JPS5863790A - Solid fuel - Google Patents

Abstract

PURPOSE:A domestic fuel, having a cylindrical or prismatic form and recess cut part and hole, and capable of improving the igniting, fire spreading and combustion characteristics. CONSTITUTION:A solid fuel obtained by adding 1-25wt% desulfurizing agent, e.g. sodium, 0-15wt% combustion accelerator, e.g. potassium nitrate, and 0- 10wt% molding assistant, e.g. bentonite, to 70-95wt% carbonaceous material, e.g. coal, coke, charcoal, carbonized wood meal or graphite, and molding the resultant mixture into a cylindrical form preferably at >=0.8 (L/M). The cut part is provided to give (95:5)-(60:40) area ratio between the main shape part (d) and the cut part (e) in the cross section cut by a line (B-B'). A hole may be further provided to improve the combustion effect.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid fuel with excellent ignition/fire characteristics, combustion characteristics, etc. That is, by providing at least one concave notch in the original shape of the solid fuel consisting of a cylinder or a prism, the combustion area of the solid fuel is increased and combustion air is easily supplied to the solid fuel layer. This provides a solid fuel with particularly excellent ignition/fire characteristics and combustion characteristics.
- In recent years, against the backdrop of changes in the energy situation triggered by the oil crisis, there has been an active review of carbonaceous fuels, mainly coal, and there is a desire to effectively and expand the use of important energy resources.

There are many major technical problems in expanding the effective use of solid fuels such as coal. Currently, for example, the major technological development issues for expanding the use of coal are (a) using coal according to its altitude to effectively utilize unused resources (e.g., effective use of pulverized coal and lignite); (b) Establish flue gas treatment technology to protect the environment and improve efficiency (e.g., pollution prevention technology); (c) liquefy coal to eliminate inconveniences in transportation, storage, etc. (e.g., 00M fuel); ) Use as a substitute for oil and natural gas (e.g. high-calorie gasification), (e) Recycling coal 1 coal ash, and developing new demand areas (e.g. household fuel). It is being considered.

Among the above technical development issues, the present invention particularly addresses (a).

This is related to (g), and provides a new type of household solid fuel that is different from conventional solid fuels, ie, charcoal briquettes and small charcoal.

Conventionally, solid fuels can be broadly classified into industrial and household uses, and the majority of solid fuels, mainly coal, are used for industrial purposes. On the other hand, the mainstream coal-based solid fuels used for household purposes are briquettes and pea charcoal, and the consumption of charcoal is decreasing year by year, and these household solid fuels are only used as an auxiliary heat source. . However, among these, charcoal is gaining importance as a heat source for high-grade cooking, and is used for cooking in hotels, restaurants, and the like.

Considering the effective use of coal, charcoal, etc. and new demand fields, it is necessary to develop new types of solid fuels with high added value, rather than using household solid fuels as an auxiliary heat source.i
This is an urgent matter. However, currently commercially available solid fuel for household use is
Commonly used are briquettes, pea charcoal and charcoal. There are some portable and emergency solid fuels such as paraffin and wax containing alcohol fuel, but demand is low.

Technological developments for such general charcoal briquettes and pea charcoal have improved their hardening properties, odor prevention, and exhaust gas characteristics, and recently, briquettes and pea charcoal with igniters have also been commercially available. Fuel also has many drawbacks. Its shortcomings are listed below.

(1) The heat capacity (specific heat) of charcoal briquettes and small charcoal is large and the ignitability is poor.

(2) It takes time to become usable, that is, to achieve stable combustion (1 to 2 hours on average).

(3) After ignition, it may go out.

(4) Smoke and bad odor are generated when ignited.

(6) A large amount of harmful gases, especially carbon oxide and sulfur dioxide, are generated during the initial and final stages of combustion.

(6) If the weight of each solid fuel is large, the heat capacity (specific heat) will also be large, and the combustion temperature will inevitably be high. This causes the combustion ash to fuse to the stove, changing the shape of the stove or further deteriorating the exhaust gas characteristics, making the stove unusable. This is because alkali metals and alkaline earth metals in the coal react with silica, alumina, etc. in the stove components at high temperatures, forming a spinel structure.

Many of the above drawbacks are caused by the solid fuel itself.

This invention aims to improve the above-mentioned drawbacks and provide a new solid fuel with excellent ignition/fire characteristics, combustion characteristics, etc.
At least one concave notch is provided in the original shape of a cylinder or a prism.

Here, the definitions of cylinder and prism will be explained.

As shown in Figure 1, what is a cylinder? A prism refers to a circle, an ellipse, or a cone, and a prism refers to an angle such as a triangle, square, equal angle, hexagon, etc., or a pyramid. The shapes of the cylinders, corners, and pillars are straight lines.

Modifications such as curved, V-shaped, or wavy shapes are possible, and mixed structures such as cylindrical-prismatic shapes, straight-curved shapes, and curved-V-shaped carvings are also included. Next, the original shape is a cylinder,
The cross-section of a prism, that is, the average cross-sectional shape of the main shape as shown in the Moum' line cross-sectional view in FIG. Further, the main shape portion and the notch portion will be explained. As shown in FIG. 2, (a) is a perspective view of an example of solid fuel, and (b) is a cross-sectional view of the original shape of (a).

(C) shows a cross section taken along the line B-B of -), (d) is the main shape portion, and <e> is the notch portion.

Next, as shown in Fig. 3, the structural requirements of the notch portion of the present invention are as follows: When the maximum cross-sectional length of the original shape of the cylinder is defined as H, and the length of the cylinder is defined as L, the ratio of L and M is as follows. The most preferred solid fuel according to the invention is one in which L/- is 0.8 or more and a concave cutout is provided in the L direction. However, both end surfaces of the original shape are preferably smooth surfaces, but may be irregular surfaces.

Next, FIG. 4 shows an example of a specific cross section of the solid fuel of the present invention. (f) is a cylinder, (q) is a prismatic cylinder, (h) is a conical cylinder, (
i) is a modification of (f), (q), and (h), and is composed of a notch and a through hole.

The solid fuel of the present invention is preferably composed of a carbonaceous material as a main component, to which a desulfurizing agent, a combustion accelerator, a forming aid, and a binder are added. Carbonaceous materials include coal, coke, charcoal, raw ash, and graphite.

Use petroleum carbon or other carbonaceous fuels.

Sodium, potassium, calcium as desulfurizing agents.

Carbonates, hydroxides, nitrates, etc. of magnesium etc. are used. Furthermore, composite materials of the above-mentioned alkali metals and alkaline earth metals can also be used.

Combustion promoters (oxidizing agents) include potassium nitrate, barium nitrate, potassium perchlorate, and magnesium oxide.

Iron oxide, aluminum powder, manganese oxide, etc. are used.

As the molding aid, commonly used bentonite, Merck, clay, kaolin, etc. are used. Binder is pitch, tar, french, molasses, and valve drainage.

Cement, glue, lime, water glass, gypsum, colloidal silica, colloidal alumina, starch, carboxymethyl cellulose, etc. are used.

Typical blending ratios are as follows.

Carbonaceous material 70-95% by weight desulfurization agent
1-26% by weight combustion accelerator
0-16% by weight Molding aid 0-10% by weight Next, in the method for producing solid fuel used in the examples. I will explain. After weighing the composition having the compounding ratio shown in Table 1, it is sufficiently dry mixed in an omni mixer, water necessary for molding is added, and thoroughly kneaded in a kneader. The molded product was extruded into an arbitrary shape and dried. After drying, the molded product was adjusted in particle size to a length of 16 to 30 m and used as a sample.

Next, the structure of the concave cutout, which is an important element of the present invention, will be explained. The concave notch configuration conditions are: (a) At least one concave notch must be provided in the original shape; (b) The intersection line between the original shape and the notch must be as acute as possible. (c) Do not insert another notch or raw-shaped part of the same shape into the notch, or have a shape that will always form a spatial layer with each other even if inserted. , is.

A solid fuel configured with a concave cutout that satisfies the above three items has the following effects compared to the conventional charcoal shape.

(1) By increasing the combustion area (contact area with air) and improving reactivity, which is a drawback of solid fuel, ignition and
Fire characteristics and combustion characteristics are improved, and unburned gas (carbon oxide, hydrocarbons, etc.) can be significantly reduced.

(2) The space in the solid fuel layer is increased, and combustion air can be easily introduced, thereby improving combustibility.

(3) Since the line of intersection between the concave cutout and the main shape part is configured to have an acute angle, the heat capacity of the line of intersection is small, ignitability is easy, and fireability can be improved.

(4) By further providing concave cutouts and through holes,
It becomes easy to introduce combustion air, and it also becomes easy to supply air to the center of the solid fuel, making it possible to significantly reduce unburned gas.

Further, by configuring the notch to have a different shape from the original shape, the ignition/fire-running characteristics and combustion characteristics can be further improved.

Hereinafter, the present invention will be explained in detail based on Examples.

FIG. 6 shows a method for measuring ignition/fire characteristics using a gas flame (hereinafter referred to as the gas flame method). This method uses a city gas table stove with the configuration shown in the figure to measure the ignition and firing characteristics of solid fuel based on the ignition time.

The ignition time at this time was that the gas flame was ignited for a certain period of time, and after the gas flame was extinguished, the flame was burned for at least 10 minutes, and the gas flame heating time was defined as the ignition/fire rotation time. In the figure, 1 indicates the stove body, which is located at a height h) 70 m away from the top surface of burner 2, with a diameter of 10011 and a length of 301.
A cylindrical fuel tray 3 is held by a support base 4.

The lower surface of the fuel receiving tray 3 is made up of six mesh wire meshes, and the receiving tray 3 is evenly filled with 200 g of solid fuel 6.

Next, in Figure 6, a combustor is used to ignite the solid fuel using an auxiliary igniter, and the ignition and fire characteristics are measured. The one that measures carbon dioxide is a partially improved version of a commercially available stove, and the combustor body 6 has one combustion air lower at the bottom of the side and eight secondary combustion air ports 8 at the top of the side. have

Further, a cylindrical hood 9 is provided at the top of the main body 6 for exhaust gas measurement. The hood is provided with eight auxiliary secondary combustion air ports 1o at the lower side of the hood, and further provided with a plurality of independent exhaust gas vents 11 at the upper surface, and an exhaust gas measuring pipe 12 is inserted into the center of the exhaust gas vents. are doing.

The main body 6 is provided with a solid fuel tray 13 made of 6-mesh wire mesh, and the tray 13 is evenly filled with 300 (i) of solid charcoal 14. On the other hand, with the composition shown in Table 2, a solid fuel tray 13 with a diameter of 5 m and a length of 6 to 15 m
2゜q of the cylindrical auxiliary ignition agent 16 of No. 11 was heated to 1 by the gas flame method.
After heating for a minute and igniting, this is filled into the upper part of the solid fuel, and immediately after filling, exhaust gas measurement is started to measure ignition/fire characteristics and combustion time.

The ignition and fire characteristics obtained using the auxiliary ignition agent method are shown in Figure 7. The time taken to reach the peak value of carbon dioxide in the exhaust gas is defined as the ignition time. - Carbon oxide shows the peak value during combustion.

Table 1 Table 2 Example 1 The cross-sectional shape shown in FIG. 8 (the diameter of the original shape is the same) was prepared by the manufacturing method described above. Table 3 shows the cross sections of these main shapes and the areas of the notches.

Table 3 The ignition/fire characteristics and combustion characteristics of these solid fuels were measured using the gas flame method and auxiliary ignition method described above, and the results are shown in Tables 4 and 6, respectively.

Further, the ignition and fire-running times in Table 6 are shown in FIG. 9, and the peak 1 of -carbon oxide is shown in FIG. 10.

Table 5 (Auxiliary ignition agent method) As is clear from the ignition/fire characteristics and combustion characteristics by the gas flame method and the auxiliary ignition method, by providing a concave notch, the ignition/fire characteristics and combustion characteristics can be improved. I was able to improve it significantly. Further, it can be said that the concave notch □ needs to have a certain shape with respect to the original shape. That is, the cross-sectional area ratio of the main shape part to the notch part is preferably in the range of 96:6 to 60:40.

In the auxiliary ignition method and the auxiliary ignition method, the ignition/fire characteristics and the amount of unburned gas (Table 6 lists only carbon monoxide, but the same trend applies to hydrocarbons) are determined based on the original state. It has almost the same characteristics as , and there is no effect of forming a concave notch.

On the other hand, if it exceeds 40%, the ignition/fire characteristics and combustion characteristics will also deteriorate. The cause of this is that the notches come into contact with each other due to the mutual solid fuel, reducing the space layer, and as a result, a large amount of unburned gas is generated. More importantly, as the notch becomes larger, the geometry becomes smaller, the apparent packing density becomes smaller, the space layer decreases, and as mentioned above, the introduction of combustion air becomes worse.

Example 2 As shown in FIG. 11, this is an example in which the shape of the notch is changed. &8 and Ya9 are composed of the original shape and a different shape, and A10 is composed of the original shape and the same shape, and the cross-sectional area ratio of the main shape part and the notch part is 85:15. Also, the original shape M is 10m and L is 1
The number was 5 to 25.

Ignition-fire characteristics and combustion characteristics were measured using the auxiliary ignition method. The results are shown in Table 6.

From the above results in Table 6, it is clear that ignition/fire-running characteristics and combustion characteristics are better when the notch has a different shape than the original shape, such as A8 and A9. This is because in the case of similar shapes like &10, even though the actual cross-sectional area ratio of the notch is the same, the apparent cross-sectional area ratio, that is, the spatial layer, becomes smaller due to mutual contact between the solid fuels. It is thought that this is because the thickness of the solid fuel layer, that is, the distance to the center, increases, making air diffusion a little worse.

Example 3 8 - As shown in FIG. 12, this is an example in which a through hole was formed in a part of the original shape. As for the shape and dimensions, M is 16Mx, L is 16~
251Ell, through hole diameter is 3M-. Further, the cross-sectional area ratio of the main shape portion to the notch portion is 85:15.

Ignition/fire characteristics and combustion characteristics were measured using the auxiliary ignition method. The results are shown in Table 7.

As is clear from the above results in Table 7, the solid fuel provided with concave notches and through holes has good ignition/fire characteristics and combustibility.

Although all examples have been explained using the original shape of a cylinder, the same effect was obtained for the original shape of a prismatic pillar.

By providing at least one concave notch in the original shape as described above, the ignition/fire characteristics and combustion characteristics can also be significantly improved.

Note that the through hole independent of the notch has a cross-sectional area ratio of 98:2 to 50 with respect to the shape consisting of the main shape and the notch.
: A preferable result was obtained in the range of 50. In particular, it is preferable that the cross-sectional area ratio of the through holes be large, but the mechanical strength is significantly reduced when it exceeds 60%.

In addition, the combustor of the example uses natural draft as the combustion air, but in order to further improve the ignition and fire circulation characteristics, combustion air can be forcibly introduced at the beginning of combustion, making it even more effective. Becomes large.

Further, as a preferable component of the solid fuel of the present invention, one solid fuel has a weight of 209 or less and an apparent density of 1.3 g/cc.
Hereinafter, in the cross section of the concave notch of the original shape with an original shape cross-sectional area of 26 to 16 oIW2 and a packing density of 0.8 g/■ or less when burning, the main shape of the notch with respect to the apparent surface area S1 of the original shape. Ratio of apparent surface area S2 82/
S is preferably 1.10 or more.

[Brief explanation of the drawing]

Figure 1 shows an example of solid fuel consisting of cylinders or prisms, (-) is a perspective view, (b) is a cross-sectional view, and Figure 2 shows the original shape, raw shape part, and notch part. Figure 3 to explain
The figure shows the definition of a cylinder and a prism, Figure 4 is a cross-sectional view showing an example of the solid fuel of the present invention, Figure 6 is a longitudinal cross-sectional view of an instrument for measuring characteristics using the gas flame method, and Figure 6 is auxiliary ignition. FIG. 7 is a diagram showing the exhaust gas characteristics of various solid fuels, FIG. 8 is a cross-sectional view of the solid fuel of Example 1, and FIG. 9 is a diagram showing its ignition and fire circulation characteristics. FIG. 10 is a diagram showing exhaust gas characteristics, FIG. 11 is a sectional view of the solid fuel of Example 2, and FIG. 12 is a sectional view of the solid fuel of Example a. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure (0/) (b) (9) (hJ (Otsu)
Fig. 5 Fig. 6 II f2 5- Fig. 8 ~ θ, 7 () Fig. 9 Loss! +1llo to ao
60”ri 10
01 Car ■B Product F Figure 10 Front area formula Figure 11 Figure 12

Claims (1)

[Scope of Claims] (1) A solid fuel in which at least one concave notch is provided in the original shape of a cylinder or a prism. @) The solid fuel according to claim 1, which has a small number of through holes (one at least) independent of the notch. The solid fuel according to claim 1, having a cross-sectional area ratio of 96=6 to 60:40.