JP3124404B2 - Hot water production equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water producing apparatus for producing hot water by mixing steam and water.

[0002]

2. Description of the Related Art Conventionally, there is a hot water producing apparatus for producing hot water by mixing steam and water. This hot water producing apparatus has an advantage that hot water can be easily obtained by using a steam source often installed in a factory. FIG. 4 shows a main part of this kind of hot water producing apparatus.

In FIG. 4, water is supplied to a mixer 7 from a water supply pipe 9 and steam is supplied from a steam pipe 11 and mixed in a mixing chamber 71 to become hot water. Taken out. A steam blowing pipe 73 having a large number of small holes 72 is inserted into the mixing chamber 71, and steam is blown out from these small holes 72 to mix with water. The steam pipe 11 is provided with a steam control valve 10 for controlling the amount of steam.

[0004]

If the steam control valve 10 is suddenly closed during the operation of the above hot water producing apparatus, unpleasant metal noise and vibration are generated. As a result of intensive pursuit of the cause by the inventors, the following has been found. That is, when the steam control valve 10 is suddenly closed and the steam flowing into the mixer 7 is suddenly cut off, the steam pipe 11
11A between the control valve 10 and the mixer 7
Then, agglomeration of steam occurs due to a decrease in temperature, and a large negative pressure is generated. As a result, water rapidly flows back into the pipe 11A from the small hole 72 of the steam blow-out pipe 73, and a water hammer phenomenon occurs. It turned out to be. The water hammer phenomenon involves an unpleasant metal sound, and also has a large energy and violent vibration, so that there is a risk of damaging pipes and equipment.

An object of the present invention is to provide a hot water producing apparatus capable of preventing the occurrence of a water hammer phenomenon and preventing the occurrence of unpleasant metal noise and the damage of piping and equipment.

[0006]

In order to achieve the above object, a hot water producing apparatus according to the present invention is provided with a vacuum break valve in a pipe between a steam control valve and a mixer for eliminating a negative pressure in the pipe. Provided.

[0007]

According to the present invention, when the steam flowing into the mixer is suddenly cut off and a large negative pressure is generated in the piping between the mixer and the steam control valve, the vacuum is released via the vacuum break valve. Atmosphere is introduced into the pipe, and the introduced air eliminates the negative pressure. Therefore, the backflow of water from the mixer into the pipe is prevented, and the occurrence of the water hammer phenomenon due to the backflow is prevented.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a circulation tank, which is provided with a first water level gauge 2 and a second water level gauge 3 at upper and lower portions thereof,
On the upper side of the circulation tank 1, a water supply pipe 4 and a return hot water pipe 5 for collecting return hot water from the user load side are provided. The water supply pipe 4 is provided with a water supply control valve 6,
By controlling the opening and closing of the control valve 6 based on the detection results of the first and second water level gauges 2 and 3, the water level of the circulation tank 1 is maintained at a constant level.

A mixer 7 is connected to the circulation tank 1 via a water supply pipe 9 provided with a pump 8 on the way.
A steam pipe 11 having a steam control valve 10 is connected to the mixer 7, and hot water is produced by mixing steam and water flowing from the steam pipe 11 and the water supply pipe 9 with water. . A discharge pipe 12 for discharging hot water from the mixer 7 to the user load side is provided on the discharge side of the mixer 7.
The discharge pipe 12 is provided with a branch pipe 13 for returning a part of the hot water to the circulation tank 1 side, and the excess hot water which is not taken out to the user load side is collected in the circulation tank 1. You.

Further, a temperature detector 1 is connected to the discharge pipe 12.
The steam control valve 10 is controlled to open and close based on the detection result, thereby adjusting the amount of steam flowing into the mixer 7 and controlling the temperature of the hot water discharged from the discharge pipe 12 to a predetermined value. Is maintained at the set temperature.
It should be noted that the pump 8 provided in the supply pipe 9 is
It is driven at a rotational speed that can ensure the maximum usage of the hot water taken out from the second. Also, in FIG.
This is a manual on-off valve provided in 11, 12, and 13.

As shown in FIG. 2, the mixer 7 has a mixing chamber 71 for mixing steam and water, into which a steam blowing pipe 73 having a number of small holes 72 is inserted. The steam blowing pipe 73 blows out the steam from the steam pipe 11 from the small hole 72 into the mixing chamber 71 in a bubble state. And
The steam blown into the mixing chamber 71 is supplied to the water supply pipe 9.
The hot water is mixed with the water supplied from the discharge pipe 12, and the hot water is discharged from the discharge pipe 12.

Further, in a pipe 11A between the steam control valve 10 and the mixer 7 in the steam pipe 11, a vacuum breaking valve 1 is provided.
6 are provided. The vacuum break valve 16 is broken when the pressure in the pipe 11A becomes negative,
The inside is communicated with the atmosphere. For example, a known structure as shown in FIG. 3 is used.

In FIG. 3, the vacuum break valve 16 has a body 17 and a cap 18 screwed to the upper part thereof. A passage 19 penetrating in the axial direction is formed in the body 17.
A spherical valve element 20 and a spring element 21 for pressing the valve element 20 in the closing direction are inserted into the passage 19. At the upper end of the passage 19, a filter 22 made of a punching plate is mounted. The cap 1
The inner space 23 of 8 communicates with the passage 19 and with the atmosphere through an open hole 24. The vacuum break valve 16 having the above-described structure is provided with a screw portion 17a at a lower portion of the body 17.
Is attached to the pipe 11A by screwing it into the pipe 11A.

In the above configuration, the steam control valve 10 provided in the steam pipe 11 is suddenly closed, so that the flow of steam into the mixer 7 is suddenly stopped, and the temperature in the pipe 11A is reduced. The pipes 11A
When a large negative pressure is generated inside the vacuum release valve 1
6 is automatically opened and air is introduced into the pipe 11A, and the introduced air releases the negative pressure. That is, since the pressure above the valve element 20 in the passage 19 of the vacuum break valve 16 is always atmospheric pressure, when the pressure in the pipe 11A becomes negative, the valve element 20 is pushed down by the pressure difference to open, and the pipe 11A is opened. The vacuum inside is broken, and the atmospheric pressure
A is introduced into A. Therefore, the water in the mixer 7 is
The occurrence of the water hammer phenomenon caused by flowing into 1A is prevented, whereby the generation of unpleasant metal sounds,
In addition, damage to pipelines and equipment is prevented.

When the negative pressure in the steam pipe 11 is released by opening the vacuum break valve 16 and the internal pressure is equalized to the atmospheric pressure, the valve body 20 is automatically moved by the spring force of the spring body 21. The valve is returned to the closed position at
Is closed. In this way, the subsequent hot water production operation is performed without any trouble.

[0016]

As described above, according to the present invention, the water between the steam control valve and the mixer is provided with a simple structure in which the vacuum break valve for eliminating the negative pressure of the pipe is provided. The occurrence of the hammer phenomenon can be prevented, and the generation of unpleasant metal noise and the damage to piping and equipment can be prevented.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a hot water producing apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic front view of the mixer in the embodiment.

FIG. 3 is a longitudinal sectional view showing a vacuum break valve in the embodiment.

FIG. 4 is a configuration diagram showing a main part of a conventional hot water production device.

[Explanation of symbols]

7 ... mixer, 10 ... control valve for steam, 11A ... pipe, 16
... Vacuum release valve.

Continuation of the front page (72) Inventor Toshiharu Takegawa 2-30-30 Tagawakita, Yodogawa-ku, Osaka-shi, Osaka Miyawaki Co., Ltd. (56) References Japanese Unexamined Patent Publication No. 175811 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24H 1/22 301 F24D 17/00 F24H 1/10

Claims (1)

(57) [Claims] 1. A mixer for mixing water and steam to produce hot water, and a steam control valve for controlling a flow rate of steam flowing into the mixer so that the hot water produced by the mixer has a predetermined temperature. A hot water production apparatus, comprising: a pipe between the steam control valve and the mixer, which is provided with a vacuum break valve for eliminating a negative pressure in the pipe.