JP5713413B2 - Bamboo heat treatment equipment - Google Patents

Description

  The present invention relates to a heat treatment apparatus for bamboo with water vapor.

Bamboo is a unidirectional reinforcement with vascular bundles arranged in the longitudinal direction. One vascular bundle is composed of a plurality of vascular sheaths, conduits and phloem. A vascular sheath is a collection of many cellulose fibers (microfibrils). In the vascular sheath, almost no pores are seen in the fiber cross section, and the fibers arranged in one direction (bamboo fibers) support the strength of the bamboo.
Bamboo is an abundant biomass resource, and bamboo fibers extracted from bamboo have a wide range of uses.

The materialization of bamboo, in other words, the extraction of bamboo fiber from bamboo, begins by unraveling its hard structure. Conventionally, many physical methods for crushing or crushing bamboo have been disclosed. For example, using a gear or screw toothbrushing machine to grind bamboo in a cotton form at room temperature, or first grinding a hard surface, then dividing the trunk material into multiple equal intervals to obtain a plate-like bamboo material In addition, this bamboo bamboo material is crushed into powder, bamboo powder production equipment with special rotating cutting teeth, and oga powder production equipment. A technique for making bamboo powder by retransmitting a large powder to an oga powder manufacturing apparatus again is disclosed.
However, in order to physically produce bamboo powder (bamboo fiber), a special pulverization apparatus is required as described above, or the processing takes a great deal of time. There is also a problem that it is difficult to take out bamboo fibers that are long in the fiber direction (a large aspect ratio).

In order to solve these problems, natural bamboo material cut into a predetermined length is put into a pressure can body having a pressure resistance of 10 kg / cm ² , for example, at a temperature of 100 ° C. or higher, for example, 170 to 175 ° C. and its temperature. A method for producing bamboo fibers is disclosed in which bamboo fibers are separated from each other by a blasting treatment in which a pressure heating operation for supplying water vapor with a pressure corresponding to the pressure and a pressure reduction operation for rapidly releasing the pressure are repeated 8 to 10 times. (See Patent Document 1).
However, the use of pressure vessels is not only costly due to the high pressure, but also requires safety and is considered difficult to scale up.

  In addition, the bamboo is cut into chips in advance, and then pre-hydrolyzed with water or steam at 100 to 200 ° C. in the presence of sulfur dioxide or sulfuric acid, and then with a chemical solution comprising water, alkali and anthraquinone. A technique of cooking and pulping is disclosed (see Patent Document 2). However, in this case, there is a problem of post-treatment of the used chemical substance.

  Furthermore, the present inventors have disclosed a technique for defibration after heat-treating bamboo with atmospheric superheated steam at a temperature of 180 to 320 ° C. (see Patent Document 3). According to this technique, bamboo fiber having a short fiber length rich in cellulose can be obtained without chemical treatment operation, high-pressure treatment operation, or after-treatment of the used chemical substance.

JP 2003-155679 A Japanese translation of PCT publication No. 2008-501074 JP 2012-040701 A

  The problem to be solved is that it is required to further improve the technique disclosed in the present inventors for heat-treating bamboo with atmospheric superheated steam.

The bamboo heat treatment apparatus according to the present invention includes a hollow cylindrical reaction vessel in which an extending portion extending in the axial direction is provided on the inner peripheral surface, an atmospheric pressure superheated steam introduction mechanism, and the hollow cylindrical reaction vessel. Bamboo provided at one end of the hollow cylindrical reaction vessel having a rotation mechanism and having an inlet for introducing atmospheric superheated steam and an outlet for extracting water vapor connected to the hollow cylindrical reaction vessel A bamboo extraction part provided at the charging part and the other end, the water vapor inlet is provided on the bamboo extraction part side of the hollow cylindrical reaction vessel, and the water vapor outlet is on the bamboo insertion part side It is provided in .

The bamboo heat treatment apparatus according to the present invention is preferably provided with a first protrusion on the inner peripheral surface of the hollow cylindrical reaction vessel in the vicinity of the bamboo extraction portion of the hollow cylindrical reaction vessel , and the hollow A central axis is provided on the axis of the cylindrical reaction vessel, the center axis having a second protrusion that extends toward the inner peripheral surface and faces the first protrusion.

  The bamboo heat treatment apparatus according to the present invention is preferably characterized in that a heating section is provided on the outer peripheral surface of the hollow cylindrical reaction vessel.

  In the bamboo heat treatment apparatus according to the present invention, preferably, the hollow cylindrical reaction vessel is disposed with an axis inclined with respect to a horizontal plane, and the bamboo charging portion is provided on a higher position side of the hollow cylindrical reaction vessel. The bamboo extraction part is provided on the lower position side.

In addition, the bamboo heat treatment apparatus according to the present invention is preferably further provided with a bamboo vinegar solution recovery mechanism connected to the outlet port by cooling and condensation .

  The bamboo heat treatment apparatus according to the present invention includes a hollow cylindrical reaction vessel in which an extending portion extending in the axial direction is provided on the inner peripheral surface, an atmospheric pressure superheated steam introduction mechanism, and a circuit that rotates the hollow cylindrical reaction vessel. Bamboo loading portion provided at one end of the hollow cylindrical reaction vessel, having a moving mechanism and connected to the hollow cylindrical reaction vessel, having an inlet for introducing atmospheric superheated steam and an outlet for deriving water vapor And since it has the bamboo extraction part provided in the other edge part, the hemicellulose component of bamboo is decomposed | disassembled preferentially, the bamboo after heat processing hold | maintains the short fiber structure of a cellulose, and a bamboo is crushed.

FIG. 1 is a diagram showing a schematic configuration of a bamboo heat treatment apparatus according to the present embodiment. FIG. 2 is a perspective view of an example of the extending portion of the bamboo heat treatment apparatus according to the present embodiment. FIG. 3 is a perspective view of an example of the central axis and protrusions of the bamboo heat treatment apparatus according to the present embodiment. FIG. 4 is a diagram showing a schematic configuration of a bamboo heat treatment apparatus according to a first modification of the present embodiment. FIG. 5 is a diagram showing a schematic configuration of a bamboo heat treatment apparatus according to a second modification of the present embodiment. FIG. 6 is a diagram showing a schematic configuration of a bamboo heat treatment apparatus according to a third modification of the present embodiment. FIG. 7 shows an example of the state of bamboo crushing by rotary stirring when superheated steam treatment is performed.

  Embodiments of the present invention will be described below.

  In a broad sense, bamboo is a general term for a species of woody stems such as Kimoto, from the family Gramineae. It is said that there are 600 kinds of bamboo grown in Japan. Typical examples include bamboo shoots, mosouchiku, and honeybees. In the carrying of the present invention, not only common bamboo but also bamboo grass belonging to the family Gramineae bamboo subfamily such as Azumazasa, Yadatake, Azumaneza, Suzutake, Kumazasa and Chishimazasa.

  The kind of bamboo used in the embodiment of the present invention is not limited. Further, in the embodiment of the present invention, bamboo means the whole of a trunk, branches, leaves, and roots, and a trunk portion rich in cellulose fiber components is particularly preferable.

  Bamboo consists of cellulose, hemicellulose and lignin as its main constituents. Hemicellulose plays the role of an adhesive that binds cellulose and lignin or cellulose. This hemicellulose decomposes at a low temperature of 320 ° C. or lower to produce acetic acid and formic acid. On the other hand, cellulose decomposes at a high temperature of 320 ° C. or higher, and lignin decomposes in a wide temperature range of 500 ° C. or higher, partially overlapping with the decomposition temperatures of hemicellulose and cellulose. The temperature range of 170 to 320 ° C. in the embodiment of the present invention is a temperature range where preferential decomposition of hemicellulose and partial decomposition of lignin occur.

A bamboo heat treatment apparatus according to this embodiment will be described with reference to FIGS.
The bamboo heat treatment apparatus 10 includes a hollow cylindrical reaction vessel 12, an atmospheric superheated steam introduction mechanism 14, and a rotation mechanism 16.
The hollow cylindrical reaction vessel 12 is arranged horizontally in the length direction. On the inner peripheral surface of the hollow cylindrical reaction vessel 12, an extending portion 18 that extends in the axial center (center line) direction of the hollow cylindrical reaction vessel 12 is provided. The bamboo heat treatment apparatus 10 is further provided with a protrusion (first protrusion) 28a on the inner peripheral surface of the hollow cylindrical reaction vessel 12, and extends toward the inner peripheral surface on the axis of the hollow cylindrical reaction vessel 12. A central shaft 30 having a protruding portion (second protruding portion) 28b disposed oppositely so as to engage with the protruding portion 28a is provided. In FIG. 1, the extending portion 18, the projecting portions 28 a and 28 b and the central shaft 30 provided inside the hollow cylindrical reaction vessel 12 are shown by solid lines in a transparent state.
The hollow cylindrical reaction vessel 12 has an inlet 20 for introducing atmospheric superheated steam and an outlet 22 for extracting steam. A bamboo loading portion 24 is provided at one end of the hollow cylindrical reaction vessel 12, and a bamboo extraction portion 26 is provided at the other end. It should be noted that the introduction port 20 and the outlet port 22 are not excluded from being provided on the side surface instead of the end of the hollow cylindrical reaction vessel 12. Moreover, although the positions of the inlet port 20 and the outlet port 22 may be arranged as shown in FIG. 1, it is more preferable that the two are exchanged so that the normal pressure superheated steam and bamboo are brought into countercurrent contact.

The hollow cylindrical reaction vessel 12 preferably has a structure in which a heat insulating material is attached inside a steel material, but the heat insulating material can be omitted depending on the temperature conditions to be used.
The hollow cylindrical reaction vessel 12 preferably has a diameter that is three times or more the diameter of bamboo that is cut and inserted as necessary, and more preferably five or more times. Thereby, the bamboo lifted by the rotation of the hollow cylindrical reaction vessel 12 falls, collides with other bamboos, repeats rupture and crushing, and the bamboo is efficiently crushed.

The extending portion 18 provided on the inner peripheral surface of the hollow cylindrical reaction vessel 12 can be formed of an appropriate material as long as it has heat resistance and wear resistance according to the use temperature. For example, SUS314 or It is more preferable to use a material such as SUS316.
The extending portion 18 is not limited in shape, and can be, for example, a plate shape, a rod shape, a comb tooth shape, a net shape, or an appropriate shape combining them.
The extending portion 18 functions as a lifter that lifts the bamboo by the rotation of the hollow cylindrical reaction vessel 12 and has a function of moving the bamboo toward the bamboo extracting portion 26 by dropping the lifted bamboo.
As shown in the model diagram of FIG. 2, the extension dimension of the extension part 18, that is, the length dimension protruding from the inner peripheral surface of the hollow cylindrical reaction vessel 12 (indicated by L in FIG. 2) is 10 cm. It is preferable that it is above, and thereby, it is possible to reliably lift the grown bamboo shoot with a diameter of about 8 to 15 cm.
As shown in FIG. 2, the extending portions 18 are arranged in an appropriate number at an appropriate pitch according to the length of the bamboo to be loaded so that the bamboo can be lifted and moved one after another. In FIG. 1, the protrusions 28 a and 28 b and the central shaft 30 are provided in the vicinity of the bamboo extraction portion 26, but these may be omitted if necessary. An extending portion 18 is provided.
The bamboo that is lifted more reliably and efficiently by the extending portion 18 falls, so that the bamboo is more efficiently crushed.
In order to efficiently send the bamboo from which the extending portion 18 has been crushed to the bamboo extracting portion 26, the extending portion 18 has an axial line (in the direction of the bamboo extracting portion 26) in the direction of the axial outlet of the hollow cylindrical reaction vessel The angle (indicated by an angle θ in FIGS. 1 and 2) is preferably in the range of 0.5 to 60 °, and preferably 1 to 45 °. More preferably, it is in the range.

The central shaft 30 and the protrusions 28a and 28b provided in the vicinity of the bamboo extraction part 26 can be formed of an appropriate material having heat resistance and corrosion resistance. The central shaft 30 may be a fixed shaft or a rotating shaft. The shape of the protrusions 28a and 28b is not particularly limited, and for example, as shown in FIG. Further, the number of the protrusions 28a and 28b is not particularly limited, and for example, as shown in FIG. 3, a large number can be arranged at an appropriate pitch.
Bamboo moving in the hollow cylindrical reaction vessel 12 enters between the protrusions 28a and 28b and is crushed.

  The normal pressure superheated steam introduction mechanism 14 introduces normal pressure superheated steam into the inlet 20. The normal pressure superheated steam supplied from the outside is introduced into the inlet 20, or a normal pressure superheated steam generator is provided. While providing the control part which controls the flow volume of normal-pressure superheated steam, a booster is provided as needed.

  The normal pressure superheated steam in the embodiment of the present invention is different from the pressurized saturated steam obtained by heating in a constant volume state, and is obtained by further heating 100 ° C. steam in a state where it can expand, under a standard pressure. Superheated steam at 100 ° C or higher.

  The merit of the normal pressure superheated steam is that the pressure is normal pressure, that is, atmospheric pressure, so that (1) pressure resistance of the reaction vessel is unnecessary and (2) scale-up is easy. Further, (3) a component decomposed and removed by atmospheric superheated steam is distilled and collected on a steam flow, so that the decomposition product does not liquefy and stay in the reaction vessel. Further, (4) Above the reverse transition temperature of 170 ° C., the drying speed of the processed water becomes faster than that of dry air, so that the drying process of the bamboo after the treatment is unnecessary. It is easy to make it easier.

  The rotation mechanism 16 includes drive sources 16a and 16a and drive gears 16b and 16b that are driven by the drive sources 16a and 16a to rotate the hollow cylindrical reaction vessel 12, for example.

  In order to reliably decompose the hemicellulose while heat-treating the bamboo at a relatively low temperature while suppressing the decomposition of the cellulose, it is necessary to ensure a heat treatment time, in other words, a sufficient residence time of the bamboo in the hollow cylindrical reaction vessel 12, For example, it is preferably about 1 to 3 hours. From this point of view, the bamboo heat treatment apparatus 10 that moves the bamboo slowly in the horizontal direction only by engaging with the extending portion 18 without specially providing a moving mechanism such as a screw of an extruder is simple as an apparatus. It is effective.

Next, a heat treatment apparatus for bamboo according to a first modification of the present embodiment will be described with reference to FIG. In addition, in the following drawings including FIG. 4, the extending portion 18 and the like provided in the hollow cylindrical reaction vessel 12 are indicated by broken lines.
In the bamboo heat treatment apparatus 10a according to the first modification, the hollow cylindrical reaction vessel 12 is disposed with the axis inclined with respect to the horizontal plane, and the bamboo charging portion 24 is provided on the higher position side of the hollow cylindrical reaction vessel 12, The bamboo extraction part 26 is a so-called rotary kiln type provided on the lower position side, which is greatly different from the bamboo heat treatment apparatus 10. The central shaft 30 and the projections 28a and 28b provided in the vicinity of the bamboo extraction part 26 are omitted, and the extension part 18 is arranged instead. Further, the water vapor inlet 20 is provided on the bamboo extraction part 26 side of the hollow cylindrical reaction vessel 12, and the water vapor outlet 22 is provided on the bamboo insertion part 24 side.

  The bamboo heat treatment apparatus 10a can perform heat treatment by moving the bamboo more reliably at a desired speed by appropriately setting the inclination angle of the hollow cylindrical reaction vessel 12 or appropriately setting the rotation speed.

Next, a bamboo heat treatment apparatus according to a second modification of the present embodiment will be described with reference to FIG.
The bamboo heat treatment apparatus 10b according to the second modification is different from the bamboo heat treatment apparatuses 10 and 10a in that the heating unit 32 is provided on the outer peripheral surface of the main body of the hollow cylindrical reaction vessel 12.
The heating unit 32 can be appropriately selected and used as a heat source from direct fire, hot air, steam, electric heat, and the like.
In addition, since the inside of the hollow cylindrical reaction vessel 12 is directly heated by the atmospheric superheated steam that is vented, the bamboo is efficiently heated from the inside and outside of the hollow cylindrical reaction vessel 12. Electromagnetic wave heating such as wave heating may be used in combination.

Next, a bamboo heat treatment apparatus according to a third modification of the present embodiment will be described with reference to FIG.
The bamboo heat treatment apparatus 10c according to the third modification is different from the bamboo heat treatment apparatuses 10, 10a, and 10c in that it further includes a cooling / condensing mechanism 34 connected to the outlet port 22. The cooling / condensing mechanism 34 may be an air cooling system, but is more preferably a water cooling system.
The water vapor extracted from the outlet 22 is cooled and condensed and recovered as a bamboo vinegar liquid containing almost no tar content.

  It is to be noted that the bamboo heat treatment apparatuses 10, 10 a, and 10 b are also one of suitable modes in which a pendulum hammer or cutter is attached inside the hollow cylindrical reaction vessel 12. As the hollow cylindrical reaction vessel 12 rotates, the pendulum shakes and the steam-treated bamboo is crushed.

Next, a bamboo heat treatment method using the bamboo heat treatment apparatus 10, 10a, 10b will be described.
The hollow cylindrical reaction vessel 12 is rotated by the rotation mechanism 16 at a rotation speed of, for example, 0.1 to 10 rpm. Normal pressure superheated steam is introduced into the hollow cylindrical reaction vessel 12 through the inlet 20.
When the temperature of the normal pressure superheated steam is lower than 170 ° C., the bamboo is not sufficiently decomposed and the treated bamboo may not be sufficiently dried. In the case where the bamboo is decomposed more quickly, the temperature of the normal pressure superheated steam is more preferably 190 ° C. or higher. On the other hand, if the temperature of atmospheric superheated steam exceeds 320 ° C., the decomposition of cellulose begins and the decomposition of lignin is also accelerated, so the tar component increases, or when bamboo after treatment is used as a composite material, There is a risk that the utility value will decrease. In order to maximize the utility value of bamboo fiber as a composite raw material, the temperature of atmospheric superheated steam is more preferably 250 ° C. or lower.
The flow rate of the normal pressure superheated steam is preferably about 0.1 to 3.0 kg / (h · 1 kg of bamboo), for example. When the flow rate is lower than 0.1 kg / (h · bamboo 1 kg), heat supply to the bamboo may be insufficient, and decomposition of the bamboo may be insufficient. Moreover, at a flow rate exceeding 3.0 kg / 8h · bamboo 1 kg), the decomposition reaction and the distillation of the decomposition product proceed more rapidly, but a part of the excess water vapor circulates without participating in the reaction. Not right. In consideration of the progress of the decomposition reaction and the efficiency of cooling and condensation of the discharged steam, a mode in which normal pressure superheated steam is passed at a flow rate of 0.2 to 1.0 kg / (h · 1 kg of bamboo) is more preferable.

  Bamboo is charged continuously or intermittently from the bamboo charging section 24 into the hollow cylindrical reaction vessel 12 in which atmospheric superheated steam flows. At this time, the bamboo is used by being cut so that a dimension that can be accommodated in the hollow cylindrical reaction vessel 12, for example, a length dimension is several tens cm to several m. In addition, if a large-sized atmospheric pressure reaction container is used, cutting of bamboo becomes substantially unnecessary.

In the hollow cylindrical reaction vessel 12, bamboo is thermally decomposed by contacting with atmospheric superheated steam. At this time, hemicellulose is preferentially decomposed to form a short fiber structure mixture derived from a vascular sheath containing cellulose as a main component.
Bamboo is crushed by the rotation of the hollow cylindrical reaction vessel 12 and the action of the extension 18 and the protrusion 28. At this time, since steam having a temperature of 170 ° C. or higher has a drying rate larger than that of dry air, the bamboo is dried and crushing by impact is promoted. By the way, it has been confirmed that when the introduction of atmospheric superheated steam to the heat treatment equipment for bamboo is stopped, the rupture and crushing of raw bamboo does not proceed at all.
As the bamboo is stirred by the rotation of the hollow cylindrical reaction vessel 12 and the rupture and crushing of the bamboo proceeds, the contact between the bamboo and the water vapor becomes more uniform, the reaction surface area increases, and the bamboo is decomposed.・ Fracture efficiency is further accelerated. FIG. 7 shows that the bamboo is taken out from the hollow cylindrical reaction vessel 12 at regular temperature after heating at a temperature of 210 ° C., and at regular intervals after the start of the treatment (before heat treatment, 1 minute, 3 minutes, and 10 minutes after the heat treatment). It is the figure which looked at the change of the crushing condition of the bamboo by rotation stirring, taking a photograph, and taking a picture.
The ruptured and crushed bamboo is changed into a strip shape or a chip shape along the direction of the inner vascular sheath, and a fine raw material preferable as, for example, a bamboo composite is obtained by a subsequent pulverization / classification process.

10, 10a, 10b, 10c Bamboo heat treatment device 12 Hollow cylindrical reaction vessel 14 Atmospheric pressure superheated steam introduction mechanism 16 Rotation mechanism 16a Drive source 16b Drive gear 18 Extension part 20 Introduction port 22 Lead-out port 24 Bamboo loading part 26 Bamboo Extraction part 28a, 28b Projection part 30 Central axis 32 Heating part 34 Cooling / condensing mechanism

Claims (5)

A hollow cylindrical reaction vessel provided with an extending part extending in the axial direction on the inner peripheral surface, an atmospheric pressure superheated steam introduction mechanism, and a turning mechanism for rotating the hollow cylindrical reaction vessel, the hollow cylindrical reaction Connected to the vessel and having an inlet for introducing atmospheric superheated steam and an outlet for extracting water vapor, provided at one end of the hollow cylindrical reaction vessel and provided at the other end Has a bamboo extraction part,
The bamboo heat treatment apparatus , wherein the water vapor inlet is provided on the bamboo extraction part side of the hollow cylindrical reaction vessel, and the water vapor outlet is provided on the bamboo insertion part side . A first protrusion is provided on the inner peripheral surface of the hollow cylindrical reaction vessel in the vicinity of the bamboo extraction portion of the hollow cylindrical reaction vessel, and extends toward the inner peripheral surface on the axis of the hollow cylindrical reaction vessel. 2. The bamboo heat treatment apparatus according to claim 1, further comprising a central axis having a second projection facing the first projection so as to be engaged with the first projection.   The bamboo heat treatment apparatus according to claim 1, wherein a heating unit is provided on an outer peripheral surface of the hollow cylindrical reaction vessel. The hollow cylindrical reaction vessel is disposed with an axis inclined with respect to a horizontal plane, the bamboo loading portion is provided on a high position side of the hollow cylindrical reaction vessel, and the bamboo extraction portion is provided on a low position side. The bamboo heat treatment apparatus according to claim 1. The bamboo heat treatment apparatus according to claim 1 , further comprising a bamboo vinegar liquid recovery mechanism connected to the outlet port by cooling and condensation .

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