JP3617706B2 - Steam generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tank-type steam generator, and more particularly to a steam generator capable of controlling the pressure in a boiler tank to make the steam supply amount constant.
[0002]
[Prior art]
First, with reference to FIG. 6, the example which used the conventional general tank-type vapor | steam generator for the use which blows a vapor | steam directly in a liquid and heats it is demonstrated.
A heater 2 for heating the water 6 in the boiler tank 1 is provided at the bottom of the boiler tank 1, and the temperature of the water 6 in the boiler tank 1 is detected to control energization of the heater 2. A temperature controller 3 is provided.
[0003]
Further, a steam outlet pipe 5 is extended from the top of the boiler tank 1, and its tip is connected to a steam nozzle 10 via an electromagnetic on-off valve 8 whose opening time is controlled by a timer 9. The steam 7 can be taken out as required.
[0004]
In addition, when the boiler tank 1 is cooled from a high temperature and the inside of the boiler tank 1 becomes negative pressure, the outside air E is introduced into the boiler tank 1 to damage the boiler tank 1. An anti-vacuum valve 14 is provided to prevent this.
[0005]
This vacuum prevention valve 14 has a structure in which a valve seat is provided below the inside of the housing, and the ball 15 is in close contact with the valve seat by its own weight.
Further, a safety valve 13 is attached to the top of the boiler tank 1 for preventing the steam 7 from escaping when the inside of the boiler tank 1 becomes abnormally high in pressure to prevent the boiler tank 1 from being damaged.
[0006]
The safety valve 13 has a structure as shown in FIG. That is, a valve seat 19 is provided below the inside of the housing 16, and a valve rod 17 is slidably held on the housing 16 so as to face the valve seat 19. The valve rod 17 is constantly urged in the direction of the valve seat 19 by a coil spring 23, and a seal piece 18 attached to the lower end portion of the valve rod 17 is in close contact with the valve seat 19.
[0007]
Therefore, in the apparatus configured as above, when the heater 2 is energized and the water 6 in the boiler tank 1 is heated, steam 7 is generated on the water surface, and the steam pressure increases as the water temperature rises. To do. When the water temperature reaches a predetermined temperature, the temperature controller 3 turns off the power to the heater 2.
[0008]
In this state, the electromagnetic on-off valve 8 is opened by the timer 9 for a certain period of time, whereby the steam in the tank 1 is injected into the beverage 12 in the cup 11 through the steam outlet pipe 5 and the steam nozzle 10 to heat the beverage 12. It is something that can be done.
[0009]
However, in such an apparatus, when the use of the apparatus is terminated and the heater 2 is de-energized, the water temperature in the boiler tank 1 drops, and the vapor on the water surface is condensed accordingly, and the vapor pressure Also decreases.
[0010]
Then, when the inside of the boiler tank 1 becomes atmospheric pressure or less, the ball 15 in the vacuum prevention valve 14 is lifted by the atmospheric pressure and separated from the valve seat, the outside air E is introduced into the boiler tank 1, and the negative pressure in the boiler tank 1 is reduced. Is prevented.
[0011]
For this reason, air is always confined on the water surface in the boiler tank 1 before the start of heating, and when the heating of the water 6 by the heater 2 is started again with the use of the apparatus, the boiler tank 1 The air above the water surface rises in temperature and expands.
[0012]
As a result, the air pressure due to the temperature rise and expansion is added to the vapor pressure (for example, 0.07 MPa) corresponding to the temperature of the water 6 (for example, 115 ° C.) in the boiler tank 1, resulting in an abnormally high pressure (for example, 0.103 MPa).
[0013]
For this reason, when the electromagnetic on-off valve 8 is opened in this state and steam is blown into the beverage 12, a mixture of air and steam is ejected from the steam nozzle 10 at an abnormally high pressure. Since the pressure is high even when the electromagnetic on-off valve 8 is opened, a large amount of gas is ejected, and the actual amount of ejected steam, that is, the amount of heat, varies depending on the mixing ratio of the steam and air in the ejected gas, There arises a problem that the heating temperature of the beverage 12 as a result of heating cannot be controlled to be constant.
[0014]
Even in such a conventional apparatus, if the steam is repeatedly ejected from the steam nozzle 10 many times, the air in the boiler tank 1 is almost exhausted, and thereafter the pressure in the boiler tank 1 is controlled by the water 6. A constant vapor pressure corresponding to the temperature is maintained, and the same amount of steam, that is, the amount of heat is ejected from the nozzle 10 into the beverage 12 each time, and the beverage 12 can be heated to the same temperature. As described above, the outside air is introduced into the boiler tank 1, and the same problem is repeated.
[0015]
Depending on the set pressure of the safety valve 13, when the pressure in the boiler tank 1 becomes abnormally high, the valve rod 17 is pushed up and air and steam in the boiler tank 1 are released from the relief port 25, and the boiler tank 1 Although the pressure is reduced, the blow-off pressure of the safety valve 13 must be set higher than the vapor pressure corresponding to the control temperature of the temperature regulator 3, so the jet pressure from the steam nozzle 10 is higher than the normal value. In addition, the problem of instability of the steam amount remains because of the air-fuel mixture, and the safety valve 13 operates every time the boiler is heated up. There is a problem of giving to the person.
[0016]
The energization of the heater 2 for generating steam is also controlled by the pressure in the boiler tank 1, but in this case, the abnormal pressure increase at the initial stage of boiling does not occur and is controlled by the normal pressure, Since the expansion pressure is included, the vapor pressure is lowered accordingly.
[0017]
Therefore, the steam temperature is low, and the substantial amount of steam taken out from the steam nozzle 10 including the mixture with air, that is, the amount of heat, is reduced, resulting in the same problem as described above.
[0018]
[Problems to be solved by the invention]
As described above, in the conventional steam generator, air is always confined on the water surface in the boiler tank before the start of heating, and the tank in the initial stage of boiling for steam generation An abnormal increase in pressure due to the temperature rise and expansion of the air in the chamber, and a stable amount of steam cannot be extracted due to a large amount of air mixed in the extracted steam, and stable heating results cannot be obtained for applications such as steam heating. There was a problem.
[0019]
The present invention has been made based on the above circumstances, and intends to provide a steam generator capable of always taking out a stable amount of steam from the initial stage of boiling of the steam generator and obtaining a stable heating effect. Is.
[0020]
[Means for Solving the Problems]
As a first means for solving the above problems, the present invention generates steam by heating the liquid in the boiler tank by heating means to boil, and the steam is connected to the upper part of the boiler tank and opened and closed. In the steam generator that can be taken out from the boiler tank through a steam outlet pipe with a valve interposed therein, the pressure in the boiler tank opens above the boiler tank when the pressure is below atmospheric pressure. And a valve device that is closed when the liquid is boiled and opens when the pressure in the boiler tank reaches a pressure that is equal to or higher than a preset pressure.
[0021]
Further, as a second means, a boiler tank provided with a heater, a steam outlet pipe connected to an upper portion of the boiler tank, an on-off valve interposed in the steam outlet pipe, a temperature in the boiler tank or Connected to the upper part of the boiler tank, which detects the pressure and controls the energization of the heater, and opens when the pressure in the boiler tank is below atmospheric pressure, and closes by boiling the liquid in the boiler tank And it is set as the structure which comprises the atmospheric pressure open | release type safety valve which opens when the pressure in a boiler tank reaches the pressure more than the preset pressure.
[0022]
Further, as a third means, steam is generated by heating and boiling the liquid in the boiler tank with a heating means, and the steam is connected to the upper part of the boiler tank and the steam is led out with an on-off valve interposed. A steam generator that can be taken out from the boiler tank via a pipe and has a safety valve mounted on the boiler tank, wherein the safety valve is formed in a housing connected to the boiler tank and in the housing A diaphragm provided in a state of dividing the passage into a first zone communicating with the boiler tank and a second zone communicating with the escape port, and a ring-shaped valve seat fixed at the center of the diaphragm A valve seat disk provided, and a valve that is slidably attached to the valve seat disk and opens and closes a through hole formed in the valve seat disk by bringing a seal portion into and out of contact with the valve seat And a seal provided on the valve stem, a valve stem support spring that supports the valve seat of the valve seat disc and the pressure in the boiler tank so as to maintain a narrow gap when the pressure in the boiler tank is below atmospheric pressure, A valve seat disc retainer spring that is provided on the second zone side that communicates with the relief port and that presses and supports the valve seat disc, is attached to the housing, and its tip is opposed to the end face of the valve stem with a gap therebetween. A valve opening stopper, and a seal portion of the valve stem is caused by a pressure difference before and after the gap due to flow pressure reduction of the gas flowing through a narrow gap between the valve stem and the valve seat due to steam generation in the boiler tank. The through hole of the valve seat disk is closed in contact with the valve seat, and when the pressure in the boiler tank reaches a pressure higher than a preset pressure, the valve seat disk fixed to the diaphragm is The valve rod moves against the urging force of the pressing spring is what contact seal portion to the valve-open stopper is configured to open the through hole away from the valve seat.
[0023]
Further, as a fourth means, steam is generated by heating and boiling the liquid in the boiler tank with a heating means, and the steam is connected to the upper part of the boiler tank, and the steam is led out with an on-off valve interposed. A steam generator that can be taken out from the boiler tank via a pipe, connected to the upper part of the boiler tank and opened when the pressure in the boiler tank reaches a pressure higher than a preset pressure; and The valve tank is connected to the upper part of the boiler tank and opens when the pressure in the boiler tank is below atmospheric pressure, and is closed by boiling of the liquid in the boiler tank.
[0024]
According to the steam generator of the first means, the pressure in the boiler tank opens above the boiler tank when the pressure in the boiler tank is lower than the atmospheric pressure, is closed by the boiling of the liquid in the boiler tank, and in the boiler tank Since the valve is configured to open when the pressure reaches a preset pressure or higher, most of the temperature rise and expansion of the air in the boiler tank is out of the boiler tank while the boiler is boiling. As a result of the discharge, the pressure load due to the temperature expansion of the air with respect to the vapor pressure at the time of boiling can be suppressed to a very low level. As a result, the pressure in the boiler tank is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank is reduced. If the road conditions are the same, it is possible to always take out steam at the same flow rate. Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
[0025]
In addition, the safety valve does not operate every time when starting use boiling as in the conventional steam generator, and it is possible to eliminate a sense of danger due to the gas blowing sound accompanying the operation of the safety valve.
[0026]
Further, according to the steam generator of the second means, connected to the upper part of the boiler tank, the pressure in the boiler tank is opened when the atmospheric pressure is lower than the atmospheric pressure, closed by the boiling of the liquid in the boiler tank, and Since it is configured to provide an atmospheric pressure relief valve that opens when the pressure in the boiler tank reaches a pressure higher than a preset pressure, the temperature of the heated and expanded air in the boiler tank during the boiler boiling process As a result of being able to discharge most of the fuel outside the boiler tank, the pressure load due to the temperature expansion of the air with respect to the vapor pressure at the time of boiling can be suppressed to a very low level. As a result, the pressure in the boiler tank is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank is also reduced, so the pipe condition of the steam outlet pipe is the same. If there is, it is possible to always take out steam at the same flow rate. Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
[0027]
In addition, the safety valve does not operate every time when starting to use, unlike the conventional steam generator, and it is possible to eliminate the sense of danger caused by the sound of gas blowout accompanying the operation of the safety valve.
[0028]
In addition, since it is a safety valve that is open to atmospheric pressure, it has the function of a vacuum prevention valve that prevents the generation of negative pressure when the boiler tank is cooled. become.
[0029]
Further, according to the steam generator of the third means, the safety valve attached to the boiler tank opens when the pressure in the boiler tank is below atmospheric pressure, closes by boiling of the liquid in the boiler tank, and the boiler Since the atmospheric pressure relief valve opens when the pressure in the tank reaches or exceeds the preset pressure, most of the temperature rise and expansion of the air in the boiler tank is removed from the boiler tank while the boiler is boiling. As a result of the discharge, the pressure load due to the temperature expansion of the air with respect to the vapor pressure at the time of boiling can be suppressed to a very low level. As a result, the pressure in the boiler tank is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank is also reduced, so the pipe condition of the steam outlet pipe is the same. If so, it is always possible to take out steam at the same flow rate. Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
[0030]
In addition, the safety valve does not operate every time when starting to use, unlike the conventional steam generator, and it is possible to eliminate the sense of danger caused by the sound of gas blowout accompanying the operation of the safety valve.
[0031]
In addition, the safety valve is configured to open below atmospheric pressure, and it also has a function of a vacuum prevention valve that prevents the generation of negative pressure when the boiler tank is cooled, and the safety valve also functions as a vacuum prevention valve. The configuration of the generator is simplified.
[0032]
In addition, the configuration is simple, and the pressure adjustment of the safety valve can be easily performed from the outside.
Further, according to the steam generator of the fourth means, a valve device that opens when the pressure in the boiler tank is below atmospheric pressure and closes by boiling of the liquid in the boiler tank is connected to the upper part of the boiler tank. As a result, most of the temperature rise and expansion of the air in the boiler tank can be discharged to the outside of the boiler tank while the boiler is being boiled. be able to. As a result, the pressure in the boiler tank is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank is also reduced, so the pipe condition of the steam outlet pipe is the same. If so, it is always possible to take out steam at the same flow rate. Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
[0033]
In addition, the safety valve does not operate every time when the use is started unlike the conventional steam generator, and it is possible to eliminate the danger caused by the gas blowing sound accompanying the operation of the safety valve.
[0034]
In addition, in a conventional apparatus provided with a normal safety valve and a vacuum prevention valve, the conventional apparatus can be used as it is simply by installing the valve device having the above-described configuration instead of the vacuum prevention valve.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the steam generator according to the first embodiment of the present invention will be described in detail with reference to FIGS.
In FIG. 1, a heater 2 for heating water 6, which is a liquid in the boiler tank 1, is provided at the bottom of the boiler tank 1. Further, the temperature of the water 6 in the boiler tank 1 is detected and A temperature controller 3 for controlling energization of the heater 2 is provided.
[0036]
Further, a steam outlet pipe 5 is extended from the top of the boiler tank 1, and its tip is connected to a steam nozzle 10 via an electromagnetic on-off valve 8 whose opening time is controlled by a timer 9. The steam 7 inside can be taken out as required.
[0037]
The steam nozzle 10 is inserted into the beverage 12 in the cup 11. The top of the boiler tank 1 is connected with a safety valve 4 that is open to the atmospheric pressure as described below as a valve device.
[0038]
This atmospheric pressure release type safety valve 4 has a configuration shown in FIGS.
That is, it has a housing 16 connected to the boiler tank 1, and a lower zone 30 a serving as a first zone for communicating a passage 30 formed in the housing 16 with the boiler tank 1. The diaphragm 20 is provided so as to bisect into the upper zone 30b as a second zone communicating with the escape port 25.
[0039]
Further, a valve seat disk 21 having a ring-shaped valve seat 19 is fixed to the center of the diaphragm 20, and a seal piece 18 as a seal portion is provided at the center of the valve seat disk 21. A valve rod 17 that opens and closes a through hole 21a formed in the valve seat disk 21 by being brought into and out of contact with the valve seat disk 21 is slidable in the vertical direction.
[0040]
The valve rod 17 is supported at its upper end by a valve rod support spring 22 made of a coil spring, and a seal piece 18 attached to the large diameter portion of the lower end is provided in the valve seat 19 of the valve seat disk 21 and the boiler tank 1. When the pressure is less than atmospheric pressure, they face each other with a narrow gap (about 0.5 to 1 mm).
[0041]
Further, between the upper surface of the valve seat disk 21 and the housing 16, that is, on the second zone 30 a side communicating with the escape port 25, it is concentric with the valve stem 17 and the valve seat disk 21 is moved downward. A valve seat disc presser spring 23 made of a coil spring is provided in a state of being pressed against.
[0042]
In addition, from the upper part of the housing 16, a setting screw 24 as a valve opening stopper whose front end is opposed to the upper end surface of the valve rod 17 in the second zone 30b with a space therebetween can be adjusted forward and backward. It is screwed.
[0043]
The setting screw 24 is fixed in position by a lock nut 32 after the position is set.
The operation of the steam generator configured as described above will be described.
[0044]
When the water in the boiler tank 1 is cooled, the atmospheric pressure relief valve 4 is in the state shown in FIG. 2, that is, in a state where there is a gap G between the seal piece 18 of the valve rod 17 and the valve seat 19. The boiler tank 1 communicates with the outside through a safety valve 4. Therefore, the boiler tank 1 is in a state where air is contained.
[0045]
When the heater 2 is energized, the water 6 in the boiler tank 1 is heated to rise in temperature, and the air on the water surface in the boiler tank 1 is also raised and expanded with this, but the expansion is atmospheric pressure. Through the clearance G between the valve seat 19 of the open type safety valve 4 and the seal piece 18, it gently flows out from the escape port 25 to the outside, and the inside of the boiler tank 1 is maintained at atmospheric pressure.
[0046]
When the temperature of the water 6 reaches 100 ° C., boiling starts and a large amount of steam begins to be generated, and this steam also flows to the outside through the atmospheric pressure relief valve 4 like the expanded air. Is much larger than the amount of expansion air, so that the narrow gap G between the valve seat 19 and the seal piece 18 of the valve stem 17 flows at a high speed.
[0047]
As a result, flow decompression occurs at the valve seat 19 as a boundary, and a clear differential pressure is generated between the upstream side and the downstream side of the valve seat 19.
This differential pressure acts on the lower surface of the large-diameter portion 17a of the valve rod 17, and the valve rod 17 that has been in an equilibrium position by the valve rod support spring 22 and its own weight is pushed upward to move, as shown in FIG. The seal piece 18 comes into close contact with the valve seat 19 and closes the through hole 21a.
[0048]
As described above, the seal piece 18 is in close contact with the valve seat 19 and closes the through hole 21a. As a result, the steam pressure is confined in the boiler tank 1, and this steam pressure acts in the direction of pushing up the valve rod 17. The atmospheric pressure open safety valve 4 is kept closed.
[0049]
When the water temperature in the boiler tank 1 reaches a predetermined temperature (for example, 115 ° C.), the temperature controller 3 turns off the power to the heater 2, and the pressure in the boiler tank 1 is changed to a vapor pressure corresponding to the water temperature (for example, 0.07 MPa) and a pressure obtained by adding an expansion pressure after the atmospheric pressure release type safety valve 4 of the residual air is closed (for example, 0.074 MPa), which is almost equal to a normal vapor pressure.
[0050]
In this state, when the solenoid valve 8 is opened by the timer 9 for a certain time, the steam is blown into the beverage 12 in the cup 11 through the steam outlet pipe 5 and the steam nozzle 10 with some residual air, and the beverage 12 is almost the target. To a predetermined temperature.
[0051]
In addition, since the residual air in the boiler tank 1 has decreased, the mixing ratio to the jetted steam from the steam nozzle 10 is small, and the influence on the jetted steam amount is slight.
[0052]
Although the steam temperature from the steam nozzle 10 is reduced by the removal of boiling latent heat, the water temperature in the boiler tank 1 is lowered. However, when the temperature is lowered to a certain temperature, the temperature controller 3 is operated and the heater 2 is energized again. Recovery and maintenance of water temperature and vapor pressure.
[0053]
When the jets from the steam nozzle 10 are repeated, the residual air in the boiler tank 1 is almost eliminated, and the beverage 12 is heated to the same predetermined temperature by the same amount of the steam jets each time with a predetermined steam pressure.
[0054]
In the unlikely event that the water temperature in the boiler tank 1 rises abnormally due to a failure of the temperature controller 3 or the like, the pressure also rises abnormally. In such a case, the atmospheric pressure relief valve 4 is opened. It becomes a safety valve function state and is prevented from becoming an abnormally high pressure.
[0055]
That is, when the pressure in the boiler tank 1 becomes an abnormally high pressure state, this abnormally high pressure acts on the lower surface of the diaphragm 20 and resists the force of the coil spring 23 so as to be integrated with the valve rod 17 seated on the valve seat 19. Deform to go.
[0056]
Then, when approaching the safety valve blowing set pressure, the upper end of the valve rod 17 comes into contact with the lower end of the setting screw 24 to restrict its movement, and the diaphragm 20 and the valve seat disk 21 are further deformed upward.
[0057]
As a result, the valve seat 19 of the valve disc 21 is separated from the seal piece 18 of the valve stem 17 and a gap G is formed between the valve seat 19 and the seal piece 18 as shown in FIG. The safety valve 4 is opened. And the vapor | steam in the boiler tank 1 is discharge | released outside from the escape port 25, and safety is ensured.
[0058]
After the operation of the safety valve 4, when the pressure in the boiler tank 1 is reduced to some extent, the diaphragm 20 is pushed back to the coil spring 23, the valve seat 19 abuts the seal piece 18, the through hole 21a is closed, and the safety valve is closed. That is, the state returns to the state of FIG.
[0059]
Next, when the use of the steam generator is finished and the heater 2 is de-energized, the temperature of the water 6 and the steam 7 in the boiler tank 1 starts to drop, and along with this, the pressure in the boiler tank 1, That is, the vapor pressure also decreases and approaches atmospheric pressure.
[0060]
As a result, the steam pressure acting on the lower end surface of the valve rod 17 to push up the valve rod 17 is almost eliminated, and the valve rod 17 deflects the valve rod support spring 22 by its own weight and is displaced downward. By the lowering operation of the valve rod 17, the seal piece 18 attached to the lower end side of the valve rod 17 is separated from the valve seat 19, and the safety valve 4 is opened, that is, the state shown in FIG.
[0061]
Therefore, even if the water temperature in the boiler tank 1 further decreases, the outside air is prevented from flowing into the tank through the safety valve 4 and becoming negative pressure.
As described above, according to the steam generator of this embodiment, the following useful effects can be obtained.
(1) As a result of being able to discharge most of the temperature-expanded expansion of the air in the boiler tank 1 to the outside of the boiler tank 1 during the boiling of the boiler, the pressure-weighted amount due to the temperature-expanded expansion of the air with respect to the vapor pressure at the time of boiling Therefore, the pressure in the boiler tank 1 is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank 1 is also reduced. If the pipe line conditions are the same, it is possible to always take out steam at the same flow rate.
[0062]
Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
(2) The atmospheric pressure release type safety valve 4 can eliminate the sense of danger caused by the gas blowing sound associated with the operation of the safety valve without being operated every time when starting use boiling as in the conventional steam generator.
(3) The apparatus of the present invention employs an open-air safety valve 4 and is configured such that the safety valve opens at atmospheric pressure or less, and a function of a vacuum prevention valve that prevents generation of negative pressure when the boiler tank 1 is cooled. Since the safety valve also serves as a vacuum prevention valve, the structure of the steam generator is simplified.
[0063]
In the above example, the heater 2 of the boiler tank 1 is controlled by controlling the water temperature in the boiler tank 1, but the pressure in the boiler tank 1 is controlled by the pressure regulator based on the correlation between the water temperature and the steam pressure. Even if the energization control of the heater 2 is performed so as to be constant, the same operation and effect as described above can be obtained.
[0064]
Further, in the first embodiment described above, an example in which the air in the boiler tank 1 is discharged using a special safety valve, that is, the atmosphere-opening safety valve 4, is shown. However, as shown in FIG. A typical safety valve 13 may be used, and the air in the boiler tank 1 may be discharged by another open air valve device 40.
[0065]
In addition, in the conventional apparatus (see FIG. 6) provided with the normal safety valve 13 and the vacuum prevention valve 14, the conventional apparatus can be used as it is simply by installing the air release type valve apparatus 40 having the above configuration in place of the vacuum prevention valve 14. Can do.
[0066]
In addition, another air release type valve device 40 in the second embodiment (FIG. 5) is provided with a set screw as a diaphragm 20, a valve seat disc presser spring 23, and a valve release stopper from the above air release type safety valve 4. Of course, it is possible to use a very simple configuration in which 24 and the like are deleted.
In addition, it is needless to say that the present invention can be variously modified without departing from the scope of the present invention.
[0067]
【The invention's effect】
As described above, the present invention has the following effects.
According to the steam generator of claim 1, the pressure in the boiler tank opens above the boiler tank when the pressure in the boiler tank is below atmospheric pressure, is closed by the boiling of the liquid in the boiler tank, and the pressure in the boiler tank Since the valve device is configured to open when the pressure reaches a pressure higher than the preset pressure, most of the temperature rise and expansion of the air in the boiler tank is discharged to the outside of the boiler tank during the boiler boiling. As a result, the pressure load due to the temperature expansion of the air with respect to the vapor pressure at the time of boiling can be suppressed to a very low level. As a result, the pressure in the boiler tank is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank is also reduced, so the pipe condition of the steam outlet pipe is the same. If so, it is always possible to take out steam at the same flow rate. Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
[0068]
In addition, the safety valve does not operate every time when starting to use, unlike the conventional steam generator, and it is possible to eliminate the sense of danger caused by the sound of gas blowout accompanying the operation of the safety valve.
[0069]
In addition, the valve device is configured to open below atmospheric pressure, and it also has the function of a vacuum prevention valve that prevents the generation of negative pressure when the boiler tank is cooled, and the valve device also serves as a vacuum prevention valve. The configuration of the steam generator is simplified.
[0070]
The steam generator according to claim 2 is connected to the upper part of the boiler tank, opens when the pressure in the boiler tank is lower than atmospheric pressure, closes by boiling of the liquid in the boiler tank, and the boiler Since it is configured to provide an atmospheric pressure relief valve that opens when the pressure in the tank reaches or exceeds a preset pressure, a large amount of temperature rise and expansion of the air in the boiler tank during the boiling of the boiler As a result of discharging the portion out of the boiler tank, the pressure load due to the temperature expansion of the air with respect to the vapor pressure at the time of boiling can be suppressed to a very low level. As a result, the pressure in the boiler tank is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank is also reduced, so the pipe condition of the steam outlet pipe is the same. If so, it is always possible to take out steam at the same flow rate. Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
[0071]
In addition, the safety valve does not operate every time when starting use boiling as in the conventional steam generator, and it is possible to eliminate a sense of danger due to the gas blowing sound accompanying the operation of the safety valve.
[0072]
In addition, since it is a safety valve that is open to atmospheric pressure, it has the function of a vacuum prevention valve that prevents the generation of negative pressure when the boiler tank is cooled. The safety valve also functions as a vacuum prevention valve, so the structure of the steam generator is simple. become.
[0073]
According to the steam generator of claim 3, the safety valve attached to the boiler tank opens when the pressure in the boiler tank is below atmospheric pressure, closes by boiling of the liquid in the boiler tank, and the boiler tank Since the pressure inside the boiler reaches a pressure higher than a preset pressure, it becomes a safety valve that opens to the atmospheric pressure, so most of the temperature rise and expansion of the air in the boiler tank is discharged out of the boiler tank while the boiler is boiling. As a result, the pressure load due to the temperature expansion of the air with respect to the vapor pressure at the time of boiling can be suppressed to a very low level. As a result, the pressure in the boiler tank is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank is also reduced, so the pipe condition of the steam outlet pipe is the same. If so, it is always possible to take out steam at the same flow rate. Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
[0074]
In addition, the safety valve does not operate every time when starting to use, unlike the conventional steam generator, and it is possible to eliminate the sense of danger caused by the sound of gas blowout accompanying the operation of the safety valve.
[0075]
In addition, the safety valve is configured to open below atmospheric pressure, and it also has a function of a vacuum prevention valve that prevents the generation of negative pressure when the boiler tank is cooled, and the safety valve also functions as a vacuum prevention valve. The configuration of the generator is simplified.
[0076]
In addition, the configuration is simple, and the pressure adjustment of the safety valve can be easily performed from the outside.
Further, according to the steam generator of claim 4, a valve device that opens when the pressure in the boiler tank is below atmospheric pressure and closes by boiling of the liquid in the boiler tank is connected to the upper part of the boiler tank. As a result of the fact that most of the temperature expansion and expansion of the air in the boiler tank can be discharged outside the boiler tank while the boiler is being boiled, the pressure load due to the temperature expansion and expansion of the air with respect to the steam pressure at the time of boiling is minimized. Can do. As a result, the pressure in the boiler tank is controlled to almost the target steam pressure from the time of boiling, and the air component remaining in the boiler tank is also reduced, so the pipe condition of the steam outlet pipe is the same. If so, it is always possible to take out steam at the same flow rate. Therefore, when this steam is used for the purpose of heating or the like, the same heating result can always be obtained.
[0077]
In addition, the safety valve does not operate every time when the use is started unlike the conventional steam generator, and it is possible to eliminate the danger caused by the gas blowing sound accompanying the operation of the safety valve.
[0078]
In addition, in a conventional device having a normal safety valve and a vacuum prevention valve, the conventional device can be used as it is simply by installing the valve device having the above-described configuration instead of the vacuum prevention valve.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an example of use of a steam generator according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a state of a safety valve of the steam generator shown in FIG. 1 under atmospheric pressure.
FIG. 3 is a cross-sectional view showing a state where the safety valve shown in FIG. 2 is closed under a vapor pressure higher than atmospheric pressure.
4 is a cross-sectional view showing a state where the safety valve shown in FIG. 2 is opened due to abnormally high pressure.
FIG. 5 is a schematic cross-sectional view showing an example of use of a steam generator according to a second embodiment of the present invention.
FIG. 6 is a schematic cross-sectional view showing an example of use of a conventional steam generator.
7 is a cross-sectional view showing a state when the safety valve of the steam generator shown in FIG. 6 is not in operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Boiler tank, 2 ... Heater, 3 ... Temperature controller, 4 ... Atmospheric pressure relief valve (valve device), 5 ... Steam outlet pipe, 6 ... Water (liquid), 7 ... Steam, 8 ... Electromagnetic on-off valve DESCRIPTION OF SYMBOLS 9 ... Timer, 10 ... Steam nozzle, 11 ... Cup, 12 ... Beverage, 13 ... Safety valve, 14 ... Vacuum prevention valve, 15 ... Ball, 16 ... Housing, 17 ... Valve rod, 18 ... Seal piece (seal part), 19 DESCRIPTION OF SYMBOLS ... Valve seat, 20 ... Diaphragm, 21 ... Valve seat disc, 22 ... Valve rod support spring, 23 ... Coil spring (valve seat disc pressing spring), 24 ... Setting screw (valve opening stopper), 25 ... Relief port.

Claims (1)

Steam in the boiler tank is generated by heating the liquid in the boiler tank with heating means to boil, and the steam is connected to the upper part of the boiler tank and is connected to the upper part of the boiler tank through a steam outlet pipe. A steam generator that can be taken out from the boiler tank and equipped with a safety valve;
The safety valve
A housing connected to the boiler tank;
A diaphragm provided in a state of dividing the passage formed in the housing into a first zone communicating with the boiler tank and a second zone communicating with the escape port;
A valve disc having a ring-shaped valve seat fixed to the center of the diaphragm;
A valve rod that is slidably attached to the valve seat disc and opens and closes a through hole formed in the valve seat disc by bringing a seal portion into and out of contact with the valve seat;
A valve stem supporting spring that supports a seal portion provided on the valve stem so as to maintain a narrow gap when the pressure in the valve seat of the valve disc and the pressure in the boiler tank is below atmospheric pressure;
A valve-seat disc presser spring that presses and supports the valve-seat disc provided in a second zone that communicates with the escape port in the housing;
A valve opening stopper attached to the housing and having its tip opposed to the end face of the valve stem with a gap;
Comprising
The valve seat disc comes into contact with the valve seat due to the pressure difference before and after the gap due to the flow pressure reduction of the gas flowing through the narrow gap between the valve stem and the valve seat due to steam generation in the boiler tank. When the pressure in the boiler tank reaches a preset pressure or higher, the valve seat disc fixed to the diaphragm moves against the biasing force of the valve seat disc presser spring. The steam generator is configured such that the valve stem abuts on the valve opening stopper and the seal portion is separated from the valve seat to open the through hole.

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