JPH04169751A - Backflow preventing device - Google Patents

Abstract

PURPOSE:To prevent water from being overflowing at an overflow port without any relation with an installing condition by a method wherein a water level sensor is installed at a water accumulation hopper of a backflow preventing device, and when water is accumulated more than a specified water level when hot water is to be fed, a water draining solenoid valve is opened to discharge water into a water draining circuit. CONSTITUTION:A bath furnace is installed at a location higher than a specified height above a bath tub, a backflow preventing chamber 11 shows a negative pressure under a condition in which an amount of hot water feeding is less, a sealing performance of an opening or closing valve 12 of a backflow preventing chamber is deteriorated and then hot water is sometimes leaked into a water accumulation hopper 19 during feeding of hot water. In this case, as hot water more than a specified amount is leaked, it is detected by a water level sensor 21 to cause a water draining solenoid valve 24 to be released and then hot water accumulated in the water accumulation hopper 19 is discharged into a bath circuit 1. Upon completion of discharging, the water level sensor 21 is turned OFF and the water draining solenoid valve 24 is closed after a specified period of time. This operation is repeated so as to prevent an overflow from the overflow port 18.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a backflow prevention device installed in a hot water supply circuit, which is a water supply circuit, which is connected to a bath circuit, which is a miscellaneous water circuit, of a bathtub with a water heater, etc. It is.

(Conventional technology and issues) Conventionally, in devices that connect the miscellaneous water circuit (bath circuit) and the water supply circuit (the hot water supply circuit), it is necessary to prevent water from entering the water supply circuit from the miscellaneous water circuit. As a backflow prevention device, the present applicant previously proposed Japanese Patent Application No. 2-48975.This proposed a check valve and a backflow prevention chamber in the connection circuit between the miscellaneous water circuit and the clean water circuit. A water sump hopper that is open to the atmosphere and can store water in the backflow prevention chamber is provided below, and when water pressure is applied to the backflow prevention chamber between the water sump hopper and the backflow prevention chamber, it closes and the water flow pressure disappears. It is equipped with a backflow prevention chamber opening/closing valve that opens when the

This backflow prevention device has a water sump hopper that is open to the atmosphere in a branch waterway that branches from the backflow prevention chamber of the hot water supply island, and when hot water is supplied to the bathtub, the backflow prevention chamber on-off valve functions as the water sump hopper and the hot water supply passage. It closes the gap between the backflow prevention chamber and the backflow prevention chamber, but if a bathtub with a water heater equipped with a backflow prevention device is installed above a certain height from the bathtub, the backflow prevention chamber will become negative under conditions where the amount of hot water supplied is small. There was an interstitial point where hot water leaked into the water sump hopper due to pressure build-up, and the sealing performance of the backflow prevention chamber on/off valve deteriorated, causing hot water to overflow from the atmosphere communication port, which also serves as the overflow port of the water sump hopper.

The present invention improves the above problems by detecting water leakage and discharging the hot water leaking into the water storage hopper into the miscellaneous water circuit.
0 - This prevents overflow from the mouth.

(Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows.

That is, in a hot water supply circuit that connects a water supply circuit and a miscellaneous water circuit, in which a check valve and a backflow prevention chamber are provided, a water storage hopper that is open to the atmosphere and stores water in the backflow prevention chamber is installed below the backflow prevention chamber. A backflow prevention chamber opening/closing valve is provided between the water sump hopper and the backflow prevention chamber, which closes when water flow pressure is applied to the backflow prevention chamber and opens when water flow pressure disappears; A water level detector is provided to detect the water level in the water sump hopper, and a drain solenoid valve is installed in the branch waterway leading from the drain port provided at the bottom of the water sump hopper to the hot water supply circuit. When a leak occurs, the water level is detected and a drain solenoid valve is opened to drain the hot water in the water hopper to the miscellaneous water circuit.

(Function) When hot water is supplied to the bathtub, under conditions where the amount of hot water supplied is small, the backflow prevention chamber becomes negative pressure, the sealing performance of the backflow prevention chamber opening/closing valve deteriorates, and hot water leaks into the water sump hopper. When hot water leaks, the water level detector detects this water level, opens the drainage electromagnetic valve, and discharges the hot water in the water reservoir hopper from the branch waterway through the hot water supply circuit to the miscellaneous water circuit, and after a certain period of time after the discharge. The drainage solenoid valve is closed.By repeating this operation, overflowing from over 70-low can be prevented.

(Example) Fig. 1 is a schematic configuration diagram of a bathtub with water heater equipped with a backflow prevention device of the present invention, and Fig. 2 is a cutaway sectional view of essential parts of a backflow prevention device showing an embodiment of the present invention. .

(1) is a bath circuit equipped with a bath heat exchanger (2) and connected to a bathtub (3), with a three-way valve (4) and a circulation pump (5).
This is provided. (6) is used as heat exchanger N (7) for hot water supply! #2
The hot water supply circuit is connected to a three-way valve (4) provided in the bath circuit (1) via a backflow prevention device (8), so that hot water can be supplied to the bathtub (3).

The backflow prevention device (8) is equipped with a drop-in solenoid valve (9), a check valve αQ, and a backflow prevention chamber (6). A hopper valve body Q with an on-off valve (b) integrated at the bottom is housed, and this hopper valve body opening is always biased by a spring 04 in the direction of closing the inlet of the backflow prevention chamber α. has been done.

An outlet OQ to which the hot water supply circuit (6) is connected is provided on the side of the backflow prevention chamber αυ, and the hot water supply circuit (6) is It is connected to the valve (4) and hot water is supplied to the bathtub (3) via the bath circuit (1).

A water sump hopper 09 having an overflow port (G) open to the atmosphere on the side is formed below the backflow prevention chamber opening, and a backflow prevention chamber α is located between the backflow prevention chamber Ql) and the water sump hopper α9. A water handle D4 is provided for draining the remaining hot water into the water storage hopper Q9, and is opened and closed by a backflow prevention chamber opening/closing valve (b). The volume below the overflow port (to) of the water reservoir hopper Og is slightly larger than the volume of the backflow prevention chamber (b), and a water level detector such as an electrode level switch or thermistor (to )
This is provided.

Further, a drain port @ connected to the branch water w3□□□ is provided on the bottom surface of the water sump hopper α9, and a drain solenoid valve @ is provided below the drain port to open and close the branch waterway (2). The terminal end of the branch waterway (a) is connected to the terminal end of the hot water supply circuit (6), and a three-way valve (
4) to the bath circuit (1), and the drain solenoid valve (
When the three-way valve (c) opens, the hot water in the water hopper α is opened.
) so that it can be discharged to the bath circuit (1) side.

Therefore, inside the backflow prevention device (8), the drop-in solenoid valve (9
), the hot water supply circuit (6) leading to the three-way valve (4) via the check valve αq1 backflow prevention chamber entrance, the second backflow valve α force, and the backflow prevention chamber (6
), a branch circuit (2) branches out from the backflow prevention chamber opening/closing valve (b), a water sump hopper α9, a drainage electromagnetic valve (c), and reaches a three-way valve (4).

When the drop-in solenoid valve (9) is opened, the water flow causes the check valve αQ to receive water pressure and push the hopper valve body (toward) downward to open and close the backflow prevention chamber. Close the valve (b).

The backflow prevention device is filled with hot water that has flowed in, and the second check valve α force is also opened, and hot water is supplied from the hot water supply circuit (6) to the bath circuit (1) via the three-way valve (4).

If the bathtub is installed above a certain height above the bathtub, the backflow prevention device will become negative pressure under conditions where the amount of hot water supplied is low, and the sealing performance of the backflow prevention chamber opening/closing valve (I2) will deteriorate, causing the water sump hopper to Fourth, the hot water supply temperature may leak.

In this case, if more than a certain amount of hot water leaks, the water level detector @ detects this and opens the drainage solenoid valve (c), discharging the hot water accumulated in the water hopper α collar to the bath circuit (1). do. When the discharge is finished, the water level detector (2) turns OFF,
Close the drain solenoid valve (c) after a certain period of time. Control is performed to prevent overflow from the over 70-mouth (to) by repeating this operation.

When hot water supply is finished and the drop-in solenoid valve (9) is closed, the water pressure in the check valve αQ and the second check valve ση disappears, and each check valve QG and αiit are closed by spring pressure.
The backflow prevention chamber opening/closing valve opens and the remaining water in the backflow prevention chamber flows into the water sump hopper CII, and the backflow prevention chamber αυ is replaced with air flowing in from the overflow port (G). Therefore, the primary side upstream of the drop-in solenoid valve (9) and the secondary side downstream of the second check valve port are completely separated. After this,
Open the drainage solenoid valve (to) and operate the circulation pump (5) to discharge the remaining water in the 1st water hopper α collar to the secondary side.

In addition, in a steady state, the drop-in solenoid valve (9) is closed, the check valve σQ and the second check valve ση are also closed by the spring, and the check valve aq and the integrated check valve opening/closing valve ( b) is opened, and the backflow prevention chamber αυ and the water sump hopper 01 are filled with air.

(Effects of the Invention) As described above, the present invention provides a water level detector in the water sump hopper of the backflow prevention device, and when water accumulates above a certain water level during hot water supply, the drainage solenoid valve is opened to discharge the water to the miscellaneous water circuit. This makes it possible to prevent water from overflowing from the over-70-ro regardless of the construction conditions.

Furthermore, a conventional backflow prevention device can be used by simply adding a simple water level detector, making it possible to create a backflow prevention device that does not require any installation.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a bathtub with water heater using the backflow prevention device of the present invention, and FIG. 2 is a cutaway sectional view of essential parts of the backflow prevention device showing one embodiment of the present invention.・11)...Bath circuit (6)...Hot water supply circuit (8)...Backflow prevention device 00...Check valve part...Backflow prevention chamber (foundation)...Backflow prevention chamber opening/closing valve Osu...Water hopper (2)...Water level detector ■...Branch channel @...Drain port (c)...Drainage solenoid valve

Claims (1)

[Claims] In a hot water supply circuit that connects a water supply circuit and a miscellaneous water circuit, a check valve and a backflow prevention chamber are provided below the backflow prevention chamber.
A backflow prevention system that includes a water storage hopper open to the atmosphere that stores water in a backflow prevention chamber, and closes when water pressure is applied to the backflow prevention chamber between the water storage hopper and the backflow prevention chamber, and opens when water pressure disappears. A chamber opening/closing valve is provided, a water level detector is provided in the water sump hopper to detect the water level of the water sump hopper, and
A drainage solenoid valve is installed in the branch waterway leading from the drain port provided at the bottom of the water sump hopper to the hot water supply circuit, and when hot water leaks beyond a certain level into the water sump hopper, the water level is detected and the drainage solenoid valve is opened. A backflow prevention device characterized in that the hot water in the water storage hopper is drained into the miscellaneous water circuit.