JPH06128575A - Wood briquette for fuel - Google Patents

Abstract

PURPOSE:To obtain a briquette which has a calorific value equivalent to that of a high-grade charcoal made from an evegreen oak, a Japanese oak, etc., and retains a stable combustion characteristics for a long time by dispersing a carbon powder into a carbonized wood in a specified wt. ratio. CONSTITUTION:The briquette is prepd. by dispersing 2-25wt.% carbon powder, pref. a carbon black (e.g. Seast 3, a product of Tokai Carbon Co., Ltd.), into a carbonized wood pref. a carbonization product of sawdust or bark of a coniferous tree (e.g. a Japanese cryptomeria).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood-forming coal for fuel which exhibits excellent exothermic properties and long-term stable combustion sustainability.

[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 (ogalite) that uses waste wood from lumber mills and plywood manufacturing plants has become widespread.

[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,
A general process is to form sawdust or bark with an appropriately adjusted grain size, and then carbonize it in a kiln held in a non-oxidizing atmosphere.

[0004]

However, the conventional wood-forming coal generally has a poor fire endurance and has a drawback that stable combustion cannot be continued for a long time.

An object of the present invention is to provide a wood-forming coal for fuel, which has the same exothermic properties as high-grade charcoal made from oak, oak, etc. and has a stable combustion performance for a long time. It is in.

[0006]

Means for Solving the Problems To achieve the above object, a wood-forming coal for fuel according to the present invention comprises a composition in which carbon powder is dispersed and mixed in the range of 2 to 25% by weight into wood charcoal. It is a feature of the above.

The wood charcoal constituting the present invention is, for example, pine,
It is charcoal of bark and sawdust of coniferous trees such as cedar and cypress. On the other hand, as the carbon powder, natural graphite powder, artificial graphite powder, carbon black, etc. can be applied.
It is most preferable to use carbon black in terms of ignitability and combustion sustainability. An important requirement for the composition of the shaped coal is that the carbon powder is dispersed and mixed in the range of 2 to 25 wt% with respect to the charcoal. If the mixing ratio of the carbon powder is less than 2% by weight, the effect of improving the combustion sustainability is not imparted, and if it exceeds 25% by weight, the extinguishing phenomenon of combustion occurs and the practicality is impaired.

The shaped wood coal for fuel of the present invention having the above composition can be manufactured as follows. First,
Water content of sawdust or bark with grain size of 2 mm or less is 10%
Dry to a certain extent and add 2 to 2 carbon powder to it.
Disperse and mix well in the range of 5% by weight. When crushed powder from a compact is used as carbon powder, the particle size should be 2
Grind to less than mm and use. If the particle diameter exceeds 2 mm, the strength at the time of molding cannot be maintained, and the phenomenon of not being completely combusted but remaining as an unburned material is caused.

The method for molding the dispersed mixed powder is not particularly limited, and any suitable means such as molding or extrusion molding can be used. However, industrially, it is desirable to use a method of continuously performing compression extrusion molding by using an extruder type extrusion molding apparatus and supplying the mixed powder to a tapered cylinder heated to around 300 ° C. Suitable extrusion conditions at this time are as follows: molding pressure 1-2 ton / cm ² , extrusion speed 1 cm
/ sec.

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. The carbonization temperature is set to 500 to 700 ° C. for the purpose of black coal with high thermal power, and to 900 to 1000 ° C. for the purpose of white coal with good fire endurance. The carbonization yield is about 35% when the raw wood material is used alone, but it can be improved by mixing carbon powder.

[0011]

According to the composition of the shaped wood coal for fuel according to the present invention, a stable amount of carbon powder dispersed and mixed in the wood charcoal does not impair the exothermic characteristics, and thus stable combustion continuity is improved, that is, fire endurance is maintained. Works well to be good. Due to this action, even when a waste material such as coniferous sawdust or bark is used as a raw material, it exhibits the same heat generation property as that of high-grade charcoal made from a hardwood and an excellent combustion sustainability for a long time.

[0012]

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

Examples 1 to 3 and Comparative Examples 1 to 3 Cedar and cypress mixed sawdust having a particle size of 2 mm or less having a water content of 8%.
Dried until. 50 kg of this sawdust is mixed with carbon black [Tokai Carbon Co., Ltd., "Seast 3"] 2-3
The ingredients were compounded in the range of 0% by weight and sufficiently dispersed and mixed by a stirrer. The mixture was extruded into a shape having a diameter of about 55 mm (hexagonal extruded cross section) and a length of 400 mm under the conditions of a molding pressure of 1 ton / cm ² and an extrusion speed of 1 cm / sec, using an extruder type extruder.

Next, the molded body was filled in a graphite powder packing around the periphery thereof and was packed in an electric firing furnace, heated to 700 ° C. at a temperature rising rate of 50 ° C./hr and held for 2 hours. Specific gravity, calorific value,
Volatile matter, fixed carbon and carbonization yield were measured and the results are shown in Table 1.
It was shown to. For comparison, the same characteristics were measured for the wood-forming charcoal that does not contain carbon black (Comparative Example 1) and the high-quality charcoal white oak (Comparative Example 3).
The results are also shown in Table 1.

[0015]

[Table 1]

From the results shown in Table 1, it was confirmed that the example of the composition of the present invention has an improved heat generation property as compared with Comparative example 1 in which no carbon powder is mixed, and has a calorific value equal to or higher than that of high-quality charcoal, white oak charcoal. Was done. In Comparative Example 2 in which carbon black was mixed in an amount exceeding 25% by weight, high exothermic characteristics were exhibited, but when burned, the phenomenon of extinguishing occurred and it was not practical as a fuel.

Next, in order to examine the combustion state, the woody charcoal of Example 3, the white oak charcoal (highly persistent charcoal) and the black oak charcoal (good exothermic charcoal) of Comparative Example 3 were processed into the same shape.
The pieces were put in a stove (width 300 mm, length 600 mm, height 200 mm) and ignited, and an iron plate with a thickness of 1 mm was placed on the top and the temperature of the center surface was measured. FIG. 1 is a graph showing the change over time of the measured iron plate temperature. The wood-forming charcoal of Example 3 had an initial temperature slightly lower than that of the black oak charcoal, but showed stable combustion results similar to those of the white oak charcoal.

[0018]

Industrial Applicability As described above, according to the present invention, it is possible to supply the wood-forming coal for fuel having both excellent exothermic property and stable combustion sustainability. In addition, sawdust and bark waste materials discharged from a sawmill, a plywood manufacturing factory, etc. can be used as raw materials in a simple process, so that industrial production can be performed at low cost.

[Brief description of drawings]

FIG. 1 is a graph showing a combustion state of a wood charcoal and a charcoal of an example.

Claims (2)

[Claims] 1. Wood powder containing 2 to 25% by weight of carbon powder
A wood-forming coal for fuel, characterized in that it has a composition mixed and dispersed in the range of 2. The formed wood charcoal for fuel according to claim 1, wherein the wood charcoal is a coniferous sawdust or a bark charcoal, and the carbon powder is carbon black.