JP2015101765A - Solar heat magnesium reduction furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar heat magnesium reduction furnace capable of simultaneously heating many retorts.SOLUTION: High temperature heat is generated by irradiating a heat exchange member 7 with condensed sunlight L. Since expansion chambers 3 are formed in the periphery of a heating chamber 2, many retorts 10 are stored in the expansion chambers 3, and high temperature gas generated in the heating chamber 2 is circulated in the expansion chambers 3, the retorts 10 can be simultaneously heated. Therefore, magnesium can be efficiently reduced.

Description

  The present invention relates to a solar magnesium reduction furnace.

  Chemistry that collects sunlight as clean energy that does not burden the environment, converts the collected sunlight into heat energy, creates a very high temperature, and requires a high-temperature reaction environment A solar thermal reactor that advances the reaction is known (see, for example, Patent Document 1).

  On the other hand, a magnesium battery using magnesium metal is known. A magnesium battery is a primary battery that generates an electromotive force by immersing magnesium metal in an electrolyte as a negative electrode. In this magnesium battery, an insoluble oxide (magnesium hydroxide) is generated after use. It is expected that the insoluble oxide will be repeatedly used as a battery by reducing it by solar heat and restoring it again to magnesium metal.

  A cylindrical steel container called retort is used for the reduction of the oxide. Magnesium oxide and a reducing agent are put into the retort and reduced by heating to a high temperature (about 1200 ° C.), and only magnesium is vaporized and solidified and recovered in a cooling part at one end of the retort.

JP 2010-144958 A

  However, in such a conventional technique, even if a high-temperature heating chamber is formed by applying concentrated sunlight, and the retort is stored and heated there, the retort that can be stored in the heating chamber The number is limited and many retorts cannot be heated at one time.

  The present invention has been made paying attention to such a conventional technique, and an object of the present invention is to provide a solar magnesium reduction furnace capable of simultaneously heating many retorts.

  According to the first aspect of the present invention, a heating chamber is formed at a position for receiving sunlight condensed downward, and a heat exchanging member made of a heat-resistant material that can be ventilated in the vertical direction is provided in the heating chamber. The space below the exchange member is partitioned by a shielding wall, the heating chamber and the upper space communicate with each other around the heating chamber, and a plurality of retorts are inserted horizontally at a position equal to or lower than the heat exchange member. An expansion chamber is formed, and a ventilation passage for circulating gas is provided between the lower space of the heating chamber and the lower space of the retort of the expansion chamber.

  The invention according to claim 2 is characterized in that a backup heating means is provided in the middle of the air passage.

  The invention described in claim 3 is characterized in that the circulated gas is an inert gas.

  According to invention of Claim 1, high temperature heat | fever generate | occur | produces when the condensed sunlight hits a heat exchange member. Furthermore, an expansion chamber was formed around the heating chamber, the retort was accommodated therein, and the high-temperature gas generated in the heating chamber was circulated to the expansion chamber side through the air passage. Therefore, many retorts can be simultaneously heated with a high-temperature gas, and magnesium can be reduced efficiently.

  According to invention of Claim 2, since the heating means for backup is provided in the middle of the ventilation path, the reduction | restoration work of magnesium can be performed also at night or rainy weather.

  According to invention of Claim 3, since the gas circulated to a heating chamber is an inert gas, the metal of the installation which gas contacts is not oxidized.

BRIEF DESCRIPTION OF THE DRAWINGS The longitudinal cross-sectional view which shows the solar-heat magnesium reduction furnace which concerns on one Embodiment of this invention. The cross-sectional view which shows a solar-heat magnesium reduction furnace. The cross-sectional view which shows the ventilation path of a solar-heat magnesium reduction furnace. Sectional drawing which follows the SA-SA line shown by the arrow in FIG. The perspective view which shows a heat exchange member.

  1 to 5 are views showing a preferred embodiment of the present invention.

  The solar magnesium reduction furnace 1 of this embodiment is installed in, for example, a beam-down solar concentrator. In this case, sunlight is collected from the top downward. Therefore, the solar magnesium reduction furnace 1 is installed in the vicinity of the condensing point. The solar magnesium reduction furnace 1 has a substantially cross shape in which rectangular extension chambers 3 are further formed in four directions of a rectangular heating chamber 2. The outer wall of the solar magnesium reduction furnace 1 is formed of a heat-resistant brick and a heat insulating material. The inside of the heating chamber 2 and the expansion chamber 3 is filled with an inert gas. The inert gas is a gas that does not contribute to the oxidation of the heating chamber 2 or the expansion chamber 3, and is, for example, a nitrogen gas or a rare gas.

  A circular opening 4 is formed in the upper part of the heating chamber 2. A cylindrical condenser mirror 5 is installed above the opening 4. The cylindrical condenser mirror 5 has a structure in which the lower opening is smaller than the upper opening and the inner surface is a mirror surface. Sunlight L is introduced into the cylindrical condenser mirror 5.

  A circular transparent window 6 is also provided in the opening 4. The transparent window 6 is made of quartz glass having heat resistance and is formed in double, and cooling air circulates in a space between them.

  A heat exchange member 7 is provided inside the heating chamber 2. The heat exchange member 7 is composed of a plurality of black and has a multi-through hole structure made of a silicon carbide film (SiC) (see FIG. 5). The heat exchange member 7 has excellent heat resistance and air permeability in the vertical direction due to the multiple through-hole structure. Accordingly, the upper space 2 </ b> A and the lower space 2 </ b> B communicate with each other via the heat exchange member 7. Similarly, a shielding wall 8 made of a silicon carbide film (SiC) is provided around the aggregate of the heat exchange members 7 so as to surround the heat exchange member 7. The shielding wall 8 extends to the bottom surface of the heating chamber 2 and defines a lower space 2B of the heat exchange member 7.

  Four retorts 10 can be horizontally inserted into the expansion chambers 3 formed on the four sides of the heating chamber 2. The retort 10 is placed horizontally on a pedestal (not shown) provided in the expansion chamber 3 at a position corresponding to the upper part of the heat exchange member 7. Gaps are formed between the retorts 10 and between the retorts 10 and the inner wall of the expansion chamber 3 (see FIG. 4). Accordingly, gas can pass through the lower space 3B and the upper space 3A separated by the retort 10 of the expansion chamber 3 through the gap.

  The retort 10 contains magnesium oxide and a reducing agent, and the inside is decompressed. The base end portion of the retort 10 protruding from the expansion chamber 3 to the outside is cooled by water cooling.

  A metal pipe 11 shown in FIG. 1 is arranged in a meandering state at the upper part of the expansion chamber 3, and water vapor is additionally obtained by passing water therethrough.

  A ventilation passage 12 is formed between the bottom surface of the lower space 2B of the heat exchange member 7 in the heating chamber 2 and the side surface of the lower space 3B of the retort 10 in the expansion chamber 3. A heat-resistant fan device 13 is provided in the middle of the air passage 12, and is formed on the side surface of the lower space 3B of the expansion chamber 3 by sucking air from the suction holes 15 formed in the bottom surface of the lower space 2B of the heating chamber 2. The gas can be discharged from the discharge hole 14. A gas burner (heating means) 16 is provided at the lower part of the air passage 12.

  Due to the structure as described above, when the sunlight L introduced from above hits the heat exchange member 7, the light energy is converted into heat energy, and the heat exchange member 7 itself is heated to a high temperature. Since the internal gas is sucked from the bottom surface of the lower space 2B of the heating chamber 2 by the blow passage 12, and is discharged to the side surface of the lower space 3B of the expansion chamber 3, the high-temperature gas H that has passed through the heat exchange member 7 is expanded. After being discharged into the lower space 3B of the chamber 3, it passes through the retort 10 portion to reach the upper space 3A, moves from there to the upper space 2A of the heating chamber 2, and is again introduced into the heat exchange member 7. That is, all the retorts 10 can be uniformly heated while passing through the retort 10 portion while the high temperature gas H circulates between the heating chamber 2 and the expansion chamber 3. Accordingly, the magnesium oxide is reduced and vaporized as metallic magnesium in the retort 10, solidified at the base end portion having a low temperature protruding from the expansion chamber 3, and returned to the metallic magnesium.

  When there is no sunlight L such as rainy weather, the gas is heated by the backup gas burner 16. Since the gas circulated through the heating chamber 2 and the expansion chamber 3 is an inert gas such as nitrogen gas, the metal of the equipment in contact with the gas is not oxidized.

  In the above description, the example in which the internal gas is circulated from the lower space 2B of the heating chamber 2 to the lower space 3B of the expansion chamber 3 may be reversed.

DESCRIPTION OF SYMBOLS 1 Solar magnesium reduction furnace 2 Heating chamber 2A Upper space 2B Lower space 3 Expansion chamber 3A Upper space 3B Lower space 7 Heat exchange member 8 Shielding wall 10 Retort 12 Air passage 16 Gas burner (heating means)
L Sunlight H Hot air

Claims (3)

A heating chamber is formed at a position for receiving sunlight condensed downward, and a heat exchange member made of a heat-resistant material that can be ventilated in the vertical direction is provided in the heating chamber,
The space below the heat exchange member of the heating chamber is partitioned by a shielding wall,
Forming an expansion chamber in which the heating chamber and the upper space communicate with each other around the heating chamber and a plurality of retorts are inserted horizontally at a position equivalent to or lower than the heat exchange member,
The solar magnesium reduction furnace characterized by providing the ventilation path which circulates gas between the lower space of a heating chamber, and the lower space rather than the retort of an expansion chamber.    The solar heat magnesium reduction furnace according to claim 1, wherein a backup heating means is provided in the middle of the air passage. The solar magnesium reduction furnace according to claim 1 or 2, wherein the circulated gas is an inert gas.

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