JP3841691B2 - Heat exchanger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchange device that circulates and uses a granular heat medium to recover sensible heat of a high-temperature gas into a low-temperature gas.
[0002]
[Prior art]
In a heat exchange device that circulates and uses a granular heat medium and recovers the sensible heat of a high-temperature gas into a low-temperature gas, various deposits adhere to the surface of the heat medium that is being used in circulation, thereby reducing the heat exchange efficiency. In addition, when high-temperature exhaust gas generated in a melting furnace or the like is used as the high-temperature gas, the gaseous metal chloride contained in the high-temperature exhaust gas is liquefied as the temperature decreases and becomes a highly sticky deposit. Such sticky deposits not only lower the heat exchange efficiency, but also cause the heat media to aggregate due to adhesion, and this aggregated heat medium may block a narrow passage or the like in the heat exchange device.
[0003]
As a heat exchange device provided with a means for crushing the heat medium thus aggregated, there is one described in JP-A-2000-283673. As shown in FIG. 4, the heat exchange device includes an upper heat exchange chamber 52 through which the high-temperature exhaust gas 51 circulates and a lower heat exchange chamber 54 through which the low-temperature gas 53 circulates, and these heat exchange chambers 52, 54 is communicated by a communication pipe (communication part) 55, and trays 56 and 57 are provided in a plurality of stages in each of the heat exchange chambers 52 and 54, respectively, and the necks in the communication pipe 55 and the upper part of the lower heat exchange chamber 54 are provided. Rotating blades 59 and 60 are provided in the channel 58, respectively.
[0004]
The granular heat medium 61 is introduced from the hopper 62 and sequentially falls to each tray 56 of the upper heat exchange chamber 52, the communication pipe 55, each tray 57 of the lower heat exchange chamber 54, and the bottom of the lower heat exchange chamber 54. Each rotation provided in the communicating pipe 55 and the neck-shaped passage 58 is a heat medium 61 which is returned from the discharge port 63 provided at the bottom of the heat exchange chamber 54 to the hopper 62 through the return path 64 and used in circulation. The blades 59 and 60 are crushed.
[0005]
[Problems to be solved by the invention]
The conventional heat exchange apparatus described above can crush the agglomerated heat medium, but sticky deposits such as metal chlorides are not removed while adhering to the surface of the heat medium. In particular, metal chlorides are highly sticky at high temperatures, and become sticky and hard at low temperatures. For this reason, if the metal chloride adhering to the surface of the heat medium is returned to the upper heat exchange chamber without being removed, there is a problem that the heat medium is condensed again due to stickiness. In addition, the heat medium to which the deposits are attached has a problem of reducing the heat exchange efficiency.
[0006]
Then, the subject of this invention is providing the heat exchange apparatus which can remove an adhesive deposit | attachment from the surface of a heat medium efficiently.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention allows heat exchange through a granular heat medium from an upper heat exchange chamber in which a high-temperature gas circulates to a lower heat exchange chamber in which a low-temperature gas circulates. In a heat exchange device that circulates and uses the heat exchange medium that has accumulated heat at the bottom, returning it to the upper heat exchange chamber via a return path, the high temperature exhaust gas is used as the high temperature gas, and the heat medium that accumulates at the bottom of the lower heat exchange chamber is used. A configuration was adopted in which stirring means for stirring was provided, and deposits adhering to the surface of these heat media were peeled off.
[0008]
That is, the heat exchanged heat medium accumulates and accumulates at the bottom of the lower heat exchange chamber, and material sealing is performed with the overlapped heat medium. At the bottom of the lower heat exchange chamber, the temperature of the heat medium is lowered by heat exchange with the low-temperature gas, so that the metal chloride adhered to the surface is solidified and loses its adhesiveness. For this reason, the adhering substance on the surface can be efficiently peeled by stirring the heat medium accumulated at the bottom of the lower heat exchange chamber and rubbing the heat mediums together.
[0009]
By providing the return path with a screen for removing the exfoliated material exfoliated from the surface of the heat medium by the stirring means, the exfoliated adhesive substance can be prevented from adhering to the heat medium again.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. 1 and 2 show a first embodiment. As shown in FIG. 1, the heat exchange device includes an upper heat exchange chamber 2 through which high-temperature exhaust gas 1 circulates and a lower heat exchange chamber 4 through which low-temperature gas 3 circulates. 4 is communicated by the communication part 5, and the trays 6 and 7 are provided in a plurality of stages in the heat exchange chambers 2 and 4, respectively. The granular heat medium 10 charged into the upper part of the upper heat exchange chamber 2 from the inlet 9 of the hopper 8 is divided into the trays 6 of the upper heat exchange chamber 2, the communication part 5, the trays 7 of the lower heat exchange chamber 4, and the lower part. It falls sequentially to the bottom of the heat exchange chamber 4, collects sensible heat in contact with the high temperature exhaust gas 1 flowing from the vent 11 to the exhaust port 12 in the upper heat exchange chamber 2, and vents in the lower heat exchange chamber 4. The sensible heat recovered in the low-temperature gas 3 flowing from 13 to the exhaust port 14 is released and heat exchange is performed.
[0011]
The heat medium 10 accumulated at the bottom of the lower heat exchange chamber 4 after the heat exchange is sequentially discharged from the discharge port 15 and transferred to the air lifter 16, and is returned and conveyed to the upper hopper 8 through the return path 17 by air. Used cyclically.
[0012]
As shown in FIG. 2, a stirring blade 19 that is rotationally driven by a motor 18 is provided at the bottom of the lower heat exchange chamber 4 where the heat medium 10 is accumulated. The temperature of the heat medium 10 accumulated at the bottom of the lower heat exchange chamber 4 is lowered due to heat exchange with the low temperature gas 3, and the metal chloride adhering to the surface of the heat medium 10 is solidified and loses its adhesiveness. Yes. Accordingly, the heat medium 10 accumulated on the bottom is rubbed with the stirring blade 19 and the sticky substance such as metal chloride attached to the surface of the heat medium 10 is peeled off from the high temperature exhaust gas 1. The exfoliated material is conveyed along the return path 18 by the air lifter 16 together with the heat medium 10 and enters the upper heat exchanging chamber 2 from the hopper 8. 12 is collected by a bag filter (not shown) provided in the exhaust path.
[0013]
FIG. 3 shows a second embodiment. The basic structure of this heat exchange device is the same as that of the first embodiment, except that a screen 20 is provided in the transfer path from the discharge port 15 to the air lifter 16. In this embodiment, the peeled material that peels off from the heat medium 10 by stirring of the stirring blade 19 is removed through the screen 20, and only the heat medium 10 is transferred to the air lifter 16.
[0014]
In each of the above-described embodiments, the rotation axis of the stirring blade that stirs the heat medium accumulated at the bottom of the lower heat exchange chamber is vertical, but the rotation axis of the stirring blade depends on the shape of the bottom of the lower heat exchange chamber. Any angle can be set.
[0015]
【The invention's effect】
As described above, the heat exchanging device of the present invention is provided with means for exchanging heat and agitating the heat medium accumulated and accumulated on the bottom of the lower heat exchange chamber, and rubbing the overlapping heat mediums together. The adhesive material such as metal chloride contained in the high-temperature exhaust gas adhering to the surface is peeled off, so that the heat exchange efficiency of the heat medium is improved and the adhesive material of the heat medium returned to the high temperature upper heat exchange chamber It is possible to prevent the blockage of a narrow passage in the heat exchange device by eliminating the aggregation due to.
[Brief description of the drawings]
FIG. 1 is a schematic longitudinal sectional view showing a heat exchange device of a first embodiment. FIG. 2 is a longitudinal sectional view showing an enlarged bottom portion of a lower heat exchange chamber in FIG. Fig. 4 is an enlarged longitudinal sectional view showing the bottom of the lower heat exchange chamber of the heat exchange device. Fig. 4 is a schematic longitudinal sectional view showing a conventional heat exchange device.
DESCRIPTION OF SYMBOLS 1 High temperature exhaust gas 2 Heat exchange chamber 3 Low temperature gas 4 Heat exchange chamber 5 Communication part 6, 7 Tray 8 Hopper 9 Input port 10 Heat medium 11 Ventilation port 12 Exhaust port 13 Vent port 14 Exhaust port 15 Exhaust port 16 Air lifter 17 Return path 18 Motor 19 stirring blade 20 screen

Claims (2)

The upper heat exchange chamber through which the high-temperature gas circulates is exchanged through a granular heat medium from the lower heat exchange chamber through which the low-temperature gas circulates, and the heat exchange heat medium accumulated at the bottom of the lower heat exchange chamber is converted into the upper heat exchange chamber. In a heat exchange device that is circulated and returned to the exchange chamber through a return path, a high-temperature exhaust gas is used as the high-temperature gas, and a stirring means for stirring the heat medium accumulated at the bottom of the lower heat exchange chamber is provided, and the heat media are rubbed together Thus, the metal chloride adhering to the surface of the heat medium is peeled off. The heat exchange apparatus according to claim 1, wherein a screen is provided on the return path to remove the exfoliated material exfoliated from the surface of the heat medium by the stirring means.

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