JPH0828857A - Method of supplying fuel of low melting point - Google Patents

Abstract

PURPOSE:To prevent fuel from being melted and adhered to a feeding part when fuel of low melting point is supplied to a combustion part in a boiler furnace and the like. CONSTITUTION:In the case that fuel of low melting point is fed to a combustion part through a fuel supplying pipe 1, inert gas of temperature lower than a melting point of the fuel is mixed with fuel through an inert gas mixing pipe 3 and the fuel supplying pipe 1 is water-cooled by a spiral cooling pipe 9 and a water-cooled jacket 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply method for supplying a low melting point fuel such as plastic to a boiler or the like.

[0002]

2. Description of the Related Art When a waste material such as plastic is used as a fuel in a boiler, it is generally put into the furnace by gravity dropping after pretreatment such as shredding and solidification.

FIG. 3 shows an example of a conventional method of supplying wastes such as plastics as fuel to a boiler. Reference numeral 1 denotes a fuel supply pipe, which has an in-furnace inlet 7 at a lower end thereof, and wastes such as plastics which have been subjected to pretreatment such as shredding and solidification inside the fuel supply pipe 1 by gravity. It falls and is charged into the furnace of the boiler through the charging port 7 in the furnace. In addition, in FIG. 3, 4
Is a heat insulating material, 5 is a refractory material, and 6 is a guide pipe surrounding the fuel supply pipe 1 for facilitating the replacement work of the fuel supply pipe 1.

[0004]

As in the fuel supply method shown in FIG. 3, when a low melting point fuel is charged into the furnace only by gravity falling, it is heated to a high temperature in the furnace. Moreover, the low melting point fuel may melt and adhere to cause clogging, and a stable fuel supply cannot be secured. Further, in order to prevent clogging, pretreatment such as solidification of the fuel is performed, so that dedicated equipment is required.

Furthermore, in a boiler in which the fuel is introduced by air in the boiler where the oxygen concentration near the fuel inlet is low, the fuel is burned by the oxygen in the inlet air,
Radiant heat from inside the boiler may cause flashback.

The present invention is intended to provide a fuel supply method capable of solving the above problems.

[0007]

The method of supplying the low melting point fuel of the present invention takes the following means. (1) When the low melting point fuel is charged into the combustion section, an inert gas having a temperature equal to or lower than the melting point of the low melting point fuel is mixed with the low melting point fuel. (2) In the low melting point fuel supply method of (1), the low melting point fuel is charged into the combustion section with water.

[0008]

In the present invention (1), when the low-melting fuel is injected into the combustion section, the low-melting fuel is mixed with a low temperature inert gas having a temperature lower than the melting point of the low-melting fuel to cool the fuel. Therefore, it is possible to prevent the low melting point fuel from melting and adhering at the charging portion to the combustion portion. Further, by using the inert gas, it is possible to prevent the flashback phenomenon in the charging section to the combustion section.

In the present invention (2), in addition to the operation of the present invention (1), the low-melting-point fuel injection section is cooled by water so that the low-melting-point injection section can be cooled. Melting / adhesion of the melting point fuel can be prevented more effectively.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. This embodiment contains a large amount of plastic discharged from a paper manufacturing plant or the like and has a low melting point (melting point 100 to 110).
Fig. 1 shows a portion for supplying the fuel to the boiler, which is related to the method for supplying the milk carton residue (° C) as a fuel to the boiler.

The portion shown in FIG. 1 is obtained by adding the following portion to the portion shown in FIG. 3. In FIG. 1, the same portions as those in FIG.
The description is omitted.

In this embodiment, a water cooling unit is provided around the fuel supply pipe 1, and the water cooling unit is provided around the upper portion of the fuel supply pipe 1 and has a spiral cooling pipe having a cooling water inlet 2. 9 and a water cooling jacket 10 connected to the spiral cooling pipe 9 and provided around the fuel supply pipe 1 below the spiral cooling pipe 9 and having a cooling water outlet 8. The water cooling jacket 10 and the heat insulating material 4 and fireproofing It penetrates through the material 5 and extends to the furnace inlet 7. Also, the fuel supply pipe 1
The inert gas mixing pipe 3 is opened in the upper part of the milk carton which has exited the upper denitration device whose temperature has been reduced by heat exchange, as will be described later. A part of the exhaust gas of the boiler having a temperature of 50 to 60 ° C. which is lower than the melting point of the residue is supplied as an inert gas.

In this embodiment, the milk carton residue as a low melting point fuel is supplied to the fuel supply pipe 1 and then drops, and in the process, the melting point of the milk carton residue after heat exchange from the inert gas mixing pipe 3. It is introduced into the upper furnace inflow port 7 that is cooled by mixing with the low temperature boiler exhaust gas having a lower temperature. The fuel supply pipe 1 is cooled by a water cooling jacket.

FIG. 2 is an exhaust gas system diagram in which low temperature boiler exhaust gas is used as the inert gas. The exhaust gas discharged from the boiler 18 is roughly dedusted by the cyclone 19, heat-exchanged by the air heater 20, dedusted by the bag filter 21, and then reaches the induction fan 22. Then, the exhaust gas is denitration device 2
After passing through 3, the gas is discharged to the stack 24, and a part of the gas is boosted by the exhaust gas assisting fan 25 and introduced into the fuel supply pipe 1 through the inert gas mixing pipe 3 to reach the temperature of 50 to 6
Cold boiler flue gas at 0 ° C is mixed with milk carton residue.

As described above, in the present embodiment, the low melting point milk carton residue supplied to the boiler furnace, which is the combustion section, is an inert gas having a temperature lower than the melting point of the milk carton residue in the fuel supply pipe 1 in the boiler. Mixed with exhaust gas,
In addition, the spiral cooling pipe 9 and the water cooling jacket 10 in the fuel supply pipe 1 cool the water to prevent the milk carton residue from melting and adhering in the vicinity of the charging port 7 in the furnace.

Further, since the boiler exhaust gas, which is an inert gas, is introduced into the boiler furnace through the furnace charging port 7 together with the milk carton residue, it is possible to prevent the flashback phenomenon at the furnace charging port 7.

Furthermore, in order to prevent the low melting point fuel from melting and adhering as described above, the pretreatment of the fuel is sufficient to be shredded, and special treatment such as solidification becomes unnecessary. .

[0018]

According to the present invention, an inert gas having a temperature lower than the melting point of the low melting point fuel is mixed with the low melting point fuel when the low melting point fuel is introduced into the combustion section, and the low melting point fuel is supplied to the combustion section. By water-cooling the charging part, it is possible to prevent the low melting point fuel from melting and adhering, to prevent the charging part from clogging the charging part of the fuel, and to stably supply the fuel.

Further, since the low-melting-point fuel that is charged into the combustion section is mixed with the inert gas, it is possible to prevent the flashback phenomenon in the charging section into the combustion section.

Furthermore, since the melting and adhesion of the low melting point fuel is prevented as described above, the pretreatment of the fuel is sufficient to be shredded, and special treatment such as solidification is unnecessary.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of a fuel supply method according to an embodiment of the present invention.

FIG. 2 is an exhaust gas system diagram of a boiler used in the embodiment.

FIG. 3 is a conceptual diagram of an example of a conventional fuel supply method.

[Explanation of symbols]

 1 Fuel Supply Pipe 2 Cooling Water Inlet 3 Inert Gas Mixing Pipe 4 Heat Insulating Material 5 Refractory Material 6 Guide Pipe 7 Reactor Inlet 8 Cooling Water Outlet 9 Spiral Water Cooling Pipe 10 Water Cooling Jacket 18 Boiler 19 Cyclone 20 Air Heater 21 Bag Filter 22 Induction Fan 23 Denitration device 24 Chimney 25 Exhaust gas assist fan

Claims (2)

[Claims] 1. A method of supplying a low melting point fuel, comprising mixing an inert gas having a temperature equal to or lower than a melting point of the low melting point fuel with the low melting point fuel when the low melting point fuel is injected into the combustion section. 2. The method for supplying a low melting point fuel according to claim 1, wherein a portion for introducing the low melting point fuel into the combustion section is water-cooled.