JPH09137907A - Low pressure steam heater by heat medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lowering of heat exchange performance due to a non- condensible gas by arranging an elector, a tank and a vacuum pump successively on the secondary side of an heat exchanger and a non-condensible gas takeoff pipe is made to communicate between the ejector and the heat exchanger through a switch gear. SOLUTION: A heat refrigerant 27 in a heat exchange tank 21 is cooled by a cooling pipe 28 down to a specified temperature and supplied to an ejector 20 by a circulation pump 22 of a vacuum pump means 7 to suck the heat medium in a jacket part 6. As the sucking force generated by the ejector 20 is determined by the temperature of a fluid passing through the ejector 20, the temperature of a liquid of the heat medium 27 in a heat exchange tank 21 can be adjusted properly to control the sucktion force of the ejector 20, namely, the degree of deceleration. When a non-condensible gas in the jacket part 6 is retained, any one or both of shutoff valves 38 and 39 are opened and the non- condensible gas is sucked by the ejector 20, reaching the tank 21 and discharged into the atmosphere room an air communication pipe 5 thereby preventing the lower of heat exchange performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating medium for heating an object to be heated by steam of a heating medium, which is used in various heating processes in the petrochemical industry, the synthetic fiber industry, the synthetic resin industry and the like. The present invention relates to a steam heating device.

[0002]

2. Description of the Related Art As an example of a conventional steam heating apparatus using a heat medium, for example, one shown in FIG. 2 has been used. This is a boiler for heat carrier as an evaporator of heat carrier.
The heat medium vapor generated in 1 is supplied to the reaction vessel 2 which is a kind of heat exchanger to heat the object to be heated in the reaction vessel 2, and the condensate of the heat medium vapor condensed by heating is stored in the tank 3. It is made to flow down and is collected in the boiler 1 by the circulation pump 4.

Although various kinds of heat mediums are commercially available and used, those having a lower pressure and a higher temperature are generally used as compared with the steam generated by boiling normal water, and the heating device is highly resistant to heat. It can be heated at a relatively high temperature without pressure design, and is widely used in various heating processes.

[0004]

When the conventional steam heating device using a heat medium is used, the non-condensable gas stays in the heat exchanger, hinders the heating by the high temperature steam, and deteriorates the heat exchange performance. There was a problem. The non-condensable gas is generated when the heat medium is heated, or is generated by slightly sucking air from the outside when the inside of the heat exchanger is in a vacuum state at atmospheric pressure or less.

Therefore, a technical object of the present invention is to obtain a low-pressure steam heating device using a heat medium, which does not cause deterioration of heat exchange performance due to noncondensable gas.

[0006]

Means for Solving the Problems The technical means of the present invention taken to solve the above-mentioned technical problem is to connect a steam supply pipe of a heat medium to a primary side of a heat exchanger, In the one that collects the condensed heat medium to the collection destination such as an evaporator,
A vacuum pump having an ejector, a tank, and a circulation pump is connected to the secondary side of the heat exchanger to connect the ejector and the heat exchanger, and an open / close valve is provided between the ejector and the heat exchanger. The non-condensable gas extraction pipe is connected.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An ejector, a tank, and a vacuum pump having a circulation pump are continuously provided on the secondary side of a heat exchanger, and the ejector and the heat exchanger are connected to each other.
By the suction force of 1, the inside of the heat exchanger can be maintained in a low pressure state around atmospheric pressure, and the object to be heated can be heated by the heat medium vapor of low pressure.

By connecting the non-condensable gas extraction pipe between the ejector and the heat exchanger, the non-condensable gas accumulated in the heat exchanger is removed by sucking the non-condensable gas in the open / close valve with the ejector. can do.

[0009]

An embodiment showing a specific example of the above technical means will be described (see FIG. 1). In this embodiment, an example in which the reaction kettle 2 is used as a heat exchanger is shown, and the same members as those in the prior art shown in FIG.

The heat medium boiler 1 as an evaporator is connected to the jacket portion 6 of the reaction kettle 2 and the lower portion of the jacket portion 6 is connected to the vacuum pump means 7 so that the vacuum pump means 7 is circulated with the tank 3. Boiler for heat medium via pump 4
1 to form a low-pressure steam heating device using a heat medium.

The heating medium boiler 1 and the reaction vessel 2 are connected by a pressure adjusting valve 8, a gas-liquid separator 9 and a heating steam supply pipe 11 via a pressure sensor 10. The pressure adjusting valve 8 adjusts the steam pressure in the heating steam supply pipe 11 detected by the pressure sensor 10 to a predetermined value, and the gas-liquid separator 9 controls the heat medium in the heating steam supply pipe 11. The vapor and the liquid are separated, and only the separated vapor is supplied to the jacket portion 6 of the reaction kettle 2,
The liquid is discharged from the steam trap 12 provided below the liquid. The gas-liquid separator 9 may be of a collision type, a centrifugal type, a filter type, or the like.

A jacket portion 6 arranged on the outer periphery of the reaction kettle 2.
The lower connection port 13 is connected to the ejector 20 of the vacuum pump means 7 by a pipe line 16 in which a steam trap 14 and a bypass valve 15 are provided in parallel. Further, the outlet of the steam trap 12 of the gas-liquid separator 9 is connected to the ejector 20 via the conduit 17.

Non-condensable gas extraction pipes 36 and 37 are connected to the ejector 20 from the upper portion and the lower portion of the jacket portion 6 via open / close valves 38 and 39, respectively. Non-condensed gas extraction pipe 3
It is desirable that 6 and 37 are not limited to the upper and lower portions of the jacket portion 6, but are provided at locations where the non-condensable gas easily accumulates, depending on the type of heat exchanger and heat medium.

The vacuum pump means 7 includes an ejector 20, a heat exchange tank 21, a circulation pump 22, and a connection conduit 23.
It consists of and. The ejector 20 is formed of a nozzle portion 25 and a diffuser portion 26. A cooling pipe 28 for cooling the heat medium 27 accumulated therein is attached to the heat exchange tank 21 via a control valve 29, and the heat medium 2 is provided in the lower portion.
A temperature sensor 30 for detecting the fluid temperature of 7 is attached, and although not shown, the temperature sensor 30 and the control valve 2
9 are connected via a temperature controller, and the heat medium 27
So that the temperature can be maintained at a predetermined value.

The vacuum pump means 7 circulates the heat medium 27 in the heat exchange tank 21 through the ejector 20 by the circulation pump 22, and the nozzle portion 25 of the ejector 20 generates a suction force so that the reaction vessel 2 The heat medium is sucked from the jacket portion 6 and the inside of the jacket portion 6 is maintained at a predetermined pressure state. A heat medium supply pipe line 31 for supplying a heat medium is connected to the upper part of the heat exchange tank 21, and an atmosphere communication pipe 5 that communicates with the atmosphere is connected.

A part of the connecting pipe line 23 of the vacuum pump means 7 is branched to connect the pipe line 32, and a part of the circulating heat medium is supplied to the pipe line 3.
3 is supplied to the tank 3, and a pipe 35 is further connected to inject a part of the circulating heat medium into the primary side of the gas-liquid separator 9 in the heating vapor supply pipe 11. Even when the heat transfer medium whose pressure is adjusted by the pressure adjusting valve 8 by the pipe line 35 becomes superheated steam, a part of the circulating heat transfer medium is injected and heat is exchanged in the gas-liquid separation unit 9 to obtain the saturation temperature. It can be steam.

Next, the operation will be described. Boiler for heat medium-1
The heat medium vapor generated in 1 is supplied to the jacket portion 6 of the reaction vessel 2 after being pressure-adjusted via the pressure adjustment valve 8. The inside of the jacket portion 6 is in a predetermined low pressure state due to the suction force of the ejector 20 of the vacuum pump means 7, and the heat medium vapor supplied to the jacket portion 6 becomes a predetermined pressure, that is, the vapor temperature and reacts. The object to be heated in the kettle 2 is heated. The heat medium vapor that has been heated and deprived of heat condenses into a liquid,
It is sucked by the ejector 20 through the steam trap 14 and reaches the heat exchange tank 21.

The heat medium 27 in the heat exchange tank 21 is cooled to a predetermined temperature by the cooling pipe 28 and supplied to the ejector 20 by the circulation pump 22 to suck the heat medium in the jacket portion 6 again. Since the suction force generated by the ejector 20 is determined by the temperature of the fluid passing through the ejector 20, the suction force of the ejector 20, that is, the suction force of the ejector 20, is adjusted by appropriately adjusting the liquid temperature of the heat medium 27 in the heat exchange tank 21. The degree of pressure reduction can be controlled. By controlling the suction force of the ejector 20, the pressure state inside the jacket portion 6 can be controlled, and the pressure inside the jacket portion 6 can be changed from a negative pressure state below atmospheric pressure to a positive pressure state above atmospheric pressure. Can be controlled.

When using, for example, Dowsum under the trade name as the heat medium, the steam temperature becomes about 210 ° C. when the steam pressure is 0.3 kg in absolute pressure, and about 260 ° C. when it is 1.1 km. The steam temperature can be controlled by controlling the steam pressure.

In the present embodiment, when the non-condensable gas stays in the jacket portion 6, the non-condensable gas is sucked into the ejector 20 by opening one or both of the opening / closing valves 38 and 39. Atmosphere communication pipe 5 reaching 21
Exhausted to the atmosphere.

In this embodiment, the reaction vessel 2 is used as the heat exchanger, but other heat exchangers such as synthetic fibers and synthetic resins, heat exchangers for food and medical products, etc. Can also be used as.

[0022]

As described above, according to the present invention, by connecting the noncondensable gas extraction pipe between the ejector and the heat exchanger through the on-off valve, the noncondensable gas accumulated in the heat exchanger is retained. It is possible to obtain a low-pressure steam heating device using a heat medium, which can be appropriately removed by sucking with an ejector and can prevent deterioration of heat exchange performance due to retention of noncondensable gas.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a low-pressure steam heating device using a heat medium according to the present invention.

FIG. 2 is a configuration diagram showing a conventional steam heating device using a heat medium.

[Explanation of symbols]

 1 Boiler for heat medium 2 Reaction kettle 5 Atmosphere communication pipe 6 Jacket 7 Vacuum pump means 20 Ejector 21 Heat exchange tank 22 Circulation pump 36,37 Non-condensable gas extraction pipe 38,39 Open / close valve

Claims (1)

[Claims] 1. A secondary side of a heat exchanger in which a steam supply pipe for a heat medium is connected to a primary side of the heat exchanger and the heat medium condensed by the heat exchanger is recovered to a recovery destination such as an evaporator. A vacuum pump having an ejector, a tank, and a circulation pump is connected to the ejector, and the heat exchanger is connected to the ejector, and a non-condensable gas extraction pipe is connected between the ejector and the heat exchanger through an on-off valve. A low-pressure steam heating device using a heat medium characterized by being connected.