JPH06136373A - Production of wood briquette for fuel - Google Patents

Abstract

PURPOSE:To produce a wood briquette for fuel which has high density and hardness and exhibits an excellent calorific power and a long-stable persistence of cocmbustion. CONSTITUTION:A wood flour comprising sawdust or bark of a conifer is smoked at 200-400 deg.C, compression molded, and carbonized. Pref. the wood flour after the smoking is pulverized to a particle size of 300mum or lower.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a wood-forming charcoal for fuel having a high specific gravity, which exhibits excellent heat generation and stable combustion for a long time.

[0002]

2. Description of the Related Art Charcoal does not generate smoke, flame, odor, etc.
It has been used as a heat source for heating or cooking for a long time as a solid fuel with good fire endurance, but due to the depletion of raw material wood and the difficulty of charcoal burning work, nowadays it is not expensive except for specific applications. Almost not produced. As an alternative solid fuel, wood-forming charcoal using waste wood from a sawmill or a plywood manufacturing plant is widely used.

[0003] This wood-forming charcoal is a kind of waste-using fuel. Conventional charcoal uses hardwood timber as a raw material, whereas sawdust and bark of coniferous wood are used as raw materials. There are advantages to be obtained. As a manufacturing method,
In general, a process of compression-molding sawdust or bark with an appropriately adjusted grain size and then carbonizing at 500 to 700 ° C. in a kiln held in a non-oxidizing atmosphere.

[0004]

Since the above-mentioned formed wood charcoal has a larger specific gravity than general charcoal (black charcoal), it is mainly used as a commercial fuel for grilling fish and meat.
Compared to Bincho charcoal, which is considered to be the most suitable fuel for this type of burnt fuel, it has a smaller specific gravity and is difficult to burn.

The present invention was developed as a result of repeated research to produce a wood-forming coal having a specific gravity comparable to that of high-grade charcoal Bincho charcoal, and its purpose is to provide excellent heat generation comparable to that of high-grade charcoal. It is an object of the present invention to provide a method for producing a wood-forming coal for fuel having a high specific gravity and hardness that exhibits combustion sustainability.

[0006]

In order to achieve the above-mentioned object, a method of producing a wood-forming coal for fuel according to the present invention is a conifer-type wood powder which is smoked at a temperature range of 200 to 400 ° C.
The structural feature is that the raw material is compression-molded and then carbonized.

The raw material of the present invention is obtained by smoldering wood powder obtained by crushing coniferous sawdust such as pine, cedar, cypress, etc. or bark into a grain size of 2 mm or less. For the smoke treatment, a sealed heating device such as a rotary kiln is used, and 200 to 4
It is performed in the temperature range of 00 ° C. If the treatment temperature is less than 200 ° C, the smoldering is insufficient and the specific gravity cannot be increased when forming coal, and if it exceeds 400 ° C, carbonization of wood powder occurs and compression molding becomes difficult. . By this smoldering treatment, the weight of the wood powder is reduced by about 20 to 50% by weight. The smoked wood powder can be used as a raw material as it is, but if this is ground to a particle size of 300 μm or less and the particle size is adjusted, the specific gravity and hardness are further improved.

The smoked wood powder raw material is compression molded into a predetermined shape. The means for compression molding is not particularly limited, and an appropriate method such as molding or extrusion molding can be used. However, industrially, it is desirable to employ a method of using an extruder type extrusion molding device and supplying raw material powder to a heated tapered cylinder to continuously perform compression extrusion molding into a round bar shape. The extrusion conditions at this time are
Cylinder heating temperature 250 ~ 420 ℃, molding pressure 1.5 ~
It is preferable to set the pressure to 4 ton / cm ² and the extrusion speed to 100 to 300 mm / min, and especially when the cylinder heating temperature and the molding pressure are lower than the above lower limits, extrusion molding becomes impossible.

The molded body is then carbonized in a heating furnace in a non-oxidizing atmosphere. As the carbonization method, a sieving method, a charcoal kiln method, or the like can be used, but industrially, it is preferable to apply a method of heating in a state in which an electric firing furnace is used to surround the periphery with graphite powder packing. Carbonization temperature is 500 ~
The temperature is set in the range of 700 ° C., but it is effective to make the temperature rising rate as slow as possible in order to increase the specific gravity.

[0010]

According to the present invention, coniferous wood flour is subjected to a smoke treatment in a temperature range of 200 to 400 ° C. before molding, so that water, volatile components, etc. in the wood flour are appropriately volatilized and weighted. It is reduced and the structure is densified. By performing compression molding and carbonization treatment using the wood powder in this state as a raw material, the specific gravity and hardness increase, and it becomes possible to impart stable combustion continuity without impairing the combustion characteristics. In particular, if the smoked wood powder is crushed to a particle size of 300 μm or less and then molded,
It effectively acts to impart the above effect. For this reason, wood waste charcoal for combustion, which uses waste wood such as coniferous sawdust and bark as raw material, exhibits heat generation comparable to high-grade charcoal made from hardwood (Bincho charcoal) and excellent combustion sustainability for a long time. Is manufactured at low cost.

[0011]

EXAMPLES Examples of the present invention will be described below in comparison with comparative examples.

Examples 1 and 2 and Comparative Examples 1 to 60 60 kg of cedar sawdust (particle size 2 mm or less) was placed in a rotary kiln and subjected to a smoldering treatment at different heating temperatures. Then, using a extruder type extruder for the wood powder, a cylinder with a temperature of 300 ° C., a molding pressure of 3 ton / cm ² , and an extrusion speed of 150 mm / min, a diameter of about 55 mm (hexagonal extrusion section) and a length of 400 mm are used. It was compression extruded into a rod shape.

The molded body was packed in an electric firing furnace with graphite powder packing wrapped around it, heated to 700 ° C. at a heating rate of 50 ° C./hr, and held for 2 hours. The specific gravity, calorific value, volatile matter and hardness of each of the carbonized wood charcoal thus carbonized were measured, and the results are shown in Table 1 in comparison with the smoldering conditions (treatment temperature). In addition, for comparison, wood-forming charcoal produced under the same conditions without being subjected to a smoldering treatment (Comparative Example 1)
The same characteristics were measured for Bincho charcoal (Comparative Example 3), which is high-grade charcoal, and the results are also shown in Table 1.

Example 3 The same cedar wood powder as in Example 1 was subjected to a smoke treatment at a temperature of 250 ° C. and then pulverized with a pulverizer (Nara type, 300 μm sieve built-in) to a particle size of 300 μ or less. The crushed wood powder was compression-molded and carbonized under the same conditions as in Example 1 to produce wood-forming coal. The characteristics of the obtained formed coal were measured, and the results are also shown in Table 1.

[0015]

[Table 1]

From the results shown in Table 1, the formed wood charcoal according to the example subjected to the smoke treatment in the temperature range of 200 to 400 ° C. is improved in specific gravity and hardness as compared with Comparative example 1 not subjected to the smoke treatment, and high-grade charcoal. It has various characteristics comparable to those of Bincho charcoal. In particular, in Example 3 in which the particles were pulverized to have a particle size of 300 μm or less after being smoked, excellent property improvement was observed. However, compression molding was impossible with wood flour smoked at 450 ° C (Comparative Example 2).

[0017]

Industrial Applicability As described above, according to the present invention, it is possible to produce a wood-forming charcoal for fuel having both excellent exothermic properties comparable to high-grade charcoal and stable combustion sustainability. In addition, sawdust and bark discharged from sawmills and plywood manufacturing plants can be used as a raw material in a simple process,
This makes it possible to inexpensively industrially produce wood-forming charcoal, which is useful for pottery work.

Claims (2)

[Claims] 1. A process for producing a wood-forming coal for fuel, which comprises subjecting softwood wood powder to a smoldering treatment in a temperature range of 200 to 400 ° C., compression-molding the same as a raw material, and then carbonizing it. 2. The method for producing a wood-forming coal for fuel according to claim 1, wherein the smoked wood powder is pulverized to a particle size of 300 μm or less.