JPH0636779B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a hot water supply apparatus that utilizes the siphon effect to extract hot water from a heating tank.

(B) Conventional technology In general, those that utilize the siphon effect for hot water extraction are
It is known that when air bubbles generated from the surface of an electric heater enter the siphon tube during heating, the siphon effect is interrupted or stopped.

This phenomenon is due to the fact that the water head is large at the beginning of the extraction due to the siphon effect, so the air that has entered the siphon pipe is extracted together with the hot water, and no air pools occur in the pipe, but when the water head becomes smaller in the latter half of the siphon. As a result, the air that has entered the siphon pipe accumulates in the pipe, and as a result, the siphon effect was interrupted or stopped as described above.

As a conventional technique for solving this, for example, Japanese Patent Publication No. 51-3
Japanese Patent No. 6659 discloses a coffee pouring device in which a cup-shaped foam shelter having a plurality of holes formed in a side surface position lower than a suction port of a siphon tube is arranged.

(C) The problem to be solved by the invention The related art is such that a part of the bubbles generated from the surface of the heater is sucked into the bubble preventer through a plurality of holes and is sucked into the inside of the siphon pipe through the suction port. Inevitably, it was impossible to completely prevent air bubbles from entering the siphon tube.

The present invention, in particular, in the latter stage of hot water extraction where there is a risk of interruption or stop of the siphon effect, prevents interruption or stop of the siphon effect by preventing the generation of bubbles from the electric heater, and ensures a predetermined hot water extraction. A hot water supply device intended to be carried out.

(D) Means for Solving the Problems In order to achieve the above object, the present invention provides a hot water supply device for extracting hot water in a heating tank from a siphon pipe connected to the tank by utilizing a siphon effect, wherein the heating An electric heater for heating arranged inside the tank, a hot water temperature detecting device for detecting the hot water temperature of the heating tank to control the energization of the heater, and a water supply that opens so as to supply water to the heating tank based on a hot water supply command. A hot water supply apparatus provided with a solenoid valve and a control device for stopping the energization of the electric heater in the latter half of the hot water extraction by the siphon effect at least until the siphon effect is cut off regardless of the detection operation of the hot water temperature detection device. Is.

(E) Action According to the present invention, the hot water in the heating tank (2) in which the siphon effect is started is extracted from the siphon pipe (3), and at the latter stage of this siphon effect, even if the thermostat as the hot water temperature detecting device ( Even if the electric heater (8) is energized by (16), the electric heater (8) is controlled by the timer (22) as a control device until the siphon effect ends.
The energization of (8) is controlled to a stop state to prevent the generation of bubbles from the electric heater (8). As a result, the siphon effect ends at a predetermined position where the water level is lower than the level of the suction port (3A) of the siphon pipe (3), and a stable extraction amount can be secured.

(F) Embodiments Embodiments of the present invention will be described below with reference to the drawings. (1)
Is a hot water supply device showing a coffee brewing device, inside of which various parts including a heating tank (2) are arranged, and at the front part, one end suction port (3A) is provided at an upper part of the heating tank (2) A siphon pipe (3) communicating with the sprinkler (4) is provided at the other end.
Is installed. Below the sprinkler (4), a chamber (5) for containing coffee powder is supported on the upper surface of the filter so as to be able to be drawn out, and below the chamber (5), a decanter (6) is placed. A plate (7) is provided. (8) is an electric heater that heats water in the heating tank (2), (9) is a water supply pipe to the heating tank (2), and a water supply solenoid valve (10)
It is directly connected to the external water pipe via. (11) is a float type water level detection device for detecting the water level of the heating tank (2), for example, a pipe (12) having a lower end communicating with the lower part of the heating tank (2) and an upper part communicating with the atmosphere is provided. 12) Inside the hollow guide rod (1
3) hangs down, and a float (14) having a permanent magnet is movably supported on the guide rod (13) and the guide rod (13)
A reed switch (15) that closes the contacts at a level slightly higher than the level at which the siphon effect starts is provided therein. Reference numeral (16) is a thermostat as a hot water temperature detecting device for detecting the hot water temperature in the heating tank (2) and controlling the energization of the electric heater (8). (17) is the water supply pipe (9) and the heating tank (2)
Is an air vent pipe that communicates with the upper part of the.

Next, the operation of the present invention will be described based on the above configuration and the electric circuit of FIG. The inside of the heating tank (2) is normally kept at the water level indicated by the solid line of the float (14), but when the hot water switch (18) of the automatic reset type is pressed, the first relay (19) is excited and normally open. The relay contact (19A) of is closed and self-holding,
At the same time, the water supply solenoid valve (10) is opened, and pressurized water is supplied to the heating tank (2) through the water supply pipe (9). Due to this water supply, the water level in the heating tank (2) rises and the top (3) of the siphon pipe (3)
Beyond B), the siphon effect begins and the heating tank
Hot water in (2) is extracted through the siphon tube (3). Almost at the same time, the reed switch (15) closed and the second
When the relay (20) is excited, the normally closed relay contact (20A) connected in series with the water supply solenoid valve (10) is opened, and the normally open relay contact (serially connected with the first timer (21) described later ( 20
Close B). This completes the water supply operation to the heating tank (2).

On the other hand, the first timer (21) is a normally open timer contact (21A) that closes at the same time as the start, and the extraction time obtained in advance by experiment, for example, 1 minute 30 seconds if 2 minutes, that is, hot water extraction It has a normally open timer contact (21B) that closes when entering the latter half.

Therefore, when the first timer (21) is started by closing the relay contact (20B) of the second relay (20), the timer contact (2
1A) closes and 1 minute and 30 seconds later, timer contact (21B)
Closes and the second timer (22) starts.

This second timer (22) is an electric heater in the latter stage of hot water extraction.
A timer contact (22) for resetting the first timer (21) acts as a control device for forcibly energizing (8) regardless of the detection operation of the thermostat (16).
A) and a timer contact that keeps the second timer (22) energized
(22B) and a timer contact (22C) connected in series with the electric heater (8) and the thermostat (16). These timer contacts (22A), (22B), (22C) are the second timer (2
It is switched at the same time as the power is supplied to 2), and when a predetermined time has passed, that is, after the siphon effect ends, for example, 1 minute 2
When 0 seconds have passed, the normal state is restored.

Therefore, when the second timer (22) is started, each timer contact (22A), (22B), (22C) is opened, and the electric heater (8)
In the latter half of the hot water extraction, the power supply is forcibly cut off for a predetermined time. Therefore, it is possible to prevent bubbles from being generated from the surface of the electric heater (8), and to reliably prevent bubbles from entering the suction port (3A) of the siphon tube (3).

After that, hot water was extracted from the siphon pipe (3),
When the water level of the heating tank (2) drops below the suction port (3A) of the siphon pipe (3), air enters the siphon pipe (3) to cut off the siphon effect and finish the extraction of hot water.

After that, the second timer (22) has passed a predetermined time, and the respective timer contacts (22A), (22B), (22C) are returned to the normal state, and the second
The timer (22) is reset and the electric heater (8) also restarts the heating operation if necessary by the thermostat (16) based on the detection operation.

As in the above example, by turning off the electric heater (8) for a short time even after the siphon effect is finished, the liquid surface sways due to boiling water near the end of the siphon. It is effective to prevent siphon breakage at a given level.

(G) Effect of the invention As described above, the present invention controls electric power supply to the electric heater provided inside the heating tank, so that the electric power can be changed in the latter stage of the siphon effect which may cause interruption or stop of the siphon effect due to bubble invasion. Since the generation of air bubbles from the heater can be stopped, interruption or stop of the siphon effect can be reliably prevented, and an excellent advantage that a predetermined hot water extraction amount can be secured at all times is exhibited.

[Brief description of drawings]

FIG. 1 is an internal configuration diagram of the hot water supply apparatus of the present invention, and FIG. 2 is an electric circuit diagram of the present invention. (2) …… Heating tank, (3) …… Siphon tube, (8) …… Electric heater, (10) …… Water supply solenoid valve, (16) …… Thermostat (hot water temperature detector), (22)… … Second timer (control device), (22C) …… Timer contact.

Claims (1)

[Claims] 1. A hot water supply apparatus for extracting hot water in a heating tank from a siphon pipe connected to the tank by utilizing the siphon effect, and an electric heater for heating arranged inside the heating tank and a heating tank. A hot water temperature detection device that detects the hot water temperature and controls the energization of the heater, a water supply solenoid valve that opens so as to supply water to the heating tank based on the hot water supply command, and at least the siphon effect at the latter stage of hot water extraction by the siphon effect A hot water supply device comprising a control device for keeping the electric heater energized until it is turned off regardless of the detection operation of the hot water temperature detection device.