JPH03129248A - Reverse flow preventing device for bath burner with hot water supplying device and its using method - Google Patents

Abstract

PURPOSE:To prevent reverse flow of foul water by providing a reverse flow preventive chamber switching valve closing when passing water pressure is applied to a reverse flow preventive chamber and opening when it is eliminated among the atmosphere connection port of a branch water passage, a water storage hopper and the chamber. CONSTITUTION:A branch water passage 8 branched from a reverse flow preventive chamber 5 and connected to the suction side of a circulation pump 7 of a circulating circuit 2 is formed, and a water storage hopper 9 capable of storing water in the chamber 5, and an atmosphere connection port 10 for connecting the hopper 9 and the passage 8 to the atmosphere are provided. A reverse flow preventive chamber switching valve 11 closing when passing water pressure is applied to the chamber 5 and opening when it is eliminated is provided among the port 10 of the passage 8, the hopper 9 and the chamber 5, and a drain switching valve 12 is provided at the drain side of the hopper 9 of the passage 8. Thus, even if the valve is defective, it can prevent foul water from reversely flowing to the upstream side.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a backflow prevention device for a bathtub with a water heater, and uses the backflow prevention device to supply hot water under direct pressure to the bathtub, and also prevents the backflow of miscellaneous water when hot water is not being supplied. Regarding how to prevent this.

[Background Art] When connecting a miscellaneous water circuit, such as a circulation circuit that circulates hot water in a bathtub, to a clean water circuit, such as a hot water supply circuit, it is mandatory to take measures to prevent miscellaneous water from flowing back into the clean water circuit. ing. Conventionally, the distern method and the vacuum breaker method have been used as methods for preventing this backflow.

(Conventional Example ■) What is shown in FIG. 7 is a conventional method for preventing the backflow of miscellaneous water using the distern method. In this system, a tank 102 equipped with a float switch 101 is installed, and the discharge port of the tank 102 is connected to the suction side of a circulation pump 106 of a bath circulation circuit 105 via a three-way valve 103 or the like. The end of the hot water supply circuit 108 connected to the vessel 107 is placed inside the tank 102. Therefore, when hot water is not being supplied, the tank 102 and the hot water supply circuit 108 are not connected and the edge is cut off, so that the miscellaneous water on the tank 102 side is prevented from flowing back into the water supply circuit. On the other hand, when supplying hot water, open the drop-in on-off valve 104 of the hot water supply circuit 108,
Hot water (or water) heated by the water heater 107 is first dropped into the tank 102, and the hot water in the tank 102 is sent to the circulation circuit 105 via the three-way valve 103, and the circulation pump 106 is operated to force the hot water into the tank 102. Hot water is supplied from the circulation circuit 106 into the bathtub 109.

(Conventional example ■) The one shown in Figure 8 is a backflow prevention method using the conventional nokukumu brake force method, which uses hot water supply pressure to directly drop hot water into the bathtub from the hot water supply circuit side. be. That is, the hot water supply circuit 121 is directly connected to the delivery side of the circulation pump 123 of the circulation circuit 122, and the hot water supply circuit 121 is provided with a vacuum breaker 124, a drop-in opening/closing valve 125, a plurality of check valves 126, 127, and the like. Therefore, when hot water is not being supplied, the check valves 126 and 127 prevent miscellaneous water from flowing back to the hot water supply circuit 121 side, and when the water supply side becomes negative pressure due to a water outage, etc., the vacuum breaker 124 releases the air to the atmosphere. It has a structure in which it is opened and cuts the edge between the water heater 128 side and the circulation circuit 122 side to prevent backflow of miscellaneous water. On the other hand, when hot water is being supplied, the vacuum breaker 124 is disconnected from the atmosphere, and water is directly passed from the hot water supply circuit 121 through the circulation circuit 122 to the bathtub 1 by water pressure.
29 is pouring hot water into it.

Problem 3 to be solved by the U invention (Regarding Conventional Example I) However, in the above-mentioned distern system, the tank and the hot water supply circuit are not connected, and the hot water supply pressure on the hot water supply circuit side is not applied to the circulation circuit. Also, since the water pressure in the tank alone is not sufficient, when pouring hot water into the bathtub, it is necessary to operate a circulation pump and use the pump pressure to force the hot water into the bathtub. However,
If a strong circulation pump is used, and the bath is reheated while taking a bath, the heated water will be vigorously discharged from the bath adapter and reach a distance from the bath adapter, so it will hit the bather's body and cause discomfort and irritation. May cause a sensation of heat. Furthermore, even if a large and powerful circulation pump can be used, using a large circulation pump will cause
There are problems in that the equipment becomes expensive and the noise becomes louder. This circulation pump is generally a small and weak type.

Therefore, with the Gistern method, which uses circulation pump pressure to supply hot water, it is not possible to obtain a large flow rate when supplying hot water, and it takes a long time to open the hot water (particularly in the case of a large bathtub, the time required to fill the bathtub with hot water becomes extremely long). There are drawbacks. Additionally, if the bathtub is installed on an upper floor, such as on the second floor, the power of the circulation pump is weak, resulting in insufficient hot water supply capacity to the bathtub, and there is a problem that it cannot be used for the bathroom on the upper floor. . Furthermore, in this system, the circulation pump is operated even when hot water is being supplied, resulting in high operating costs and large noise.

(Concerning Conventional Example H) On the other hand, the vacuum breaker method shown in Fig. 8 is a water supply surface pressure type that can supply hot water using water pressure. There is a restriction that it must be installed at a height of 300 mm or more. For this reason,
If the bathtub is installed on an upper floor such as the second floor, it is necessary to separate the vacuum breaker part from the bathtub installed on the ground and place it above the bathtub, and connect the hot water supply circuit to the upper vacuum breaker. In reality, it has not been possible to deal with bathtubs on upper floors, as it requires piping to be routed to the side.

The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and its main purpose is to prevent the backflow of miscellaneous water, and to enable automatic hot water supply at a large flow rate using a water direct pressure system. To provide a backflow prevention device for a bathtub with a water heater and a method for using the same, which does not restrict the installation location of the bathtub.

[Means for Solving the Problems] For this reason, the backflow prevention device for a bath pot with a water heater of the present invention is provided with a drop-in on-off valve in the hot water supply circuit for supplying hot water from the water heater to the bath circulation circuit, and Also, a backflow prevention chamber is provided on the circulation circuit side, and a branch waterway is formed that branches from this backflow prevention chamber and is connected to the suction side of the circulation pump of the circulation circuit, and the water in the backflow prevention chamber is stored in this branch waterway. An atmosphere communication port is provided for communicating the water reservoir hopper and the branch waterway with the atmosphere, and the atmosphere communication port of the branch waterway, the water reservoir hopper, and the backflow prevention chamber are provided with an atmosphere communication port that closes when water pressure is applied to the backflow prevention chamber. It is characterized by providing a backflow prevention chamber on-off valve that opens when the water flow pressure disappears, and a drainage on-off valve on the drain side of the water sump hopper of the branch waterway.

Further, the method of using the backflow prevention device for a bathtub with a water heater according to the present invention is that in the above-mentioned backflow prevention device, the drop-in opening/closing valve is closed and the draining opening/closing valve is opened, and the suction force of the circulation pump is used. The hot water in the water storage hopper is discharged to the bath circulation circuit, and then the drop-in opening/closing valve is opened to supply hot water from the hot water supply circuit to the bath circulation circuit.

[Function] In the present invention, when hot water is supplied by opening the drop-in opening/closing valve, the backflow prevention chamber is filled with hot water, the backflow prevention chamber opening/closing valve is closed, and the branch waterway is closed, so that the hot water in the backflow prevention chamber is closed. The water pressure of the hot water supply circuit can be applied to the circulation circuit side through the . Therefore, the hot water supply circuit is directly connected to the circulation circuit, and hot water can be supplied using tap pressure, making it possible to supply hot water at a large flow rate, and even in the case of a large bathtub, hot water can be filled in a short time. Furthermore, even if the bathtub is installed on an upper floor such as the second floor, hot water can be supplied using water pressure, and there are no restrictions on where the bathtub can be installed. Furthermore, since a small-sized circular pump can be used as the circulation pump, the device can be made inexpensive, the operating cost can be reduced, and the noise caused by the circulation pump can be reduced.

On the other hand, when the drop-in opening/closing valve is closed and hot water supply is stopped, the backflow prevention chamber opening/closing valve opens and the hot water inside falls into the water sump hopper, and the inside of the backflow prevention chamber is replaced with air, so that the hot water supply side and the circulation circuit side are The hot water is cut off, and even if a check valve or the like fails, miscellaneous water in the circulation circuit can be prevented from flowing back into the hot water supply circuit.

Furthermore, the hot water that has fallen into the water storage hopper can be forcibly discharged into the circulation circuit by opening the drainage on-off valve and using the suction force of the circulation pump, so it will not leak outside the vessel.
It can be used hygienically without polluting the surrounding area. In addition, since the drain valve is opened and the circulation pump is used to forcefully discharge the water, the hot water in the water sump hopper can be reliably drained even if the bathtub is installed on the upper floor. I don't receive it.

In addition, as in the method of the present invention, if the hot water in the water storage hopper is discharged to the circulation circuit side before hot water supply, it is possible to ensure that hot water does not overflow in the water storage hopper and leak to the outside when hot water supply is stopped. It can be prevented.

[Example] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

What is shown in FIG. 1 is a schematic diagram of a bathtub equipped with a backflow prevention device 17. The bath adapter 14 of the bathtub 13 includes
A circulation circuit 2 for reheating and the like is connected, and the circulation circuit 2 is provided with a bath heat exchanger 15, a three-way valve 16, and a circulation pump 7. A hot water supply circuit 3 connected to the water heater 1 is directly connected to a three-way valve 16 of the circulation circuit 2. The hot water supply circuit 3 is provided with a drop-in opening/closing valve 4, a check valve 6, and a backflow prevention chamber 5. The check valve 6 is connected to the circulation circuit 2
It is arranged in a direction that prevents backflow from the side to the water heater 1 side. The backflow prevention chamber 5 has a structure that can hold hot water or air inside, and a branch waterway 8 is connected from the backflow prevention chamber 5.
is branched out.

The branch waterway 8 has an atmosphere communication port 10 that also serves as an overflow hole.
A water reservoir hopper 9 is provided, and the volume of the water reservoir hopper 9 below the atmosphere communication port 10 is slightly larger than the volume inside the backflow prevention chamber 5. Backflow prevention chamber 5
A backflow prevention chamber opening/closing valve 11 is provided between the backflow prevention chamber opening/closing valve 11 and the water storage hopper 9. When the backflow prevention chamber opening/closing valve 11 is closed, the backflow prevention chamber 5 can be filled with hot water, and when it is opened, the backflow prevention chamber 5 can be filled with hot water. The hot water in the chamber 5 falls into the water sump hopper 9, and the inside of the backflow prevention chamber 5 is replaced with air flowing in from the atmosphere communication port 10. Furthermore, the terminal end of the branch waterway 8 is connected to the three-way valve 1.
6 or the terminal end of the hot water supply circuit 3, and a drainage on/off valve 12 is connected to the discharge side of the water sump hopper 9 of the branch waterway 8.
is provided so that hot water in the water reservoir hopper 9 can be discharged to the circulation circuit 2 side by opening the drainage on-off valve 12.

What is shown in FIG. 2 is a detailed sectional view of the backflow prevention device 17 in which the portion surrounded by the broken line in FIG. 1 is integrally constructed.

An inlet pipe connection port 19 is opened on the upper side of the casing 18, and a hot water supply port is connected to this inlet pipe connection port 19. A hot water inlet pipe 2o constituting 83 is connected, and hot water heated by the water heater 1 is sent into the casing 18 from the inlet pipe connection port 19. A backflow prevention chamber 5 is formed in the center of the casing 18, and a water sump hopper 9 is provided below the backflow prevention chamber 5. The backflow prevention chamber 5 and the water storage hopper 9 are separated by a partition plate 21, and a water drain is provided in the center of the partition plate 21 to drain the remaining hot water in the backflow prevention chamber 5 to the water storage hopper 9 side. Hole 22
is perforated. An atmosphere communication port 10 communicating with the atmosphere is opened on the side surface of the water sump hopper 9, and the volume below the atmosphere communication port 10 of the water sump hopper 9 is slightly larger than the volume of the backflow prevention chamber 5. . In addition, water reservoir hopper 9
A drain port 23 for connecting to the branch waterway 8 is provided on the bottom of the
is open, and a drain opening/closing valve 12 is attached below the drain port 23. A second check valve storage chamber 24 is provided on the side of the backflow prevention chamber 5, and a clay pipe connection port 25 is opened at the bottom of the second check valve storage chamber 24. A hot water supply clay pipe 26 that constitutes the circuit 3 and is connected to the three-way valve 16 is press-fitted. Therefore, in terms of gauging 18 of the backflow prevention device 17, the hot water supply circuit 3 is configured by the path of inlet pipe connection 19 → backflow prevention chamber 5 → second check valve storage chamber 24 → outlet pipe connection port 25, On the other hand, a branch waterway 8 branched from the backflow prevention chamber 5 is configured by a path of water sump hopper 9 - drain port 23 - drain opening/closing valve 12 .

Further, one inlet pipe connection port communicates with a backflow prevention chamber entrance 27, and a drop-in opening/closing valve 4 is provided in a water channel 28 connecting the inflow pipe connection port 19 and the backflow prevention chamber entrance 27. The drop-in opening/closing valve 4 is a solenoid type electromagnetic valve,
The outer periphery of a diaphragm 30 disposed opposite the valve seat 29 is fixed to the casing 18, and the tip of the 21 langier 31 is connected to the center of the diaphragm 30. Therefore, when the plunger 31 is retracted by energization, the hot water supply circuit 3 is opened, and when the plunger 31 is extended, the diaphragm 30 comes into pressure contact with the valve seat 29, and the hot water supply circuit 3 is closed on the 1-water side of the backflow prevention chamber 5. will be accomplished.

The first check valve 6 and the backflow prevention chamber opening/closing valve 11 are delivered in combination into the backflow prevention chamber 5. The first check valve 6 is arranged to face the backflow prevention chamber entrance 27, and a rubber gasket 32 is attached to the upper surface of the first check valve 6 so as to surround the backflow prevention chamber entrance 27. is elastically biased. Further, a pressure plate 34 extends from the lower outer periphery of the first check valve 6.
The pressure plate 34 has approximately the same dimensions as the inner dimensions of the backflow prevention chamber 5. The pressure plate 34 receives the water flow pressure of the hot water flowing in from the inlet 27 over its entire surface to ensure the operation of the first check valve 6, and furthermore, the outer peripheral surface is formed inside the backflow prevention chamber 5. It is in sliding contact with the wall surface and acts as a guide so that the first check valve 6 can slide smoothly without tilting. A recess 35 is provided on the lower surface of the first check valve 6.
A bearing hole 36 is bored in the center of the partition plate 21 at the bottom of the backflow prevention chamber 5, and the head 37 of the backflow prevention chamber opening/closing valve 11 is slidably inserted into the recess 35. A bearing for the shaft portion 38 is slidably inserted into the hole 36 and held so as to be slidable in the vertical direction, and is further held by a spring 39.
is elastically biased upward by. The outer diameter of the head 37 of the check valve 11 is smaller than the inner diameter of the recess 35 on the lower surface of the first check valve 6, so that a gap is created between the head 37 and the recess 35. The backflow prevention chamber opening/closing valve 1
An air passage hole 10 is perforated vertically through the axis of the valve 1, and an O ring 41 is held at the upper end of the check valve 11 so as to surround the air passage hole 40.

Further, a rubber gasket 42 is attached to the lower surface of the backflow prevention chamber opening/closing valve 11 so as to surround the plurality of drain holes 22.

However, when the drop-in opening/closing valve 4 is opened,
The first check valve 6 is pushed down against the spring 33 by the hot water supply pressure to open the inlet 27, and the backflow prevention chamber opening/closing valve 11 is also pushed down by the first check valve 6 (the state at this time is shown in Figure 2). (shown by the left half of the first check valve 6 and the check valve 11), in this case, the rubber gasket 42 of the check valve 11 is pressed against the partition plate 21, and the drain hole 22 and the bearing are The hole 36 is closed, and at the same time, the head 37 is brought into pressure contact with the recess 35 via the O-ring 41, and the air passage hole 40 is also closed. Therefore, at this time, the hot water that has flowed into the backflow prevention chamber 5 fills the backflow prevention chamber 5 without leaking from the water drain hole 22 or the air vent hole 40 to the water sump hopper 9 side, and is further stored in the second check valve. The hot water is sent to the chamber 24 side (the second check valve 44 is open), and is supplied to the circulation circuit 2 side.

Conversely, when the drop-in opening/closing valve 4 is closed, no water flow pressure is applied to the first check valve 6, so the first check valve 6
When the check valve 1 rises and the first check valve 6 rises a little, a gap is created between it and the check valve 11, and the air passage hole 40 opens.

When air flows into the backflow prevention chamber 5 from the water storage hopper 9 side through the opened air vent 10, the pressure inside the backflow prevention chamber 5 is quickly reduced, and the first check valve 6 rises to close the inlet 27. At the same time, the backflow prevention chamber opening/closing valve 11 rises to open the drain hole 22, and the inside of the backflow prevention chamber 5 is immediately replaced with air. ), therefore, the first check valve 6 is closed and the backflow of miscellaneous water is prevented, and the inside of the backflow prevention chamber 5 is replaced with air, so that the water heater 1 The border between the side and the circulation circuit 2 side is cut. Note that when replacing water with air, water is drained from the water drain hole 22 at the bottom of the backflow prevention chamber 5, and air is injected from the upper end of the air hole 40 located above the drain hole. Also, the flow of air becomes smoother, and water is quickly replaced by air.

An annular valve seat 43 is provided on the backflow prevention chamber 5 side in the second check valve storage chamber 24, and a second check valve seat 43 is provided in the second check valve storage chamber 24 opposite to the valve seat 43. A valve 44 is delivered so as to be slidable laterally, and the second check valve 44 is elastically biased in the closing direction by a spring 45. therefore,
The second check valve 44 opens when the backflow prevention chamber 5 is filled with hot water and water flow pressure is applied to the second check valve 44.
When the inside is replaced with air, it is opened and the hot water supply earthen pipe 26
Backflow from the side to the backflow prevention chamber 5 side is prevented.

The atmosphere communication port 10 may be provided separately from the water sump hopper 9, but in the illustrated example, the atmosphere communication port 10 is formed integrally with the water sump hopper 9, and the atmosphere communication port 10 is connected to the overflow pipe 46 that is open to the atmosphere. The atmosphere communication port 10 is connected to the atmosphere through an overflow pipe 46. Therefore, when replacing with air, air is supplied to the backflow prevention chamber 5 through the overflow pipe 46 → atmosphere communication hole 10 → air passage hole 40. Furthermore, the drainage on-off valve 12 is normally closed, and water that has fallen from the backflow prevention chamber 5 into the water sump hopper 9 is temporarily stored in the water sump hopper 9. and,
Normally, the hot water in the water storage hopper 9 is drained from the branch waterway 8 to the circulation circuit 2 by opening the drain valve 12, but due to a malfunction of the backflow prevention chamber valve 11, etc. When the amount of water in the water reservoir hopper 9 overflows, it is discharged from the atmosphere communication port 10 to the overflow pipe 46.

FIGS. 3, 4, and 5 are explanatory diagrams showing the operations of the bathtub with the water heater 1 equipped with the backflow prevention device 17 during hot water supply, hopper drainage, and circulation, respectively. These explanatory diagrams show the configuration in slightly more detail than in Figure 1.
In the water supply circuit 47, 48 is a flow rate sensor, 49 is a temperature sensor, and in the hot water supply circuit 3, 50 is a flow rate sensor, 51
is a temperature sensor, 52 is a hot water outlet servo pulp, and a bypass valve is disposed between the hot water outlet circuit 53, which is branched from the hot water supply circuit 3 and connected to a bathroom door, etc., and the water inlet circuit 47. Further, 55 in the circulation circuit 2 is a pressure sensor;
6 is a water flow switch, and a check valve 58 is inserted into a bypass circuit 57 that is piped to bypass the three-way valve 16 so that the direction is forward from the suction side of the circulation pump 7 to the bus adapter 14 side. be.

To explain the operation during hot water supply in Figure 3 (the flow of hot water is shown by the thick line), the three-way valve 16 of the circulation circuit 2 is switched so that the suction side of the circulation pump 7 and the hot water supply circuit 3 side communicate with each other. When the drop-in opening/closing valve 4 is opened in this state, the first check valve 6 of the backflow prevention device 17 is pushed open by the water flow pressure, and the opening/closing valve 11 of the backflow prevention chamber between it and the water storage hopper 9 is accordingly pushed open.
is closed. Therefore, the backflow prevention chamber 5 is filled with hot water without leaking to the water storage hopper 9 side, and the second check valve 44 is pushed open by the water flow pressure, and hot water is supplied to the three-way valve 16 side. The hot water that has passed through the three-way valve 16 is sent to the circulation pump 7.
The hot water flows to the side and the check valve 58 side, and is supplied to the bathtub 13 by both conveyances. In the case of this hot water supply system, hot water can be dropped into the bathtub 13 using the water pressure on the water supply side, so even if the bathtub 13 is installed on an upper floor such as the second floor, the large flow rate will allow hot water to flow in a short period of time. It becomes possible to pour hot water into the

Note that, at this time, the drainage on-off valve 12 is closed. After this, when the drop-in opening/closing valve 4 is closed and hot water supply is stopped,
The first check valve 6 and the second check valve 44 are closed, and the check valve 11 is accordingly opened. Therefore, the hot water in the backflow prevention chamber 5 falls into the water sump hopper 9, and the backflow prevention chamber 5 is filled with air from the atmosphere communication port 10. Therefore, when the check valves 6 and 44 are closed, the backflow prevention chamber 5
By filling the inside with air, the water heater 1 side and the miscellaneous tree side are separated, and backflow of miscellaneous water is reliably prevented. Furthermore, since the hot water in the backflow prevention chamber 5 is temporarily stored in the water sump hopper 9, no water leaks from the backflow prevention chamber 5 to the outside of the vessel.

After hot water supply is stopped, hot water will remain in the water reservoir hopper 9, so if the next hot water supply is continued, there is a risk that water will overflow 46 from within the water reservoir hopper 9 and leak to the outside of the vessel when the hot water supply is stopped. . Therefore, it is necessary to drain the hot water in the water reservoir hopper 9 after or before hot water supply. FIG. 4 shows this hopper drainage method (the flow of drainage is shown by thick lines). When draining the hopper, the three-way valve 16 of the circulation circuit 2 is switched to communicate between the suction side of the circulation pump 7 and the branch waterway 8 side, the drain on-off valve 12 is opened, the circulation pump 7 is operated, and the water storage hopper 9 is opened. The hot water inside is forcibly discharged into the bathtub 13 by the force of the circulation pump 7. This prevents the hot water in the backflow prevention chamber 5 from being inadvertently discharged to the outside and allows it to be reused. Furthermore, since the water is forcibly discharged by the force of the circulation pump 7, even if the bathtub 13 is installed on the upper floor, the water can be reliably drained through the hopper. Note that if this hopper draining takes too long and continues even when there is no more water in the water sump hopper 9, the air in the water sump hopper 9 will be drawn into the circulation circuit 2. It is preferable to measure the time required to drain the water in the hopper and to operate the circulation pump 7 for that period of time to drain the hopper.

The one shown in Fig. 5 shows the circulation operation such as reheating (the flow of hot water is shown by the thick line), and the three-way valve 1 of the circulation circuit 2
6 on the hot water supply circuit 3 side and communicated within the circulation circuit 2,
The circulation pump 7 is operated.

In this case, the check valve 58 of the bypass circuit 57 is closed, and the hot water circulated by the circulation pump 7 is heated by the bath heat exchanger 15 and returned to the bathtub 13.

Note that the above-mentioned hopper drainage may be performed immediately before hot water supply, immediately after hot water supply ends, or when the circulation pump 7 is operated for circulation operation. for example,
If the hopper is to be drained during the circulation operation, the circulation pump 7 is operated, the three-way valve 16 is switched to the hopper drain mode, the drain on-off valve 12 is opened, the hopper is drained for a few seconds, and then the drain on-off valve is opened. 12 is closed, the three-way valve 16 is switched to circulation mode, and hot water can be circulated within the circulation circuit 2. However, in order to reliably eliminate overflow in the water sump hopper '9 in consideration of failure of the backflow prevention chamber on-off valve 11, etc., it is preferable to drain the hopper immediately before the hot water supply operation.

Now, what is shown in Fig. 6 is a flowchart for automatically supplying hot water in an automatic bath pot having the structure shown in Figs. is adopted. This flow will be explained along with FIG. First, when the automatic switch is turned on (step 71), the circulation pump 7 is operated to drain water for a certain period of time (step 72). A certain amount of hot water (ql) of this residue is dropped into the bathtub 13 (step 73), and at the same time, the air in the circulation circuit 2 is purged, and then a circulation judgment is performed (step 7).
4). That is, the circulation pump 7 is operated to circulate hot water in the circulation circuit 2, and the running water switch determines whether the remaining water is above the bath adapter level (step 75).At this time, the running water switch is turned on. If so, there is residual water above the bus adapter level, so the specified flow (
(not shown) is executed. If the running water switch is off and it is determined that the remaining water is below the level of the bus adapter 14, the hopper is drained again (step 76) to empty the water storage hopper 9, and the hot water supply circuit 3 to Q2 (90J
) is poured in (step 77), and the circulation pump 7 is operated to determine circulation (step 78). If the water flow switch is off as a result of this circulation determination, there is a possibility that the drain valve has been forgotten to be closed, so a message to that effect is displayed (step 79). On the other hand, after confirming that the water flow switch was on and the remaining water was at the bus adapter level 14 or above, the hopper was drained (step 80), and the water was drained again at a certain amount q3.
of hot water (step 81), and the rise in water level at this time is detected by the pressure sensor (step 82).
). From this, the cross-sectional area S of the bathtub 13 is determined by q 3 /h. Next, the drop amount q4 required to fill the bathtub with hot water to a set water level based on the bottom surface of the bathtub 13 or the level of the bath adapter 14 is determined (step 83). Thereafter, the circulation pump 7 is operated to drain the hopper (step 84), and then the determined amount of hot water q4 is dropped into the bathtub 13 (step 85), and reheated if necessary (step 86). Also, when the hot water gets cold or the amount of hot water decreases, heat retention and water replenishment are performed.

[Effects of the Invention] According to the present invention, hot water can be dropped from the hot water supply circuit into the bathtub using a direct connection system to the water supply, so by dropping a large flow of hot water, even a large bathtub can be filled with hot water in a short time. . Furthermore, even if the bathtub is installed on an upper floor such as the second floor, hot water can be pumped up to the bathtub on the upper floor using water pressure. On the other hand, since the backflow prevention chamber is filled with air when hot water is not being supplied, the water heater side and the circulation circuit side, which is the miscellaneous water circuit, are separated, and even if the check valve malfunctions, the miscellaneous water Backflow to the water side can be prevented. When the hot water supply is stopped, the hot water in the backflow prevention chamber is temporarily stored in the water sump hopper, so there is no leakage outside the device, and the water in the water sump hopper can be drained to the circulation circuit side. Therefore, the waste water can be completely treated internally.Moreover, this hopper drainage can be done using a circulation pump, so if the bathtub is installed on the upper floor, there is no need for large water pressure to flow from the bathtub side into the water sump hopper. Hopper drainage can be carried out reliably even when the hopper is overflowing. Therefore, the bathtub using the backflow prevention device of the present invention can be used even when the bathtub is installed on an upper floor such as the second floor.
Restrictions on usage can be reduced.

Furthermore, according to the method of the present invention, since the hopper is drained before hot water supply operation, hot water can be supplied with the water reservoir hopper empty, and hot water overflows in the water reservoir hopper when hot water supply is completed. There is no risk of water leaking outside.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a bathtub with water heater using the backflow prevention device of the present invention, Figure 2 is a detailed sectional view of the same backflow prevention device, and Figures 3, 4, and 5 are respectively An explanatory diagram of the operation of the same bath pot with a water heater as shown above during hot water supply, hopper drainage, and circulation. Fig. 6 is a flowchart explaining the automatic hot water supply operation using the above bath pot with a water heater. Fig. 7 is a conventional diagram. FIG. 8 is a schematic explanatory diagram of another conventional example. 1... Water heater 2... Circulation circuit 3... Hot water supply circuit 4... Drop-in opening/closing valve 5... Backflow prevention chamber 7... Circulation pump 8... Branch waterway
9...Water hopper 10...Atmosphere communication port 1
1... Backflow prevention chamber on-off valve 12... Drainage on-off valve 2.

Claims (2)

[Claims] (1) A drop-in on-off valve is provided in the hot water circuit for supplying hot water from the water heater to the bath circulation circuit, a backflow prevention chamber is provided on the circulation circuit side of the drop-in on-off valve, and a backflow prevention chamber is branched from this backflow prevention chamber for circulation in the circulation circuit. A branch waterway connected to the suction side of the pump is formed, and a water sump hopper that can store water in the backflow prevention chamber is provided in the branch waterway, and an atmospheric communication port is provided to communicate the branch waterway with the atmosphere. A backflow prevention chamber opening/closing valve that closes when water flow pressure is applied to the backflow prevention chamber and opens when water flow pressure disappears is provided between the mouth, the water sump hopper, and the backflow prevention chamber, and drains the water sump hopper of the branch waterway. A backflow prevention device for a bathtub with a water heater, characterized by having a drain opening/closing valve on the side. (2) A drop-in on-off valve is provided in the hot water circuit for supplying hot water from the water heater to the bath circulation circuit, a backflow prevention chamber is provided on the circulation circuit side of the hot water supply circuit, and the circulation circuit branches off from this backflow prevention chamber. A branch waterway connected to the suction side of the circulation pump is formed, and a water sump hopper that can store water in the backflow prevention chamber is provided in the branch waterway, and an atmospheric communication port is provided to communicate the branch waterway with the atmosphere. A backflow prevention chamber opening/closing valve that closes when water flow pressure is applied to the backflow prevention chamber and opens when water flow pressure disappears is provided between the atmosphere communication port, the water sump hopper, and the backflow prevention chamber, and the backflow prevention chamber opening/closing valve is provided between the water sump hopper and the backflow prevention chamber. In a backflow prevention device equipped with a drainage on-off valve on the drainage side, the drop-in on-off valve is closed and the drainage on-off valve is opened, and the hot water in the water storage hopper is transferred to the bath circulation circuit by the suction force of the circulation pump. A method for using a backflow prevention device for a bathtub with a water heater, which comprises: discharging the water, and then opening the drop-in opening/closing valve to supply hot water from the hot water supply circuit to the bath circulation circuit.