JPH0213716A - Controller for bath furnace or the like - Google Patents

Abstract

PURPOSE:To effectively stop a no-water burning and to safely protect a heat exchanger and the like by detecting the operation of a temperature detector attached to the exchanger, storing the number of operations of the detector, and providing means for displaying it if it becomes a predetermined number or more and stopping the combustion of a burner. CONSTITUTION:If first no-water burning occurs, a temperature detector 5 operates to open a contact so that the voltage of the clock terminal 16 of a counter IC 15 alters from low to high and lights a first display lamp 26 through a memory circuit 25. On the other hand, a high voltage is also applied to a relay coil 19 though a diode 28, a relay contact 19b is opened from its closure, and a solenoid valve 3 is closed to extinguish a burner 2. In case of second no-water burning, the same operation as that in the first place is conducted. ln case of third no-water burning, a voltage is also applied to the coil 21a of a relay 21, and a contact 21b is opened from its closure. Thus, even if the contact of the detector 5 is closed, the clock terminal 16 of the IC 16 remains high. Accordingly, since no voltage is applied to the valve 3, the burner 2 is not burned, a third display lamp 20 continuously lights, and a bath furnace cannot be used.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a control device for a bath kettle, etc., which detects the number of times a bath kettle, etc. is heated dry, and automatically stops operation when a specified number of times the boil boil is reached. .

BACKGROUND OF THE INVENTION Generally, to boil a bath, water is poured into the bathtub, and when the specified amount of water is reached, the bath kettle is ignited. and the size of the bathtub,
It is necessary to allow the bath kettle (combustion) to run for a time commensurate with the water temperature and amount of hot water.

Incidentally, bathtubs are covered with lids to shorten the operating (combustion) time of the bathtub or to increase the heat retention effect of the bathtub. Because of this lid, the bathtub can be ignited and operated (combusted) without checking the amount of water poured into the bathtub.
In order to do so, it will be in an empty state. For this reason, when the bathtub is in an empty heating state, the temperature of the heat exchanger rises, and the temperature detector attached to the heat exchanger operates to stop the bathtub.

For this reason, conventional bathtubs have been equipped with temperature detectors to prevent empty heating.

Problems to be Solved by the Invention However, in the conventional configuration, since dry heating is assumed, a bimetallic switch called an automatic return type is used as the temperature detector. When the temperature of the heat exchanger increases, the contact opens, and when the temperature of the heat exchanger decreases, the contact automatically returns to its original state, allowing the bathtub to be used.

And, dry heating causes great damage to the heat exchanger. The heat exchanger is made of copper, so when it is heated dry, the steel material turns into copper oxide. In other words, when the heat exchanger is heated dry, the space between the many fins of the heat exchanger is filled with copper oxide. If the space between the fins of the heat exchanger is blocked, the exhaust gas from the burner will not be exhausted sufficiently, resulting in poor combustion, and the space between the fins of the heat exchanger will be further blocked with soot (carbon).

If the bathtub is used in this condition, the fire from the burner will transfer to the soot on the fins of the heat exchanger. As a result, the intake/exhaust fan becomes hot due to the heat generated by the soot between the fins of the heat exchanger, and there is a risk that the intake/exhaust fan may be damaged.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide a bathtub control device that counts the number of times a bathtub or the like is heated empty, and controls the bathtub to not perform a combustion operation when a certain number of times is exceeded.

Means for Solving the Problems In order to achieve the above object, the control device for a bathtub or the like of the present invention includes a heat exchanger, a burner that heats the heat exchanger,
A fan for intake and exhaust of combustion air and exhaust gas, a temperature sensor attached to the heat exchanger, and a temperature sensor that detects the operation of the temperature sensor and stores the number of times of operation, and when a certain number of times or more is exceeded. This configuration includes means for displaying the information and for stopping the combustion of the burner.

Effects According to the present invention, with the above-described configuration, dry heating is detected by a temperature detector attached to the heat exchanger, and the previous number of times for counting the number of dry heating operations is stored by a means for storing the number of times. This number of times is determined to be 0 by a determining means that determines whether or not it is a predetermined number of times.The determining means automatically forcibly stops the bathtub.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 3 is a block diagram of a gas bath pot employing an embodiment of the present invention. 1 is an exterior, 2 is a burner, and has a solenoid valve 3 in the middle. 4 is a heat exchanger, and a temperature detector 5 (here, a bimetal switch) is provided on the outside. 6 is an intake/exhaust fan that sucks in combustion air from the burner 2 and exhausts combustion exhaust gas.

An electrical signal obtained by converting the temperature signal from the temperature detector 5 is input to a control device 7 located inside the external device.

The control device 7 includes a counter circuit 15 as shown in FIG.
and its peripheral circuits. And counter circuit 1
Reference numeral 5 denotes a detection means 8 for inputting the output of the temperature sensor 5, a number calculation means 9 for counting the number of input signals of the detection means 8, a number storage means 1o for storing the number of times, and a number of times can be determined in advance. The number of times of a certain setting section 11a and the number of times storage means 1
a number determination means 11 that compares and determines the number of times from 0;
It is comprised of a combustion stop means 12 which automatically forcibly stops the operation of the bathtub (combustion of the burner 2) based on the output of the determination means 11. Note that 13 and 14 are connection ports between the heat exchanger 4 and the bathtub.

Next, with reference to FIG. 2, the principle of determination of dry firing will be explained.

The solenoid valve 3 is opened and the burner 2 supplied with gas is ignited to heat the heat exchanger 4 connected to the bathtub. The temperature detector 5 indirectly detects the water temperature within the heat exchanger 4.

If there is water in the heat exchanger 4, the temperature of the heat exchanger 3 will not exceed the boiling point of water. However, without water, the temperature of the heat exchanger 4 will rise rapidly and exceed the boiling point of water. This temperature difference is important, and the operating temperature of the temperature detector 5 is 100
Set the temperature above ℃.

The contact structure of the temperature detector 5 is such that it is closed from normal temperature to the operating temperature, opened when the temperature is above the operating temperature, and closed again when the temperature drops by about 20° C. from the operating temperature.

FIG. 1 shows an example of a specific circuit of the main part of the control device 7. As shown in FIG. The control device 7 includes a counter circuit 15 (counter circuit 1
(also referred to as c) and peripheral circuits. The counter circuit 15 shown here is a so-called 1G counter circuit composed of a plurality of 7 lip-flop circuits.

It incorporates a number calculation means 9 for counting the number of times described above and a number storage means 10 for storing the number of times.

1C15 for counter is clock terminal 16 corresponding to input
has. The clock terminal 161 is connected to the next circuit. A circuit corresponding to the output of the temperature detector 5, that is, an intersection point 8 of a circuit in which the resistor 17 and the temperature detector 5 are connected in series is connected to the clock terminal 16. This is the detection means 8 mentioned above.
become. Further, the counter ICl3 has a plurality of bar outputs. In this embodiment, since the operation is stopped at the third dry firing, attention is paid to the third output terminal 33 of the counter IC 15. This corresponds to the above-mentioned "number of times determination means 11 that compares and determines the number of times determined in advance and the number of times of dry firing". A diode 18 is connected to the third output terminal 33.
Through the relay (relay) 19 cari tv i 9 m
and an indicator light 2o are connected respectively. Also, the third output terminal 33 is connected to the coil 21 of another leap relay 21.
0 is connected. A normally closed contact 21b of this relay 21 is connected in series to the detection means 8. This part is the means 12 for forcing a stop.

Reset terminal 2 provided for counter +c15i
2 is connected to the intersection of a series circuit of a resistor 23 and a reset switch 24. The reset switch 24 is a normally closed type.

The "first output terminal 31" and "second output terminal 32" provided in the counter ICl 3 are connected via a memory circuit 25 to a first indicator light 26 as an indicator for the first dry firing, and a first indicator light 26 as an indicator for the second dry firing. A second indicator light 27 is connected as an indicator.

Diodes 28 and 29 are connected to the relay 19 so as to operate during the first and second 5-dry firings. Note that the contact 19b of the relay 19 is connected to the solenoid valve 3. Contact 1
9b uses a normally closed contact.

Next, the operation of the gas bathtub constructed as described above will be explained.

When the first dry heating occurs due to lack of water in the bathtub, etc., when the temperature detector 5 exceeds the operating temperature and operates, its contact opens. Then, since the voltage at the clock terminal 16 of the counter ICl3 changes from low to high, the first output terminal 31 of the counter +c15 also changes from low to high. Then, memory circuit 2
5, the first indicator light 26 of the first dry firing is lit.

On the other hand, via the diode 28, the relay coil w 19
A high voltage is also applied to a. Then, the relay contact 19b changes from closed to open, and the solenoid valve 3 closes because no voltage is applied thereto. Therefore, the burner 2 is extinguished and the temperature rise in the heat exchanger 4 is stopped. Therefore, the temperature of the temperature detector 5 stops rising, and the temperature now falls.

Then, when the temperature of the temperature detector 5 becomes 20° C. or lower than the operating temperature, the contact closes again. Then the counter I
Clock terminal 16 of Cl3 goes low. IC for counter
The output of the "first output terminal 31" of l3 also becomes low. or,
Other "2nd output terminal 32", "3rd output terminal 3"
3" also remains low. The voltage of the relay coil 19a becomes low and its contacts 1'9b also close. On the other hand, the indicator light 26 for the first time of dry firing continues to be displayed by its memory circuit 25.

The second dry firing is the same as the first.

To explain the problem of the third dry firing, when the temperature detector 5 exceeds the operating temperature and operates, its contact opens.

Then, since the voltage at the clock terminal of the counter 1c15 changes from low to high, the "third output terminal 33" of the counter ICl3 also changes from low to high.

Then, a voltage is applied to the relay coil 19m via the diode 18. Then, the relay contact 19b changes from closed to open, and the lightning valve 3 closes because no voltage is applied thereto. Therefore, the burner 2 is extinguished and the temperature rise in the heat exchanger 4 is stopped.

Therefore, the temperature rise of the temperature detector 5 stops, and the temperature thereafter decreases. Then, when the temperature of the temperature detector 5 becomes 20° C. or lower than the operating temperature, the contact closes again.

However, this time, voltage is also applied to the coil lv21m of the relay 21, and its contact 21b changes from closed to open.

Therefore, even if the contact of the temperature detector 5 is closed, the clock terminal 16 of the counter 1c15 remains high because the contact of the relay contact 21b is open.

, Therefore, the "third output terminal 33" remains high.

In other words, this state will continue forever because feedback is being applied. In other words, at the "third dry firing"), no voltage is applied to the solenoid valve 3, so gas is not supplied to the burner 2 and no combustion occurs. Also, the third indicator light 2
o continues to be lit ◎ And 1. The bath kettle cannot be used during the ``3rd'' dry firing.

According to the configuration of the above-mentioned embodiment, the bathtub becomes unusable after the "third time" of empty heating, and safety is greatly improved. To use it again, open the reset switch 24 and close it again to start the operation from the "0th time" dry firing state.

Effects of the Invention As is clear from the above embodiments, the present invention stores the number of times the temperature detector attached to the heat exchanger is operated, displays the number of times the temperature detector is attached to the heat exchanger, displays the number of times the temperature sensor is operated, and stops the combustion of the burner. Therefore, it is possible to reliably stop the heating after dry heating the specified number of times, and it is possible to realize a bath kettle, etc., which has the excellent effect of safely protecting the heat exchanger, etc. .

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a main part of a bath kettle control device according to an embodiment of the present invention, Fig. 2 is a diagram explaining the principle of the same temperature detector, and Fig. 3 is a configuration diagram of a bath kettle in which the same device is implemented. . 2... Burner, 3... Solenoid valve, 4...
... Heat exchanger, 5 ... Temperature detector, 6 ...
...Intake and exhaust fan, 7...Control device, 20
...Indicator light, 15...C0 for counter

Claims (1)

[Claims] A heat exchanger, a burner for heating this heat exchanger, a fan for intake and exhaust of combustion air and exhaust gas of this burner, a temperature detector attached to the heat exchanger, and operation of this temperature detector 1. A control device for a bathtub or the like, characterized in that it is equipped with means for detecting the number of operations, storing the number of operations, displaying a display when the number of operations exceeds a certain value, and stopping combustion of the burner.