JP6084394B2 - Reaction cell structure of hydrogen generator - Google Patents

Description

  The present invention relates to a reaction cell structure containing a reactant in a hydrogen generator that decomposes water using an alkali hydroxide as a reactant.

  An alkali metal hydroxide (NaOH, KOH) as a reactant is housed in a stainless steel reaction cell, which is heated to 500 ° C. or more to emit fine particles from the molten salt. The present inventor has already filed an application for a hydrogen generator that reacts in a stainless steel component atmosphere to decompose water and generate hydrogen.

International Publication WO2010 / 084790

  However, in the hydrogen generator in Patent Document 1, sufficient studies have not been made on how to uniformly heat the reactants stored in the reaction cell. That is, as a result of various experiments, it has been found that the reactant is heated uniformly, and whether the heat is sufficiently conducted therein has a great influence on the reactivity, and improvement based on this knowledge is necessary.

  Therefore, the hydrogen generator of the present invention accommodates a reactant in a stainless steel cylindrical reaction cell, heats the reaction cell to a temperature higher than the melting point of the reactant, supplies water into the reaction cell, In the hydrogen generator for generating hydrogen from the reaction cell, the reaction cell has a large-diameter outer case, a medium-diameter inner case disposed therein, a heater pipe disposed in the inner case, and the heater An electric rod heater as an inner heating device that is inserted into the pipe, an outer heating device that heats the outer peripheral surface of the outer case, an outer reactant receiver that holds the reactant between the outer case and the inner case, It consists of an inner reactant receiver that holds the reactant between the inner case and the heater pipe.

  In addition, the outer case and the inner case are elongated by a predetermined length in the axial direction of the outer reactant receiver and the inner reagent receiver and are closed by end plates, and only the portions corresponding to the reactant receivers are heated. It is preferable.

  Furthermore, a water pipe for sending water into the reaction cell is connected to one end plate of the reaction cell, and a hydrogen discharge pipe for discharging hydrogen is attached to the upper part of the other end plate. It is preferable that a drain pipe is provided below the end plate.

  Furthermore, the first space in which the outer reactant receiver is installed and the second space in which the inner reactant receiver is installed are independent spaces, and a water pipe and a hydrogen discharge pipe are attached corresponding to these independent spaces. It is preferable that

  Furthermore, it is preferable that a water jacket is formed in the vicinity of the outer end plate of the outer case, and this water jacket is operated when the reactant is washed.

  There is an electric bar heater in the center of the reaction cell, the outer case is heated from the outside by the outside heating device, the reactant is heated from the outside and inside, and the reaction cell is formed in a cylindrical shape. Since the reactant having the same thickness is heated from the inside and the outside, the reactant is heated uniformly and the reaction becomes active. In addition, when a current is passed through the bar heater, magnetic field lines are generated, and these magnetic field lines attract fine particles of the reactant scattered in the reaction space and activate the reaction with the stainless steel surface.

  Furthermore, if only the portion corresponding to the reactant receiver in each case is heated, the temperature of the end plate portion of the case with many welded portions can be lowered, and the life of the apparatus can be extended.

  In addition, if the two reaction spaces on the outside and the inside are made independent of each other, even if leakage occurs in one reaction space, the other space is not affected, and each reaction space is heated independently during washing. If it sends, the space where heating steam will be sent is divided, the fall of the pressure decreases, and the cleaning effect becomes large. If the heated steam after washing is cooled by a water jacket during washing, impurities as water drain can be efficiently discharged from the drain pipe to the outside.

It is a longitudinal cross-sectional view of the reaction cell used for the hydrogen generator of this invention. It is a cross-sectional view of the reaction cell of FIG. FIG. 3 is a cutaway perspective view of the reaction cell shown in FIGS. It is an oxide film formation state explanatory drawing at the time of reaction. It is a state figure of the reactant container used at the time of washing. It is explanatory drawing of the accommodation state of the reactant in a storage box.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1, 2 and 3, a stainless steel reaction cell 1 used in the hydrogen generator M of the present invention comprises a cylindrical large-diameter outer case 2 and a medium-diameter inner case 3 housed therein. A small-diameter heater pipe 4 disposed in the center of the inner and outer cases 2 and 3, an electric bar heater 5 as an inner heating device inserted into the heater pipe 4, and the outer case 2 are wound around. For example, a planar heater 6 serving as an outer heating, and a bowl-shaped outer reactant receiver 7 positioned in the axially central portion of the reaction cell 1 of the ring-shaped first space S ₁ between the inner and outer cases 3 and 2. And a bowl-shaped inner reactant receiver 8 located in the center portion in the axial direction of the reaction cell 1 in the ring-shaped second space S ₂ between the inner case 3 and the heater pipe 4.

  The outer reactant receiver 7 is in contact with the inner wall of the outer case 2, and the inner reactant receiver 8 is in contact with the inner wall of the inner case 2, and the heater pipe 4 and the outer case corresponding to the both reactant receivers 7, 8. Only the portion 2 is heated, and the bar heater 5 also has a structure in which only the portion 5 a corresponding to the reactant receiver 8 generates heat.

Both ends in the axial direction of the reactant receptacles 7 and 8 are closed by end plates (the end plate 8a of the receptacle 8 is shown in FIG. 3), and NaOH or KOH as a reactant is contained in these receptacles 7 and 8. When these reactants are heated above their melting point (300 ° C. or higher), they become molten salt, and fine particles scatter from the liquid surface into the spaces S ₁ and S ₂ , where water vapor is supplied. And the water reacted in the stainless steel atmosphere (Fe, Ni, Cr in the case of SUS304). As shown in FIG. 6, the reactants R ₁ and R ₂ held in the reactant receivers 7 and 8 are in a semi-ring shape, and the thickness t is uniform, so there is no bias in the conduction of heat and the uniformity. It is heated and becomes a reactive agent with good reactivity.

Wherein both ends of the reaction cell 1 is an end plate 1a, is closed by 1b, the first space S ₁ and the second space S ₂ is partitioned independently of each other, the reaction is carried out separately, and so leaks one space It does not affect the space.

Non-heating portions N ₁ and N ₂ are formed in the axial direction, front and rear of the reactant receivers 7 and 8, and the temperatures near the end plates 1a and 1b are heated by the non-heating portions N ₁ and N _2. Since it is lower, the welded part is protected and the life of the reaction cell 1 is extended.

With three water pipes 9 are provided at positions corresponding to the first space S ₁ of the front end plate 1a, a position corresponding to the second space S ₂ is provided further three water tubes 10, thus The reason why the plurality of water pipes 9 and 10 are provided is that these water pipes 9 and 10 are used as superheated steam injection pipes during cleaning (described later).

The water pipes 9 and 10 are connected to a water supply system w ₁ , and the water supply system w ₁ supplies water in the water tank 20 to the first and second spaces S ₁ and S ₂ through a valve 21. On the other hand, the water pipes 9 and 10 are also connected to a cleaning system w ₂ for cleaning the _first and second spaces S ₁ and S ₂ , and the cleaning meter w ₂ uses high-frequency induction heating of saturated water vapor from the boiler 22. This is for feeding to both the spaces S ₁ and S ₂ through the device 23 and also includes a valve 24.

Wherein the upper side of the end plate 1b after reaction cell 1, the hydrogen discharge pipe 30, 31 for discharging the generated hydrogen is provided corresponding to the first space S ₁ and the second space S _2, the end Under the plate 1b, drain pipes 32 and 33 for discharging drains during cleaning are provided corresponding to the first and second spaces S ₁ and S _2. On-off valves 34 and 35 are provided. Further, the projecting end of the non-heated part N ₂ of the outer casing 2, a water jacket 40 is provided, the water jacket 40, the superheated steam to be sent at the time of washing is operated during cleaning position reactant partial After being washed, it is cooled and discharged smoothly from the drain pipes 32 and 33 as drains.

A vacuum pump 42 is connected to the hydrogen discharge pipes 30 and 31 through a valve 41. The vacuum pump 42 reduces the pressure of the first and second spaces S ₁ and S ₂ to 1 atm or less. Underneath, the steam and the reactant are reacted.

  Next, cleaning will be described.

When NaOH is used as the reactant, the lower oxide (NaFeO ₂ ) is first converted into 2Fe + 2NaOH + 2H ₂ O → 2NaFeO ₂ + 3H _2.
Furthermore, this NaFeO ₂ reacts with water and iron, and 3NaFeO ₂ + 2Fe + 3H ₂ O → Na ₃ Fe ₅ O ₉ + 3H ₂ according to the following reaction formula
A high-order iron oxide film (Na ₃ Fe ₅ O ₉ ) is generated. This high-order iron oxide film acts as a catalyst and decomposes water. Although hydrogen is generated in this process, the iron (Fe) component in the stainless steel simultaneously generates oxides such as FeO, Fe ₂ O ₃ , and Fe ₃ O _4. Therefore, it is necessary to clean these oxides as impurities. For example, the cleaning operation is performed when the operation of the day is completed. As shown in FIG. 4, the higher-order special function oxide film (Na ₃ Fe ₅ O ₉ ) 1 is formed of an inner wall of the stainless outer case 2, an inner / outer wall of the inner case 3, and each reagent receiver (made of stainless steel). ) Impure oxides O, O... O that do not contribute to the reaction but adhere to the inner walls of 7 and 8 are deposited on each oxide film l. Water supply of this impure oxide is stopped (valve 21 is closed), valve 24 is opened, and superheated steam (200 ° C. or higher) is sent to the first and second spaces S ₁ and S ₂ at a high pressure. O is washed away, and the dirty superheated water vapor is made liquid at the position of the water jacket 40 and discharged to the outside through the drain pipes 32 and 33. If the surface of the high-order special function oxide is washed after reacting for a certain time in this way, the deterioration can be effectively prevented.

When cleaning, if superheated steam is passed through the storage box 50 containing the reactant R and then sent into the first and second spaces S ₁ and S _{2 as shown} in FIG. Can be supplied together with superheated steam into the space to replenish the reactants at the same time as washing, and the effect of the reactants can be maintained for a long time.

DESCRIPTION OF SYMBOLS 1 ... Reaction cell 2 ... Outer case 3 ... Inner case 4 ... Heater pipe 5 ... Electric rod heater 7 ... Outer reactant receptacle 8 ... Inner reactant receptacle 9 ... Water pipe 10 ... Water pipe 20 ... Water tank 23 ... High frequency induction heating apparatus

Claims (5)

Reactant consisting of alkali hydroxide is housed in a stainless steel cylindrical reaction cell, the reaction cell is heated above the melting point of the reactant, and water is supplied into the reaction cell to generate hydrogen from the water. In the hydrogen generating apparatus, the reaction cell has a large-diameter outer case, a medium-diameter inner case disposed therein, a heater pipe disposed in the inner case, and a heater pipe inserted into the heater pipe. An electric bar heater as an inner heating device, an outer heating device that heats the outer peripheral surface of the outer case, an outer reactant receiver that holds a reactant between the outer case and the inner case, an inner case and a heater A reaction cell structure of a hydrogen generator comprising an inner reactant receiver that holds the reactant between pipes.   The outer case and the inner case are extended by a predetermined length in the axial direction of the outer reactant receiver and the inner reactant receiver and closed by each end plate, and only the portions corresponding to the respective reactant receivers are heated. The reaction cell structure of the hydrogen generator according to claim 1.   A water pipe for sending water into the reaction cell is connected to one end plate of the reaction cell, and a hydrogen discharge pipe for discharging hydrogen is attached to the upper part of the other end plate. The reaction cell structure of the hydrogen generator according to claim 1 or 2, wherein a drain pipe is provided at a lower part.   The first space in which the outer reactant receiver is installed and the second space in which the inner reactant receiver is installed are independent spaces, and a water pipe and a hydrogen discharge pipe are attached corresponding to these independent spaces. The reaction cell structure of the hydrogen generator according to claim 3.   The reaction cell structure of the hydrogen generator according to claim 3, wherein a water jacket is formed in the vicinity of the outer end plate of the outer case, and the water jacket is activated when the reactant is washed.

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