JP2001227879A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat exchanger having an enhanced heat recovery rate in which noncondensed gas stored during heat exchange can also be discharged to the outside. SOLUTION: A first ejector 5 is coupled with the bottom section of a heat exchanger vessel 1 and a second ejector 22 is coupled with the top section of the heat exchanging vessel 1. The ejectors 5, 22 are coupled, on the inlet side thereof, with a cooling fluid supply pipe 4 and, on the outlet side thereof, with a coiled cooling fluid supply pipe 11. Drain condensed in the heat exchanging vessel 1 is sucked by the first ejector 5 and mixed with cooling fluid before being fed to the coiled cooling fluid supply pipe 11 for further heat exchange. Noncondensed gas stored in the heat exchanging vessel 1 during heat exchange is sucked by the second ejector 22 and discharged to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a technique for condensing steam remaining in a steam-using apparatus or re-evaporated steam generated from a high-temperature drain by exchanging heat with a cooling fluid such as water. The present invention relates to a device that eliminates steam that can accumulate with a moyamoya gas or uses hot water whose temperature has been increased by exchanging heat with a cooling fluid to separately use the retained heat of the steam.

[0002]

2. Description of the Related Art A conventional heat exchanger of this type is disclosed, for example, in Japanese Patent Application Laid-Open No. 60-120186. This is achieved by installing a cooling pipe inside a heat recovery chamber having a steam supply port, connecting the air release section to this heat recovery chamber, and storing condensate in the air release section and the lower part of the heat recovery chamber.
It is possible to prevent non-condensable gas, for example, air, from flowing into the heat recovery chamber and efficiently exchange heat.

[0003]

In the above-mentioned conventional heat exchanger, the cooling fluid that has exchanged heat with the steam through the cooling pipe and the drain in which the steam has condensed are separately collected. There was a problem that the rate was kept at a relatively low value of about 90%. This is because both the cooling fluid and the drain that have undergone heat exchange have a low temperature of about 50 ° C. to 60 ° C., and if they are collected separately, heat loss is large and the heat recovery efficiency is not improved.

In the above-mentioned conventional heat exchanger, it is possible to prevent the inflow of non-condensable gas such as air from the outside of the heat recovery chamber. , There is a problem that the non-condensable gas cannot be discharged to the outside.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the heat exchange rate by improving the heat recovery rate by increasing the temperature of the low-temperature recovered fluid as much as possible while allowing the non-condensable gas staying during the heat exchange to be discharged to the outside. Is to get a bowl.

[0006]

Means taken to solve the above problem is to supply steam and a cooling fluid to a heat exchange container, and to condense the steam by exchanging heat with the cooling fluid. The bottom of the heat exchange container communicates with the suction chamber of the first ejector, the top of the heat exchange container communicates with the suction chamber of the second ejector, and the inlet side of the first and second ejectors communicates with the cooling fluid. It is connected to a supply source, and the outlet sides of both ejectors are connected to the heat exchange container.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The suction chamber of a first ejector connected to a source of cooling fluid communicates with the bottom of the heat exchange container, so that the drain condensed in the heat exchange container is sucked into the first ejector and is cooled. And supplied again from the outlet side into the heat exchange container. The supplied mixed fluid of the cooling fluid and the drain exchanges heat with the steam in the heat exchange vessel to form steam and drain, and the temperature of the mixed fluid increases.

[0008] Instead of separately collecting the condensed drain and the cooling fluid exchanged with heat, the condensed drain is sucked by the first ejector, mixed with the cooling fluid, and further exchanged with steam to recover. The heat recovery rate can be improved by increasing the temperature of the fluid.

By communicating the top of the heat exchange container with the suction chamber of the second ejector, non-condensable gas such as air accumulated in the container during heat exchange can be removed from the top of the heat exchange container by the second ejector. It can be sucked and discharged to the outside.

On the other hand, when the non-condensable gas stays at the bottom of the heat exchange vessel, the first ejector sucks and discharges the non-condensable gas together with the condensed drain.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a heat exchange vessel 1, a steam supply pipe 2 for supplying steam to be condensed, a drain discharge pipe 3 for discharging a drain condensed with steam, and a first pipe connected to the drain discharge pipe 3 are shown. , The second ejector 22 communicating with the top of the heat exchange vessel 1, and the cooling fluid supply pipe 4 connected to a cooling fluid supply source (not shown) constitute a heat exchanger.

The heat exchange vessel 1 is a closed tank. The cooling fluid supply pipe 4 communicates with the coil 11 through a valve 6 downward through a valve 6, and is connected to a hot water recovery pipe 8 via a valve 7 from above. The steam supply pipe 2 is connected to the upper side of the heat exchange vessel 1 via a valve 21. By the steam supplied from the steam supply pipe 2, the cooling fluid in the coiled cooling fluid supply pipe 11 is heated and the temperature rises, and the steam deprived of heat is condensed to drain and flow down to the lower part of the tank 1. Is what you do.

The bottom of the heat exchange vessel 1 and the suction chamber 12 of the first ejector 5 are connected by a drain discharge pipe 3. A steam trap 13 and a valve 14 are attached to the drain discharge pipe 3 in parallel, and a steam trap 13 that allows only the drain to flow down and does not allow steam to pass therethrough.
Drain generated in the heat exchange vessel 1 is a steam trap 1
3 and / or the valve 14
Is sucked into the suction chamber 12 of the ejector 5.

The top of the heat exchange vessel 1 and the second ejector 22
The suction chamber 23 is communicated by a pipe 24. The second ejector 22 sucks non-condensable gas such as air collected above the heat exchange container 1.

The inlet sides of the first and second ejectors 5 and 22, that is, the suction chambers 12 and 23 are connected to the cooling fluid supply pipe 4 via a pump 15. Further, the outlet side is connected to the coil-shaped cooling fluid supply pipe 11 by the pipe lines 16 and 25. Pipe line 1
6 is provided with a discharge pipe 18 provided with a valve 17,
5 is connected to a discharge pipe 27 provided with a valve 26. An air vent line 20 provided with an automatic air vent valve 19 is connected to the inlet side of the coiled cooling fluid supply pipe 11. The cooling fluid supplied from the cooling fluid supply pipe 4 passes through the first and second ejectors 5 and 22 to generate suction force in the respective suction chambers 12 and 23, and the suction fluid does not communicate with the drain in the heat exchange vessel 1. The condensed gas is sucked, mixed with the cooling fluid, and the coiled cooling fluid supply pipe 1
1 is sent.

A steam supply pipe 2 provided on the upper side of the heat exchange vessel 1 is connected to an outlet side of a steam-using device such as a blower or a shrink tunnel (not shown) or a re-evaporation tank or the like to exchange heat for condensing steam. Supply to container 1.

When heat exchange is started, air as non-condensable gas stays in the tank 1, and it is necessary to quickly remove this air in order to perform heat exchange efficiently. Accordingly, the steam is supplied from the steam supply pipe 2 into the tank 1 and the cooling fluid is supplied to the ejectors 5 and 22 to generate a suction force, and the valve 14 of the drain discharge pipe 3 and the valves of the discharge pipes 18 and 27 are generated. 17 and 26 are fully opened, and the staying air in the tank 1 is quickly discharged out of the system from both the ejectors 5 and 22.

By sucking and discharging the staying air by the ejectors 5 and 22 as described above, the staying air can be removed more than when steam is simply supplied into the tank 1 and replaced with the staying air and discharged outside the system. It can be reliably discharged out of the system in a short time.

The heat exchange vessel 1 from which the initial accumulated air has been discharged.
The inside is decompressed because the steam supplied from the steam supply pipe 2 is condensed by heat exchange to form a drain, and the volume thereof is rapidly reduced. The condensed drain is sucked into the first ejector 5 from the steam trap 13 of the drain discharge pipe 3. On the other hand, air as non-condensable gas mixed in the supplied steam is sucked into the second ejector 22 by staying in the upper part of the heat exchange container. The drain and cooling fluid of the first ejector 5 and the second ejector 22
The air and the cooling fluid are mixed with each other to reach the coil-shaped cooling fluid supply pipe 11, exchange heat with steam, raise the temperature, and are recovered from the hot water recovery pipe 8 to a predetermined recovery location.

As described above, by mixing the condensed drain and the cooling fluid in the first ejector 5 and exchanging heat, the temperature of the recovered hot water can be increased, and the heat recovery rate can be increased.

In this embodiment, the non-condensable gas remaining in the vessel 1 during the heat exchange can also be sucked by the second ejector 22. In this case, the non-condensable gas sucked by the ejector 22 can be discharged out of the system from the automatic air vent valve 19 provided in the air vent line 20. However, when there is no problem even if non-condensable gas is mixed in the heat-exchanged hot water, it is not necessary to discharge the non-condensable gas out of the system by the automatic air release valve 19.

[0022]

According to the present invention, the suction chamber of the first ejector connected to the cooling fluid source communicates with the bottom of the heat exchange container,
By connecting the outlet side of the first ejector to the heat exchange container again, the condensed drain and the cooling fluid exchanged with heat are not collected separately, but the condensed drain is sucked by the first ejector and cooled. After mixing with the fluid, heat exchange with the steam further increases the temperature of the recovered fluid, thereby improving the heat recovery rate.

Further, according to the present invention, by communicating the top of the heat exchange container with the suction chamber of the second ejector, non-condensable gas such as air accumulated in the container during heat exchange can be removed. Can be sucked into the second ejector from the top and discharged to the outside.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a heat exchanger of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchange container 2 Steam supply pipe 3 Drain discharge pipe 4 Cooling fluid supply pipe 5 First ejector 8 Hot water recovery pipe 12 Suction chamber 19 Automatic air release valve 22 Second ejector 23 Suction chamber

Claims (1)

[Claims] 1. A method for supplying steam and a cooling fluid to a heat exchange vessel and condensing the steam by exchanging heat with the cooling fluid, wherein a bottom of the heat exchange vessel communicates with a suction chamber of a first ejector, The top of the heat exchange vessel is communicated with the suction chamber of the second ejector, the inlet sides of the first and second ejectors are connected to a cooling fluid supply source, and the outlet sides of both ejectors are connected to the heat exchange vessel. A heat exchanger characterized by being connected.