and lower sections, the water inlet is always open to the atmosphere through the overflow port, so in the unlikely event that the city water supply side Even if the pressure becomes negative, the wastewater in the liquid injection tank will not flow back. Furthermore, when pouring liquid into the liquid injection tank, even if the liquid level in the liquid injection tank becomes high and the drop from the hopper outlet becomes small, air separation occurs in the hopper and the liquid is introduced into the communication pipe. Therefore, the liquid can flow smoothly into the liquid injection tank without being obstructed by air pockets in the communication pipe.

[Brief explanation of the drawing]

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 reheating pot incorporating the backflow prevention device of the present invention, and FIG. FIG. 2 is a side sectional view of a conventional backflow prevention device. 10...Hopper, 11...Drain port,
12...Communication pipe, 13...Overflow port, 14...Water inlet, 15...Nozzle,
16... Small hole, 17... Guide tube, 1
8... Space, 19... Partition plate, 20.
·····gap. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (1)

[Claims] A cylindrical hopper with a water inlet at the top, a discharge port at the bottom, and an overflow port on the side wall, and a small hole at the bottom with a diameter slightly larger than the water inlet, located inside this hopper to face the water inlet. and a guide tube arranged with a space provided around the outer periphery of the nozzle, the guide tube having an upper end above the upper end of the overflow port and a lower end below the lower end of the overflow port. The backflow prevention device is further characterized in that a partition plate is provided above the upper end of the overflow port on the outer periphery of the guide cylinder with a gap therebetween so as to divide the interior of the hopper into upper and lower sections.