JP4472102B2 - Steam heating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for heating an object to be heated in a heat exchanger with steam, and more particularly to a steam heating apparatus suitable for heating at a relatively low temperature of about 100 ° C. Specifically, it is used for steam heating of various reaction kettles used for polymerization reactions and the like, food distillers, concentrators, and sterilizers. The objects to be heated in these cases often cause thermal damage or thermal degradation due to slight temperature changes, and it is necessary to maintain the heating temperature at a predetermined value with high accuracy.
[0002]
[Prior art]
As a conventional steam heating device, for example, a device as shown in JP-A-7-328423 has been used. This is because the steam supply pipe 17 is connected to the nozzle 18, two passages 45, 46 are provided in the suction chamber 44 formed on the outer periphery of the nozzle 18, one passage 45 is connected to the jacket portion 16, and the other The valve means 47 is connected to the passage 46.
[0003]
By opening the valve means 47, the residual air in the jacket portion 16 is sucked into the suction chamber 44 to reduce the pressure in the jacket portion 16, and then the valve means 47 is closed to enter the jacket portion 16. The object to be heated can be heated with low-temperature steam of 100 ° C. or less by supplying low-pressure steam.
[0004]
[Problems to be solved by the invention]
In the above conventional steam heating apparatus, it is possible to perform the steam heating by sucking out the remaining air in the initial stage of heating, but the air that gradually accumulates during the heating operation cannot be excluded, There is a problem that the heated air hinders the heat transfer from the steam to the object to be heated and the heating temperature cannot be accurately maintained at a predetermined value. When the heating device is in a reduced pressure state below the atmospheric pressure, air is sucked from various connection portions such as a lid, a tube, a valve and the like of the device, and air accumulates inside the heating portion. Further, air may be mixed in the supplied heating steam, and air accumulates not only in the initial stage of heating but also in the heating operation.
[0005]
Further, in the conventional steam heating device, for example, when the amount of steam supplied for heating is constant and the amount of the object to be heated is small, the supplied steam is more than the consumed steam. As a result, there is a problem that the steam pressure rises, that is, the steam temperature rises.
[0006]
Accordingly, an object of the present invention is to obtain a steam heating apparatus that prevents fluctuations in the heating temperature by preventing an increase in the steam temperature and eliminating air accumulated inside not only in the initial stage of heating but also during the heating operation. is there.
[0007]
[Means for Solving the Problems]
The means of the present invention taken in order to solve the above-mentioned problems is a condensate recovery device that forms a heating section in a heat exchanger, connects a heating steam supply pipe, and discharges condensate generated by heating. In the connected one, the heating part and the suction chamber of the steam ejector are communicated via a check valve, the steam supply pipe is connected to the inlet side of the steam ejector, and the pressure at which the pressure fluctuation of the heating part is detected and opened and closed Connect the responsive valve to the steam ejector, and use the pressure responsive valve as a self-acting pressure regulating valve. The self-acting pressure regulating valve has a diaphragm and a tension coil spring for adjusting the pressure, and communicates with the lower chamber of the diaphragm. An opening is provided, and the communication port communicates with the heating unit through a pressure communication pipe. When the pressure of the heating unit rises by a predetermined value, the pressure responsive valve opens and the air or steam in the heating unit is sucked by the suction force of the steam ejector. The It is intended.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Attach a pressure responsive valve that opens when the pressure of the heating part rises by a predetermined value, and when the suction part of the steam ejector communicates with the heating part, air accumulates in the heating part and the pressure rises by a predetermined value, or When the supply steam amount becomes excessive and the steam pressure rises by a predetermined value, the pressure responsive valve is opened, and air or excess steam is sucked by the suction force of the steam ejector and is discharged outside.
[0009]
【Example】
In this embodiment, as shown in FIG. 1, an example in which a reaction kettle 1 is used as a heat exchanger will be described.
A jacket portion 2 as a heating portion is formed on the outer periphery of the reaction kettle 1 and connected to the steam supply pipe 3. The pressure responsive valve 12 connected to the branched steam supply pipe 4, the steam ejector 5, and the jacket portion 2 A steam heating apparatus is comprised with the condensate collection | recovery apparatus 6 arrange | positioned at the lower part.
[0010]
Pressure control valves 7 and 8 are attached to the steam supply pipe 3 and connected to the jacket portion 2. The pressure control valves 7 and 8 are set so that the steam pressure, that is, the temperature supplied to the jacket portion 2 becomes a predetermined value. When saturated steam is used as the steam for heating, the pressure and temperature of the steam are uniquely determined. Therefore, the steam temperature can be set to a predetermined value by setting the steam pressure to a predetermined value. The steam supply pipe 3 is connected to the high-pressure operating fluid inlet 10 of the condensate recovery device 6 through a pipe 9.
[0011]
A steam ejector 5 is connected to the branched steam supply pipe 4 via an on-off valve 11 and a pressure responsive valve 12. The suction chamber 13 of the steam ejector 5 and the jacket portion 2 are communicated with each other by a pipe line 15 through a check valve 14. The check valve 14 allows only passage of fluid from the jacket portion 2 toward the suction chamber 13 and does not allow passage of fluid in the opposite direction. A conduit 16 is connected to the outlet side of the steam ejector 5.
[0012]
In this embodiment, the pressure responsive valve 12 is an example using a self-acting pressure regulating valve as shown in FIG. In FIG. 2, the inlet 30 is connected to the steam supply pipe 4, and the outlet 31 is connected to a nozzle (not shown) in the suction chamber 13 of the ejector 5. A valve element 33 is disposed opposite to a valve seat 32 that partitions the inlet 30 and the outlet 31. The valve body 33 is connected to the upper diaphragm 35 by a connecting rod 34. A tension coil spring 36 for adjusting the pressure is disposed on the upper portion of the diaphragm 35. The coil spring 36 biases the diaphragm 35 upward. A rotary handle 38 is attached to the upper part of the coil spring 36 via an adjustment screw 37. By rotating the rotary handle 38 to the left and right, the adjustment screw 37 can be moved up and down to adjust the tensile force of the coil spring 36 as appropriate.
[0013]
A communication port 40 is provided in the lower chamber 39 of the diaphragm 35. The communication port 40 communicates with the jacket portion 2 of the reaction kettle 1 shown in FIG. Accordingly, when the pressure of the jacket portion 2 rises, the pressure of the diaphragm lower chamber 39 also rises, and the diaphragm 35 is displaced upward, so that the valve element 33 is separated from the valve seat 32 and opened.
[0014]
When the pressure responsive valve 12 is opened, high-pressure steam is supplied from the steam supply pipe 4 of FIG. 1 to the ejector 5, generating a suction force in the suction chamber 13 of the ejector 5, and causing the air staying in the jacket portion 2 to flow. Alternatively, excess steam is sucked and discharged from the pipe line 16 to the outside.
[0016]
The lower part of the jacket part 2 and the condensate inlet 20 of the condensate recovery device 6 are connected via a pipe line 21 via a valve 22 and a check valve 23. The check valve 23 allows passage of fluid only from the jacket portion 2 in the direction of the condensate recovery device 6, and does not allow passage of fluid in the reverse direction. A condensate pressure feed line 26 is also attached to the condensate reduction port 24 of the condensate recovery device 6 via a check valve 25. This check valve 25 allows the fluid to pass only in the outward direction from the condensate recovery device 6 to the condensate pressure feed line 26 side.
[0017]
A high-pressure operating fluid discharge circulation port 27 is provided on the side of the high-pressure operating fluid inlet 10 at the top of the condensate recovery device 6 and is connected to the conduit 28. The pipe line 28 is connected to a header (not shown) in the same pressure state as that of the jacket part 2 or a lower pressure state part than the separate jacket part 2.
[0018]
In the condensate recovery device 6, when a float (not shown) disposed inside is located in the lower part, the inlet 10 for the high-pressure operating fluid is closed, while the discharge circulation port 27 is opened, and the reverse of the conduit 21. When the condensate in the jacket portion 2 flows into the recovery device 6 through the stop valve 23 and the condensate inlet 20, and the condensate accumulates in the recovery device 6 and the float is positioned at a predetermined upper portion, the discharge circulation port 27 On the other hand, the high-pressure operating fluid inlet 10 is opened, and high-pressure steam from the steam supply pipe 3 flows into the recovery device 6 as a high-pressure operating fluid, and the internal condensate is reversed from the reducing port 24. It is pumped to a condensate recovery destination through a stop valve 25 and a pipe line 26 and recovered.
[0019]
When the condensate is recovered and the water level in the recovery device 6 decreases, the high-pressure operating fluid inlet 10 is closed again and the discharge circulation port 27 is opened, whereby the condensate is recovered from the condensate inlet 20. It flows down into 6. By repeating such an operation cycle, the condensate recovery device 6 recovers the condensate generated in the jacket portion 2.
[0020]
In FIG. 1, when heating an object to be heated in the reaction vessel 1, first, steam is supplied from the pressure control valves 7 and 8 to the jacket portion 2. Since the initial residual air remains in the jacket portion 2 and the pressure is also in the atmospheric pressure state and is higher than the reduced pressure state, the pressure responsive valve 12 is opened and the suction chamber 13 of the steam ejector 5 is opened. The residual air is sucked and discharged to the outside. When the inside of the jacket part 2 reaches a predetermined pressure below atmospheric pressure, the pressure responsive valve 12 is closed, and the heating steam supplied from the pressure control valves 7 and 8 is supplied to the jacket part 2 to heat the reaction kettle 1. To do.
[0021]
The steam heated in the reaction kettle 1 condenses to become condensate, and flows down into the condensate recovery device 6 via the conduit 21. By supplying heated steam having a predetermined pressure, that is, temperature, into the jacket portion 2 from which air has been removed, the reaction kettle 1 is heated with steam having a predetermined temperature. For example, when steam at 60 ° C. below atmospheric pressure is supplied from the pressure control valves 7, 8, the reaction kettle 1 is heated at 60 ° C.
[0022]
When the inside of the jacket part 2 is set to a pressure state equal to or lower than the atmospheric pressure, atmospheric pressure is applied from each connection part of the jacket part 2, and a part of air is mixed in the jacket part 2 or is supplied to the supplied steam. The pressure rises when air is accumulated in the jacket portion 2 by the mixed air. The pressure rise in the jacket portion 2 is transmitted from the pressure communication pipe 19 to the diaphragm lower chamber 39, and the diaphragm 35 is displaced upward, so that the valve body 33 is separated from the valve seat 32, and high-pressure steam is applied to the steam ejector 5. By being supplied, a suction force is generated in the suction chamber 13 of the steam ejector 5. By this suction force, the staying air in the jacket portion 2 is sucked and discharged to the outside. Thus, in the present embodiment, not only the initial stage of the steam heating apparatus but also the air accumulated during the heating operation can be sucked by the steam ejector 5 and discharged to the outside.
[0023]
When the amount of steam supplied from the pressure control valves 7 and 8 is larger than the amount of steam consumed by the jacket part 2, the steam pressure in the jacket part 2 increases. The pressure thus increased is transmitted from the pressure communication pipe 19 to the pressure responsive valve 12, and the pressure responsive valve 12 is opened to generate a suction force in the steam ejector 5. Is prevented by being sucked and discharged to the outside.
[0024]
The steam heated in the reaction kettle 1 condenses and becomes condensate, whereby the inside of the jacket portion 2 is maintained at the initial pressure state. On the other hand, the condensed condensate flows down into the condensate recovery device 6 and is pumped to the condensate recovery destination by repeating the above-described operation.
[0025]
【The invention's effect】
As described above, according to the present invention, when the pressure of the heating unit rises by a predetermined value, the pressure responsive valve opens and the fluid in the heating unit is sucked into the suction chamber of the steam ejector, so that air accumulates in the heating unit. When the pressure rises by a predetermined value, and when the amount of steam to be supplied becomes excessive and the steam pressure rises, the fluid corresponding to the rise is sucked by the suction force of the steam ejector and removed to the outside. Therefore, it is possible to prevent the temperature fluctuation associated with the pressure rise and to heat the object to be heated with a predetermined temperature.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of a steam heating apparatus according to the present invention.
FIG. 2 is a schematic configuration diagram of a pressure responsive valve used in the steam heating apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reaction kettle 2 Jacket part 3 Steam supply pipe 5 Steam ejector 6 Condensate recovery device 10 High pressure operation fluid inlet 12 Pressure responsive valve 13 Suction chamber 19 Pressure communication pipe 20 Condensate inlet 24 Condensate reduction inlet 27 Discharge circulation outlet 30 Inlet 31 outlet 32 valve seat 33 disc

Claims (1)

A heating unit is formed in the heat exchanger, a steam supply pipe for heating is connected, and a condensate recovery device that discharges condensate generated by heating is connected. The heating unit and the suction chamber of the steam ejector are non-returned. A steam supply pipe connected to the inlet side of the steam ejector, connected to the pressure responsive valve that opens and closes by detecting pressure fluctuations in the heating unit, and the steam responsive valve, The self-acting pressure regulating valve is equipped with a diaphragm and a tension coil spring for adjusting the pressure, and a communication port is provided in the lower chamber of the diaphragm, and the communication port communicates with the heating unit through a pressure communicating tube. In addition, when the pressure of the heating unit rises by a predetermined value, the pressure responsive valve opens to suck the air or steam of the heating unit by the suction force of the steam ejector.

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