JP2001227878A - 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: An ejector 5 communicates with the bottom section of a heat exchanging vessel 1 coupled with a vapor supply pipe 2 and communicates with a noncondensed gas discharging pipe 22 through a temperature response valve 23. The ejector 5 is 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 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 ejector 5 through the temperature response valve 23 and discharged to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method of condensing steam remaining in a steam-using device or reevaporated 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.

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 generated 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 condense the steam by exchanging heat with the cooling fluid. The bottom of the heat exchange container communicates with the suction chamber of the ejector, and the noncondensable gas reservoir in the heat exchange container communicates with the suction chamber of the ejector via valve means. The inlet side of the ejector is connected to the cooling fluid supply source. The outlet of the ejector is connected to the heat exchange container.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS By connecting the suction chamber of the ejector connected to the cooling fluid source to the bottom of the heat exchange container, the drain condensed in the heat exchange container is sucked by the ejector, mixed with the cooling fluid and exited. Is supplied again 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 that has undergone heat exchange, the condensed drain is sucked by an ejector, mixed with the cooling fluid, and then heat-exchanged with steam to thereby increase the temperature of the recovered fluid. And the heat recovery rate can be improved.

By communicating the non-condensable gas reservoir in the heat exchange container with the suction chamber of the ejector through the valve means, the non-condensable gas such as air accumulated in the container during heat exchange is opened. The valve ejector can be sucked and discharged to the outside.

[0010]

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 non-condensable gas discharge pipe 2
2, a cooling fluid supply pipe 4 connected to a cooling fluid supply source (not shown), and an ejector 5 connected to the cooling fluid supply pipe 4.
And constitute a heat exchanger.

The heat exchange vessel 1 is a closed tank. The cooling fluid supply pipe 4 communicates with the coil 11 downward through a valve 6 via 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 part of the heat exchange vessel 1, and the atmosphere communication pipe 10 and the opening / closing valve 9 are attached. 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 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. The drain generated in the heat exchange container 1 is sucked into the suction chamber 12 of the ejector 5 from one or both of the steam trap 13 and the valve 14.

An uncondensable gas discharge pipe 22 is arranged in parallel with the drain discharge pipe 3 and communicates with the suction chamber 12 of the ejector 5 via a temperature responsive valve 23 as a valve means. The non-condensable gas discharge pipe 22 is connected to a pipe 24 in the heat exchange vessel 1, and an upper end 25 of the pipe 24 is open to a reservoir where the non-condensable gas easily accumulates. In this embodiment, the pipe 24
Although the example in which the opening 25 is disposed only in the upper part of the heat exchange container 1 is shown, the opening 25 may be disposed not only in the upper part but also in a plurality of places in the central part, the lower part, etc. of the container 1.

The temperature responsive valve 23 is automatically opened when the temperature of the temperature sensing tube 26 falls below a predetermined temperature by connecting the temperature sensing valve 26 to the temperature sensing tube 26 attached to the upper end of the heat exchange vessel 1 by a capillary tube 27. The valve is communicated with the opening 25 and the ejector 5 to suck and discharge air or the like as non-condensable gas. When the temperature of the temperature sensing tube 26 increases, the temperature responsive valve 23 automatically closes.

The inlet side of the ejector 5, that is, the suction chamber 12 side,
The cooling fluid supply pipe 4 is connected via a pump 15, and the outlet side is connected to the coiled cooling fluid supply pipe 11 via a pipe 16. The pipe 16 has a discharge pipe 18 provided with a valve 17 and an air bleed pipe 2 provided with an automatic air bleed valve 19.
0 is connected in series. The cooling fluid supplied from the cooling fluid supply pipe 4 passes through the ejector 5 to generate a suction force in the suction chamber 12, sucks the drain in the heat exchange container 1, mixes with the cooling fluid, and supplies the coiled cooling fluid. It is sent to the tube 11.

A steam supply pipe 2 provided at the upper part of the heat exchange vessel 1
Is connected to the outlet side of a steam-using device such as a blower or a shrink tunnel (not shown) or a re-evaporation tank via a valve 21 to supply steam to the heat exchange vessel 1 for condensation.

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 ejector 5 to generate a suction force, via the temperature responsive valve 23 which is opened because the temperature in the tank 1 is low. At the same time, the valve 14 of the drain discharge pipe 3
Then, the valve 17 of the discharge pipe 18 is fully opened, and the air remaining in the tank 1 is discharged out of the system.

As described above, by sucking and discharging the staying air by the ejector 5, the staying air can be shortened for a shorter time than when the steam is simply supplied into the tank 1 and replaced with the staying air and discharged out of the system. , And can be reliably discharged out of the system.

The inside of the heat exchange vessel 1 from which the staying air has been discharged is:
When the steam supplied from the steam supply pipe 2 is condensed by heat exchange to form a drain, the volume of the steam suddenly decreases, so that the pressure is reduced. The condensed drain is sucked into the ejector 5 from the steam trap 13 of the drain discharge pipe 3 and mixed with the cooling fluid to reach the coil-shaped cooling fluid supply pipe 11, which exchanges heat with steam to increase the temperature, and from the hot water recovery pipe 8. Collected at a predetermined collection point.

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

If non-condensable gas such as air is mixed in the steam supplied from the steam supply pipe 2, the air stays in the heat exchange container 1 and the heat exchange efficiency is reduced. As described above, the temperature of the air staying in the container 1 is reduced by the heat radiation, and the temperature is detected by the temperature-sensitive cylinder 26. The temperature-responsive valve 23 is automatically opened to be sucked and discharged to the ejector 5.

The non-condensable gas sucked into the ejector 5 can be discharged out of the system from an automatic air vent valve 19 provided in the air vent line 20. On the other hand, if 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 vent valve 19.

[0023]

According to the present invention, the suction chamber of the ejector connected to the cooling fluid source is communicated with the bottom of the heat exchange container, and the outlet side of the ejector is connected to the heat exchange container again, so that the condensed drain is removed. Rather than recovering the heat exchanged cooling fluid separately, the condensate drain is sucked by the ejector and mixed with the cooling fluid, and then heat exchanged with steam to raise the temperature of the recovered fluid to increase the heat recovery rate. Can be improved.

Further, according to the present invention, the non-condensable gas reservoir in the heat exchange container and the suction chamber of the ejector are communicated via the valve means, so that the air or the like accumulated in the container during heat exchange can be prevented. The condensed gas can be discharged to the outside by opening the valve means and causing the ejector to suck the condensed gas.

[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 Ejector 8 Hot water recovery pipe 12 Suction chamber 13 Steam trap 19 Automatic air release valve 22 Non-condensable gas discharge pipe 23 Temperature-responsive valve 26 Temperature-sensitive cylinder

Claims (1)

[Claims] 1. A method for supplying steam and a cooling fluid to a heat exchange container and condensing the steam by exchanging heat with the cooling fluid, wherein a bottom portion of the heat exchange container communicates with a suction chamber of an ejector. The non-condensable gas reservoir in the inside and the suction chamber of the ejector are communicated via valve means, the inlet side of the ejector is connected to a cooling fluid supply source, and the outlet side of the ejector is connected to the heat exchange container. And heat exchanger.