JPH07222906A - Hot water purifier of bathtub - Google Patents

Abstract

PURPOSE:To accurately detect the clogging of a filter material without causing the adhesion of the contaminant in hot water to a sensor and generating the erroneous operation of the sensor caused due to the arranging position of a hot water purifier. CONSTITUTION:In a hot water purifier of a bathtub constituted so that the hot water 2 in a bathtub 1 is forcibly circulated by a circulation pump 6 to be filtered by the filter tank 5 arranged to a hot water purifier main body 4 and subjected to purifying treatment such as the ozone sterilization by an ozonizer 8 while heated by a heater, a differential pressure sensor 34 detecting the pressure difference between the hot water suction pipe 3 being the inflow pipeline of the filter tank 5 and the hot water jet pipe 9 being the outflow pipeline thereof is connected to both pipes 3, 9 through branch pipes 32, 33. The reduction in differential pressure caused by the clogging of a filter material is detected by the sensor 34 and the sensor 34 is not affected by the arranging place of the purifier and not contaminated by stained hot water because not directly arranged in the flow of hot water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bath device, and in particular, clogging of a filter device in a bath hot water cleaning device for performing cleaning treatment such as filtration and sterilization while forcibly circulating hot water in a bathtub. The present invention relates to the detection device.

[0002]

2. Description of the Related Art Recently, a bathtub hot water purifying device has been widely used, which keeps the hot water in the bathtub clean and at an appropriate temperature, makes it possible to comfortably bathe 24 hours a day and saves water. .

In order to remove dirt in the bathtub, this bathtub cleaning device is always provided with one or a plurality of filter devices loaded with a wound filter or a granular filter medium such as activated stone or activated carbon.

In such a bath water cleaning device,
Whenever the equipment continues to operate, the filter media of the filtration equipment becomes dirty and clogged, the amount of circulating hot water decreases, and the cleaning ability decreases.

For this purpose, it is necessary to immediately wash or replace the filter medium loaded in the filter device when it is clogged to a certain degree or more. Whether to do it, or to detect the decrease in water volume with a water flow sensor installed in the pipeline,
Of course, if the water flow sensor detects clogging, it is possible to wash or replace the filter medium at an appropriate time.

An apparatus provided for detecting clogging of a filter medium by a conventional water flow sensor is as shown in FIG.
The hot water 2 in the bathtub 1 is sucked by the circulation pump 6 from the hot water suction pipe 3 to the main body 4 of the apparatus in which various cleansing treatment devices are collectively housed, and is cleaned. It is configured so as to be jetted again into the bathtub 1 from 9.

A prefilter 10 is provided at the tip of the hot water pipe 3 and has a sponge as a filter medium for removing large dirt in the hot water.
The jet nozzle 11 is provided at the tip of the spouting device 9 for ejecting the purified hot water as a jet flow together with the inhaled air by the negative pressure formed by accelerating the flow velocity of the hot water in the ejector section. It has been deployed.

A filtration tank 5 as a filtration device filled with various granular filter media such as activated carbon, barley stone, zeolite, etc., a heater 7 for keeping the hot water at an appropriate temperature, and forced circulation of the hot water. The circulating pump 6 and the like are connected in series by connecting pipes, one end of the hot water pipe 3 is connected to the inlet of the filtration tank 5, and one end of the spray pipe 9 is connected to the outlet of the circulating pump 7. Forming a series of circulation circuits for the hot water 2 in the bathtub 1.

Further, the apparatus main body 4 is provided with a filter tank 5 filled with a granular filter material as a filtering device in order to enhance the filtering capacity in the cleaning circuit, and a filter tank loaded with a wound filter is also provided. In some cases.

The jet nozzle 11 attached to the tip of the spout tube 9 is connected with an intake pipe 12 at an ejector portion where a negative pressure is formed to form ozone air to ozone the sucked air and sterilize the hot water. An ozonizer 8 is installed.

In the above apparatus, the hot water 2 in the bathtub 1 is sucked up from the hot water suction pipe 3 while the large dirt is removed by the prefilter 10 by the operation of the circulation pump 6, and the apparatus main body 4
First, it is filtered in the filtration tank 5, and then the heater 7
After being kept warm by, it is jetted again into the bathtub 1 from the jet nozzle attached to the tip of the spout tube 9.

At this time, air is sucked into the intake pipe 12 when the electromagnetic valve 13 provided at the intake port is opened, and a jet flow mixed with air is jetted from the jet nozzle 11 into the bathtub 1.
It becomes a so-called bubble bath that is jetted into the interior, and when the ozonizer 8 is operating, the air that is drawn in is ozoned,
The hot water 2 in the bathtub 1 is sterilized by ozone.

Further, in this apparatus, a water flow sensor 14 for detecting the flow rate of the hot water is provided in the middle of the spout tube 9, and a hot water temperature sensor 15 for detecting the hot water temperature is provided in the middle of the pipe line. Signals from these water flow and hot water temperature sensors 14 and 15 are sent to a controller (not shown) to perform control for determining hot water temperature and clogging of the filter medium.

The structure of the water flow sensor 14 is as shown in FIG. 7, in which a float is placed in a cylindrical case 16 having a horizontal water inlet 17 on the upper side surface and a vertical water outlet 18 on the bottom surface. The switch 19 is mounted vertically.

The float switch 19 has two signal lines 2
A magnet-equipped float 23 is slidably fitted to a mounting shaft 22 of a reed switch 20 to which 1 is connected, while receiving a biasing force upward by a spring 24.

Therefore, the hot water flows into the water flow sensor 14 from the water inlet 17 to the water outlet 18, and at this time, if the filter medium in the filtration tank 5 is not clogged, the flow rate of the hot water is increased. Since the water pressure is high and the water pressure is high, the float 23 goes down against the urging force of the spring 24, the float switch 20 is turned on, and this signal is sent from the signal line 21 to the control device.

On the other hand, when the filter material of the filtration tank 5 is clogged, the flow rate of the hot water is reduced and the water pressure is lowered, so that the float 23 is lifted up by the urging force of the spring 24 and the float switch 20 is turned off. The signal line 21 is sent to the control device, and clogging is displayed.

However, when the water flow sensor 14 detects clogging of the filter material of the filtration tank 5, the water flow sensor 14 is disposed in the middle of the pipe line and dirty water flows inside, so that dirt or foreign matter is not generated. There was a drawback that it could get caught and malfunction.

Therefore, as shown in FIG. 8, a branch pipe 25 is provided in the hot water pipe 3 and a pressure sensor 26 is provided in the branch pipe 25 in place of the water flow sensor arranged in series in the middle of the pipe in which the hot water flows. A device was also developed, which was installed so as to detect the pressure in the pipeline at a position where the hot water did not flow directly and thereby to know that the filter medium was clogged and the flow rate of the hot water decreased.

As shown in FIG. 9, the pressure sensor 26 slidably fits the sliding piece 27 to the branch pipe 25 while urging the branch pipe 25 to the right by a spring 28 and covers the rear end with a rubber cap 29. A limit switch 30 is arranged via a mounting plate 31 so as to face the rubber cap at a predetermined interval.

When the pressure sensor 26 is provided on the negative pressure side of the circulation pump 6 as described above, the pressure sensor 26 has a normal pressure in the pipe when the circulation pump 6 is not operated and the hot water is not flowing through the hot water suction pipe 3. , (A) as shown in FIG.
Is positioned to the right by the urging force of the spring 28, and the limit switch 30 is off.

When the circulation pump 6 is operated and the hot water flows through the hot water suction pipe 3, the pressure inside the pipe becomes negative, so that the sliding piece 29 moves to the left as shown in FIG.
0 turns ON.

Therefore, if the pressure of the spring 28 is appropriately adjusted, the pressure sensor 30 turns on and off the limit switch 30 according to the negative pressure inside the hot water pipe 3 which changes according to the flow rate of the hot water. Therefore, the clogging of the filter material in the filtration tank 5 can be detected.

In the above-mentioned embodiment, the pressure sensor 26 is provided on the suction pipe 3 on the negative pressure side and the clogging of the filter medium is detected by the change in the degree of negative pressure, but of course it is provided on the positive pressure side such as the spout pipe 9 for positive pressure. The degree of change can detect clogging of the filter medium, and in any case, the hot water does not flow directly through the pressure sensor 26, so that there is no possibility of malfunction due to contamination as in the case of the water flow sensor.

[0025]

However, even if the pressure sensor is used to detect the clogging of the filter material of the filtration tank as described above, the pressure changes depending on the installation height of the apparatus, so that the accurate detection cannot be performed. .

That is, as shown in FIG. 10, when the cleaning device is installed at an A position where the pressure sensor is 20 cm lower than the molten metal surface and at a B position where the pressure sensor is 50 cm higher than the molten metal surface. When the relationship between the flow rate and the negative pressure is compared, it becomes as shown in FIG.

In FIG. 11, C indicated by a solid line is a case where the pressure sensor is arranged at the same position as the molten metal surface, and A indicated by a chain line indicates that the pressure sensor is 20 cm lower than the molten metal surface.
This is the case of the position state, and B shown by the dotted line is the case of the B position state in which the pressure sensor is 50 cm higher than the molten metal surface.

As is apparent from this figure, the negative pressure at the same flow rate is 20 cm lower than the position of the molten metal surface in the A position state, so 0.02 kgf of water pressure per square cm is received from the bath water. Therefore, the pressure sensor is lower than C which is the same as the surface of the bath by 0.02 kgf per 1 cm 2, and in the B position, the pressure sensor is 50 cm higher than the position of the surface of the bath, so that
Since the pressure sensor receives the water pressure of 0.05 kgf, the pressure sensor is higher than C which is the same as the surface of the molten metal by 0.05 kgf per 1 cm 2.

As a result, since it is desired to warn if the filter medium is clogged and the flow rate becomes 8 l / min, the negative pressure degree per square cm is − considering that the pressure sensor is arranged at the same position as the molten metal surface. If the limit switch is set to operate when the pressure reaches 0.05 kgf, the pressure sensor still operates at a flow rate of about 10 l / min in the A position state, and the flow rate must be almost 0 in the B position state. Does not work.

The present invention eliminates the above-mentioned drawbacks of the prior art, and there is no fear of malfunction due to dirt in the hot water or the installation position of the apparatus, and a bath water cleaning apparatus capable of accurately detecting clogging of the filter medium. The purpose is to provide.

[0031]

[Means for Solving the Problems] That is, according to the present invention, the hot water in the bathtub is forcibly circulated by a circulation pump, and is cleaned by a cleaning device such as a filtering device provided in the circulation path. In the apparatus, a pressure difference sensor for detecting clogging of a filter medium due to a pressure difference between both pipes on the inflow side and the outflow side with respect to the filtering device is provided via a branch pipe for cleaning hot water in a bathtub. It is an oxidizer.

[0032]

The present invention is constructed as described above, and the pressure sensor for detecting the clogging of the filter medium is arranged through the branch pipes of the inflow and outflow side pipes to the filtering device, and is directly in the flow of the hot water. There is no need to worry about the hot water becoming dirty as it is not deployed at.

Since the clogging of the filter medium is judged not by the absolute pressure of the pipe line but by the pressure difference between the inflow side pipe line and the outflow side pipe line with respect to the filter device, the clogging of the bath water from the bath water depending on the installation position of the device is detected. The water pressures cancel each other out and have no effect on the discrimination result.

As a result, the clogging of the filter material of the filter is
Accurate detection is possible without malfunction due to hot water stains or the installation position of the device.

[0035]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 shows a first embodiment of the present invention. Since the basic structure is exactly the same as that of the conventional example, its explanation is omitted.
Only the configuration for detecting clogging of the filter material of the filtration tank 5 will be described.

In the present embodiment, the pressure difference between the inflow side and the outflow side of the filtration tank 5 is the difference between the pressure of the hot water suction pipe 3 as the inflow side and the pressure of the spout hot water pipe 9 as the outflow side. In order to detect the difference, a branch pipe 32 is provided in the hot water pipe 3 and the hot water pipe 9
Also, the branch pipe 33 is provided, and the differential pressure sensor 34 is provided between the branch pipes 32 and 33.

The structure of the differential pressure sensor 34 is as shown in FIGS.

Reference numeral 35 denotes a tubular low pressure chamber case having one end opened and a closed low pressure side connection port 36 provided at the other end.
Like the low pressure chamber case 35, 37 is a cylindrical high pressure chamber case having one end opened and a high pressure side connection port 38 provided at the other closed end. Both cases 35 and 37 are made of thin rubber between them. After aligning the open ends with a diaphragm 39 such as a sheet sandwiched between them, the flange portion is fastened with a screw 40, and the low pressure side connection port 36 and the high pressure side connection port 38 are provided at both ends.
9 forms a slider chamber 41 which is partitioned into a low pressure side and a high pressure side.

Reference numeral 42 is a slider having a magnet 43 fitted in the center thereof. The slider 42 is pushed toward the high pressure chamber by a return spring 44 inserted in a hole provided in the peripheral portion of the slider chamber 41. It is slidably fitted in the low pressure chamber case 35 forming the low pressure side.

Reference numeral 45 is a reed switch which is attached to the outside of the closed end of the low pressure chamber case 35 and operates when a magnetic force is applied.

In the differential pressure sensor 34 having the above-mentioned structure, the low pressure side connection port 36 of the low pressure chamber case 35 is connected to the hot water pipe 3 which is the inflow side pipe line to the filtration tank 5 and the high pressure side of the high pressure chamber case 37. The spout 38 is connected to the spout tube 9 which is an outflow side conduit for the filtration tank 5 through branch pipes 32 and 33 and a connecting pipe.

If the circulation pump 6 is not operated, the hot water does not flow in the pipeline, so that neither the suction pipe 3 nor the spout pipe 9 generate any pressure due to the circulation of the hot water. Therefore, the differential pressure sensor 34 There is no pressure difference between the low pressure side and the high pressure side.

Therefore, in the slider chamber 41, no differential pressure is generated between the low pressure side and the high pressure side with the diaphragm 39 as a boundary, so that the slider 42 is pushed by the return spring 44 as shown in FIG. It is pressed against the closed end of the high-pressure chamber case 37 together with the diaphragm 39.

As described above, when the slider 42 is separated from the lead switch 45, the lead switch 45 is in the OFF state because it is not affected by the magnetic force of the magnet 43 fitted in the slider 42.

On the other hand, when the circulation pump 6 is operated, the hot water flows in the hot water suction pipe 3 and the hot water jet pipe 9, and a negative pressure is generated in the hot water suction pipe 3 upstream of the circulation pump by the circulating hot water. Becomes a low pressure, and a positive pressure is generated in the spout tube 9 downstream of the circulation pump to become a high pressure.

As a result, the differential pressure sensor 34 connected to the hot water pipe 3 and the hot metal pipe 9 via the branch pipes 32 and 33 is provided on the low pressure side and the high pressure side of the slider chamber 41 with the diaphragm 39 as a boundary. Differential pressure is generated.

Then, as shown in FIG. 5, the diaphragm 39 resists the spring force of the return spring 44 and the low pressure chamber case 3
5, the slider 42 is pressed against the closed end of the low pressure chamber case 35.

As a result, the read switch 45 is turned on under the influence of the magnetic force because the magnet 43 of the slider 42 approaches.

As described above, the differential pressure sensor 34 for detecting the difference in pressure generated when the hot water flows in the inflow side and outflow side of the filtration tank 5 is provided by appropriately adjusting the pressure of the spring 44. If the filter medium in the filtration tank 5 is not clogged, the flow rate of the hot water is large, so that a large differential pressure is generated and the differential pressure sensor 34 becomes O.
When the filter medium becomes N and the flow rate of the hot water becomes small due to the clogging of the filter medium, the differential pressure becomes small and the differential pressure sensor 34 is turned off to detect clogging.

Here, how the differential pressure sensor 34 can accurately detect the clogging of the filter medium regardless of the installation location of the apparatus will be described.

FIG. 12 shows the relationship between the flow rate change and the pressure detected by the differential pressure sensor 34 as a table when the installation state of the apparatus is changed as shown in FIG.

FIG. 10A shows the case where the apparatus is installed at the position A in FIG. 10, and the hot water pipe 3 which is the inflow side pipe line to the filtration tank 5 at a flow rate of 15 l / min.
The pressure per square cm received by is 0.02 kgf, which is the sum of −0.04 kgf received from the circulating hot water and 0.02 kgf received from the bath water.

Further, the pressure per square cm received by the spout tube 9 which is the outflow side pipe to the filtration tank 5 is 0.13 kgf received from the circulating hot water and 0.02 received from the bath water.
It is 0.15 kgf which is the sum of kgf.

Therefore, the pressure difference between the hot water suction pipe 3 as the inflow pipe and the hot water pipe 9 as the outflow pipe with respect to the filtration tank 5 is 0.17 kgf per square cm.

When the flow rate is lowered to 8 l / min, the pressure per square cm received by the hot water pipe 3 which is the inflow side pipe to the filtration tank 5 is −0.0 from the circulating hot water.
The sum of 2 kgf and 0.02 kgf received from the bath water is 0.00 kgf, and the pressure per square cm received by the spout tube 9 which is the outflow side pipe is 0.05 kgf received from the circulating hot water and the bath water. It becomes 0.07 kgf which is the sum of 0.02 kgf, and the differential pressure decreases to 0.07 kgf per square cm.

FIG. 10B shows the case where the apparatus is installed at the position B in FIG. 10, and the hot water pipe 3 which is the inflow side pipe line to the filtration tank 5 at a flow rate of 15 l / min.
The pressure per square centimeter received by -0.04 kgf from circulating hot water and -0.05 kgf from bath water
Is -0.09 kgf.

Further, the pressure per square cm received by the hot water pipe 9 which is the outflow side pipe for the filtration tank 5 is 0.13 kgf received from the circulating hot water and −0.0 received from the bath water.
It is 0.08 kgf, which is the sum of 5 kgf.

Therefore, the pressure difference between the hot water suction pipe 3 as the inflow pipe and the hot water spout pipe 9 as the outflow pipe to the filtration tank 5 is 0.1 per 1 cm 2 as in the case of (a).
It becomes 7 kgf.

When the flow rate decreases to 8 l / min, the pressure per square cm received by the hot water pipe 3 which is the inflow side pipe line to the filtration tank 5 is -0.0 from the circulating hot water.
The sum of 2 kgf and −0.05 kgf received from the bath water is −0.07 kgf, and the pressure per square cm received by the spout tube 9 which is the outflow side pipe is 0.05 kgf received from the circulating hot water and the bath water. Received from -0.05kgf
Is 0.00 kgf, and the differential pressure is 1 cm 2.
Per 0.07 kgf, which is the same value as in the case of (a).

As described above, when the pressure difference between the inflow side and the outflow side with respect to the filtration tank 5 is detected by the differential pressure sensor 34 as the clogging of the filter medium, the differential pressure depends on the clogging of the filter medium. As long as the differential pressure sensor 34 is fixedly installed in the device, the pressures received from the bathtub hot water by the inflow side and outflow side pipes are the same and are offset as a differential pressure. The same flow rate will be used regardless of location.

FIG. 13 is a graph showing the relationship between the flow rate of the hot water and the differential pressure. For example, when a warning of clogging is to be issued when the flow rate reaches 8 l / min, the spring of the differential pressure sensor 34 is shown. 44 may be set to operate at a pressure of 0.07 kgf / cm 2.

A second embodiment is shown in FIG. 2. In this case as well, the basic construction of the apparatus is the same as the conventional example as in the first embodiment, and therefore its explanation is omitted and the differential pressure sensor 34 is provided. Only the state will be described.

In this embodiment, the differential pressure sensor 34 is connected to the hot water suction pipe 3 as an inflow side pipe line to the filtration tank 5 and the connecting pipe 46 of the filtration tank 5 circulation pump 6 as an outflow side pipe line to the branch pipe 32. And 47.

In this embodiment, in the differential pressure sensor 34, not only the hot water suction pipe 3 which is the inflow side pipe line to the filtration tank 5 but also the connection pipe 46 which is the outflow side line is heated upstream of the circulation pump 6. It is connected to a pipeline that receives negative pressure when circulating.

In this case, the differential pressure sensor 34, the low-pressure side connection port 36 of the low-pressure chamber case 35 is filtered to the connection pipe 46 which is the outflow side pipe line to the filtration tank 5, and the high-pressure side connection port 38 of the high-pressure chamber case 37 is filtered. The hot water suction pipe 3 which is the inflow side pipe line to the tank 5 is connected to the hot water suction pipe 3 through the branch pipes 47 and 32 and the connecting pipe in the reverse of the case of the first embodiment.

Therefore, when the flow rate of the hot water is large without the filter medium being clogged, the negative pressure degree of the connecting pipe 36, which is the outflow side conduit, is higher than the negative pressure degree of the hot water suction pipe 3, which is the inflow side conduit. However, since the differential pressure is small, the differential pressure sensor 34 turns off the reed switch 45, and when the filter medium is clogged and the flow rate decreases, the negative pressure of the hot water suction pipe 3 that is the inflow side pipe decreases. The negative pressure degree of the connecting pipe 36, which is the outflow side pipe line, increases and the differential pressure increases, and the differential pressure sensor 34 turns on the reed switch 45 to detect clogging of the filter medium.

FIG. 3 shows a third embodiment. In this device, a filter tank 5 as a filtering device and a filter tank 48 loaded with a wound filter are provided. Of course, the filtering device is not provided. The arrangement order of the filtration tank 5 and the filter tank 48 may be exchanged.

When a plurality of filtration devices are provided in this way, the differential pressure of the outflow and outflow pipes for each filtration device is not detected, but the inflow side pipe line and the most downstream filtration line for the most upstream side filtration device are detected. The clogging state of the filter material as the filtering device may be comprehensively detected by the pressure difference between the outlet side pipe line of the device.

For this reason, in this embodiment, just as in the first embodiment, the hot water suction pipe 3 as an inflow side conduit to the filtration tank 5 which is the upstream filtration device of the two filtration devices and the downstream filtration device. A differential pressure sensor 34 is connected via branch pipes 32 and 33 to the molten metal pipe 9 as an outflow side pipe of a filter tank 48 as a device.

As a result, the clogging state of the filter media of the filtration tank 5 and the filter tank 48 cannot be detected individually, but the comprehensive clogging condition of the filter media of the two filtration devices is detected, and the maintenance of the device is thereby detected. You can do enough inance.

As is apparent from the above-mentioned three embodiments, the differential pressure sensor is provided with branch pipes provided at arbitrary positions of the inflow side pipe line and the outflow side pipe line of the filtering device for detecting clogging. It is enough to connect it, and if it is fixed in the device so that the position does not change, the filter material will not be affected by the pressure of the bath water regardless of the position of the device with respect to the bathtub. Can be accurately detected.

[0073]

The present invention has the above-described structure and operation, and has an extremely simple and inexpensive structure, and does not cause an error due to adhesion of hot water on the sensor or the influence of the installation position of the device. (EN) Provided is a bath water purifying device capable of accurately detecting clogging of a filter medium.

This facilitates maintenance of the bath water purifying device, and the filter material of the filtering device can be washed or replaced at an appropriate time to keep it constantly unclogging,
Since the amount of hot water circulating to the cleaning pipe does not decrease, the cleaning process can be effectively performed, and you can enjoy comfortable bathing with clean water 24 hours a day.

[Brief description of drawings]

FIG. 1 is a first embodiment,

FIG. 2 is a second embodiment,

FIG. 3 shows a third embodiment,

FIG. 4 is a differential pressure sensor (OFF state),

FIG. 5: Differential pressure sensor (ON state),

FIG. 6 is a conventional example,

FIG. 7 Water flow sensor,

FIG. 8 is a conventional example,

FIG. 9 is a pressure sensor,

FIG. 10 is a device installation example,

FIG. 11 shows the flow rate and the pipe line pressure at each device installation position,

FIG. 12 is a differential pressure between the inflow and outflow side pipes with respect to the filtration device at each device installation position,

FIG. 13: Flow rate and differential pressure between inflow and outflow lines for a filtration device.

[Explanation of symbols]

 1 Bathtub 2 Hot water 3 Hot water suction pipe 4 Device body 5 Filtration tank 6 Circulation pump 7 Heater 8 Ozonizer 9 Fountain pipe 32 Branch pipe 33 Branch pipe 34 Differential pressure sensor 47 Branch pipe 48 Filter tank

Claims (1)

[Claims] 1. A cleaning device for hot water in a bathtub in which hot water in a bathtub is forcibly circulated by a circulation pump and is cleaned by a cleaning device such as a filtering device provided in a circulation path, on the inflow side of the filtering device. In addition, a bathtub hot water cleaning device is provided with a differential pressure sensor for detecting clogging of a filter medium due to a pressure difference between the two pipes on the outflow side pipe via a branch pipe.