JPH0629629Y2 - Venturi device that also serves as a water drain plug for a gas water heater - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention provides a venturi device for introducing a negative pressure to a diaphragm secondary chamber (low pressure chamber) of a water pressure responsive device in a gas water heater. The present invention relates to a venturi device also used as a water drain plug of a gas water heater, which is incorporated in a water drain plug for draining water.

[Conventional technology]

Conventionally, in a gas water heater, a drain plug having a Venturi device is screwed at an appropriate position in a water supply passage, and the negative pressure generated in the device is applied to a diaphragm secondary chamber (low pressure chamber) of a water pressure response device.
In accordance with the differential pressure from the negative pressure of the Venturi device, the diaphragm of the hydraulic pressure responding device is displaced, and the drain plug is pulled out to enable draining of water in the gas water heater. is there.

In this device, a water drainage hole 3'is provided in communication with a water supply passage 2a ', and a water drainage plug 5'having a venturi member 1'is detachably fitted in the water drainage hole 3', and the venturi member 1'is attached.
A through hole 8'provided at a right angle to the water flow direction on the inner side wall of is connected to a passage 11 'for guiding a negative pressure to the diaphragm secondary chamber 10' of the hydraulic actuator A ', and a negative pressure is generated on the inner surface of the venturi member 1'. The negative pressure of the portion a'is guided to the secondary chamber 10 ', and a water supply hole 20' is provided at the center of the water drain plug 5'communicating with the venturi member 1 ', and the rear end of the water supply hole 20' is provided. The venturi member 1'is also pulled out from the water supply passage 2a 'by connecting the water pressure responding device A'to the primary chamber 9'through the water supply passage 2b' and removing the water drain plug 5'from the water drain hole 3 '.
a'is widened so that the heat exchanger, the water supply passage 2 ', the water pressure responsive device A', etc. can be easily drained.

[Problems to be solved by the device]

However, since the above-mentioned device uses a conventionally known venturi device in which a through hole 8'is provided in the inner wall of the venturi member at a right angle to the water flow direction, the static pressure is obtained, so that the negative pressure is small and the hydraulic pressure responsive device operates. It is difficult to reduce the water pressure.
Also, since the passage 11 'needs to be arranged at the lower end of the diaphragm chamber, the venturi member 1'must be inserted at the same horizontal position or extending downward from the venturi member 1'. However, there is a disadvantage that the installation position is limited, and the insertion part 30 'of the water drain plug 5'is considerably protruded from the main body of the hydraulic pressure responding device A'and becomes large.

In view of the above points, the present invention provides a venturi nozzle in the water flow direction, and instead of taking a static pressure in a direction perpendicular to the water flow direction as in a conventional venturi device, a negative dynamic pressure is taken in the water flow direction. To maximize the Venturi effect,
While reducing the operating water pressure of the water pressure response device, the venturi nozzle that constitutes the venturi device is provided integrally with the water drain plug, and when draining water, the venturi nozzle is also pulled out together with the water drain plug to form a wide water supply passage, The cross-sectional area of the passage of the diaphragm secondary chamber and the venturi section is made as large as possible and the length is made as short as possible to facilitate draining of water.

[Means for Solving the Problems]

The present invention solves the above-mentioned problems by providing a venturi portion 1 in a water supply passage 2a, connecting drainage holes 3 on the same axis of the water supply passage 2a, and connecting the drainage hole 3 to a diaphragm. A drainage passage 12 for draining water of the primary difference 9 is provided in communication with each other, and a drainage plug 5 having a Venturi nozzle 4 is detachably and tightly fitted into the drainage hole 3.
When fitted, the tip of the venturi nozzle 4 is inserted up to the venturi portion 1, and the tip of the venturi nozzle 4 is arranged so as to be concentric with the venturi portion 1. The tip outer peripheral surface of the venturi nozzle 4 and the inner circumference of the venturi portion 1 are arranged. A gap with the surface is used as a negative pressure generating portion a, and the negative pressure generating portion a is communicated with a conduction hole 6 formed at the center of the water drain plug 5, and the conduction hole 6
Through the through hole 7 continuously provided at the rear end thereof, and is communicated with the diaphragm secondary chamber 10 through the passage 11 connecting the through hole 7 and the diaphragm secondary chamber 10 of the hydraulic actuator A.

[Action]

With the above configuration, when water supply (hot water supply) is started, the water flows into the diaphragm primary chamber 9 of the water pressure responding device A, causes the water pressure to act on the diaphragm 8 and flows into the rear water supply passage 2a, and the tip outer peripheral surface of the venturi nozzle 4 and the venturi portion. Water is supplied from the water supply passage 2 to the heat exchanger 16 through a gap between the inner peripheral surface of the heat exchanger 1 and the heat exchanger 16.
The water flowing into the water supply passage 2a has the highest flow velocity in a gap (negative pressure generating portion a) having a small flow cross-sectional area sandwiched between the tip outer peripheral surface of the Venturi nozzle 4 and the inner peripheral surface of the Venturi portion 1, and the water flows thereafter. On the side (heat exchanger side), since the cross-sectional area of water flow becomes large and the flow velocity becomes slow, a large negative dynamic pressure is generated in the negative pressure generating portion a, and this large negative pressure is generated by the opening of the conduction hole 6 of the venturi nozzle 4. And is introduced into the diaphragm secondary chamber 10 of the hydraulic pressure responding device A through the through hole 6, the through hole 7 and the passage 11, and the diaphragm 8 operates sensitively to fluctuations in the water supply pressure and low water supply pressure.

When removing the water from the gas water heater, when the water drain plug 5 is removed from the water drain hole 3, the venturi nozzle 4 is also pulled out from the venturi portion 1 and the water supply passage 2a, and the venturi portion 1 is removed. The cross-sectional area of water flow is expanded, and the water in the heat exchanger 16 and the water supply path 2 to the heat exchanger 16 quickly flows out from the drain hole 3, and the diaphragm primary chamber 9 and the diaphragm secondary chamber of the water pressure response device A are also provided. The water in 10 also drains from the water draining hole 3 through the water draining passage 12 and the passage 11.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

1 to 3, reference numeral 2a denotes a water supply passage in the vicinity of the hydraulic pressure responding device A of the water supply passage 2 for supplying water to the heat exchanger 16. The water supply passage 2a is provided with the venturi portion 1 constituting the venturi device. The water drainage hole 3 is formed in a constricted manner, and is connected to the water supply passage 2a on the same axis as the water supply passage 2a and having one end opened to the outer lower surface of the insertion portion 31 of the housing 30. Denoted at 5 is a drain plug that is detachably attached to the drain hole 3 and tightly screwed, and has a venturi nozzle 4 at the tip.
A vent hole is formed at the center of the venturi nozzle 4 and a through hole 6 is provided at the center of the venturi nozzle 4 and a through hole 7 is formed at the rear end of the through hole 6 at right angles to the through hole 6 through the water drain plug 5. Is provided.

The venturi nozzle 4 has the venturi portion 1 when the water drain plug 5 is screwed into the water drain hole 3 with the proximal end thread portion 18.
It is inserted inside and is concentric with the venturi portion 1, and the gap between the tip outer peripheral surface of the venturi nozzle 4 and the inner peripheral surface of the venturi portion 1 is sufficiently small to form a negative pressure generating portion a. Reference numeral 11 denotes a passage which is formed in the boss portion 32 of the housing 30 to connect the diaphragm secondary chamber 10 of the hydraulic pressure responding device A and the drain hole 3 to each other. When draining water, this is the water in the diaphragm secondary chamber 10. It serves as a drainage passage and is usually connected to the through hole 7 of the water drain plug 5 and is connected to the negative pressure generating portion a.
It serves as a passage for guiding the negative pressure of (1) to the secondary chamber 10 of the diaphragm. Reference numeral 19 is an O-ring that closely contacts the water drain plug 5 with the water drain hole 3 when screwed. The hydraulic pressure responding device A is divided by a diaphragm 8 into a diaphragm primary chamber (high pressure chamber) 9 and a diaphragm secondary chamber (low pressure chamber) 10, and an inlet 13 and a diaphragm into which water flows from the water supply passage 2 into the diaphragm primary chamber 9. An outlet 14 that flows out from the primary chamber 9 is provided, and a drainage passage 12 that is bored in a boss portion 33 that drains water from the diaphragm primary chamber 9 is provided in open communication with the drainage hole 3. There is. Reference numeral 15 is a temperature control valve provided in the path from the diaphragm primary chamber 9 to the water supply channel 2a, and the degree of polymerization between the through hole 15a formed in the temperature control valve 15 and the outflow port 14 is changed to change the water supply channel. The outlet water temperature is adjusted by adjusting the amount of water flowing into 2a. 1
A heat exchanger 6 is supplied with water from the water supply passage 2a through the water supply passage 2, and the hot water heated here is discharged through the hot water supply pipe 17. Further, 21 is a bypass passage branched from the water supply passage 2, 34 is a water amount correction valve, and 35 is packing.

According to this embodiment, when water supply (hot water supply) is started when the gas water heater is used, the water flows from the water supply passage into the diaphragm primary chamber 9 through the water supply hole 13, and the water supply pressure acts on the diaphragm 8. The diaphragm 8 is displaced according to the water supply pressure, and controls a gas valve (not shown) that adjusts the amount of gas supplied to the burner via the rod 20. The water that has flowed into the diaphragm primary chamber 9 flows from the outflow port 14 through the temperature control valve 15 into the water supply passage 2a, that is, the gap between the outer peripheral surface of the venturi nozzle 4 and the inner peripheral surface of the water supply passage 2a. Passes through a gap between the outer peripheral surface of the tip of the and the inner peripheral surface of the Venturi portion 1, and at this time, this gap serves as a negative pressure generating portion a to generate negative pressure, and then water is supplied from the water supply passage 2 to the heat exchanger 16. It is heated and discharged from the hot water supply pipe 17.

Then, the negative pressure of the negative pressure generating portion a is taken in from the tip of the Venturi nozzle 4, passes through the through hole 6 and the through hole 7, and passes through the passage 11 to the diaphragm secondary chamber 10 of the hydraulic pressure responding device A.
Be led to. At that time, the water in the through hole 6 is sucked by the flow pressure of the water flow flowing through the water supply passage 2a, so that the diaphragm secondary chamber 10 becomes a large negative pressure, the diaphragm 8 is easily displaced, and is sensitive to the fluctuation of the water supply pressure. Reacts to and reliably operates even with low water pressure.

Next, when draining water in order to prevent freezing of the gas water heater, the drain plug 5 is removed from the drain hole 3, and along with this, the venturi nozzle 4 also comes from the venturi portion 1 and the water supply passage 2a. The water in the heat exchanger 16 and the water supply passage 2 is quickly extracted from the drain hole 3 by expanding the water cross-sectional area of the venturi portion 1. Further, the water in the diaphragm primary chamber 9 of the hydraulic pressure responding device A passes through the drainage passage 12 and the water in the secondary chamber 10 passes through the passage 11 and is discharged from the drainage hole 3.

[Effect of device]

As described above, in the present invention, the venturi nozzle is provided in the water flow direction so as to obtain the negative dynamic pressure of the flowing water, so that the venturi effect can be maximized, and the diaphragm secondary chamber of the water pressure responding device can have a large negative pressure. Therefore, the displacement reaction of the diaphragm with respect to the water supply pressure becomes sensitive, the operating water pressure of the water heater can be reduced, and the diaphragm can operate following a slight change in the water supply pressure. Therefore, there is an advantage that the gas valve connected to the diaphragm is accurately controlled in proportion to the water supply pressure, and combustion heating corresponding to the water supply amount is always secured.

In addition, when draining water, when removing the water drain plug, the venturi nozzle is also pulled out from within the venturi portion and the water supply passage so that there is no narrow passage, and the distribution cross-sectional area of the venturi portion where the water supply passage is narrowed is widened. , The drainage passage is also very short, so the heat exchanger and the water supply path to the heat exchanger,
The water in the primary and secondary chambers of the diaphragm chamber is quickly drained. Further, since the through hole and the through hole having a small water passage diameter are provided in the water drain plug, the processing of the small through hole and the through hole is easier than the conventional drilling in the housing. It is easy to manufacture, and when water is drained, water droplets adhering to the inner surface of the water supply channel or the like do not flow down, and the surface tension of the water does not block the small-diameter through-holes or through-holes, and does not freeze and block.

Further, the water drainage passage is very short, that is, the boss portion of the housing forming the passage and the insertion portion of the water drainage plug are also short, so that the housing including the water pressure response device can be made compact.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a venturi device for a water heater of the present invention which also serves as a water draining plug, and FIG. 2 is a cross-sectional view of the main part of FIG. FIG. 3 is a perspective view showing an embodiment of the present invention, FIG. 4 is a schematic development view for explaining the operating principle of the above embodiment of the present invention, and FIG. 5 is a sectional view of a main part of a conventional example. . 1 ... Venturi part, 2a ... water supply channel, 3 ... drainage hole, 4 ... venturi nozzle, 5 ... water drain plug, 6 ...
… Conducting hole, 7 …… Through hole, 9 …… Primary diaphragm chamber,
10 ... diaphragm secondary chamber, 11 ... passage, 12 ...
Drainage passage, a ... Negative pressure generating part, A ... Water pressure response device.

Claims (1)

[Scope of utility model registration request] 1. A venturi portion (1) is provided in a water supply passage (2a), a water drainage hole (3) is connected to the water supply passage (2a), and a diaphragm primary chamber (9) is provided in the water drainage hole (3). A water drain passage (12) for draining the water is provided in communication with each other, and a water drain plug (5) equipped with a venturi nozzle (4) is detachably fitted in the water drain hole (3). Of the venturi nozzle (4) is located concentrically with the venturi portion (1), and the gap between the tip outer peripheral surface of the venturi nozzle (4) and the inner peripheral surface of the venturi portion (1) is used as a negative pressure generating portion (a). The generating portion (a) is communicated with a conduction hole (6) provided at the center of the venturi nozzle (4), and a through hole (7) is provided at the rear end of the conduction hole (6), and a through hole is formed. A passage (11) connecting (7) and the diaphragm secondary chamber (10) of the hydraulic pressure responding device (A). Drain plug also serves venturi device for a gas water heater, characterized in that communicating with the secondary chamber (10) through.