JPH0584403B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a water supply device for a low-pressure small steam boiler used as a heat source device for heating or the like.

[Prior art and its problems] Conventionally, water supply devices mainly used in small steam boilers with an equivalent evaporation rate of about 40 kg/h or more monitor the boiler water level using electrodes to turn on and off the water pump. Ta.

This type of boiler is often used in the food processing industry, cleaning industry, etc., and it is customary to undergo periodic maintenance inspections.

On the other hand, steam boilers used for home heating with an equivalent evaporation rate of about 10 to 20 kg/h must meet certain requirements, such as being able to be used without daily or periodic inspections, being compact, and being inexpensive. However, the above-mentioned conventional type of boiler cannot meet these conditions, and in particular, the corrosion and wear of the electrodes used for water supply control, the reliability and high cost of the water supply pump have become obstacles to production.

[Object of the present invention] An object of the present invention is to obtain a device for detecting the water level in a steam boiler without using electrodes that cause corrosion, and automatically supplying water without using a pump.

[Configuration of the present invention] The configuration of the present invention is as follows.

Steam is generated by heating the water sealed in the steam boiler, and this steam is conveyed to the heat radiating section via the outbound pipe, and the condensed water that is condensed through heat exchange in the heat radiating section is sent through the return pipe. When the amount of water in the steam boiler decreases to the operating low water level, the condensed water stored in the return water tank is supplied to the steam boiler to restore the water amount to the operating high water level. In a type of steam boiler, a water supply tank is placed between the return water tank and the steam boiler at a position higher than the operating high water level of the steam boiler, and the upper part of the water supply tank and the lower part of the return water tank are connected by a condensate water pipe. The bottom of the water supply tank and a connection port opened at a low operating water level position in the side wall of the steam boiler are communicated with each other through a water supply pipe, and the condensed water pipe and the outflow pipe are communicated with each other through a steam communication pipe, A control valve is installed in the middle of the condensate water pipe and the water supply pipe, and a control valve is also installed in the steam communication pipe, a lower temperature sensor is installed at the lower part sandwiching the control valve installed in the water supply pipe, and an upper temperature sensor is installed at the upper part. Attach the
The control valve attached to the steam communication pipe is configured to open when the lower temperature sensor detects a temperature higher than a certain set temperature and close when the upper temperature sensor exceeds a certain set temperature. Water supply device.

[Action of the present invention] The present invention generates steam in a steam boiler,
This is led to the heat radiating section via the steam pipe, where the heat is released. The water that has released heat and condensed is stored in a return water tank via a return pipe. Then, when the water level in the steam boiler falls and this water level hits the connection port, steam enters the water supply pipe through the connection port, causing the temperature of the water supply pipe to rise rapidly. When the temperature of the water supply pipe increases, a temperature sensor detects this and opens a control valve attached to the steam communication pipe. When the control valve is opened, steam enters the water tank through the steam communication pipe, and the pressure in the water tank and the steam boiler becomes the same. In this way, when the pressure inside the water tank becomes the same as that inside the steam boiler, the water pressure inside the water tank acts on the control valve, which opens this valve, and due to the difference in head pressure, all the water in the water tank flows into the steam boiler. However, the water level inside the steam boiler returns to the initial water level, which is the operating high water level. During this time, the temperature sensor (water supply pipe) between the water tank and the steam boiler
is cooled. When this action is performed, the inside of the water supply tank is filled with steam via the steam communication pipe, and this steam also flows into the water supply pipe from the water supply tank and heats the water supply pipe. As a result, a temperature sensor installed between the control valve and the water tank detects this high temperature and closes the control valve. When the control valve closes, the inflow of steam stops, the water tank is naturally cooled, and the pressure inside it is reduced. In other words, the water vapor remaining in the water supply tank condenses and the interior of the water supply tank becomes a vacuum state. As a result, the control valve in the condensed water pipe opens, and the condensed water accumulated in the return water tank flows into the water supply tank via the condensed water pipe and waits for the next water supply.

In addition, in the above-mentioned operation, the heating of the steam boiler continues, and the generation and delivery of steam are also performed continuously. However, although there is some temperature drop when water is supplied from the water supply tank, the design allows for continuous delivery of steam by keeping the absolute amount of water supplied small.

[Example] Reference numeral 1 indicates a steam boiler heated by a gas burner 1a, and boiler water 15a is contained therein. A, B, and C are symbols added to represent the water level of the steam boiler, where A is the operating high water level, B is the water level at the upper edge of the connection port where steam enters, and C is the operating low water level. 2 is a water tank;
The water supply pipe 10 coming out from the bottom of the water supply tank 2 is connected to the steam boiler 1 at an upward slope toward the water supply tank 2 side so that its connection port 9 is approximately equal to the operating low water level C of the steam boiler 1. A check valve 4 is interposed in the middle, and a temperature sensor 12 is installed above the check valve 4.
However, a temperature sensor 11 is attached to the lower part. 7 is a steam header, and a steam pipe (outgoing pipe) 13 and a steam communication pipe 8 branch from the steam header 7 to a radiator 13a. The steam communication pipe 8 is connected to the water supply tank 2, and a solenoid valve 3 is interposed in the middle thereof. 6 is a return water tank that is open to the atmosphere.
It is located below the operating water level (A level) of the steam boiler. 14 is the bottom of the return water tank 6 and the water supply tank 2
This is a condensate water pipe that connects the top of the pipe, and a check valve 5 is interposed in the middle.

16 is a return pipe from the heat radiation part 13a, and is connected to the water return tank 6.

17 is a vacuum regulating valve branched from the steam header 7.

The embodiment has the above configuration, and an example of its operation will be explained next.

At the start of operation, the water level in the steam boiler 1 is at level A, the water tank 2 is full of water, and the solenoid valve 3 is closed. When the temperature inside the steam boiler 1 exceeds 100°C, the steam is transferred to the heat radiating section 13a through the outgoing pipe 13, and the condensed water that is condensed through heat exchange in the heat radiating section 13a passes through the return pipe 16 to the return water tank 6. It can be saved. When the water level in the steam boiler 1 drops to the upper edge of the connection port 9 (level B), the water in the water supply pipe 10 begins to replace steam, and the temperature at the temperature sensor 11 rises rapidly by the time it drops to level C. When this temperature exceeds the set temperature, the solenoid valve 3 is opened, and when the solenoid valve 3 is opened, the water tank 2 is communicated with the steam boiler 1 and steam enters, and the water 15b in the water tank 2 is The water flows down into the steam boiler 1 due to the action of gravity (water head difference), and the water level in the steam boiler 1 recovers from the C level to the A level. At this time, the temperature at the lower temperature sensor 11 drops because the low temperature water 15b flows into the steam boiler 1 through the water supply pipe 10. Since the temperature inside the steam boiler decreases according to the amount of water supplied, the steam pressure slightly decreases, but this does not impede steam transport and steam continues to be continuously sent to the heat radiating section 13a.

When the water 15b in the water tank 2 finishes flowing down into the steam boiler 1, the steam passes through the water tank 2 and flows into the water pipe 10.
The temperature of the upper temperature sensor 12 rises because the water also flows into the upper temperature sensor 12. When this temperature exceeds the set temperature, the solenoid valve 3 is closed. When the solenoid valve 3 is closed, the water tank 2
The steam flowing into the tank is cooled and condensed, resulting in a reduced pressure state, so the check valve 4 is closed and the check valve 5 is opened, and the condensed water 15c accumulated in the return water tank 6 flows into the condensed water pipe 1.
4 and flows into the water tank 2 where it is stored. The water level in the steam boiler 1 is increased again at the connection 9 of the water supply pipe 10.
(B level), water is supplied to the steam boiler 1 and water tank 2 while the solenoid valve 3 is opened and closed by detecting the temperature rise of the temperature sensors 11 and 12 as described above.

When the boiler operation is stopped, the inside of the steam boiler 1 becomes vacuum, the check valves 4 and 5 open, and the condensed water 15c
flows into the steam boiler 1. However, if the steam boiler 1 is not filled with water, air will further flow in, so there is a risk that the water 15b in the water tank 2 will be replaced with air. In this embodiment, in order to avoid this, when a vacuum is created in the steam boiler 1,
Air is allowed to flow into the steam boiler 1 through a vacuum regulating valve 17 to break the vacuum. In addition, since the return water tank 6 is installed below the operating high water level of the steam boiler 1, the condensed water 15
c will not leak into the steam boiler 1.
Check valves 4 and 5 prevent water in the steam boiler 1 from flowing back into the water return tank 6.

Note that when the steam boiler 1 is filled with water when the boiler is stopped, the vacuum regulating valve 17 is not necessary because the water in the water tank 2 is not replaced with air, and the condensation There are no restrictions on the position of the liquid reservoir 6.

Also, the temperature sensor 12 attached to the water supply pipe 10 above the check valve 4 is omitted, and the check valve 4
It is also possible to detect the water level in the steam boiler 1 using only the temperature sensor 11 located below.

However, the temperature sensor 11 must be installed above the operating high water level (A level) of the steam boiler 1.

As explained in the embodiment, when the water level in the steam boiler 1 falls to the upper edge of the connection port 9 of the water supply pipe 10, that is, the B level, the water inside the water supply pipe 10 is replaced with steam, and the temperature at the temperature sensor 11 rises rapidly. Then, the solenoid valve 3 is opened.

Since the steam boiler 1 and the water supply tank 2 are in communication, the water 15b in the water supply tank 2 flows down to the steam boiler 1 under the action of gravity, and the temperature at the temperature sensor 11 drops at this time.

When the water 15b finishes flowing down, steam subsequently flows into the water supply tank 2 and the water supply pipe 10, so that the temperature at the temperature sensor 11 rises rapidly.

In the above embodiment, the structure in which the outgoing pipe and the steam communication pipe for transporting steam are connected to the top and the connection port of the water supply pipe is opened to the side is a steam drum of a water tube boiler or a steam-water separator of a once-through boiler. It is also possible to configure it so that.

Furthermore, the check valves 4 and 5 interposed in the middle of each of the water supply pipe 10 and the condensed water pipe 14 may be electromagnetic valves.

Alternatively, the control valves 3 and 5 interposed in the middle of the steam communication pipe 8 and the condensed water pipe 14 may be electromagnetic valves, and the control valve interposed in the middle of the water supply pipe 10 may be a check valve.

Further, the control valves 3 and 4 interposed in the middle of the steam communication pipe 8 and the water supply pipe 10 may be solenoid valves, and the control valve interposed in the middle of the condensed water pipe 14 may be a check valve.

Further, a vacuum regulating valve may be installed in the middle of the steam boiler or the steam inlet pipe 13 to prevent the steam boiler 1 from being in a vacuum state when the operation is stopped.

Further, the temperature sensor 12 may be attached to a part of the water tank 2 instead of the water supply pipe 10.

[Effects of the present invention] The present invention provides a water supply tank that is arranged above the operating high water level in a steam boiler, and a water supply pipe that connects the bottom of the water tank and the operating low water level of the steam boiler. and the top of the water tank with a steam communication pipe,
Furthermore, the return water tank and the water supply tank are connected by a condensate water pipe, a control valve is installed in the middle of each pipe, and temperature sensors are installed above and below the control valve attached to the water supply pipe, so the steam boiler When the water level in the water supply tank reaches the operating low water level, the water in the water supply pipe replaces steam and the temperature of the lower temperature sensor rises rapidly.This temperature rise is caught and the control valve in the middle of the steam communication pipe is opened to drain the water in the water supply tank. Water is supplied downstream to the steam boiler, and after water supply is complete, the temperature that rises rapidly when steam enters is detected by the upper temperature sensor, and the control valve in the middle of the steam communication pipe is closed, causing a depressurized state in the water supply tank as steam condenses. By repeatedly introducing condensed water from the return water tank, it was possible to automate water supply while continuously generating steam.

Therefore, this water supply system eliminates the need for electrodes to detect the water level in the steam boiler, which eliminates malfunctions due to corrosion and wear and impurity accumulation, and eliminates the need for a water supply pump, which eliminates noise, vibration, and breakdowns. This has the effect of reducing auxiliary power and cost.

[Brief explanation of drawings]

The figure is an embodiment diagram of the present invention. 1... Steam boiler, 2... Water supply tank, 3... Solenoid valve, 4, 5... Check valve, 6... Return water tank, 7... Steam header, 8... Steam communication pipe, 9... Connection mouth,
10... Water supply pipe, 11, 12... Temperature sensor, 1
3... Outgoing pipe, 14... Condensed water pipe, 15a, 15
b, 15c...water, 16...return pipe.

Claims (1)

[Scope of Claims] 1. Steam is generated by heating water sealed in a steam boiler, and this steam is conveyed to a heat radiating section via an outbound pipe, where it is exchanged with heat and condensed. The condensed water collected in the return water tank is led to a return water tank via a return pipe, and when the amount of water in the steam boiler decreases to an operating low water level, the condensed water stored in the return water tank is supplied to the steam boiler. In a steam boiler of the type that restores the water amount to the operating high water level, a water supply tank is arranged between the return water tank and the steam boiler at a position higher than the operating high water level of the steam boiler, and the upper part of the water supply tank and the A condensate water pipe connects the bottom of the water tank, and a water supply pipe connects the bottom of the water supply tank to a connection port opened at the low operating water level on the side wall of the steam boiler. A control valve is installed in the middle of the condensate water pipe and the water supply pipe, and a control valve is also installed in the steam communication pipe, and a lower temperature sensor is installed at the lower part of the water supply pipe that is in between the control valve. At the same time, an upper temperature sensor is installed on the top.
The control valve attached to the steam communication pipe is configured to open when the lower temperature sensor detects a temperature higher than a certain set temperature and close when the upper temperature sensor exceeds a certain set temperature. Water supply device. 2. A water supply system for a steam boiler according to claim 1, wherein the water supply pipe has an upward slope between the control valve and the connection port toward the control valve. 3. A patent claim in which the component to which the outgoing pipe and steam communication pipe for transporting steam are connected to the top and the connection port of the water supply pipe is opened to the side is a steam drum of a water tube boiler or a steam-water separator of a once-through boiler. A water supply device for a steam boiler according to item 1. 4. The water supply system for a steam boiler according to claim 1, wherein the control valves interposed in the middle of each of the steam communication pipe, the water supply pipe, and the condensed water pipe are electromagnetic valves. 5. The steam according to claim 1, wherein the control valve installed in the middle of each of the steam communication pipe and the condensed water pipe is a solenoid valve, and the control valve installed in the middle of the water supply pipe is a check valve. Boiler water supply system. 6. The steam according to claim 1, wherein the control valve installed in the middle of each of the steam communication pipe and the water supply pipe is a solenoid valve, and the control valve installed in the middle of the condensed water pipe is a check valve. Boiler water supply system. 7. Claim 1, wherein the control valve installed in the middle of the steam communication pipe is a solenoid valve, and the control valves installed in the middle of each of the water supply pipe and the condensed water pipe are check valves.
Water supply equipment for steam boilers as described in . 8. A water supply system for a steam boiler according to claim 1, wherein a vacuum regulating valve is installed in the steam boiler or in the steam inlet pipe to prevent the steam boiler from being in a vacuum state when the operation is stopped. 9. A water supply system for a steam boiler according to claim 1, wherein a temperature sensor is attached below a control valve attached to a water supply pipe and in a water supply tank.