JPS5945948A - Use of waste fluidized medium from fluidized bed boiler - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The fluidized bed boiler has the following excellent characteristics:
This is attracting attention as a new direction for power generation boilers in the future.

Q) The heat transfer coefficient is 5 to IO times higher than that of conventional boilers, so the boiler can be made compact.

(Re) By mixing limestone, quicklime, or slaked lime in the flow direction, high-temperature direct desulfurization is possible, making it possible to omit or downsize the flue gas desulfurization equipment.

■ Since the combustion moisture level is as low as ~900', NOx is produced less, and denitrification equipment is not required, or even if it is necessary, the cost of denitrification is low.

In addition, coal ash does not melt, handling is fluid, and there is no corrosion due to the high temperature of the material. There is no need to use I-valent materials.

■ For example, when coal is used as fuel, (Jl), the average particle size of the supplied fuel coal is large, so the power required for pulverization is small. In other words, when pulverized coal is burned, the remaining 200 m² is about 15%. On the other hand, 'tk, moving bed boiler has a diameter of 5 to 6 mm.
The following is fine.

However, this fluidized bed boiler also has the following problems, and solving them is a major problem for practical use. In other words, flow Ev
Right gray as a fluidized medium skin desulfurization medium for J scrap boiler 1.
OaO produced from quicklime or slaked/i ash reacts with 802 in the combustion residue to produce Oa SO4. This is taken out of the JIQ outside the fluidized bed boiler and transferred to OaO at 14/, t.
! There is a way to use the L shield ring.

The cost required for ++1 raw king culm is 1lIIr+lli, so it is not economically viable.

In addition, in order to ensure sufficient desulfurization, the Oa fraction ■1 should be set to 08
It is essential that the molar ratio Oa/S≧2 between minute and 8 minutes in the fuel coal is 2. Therefore, the fluidized bed waste contains a large amount of OdO, and if it is discarded as it is, it will become a strong alkali! J
+'l, which poses a pollution problem. Furthermore, a large amount of neutralizing agent is required to neutralize and dispose of the product.

The present invention was proposed to solve the problems listed in -1-. This invention relates to a method for disposing waste media in a fluidized bed boiler, which processes waste lime and coal ash and takes advantage of the thermoeconomic aspects of a cement plant by introducing a mixture of coal ash into a cement plant.

The method of the present invention can be used for commercial power generation plano I・, −, ]f
In terms of material balance and in terms of material balance in the Semenodo plant, it is composed of 1-component (1-)'l-) from the viewpoint of the product quality of the seven products.

Next, the 77 method of the present invention will be explained in detail with reference to Examples.

Table 1 shows that the power generation scale is 10008 11V, and the Blatt's material 11V t of the size of 2000 T/1 produced in Himenotono 1-[i 2000 T/1] is small.

17f1 of 10100O in Table 1. Double layer power generation Plano i・
Implementation 1 when the entire amount of waste media generated from 2000 'i'/El is supplied as raw material to Pimeno) and Plano). /11 is shown in Table 3.

Table 2 shows the composition of the raw materials used.

From Table 3, it is clear that even if all 1■ of waste media is supplied to Semenodoplat, the coefficient, Kritka composition, and K7K mineral composition will be different from the comparative example in which no waste media is used, and it can be used publicly. be. By using waste media, the usage of soft silica (i) and iron raw materials increases, but conversely, the usage of clay (h) decreases even more.
0 is 1++ of the natural Y-+ which accounts for most of the cement raw materials
It can be used as 1f, and unlike limestone, it does not absorb heat due to thermal decomposition, so it is useful for reducing the amount of heat used in calcination. In addition, the Kritsuka (approximately 2000 T/l-1) 808 produced by S08 supplied from gypsum has a 045 weight fit%, but at this level it can be used publicly without any operational troubles. It is.

In this way, the use of fluidized bed waste media from fluidized bed power plants as a raw material for cement completely solves the problem of disposing of lime for desulfurization, which is the biggest problem with fluidized bed boilers, and also solves the problem of disposing of coal ash. They will solve it together. Also, from the point of view of Shichimetsudobunt, some of the raw materials are replaced with waste, which helps reduce cement costs.

In actual plants, the fluidized bed waste medium discharged from the fluidized bed boiler is wetted by rIh, so it is easier to handle it if the temperature is lowered to an appropriate temperature of 1°. In addition, in order to use it as a raw material for cement, it is necessary to reduce the particle size to several lθμ'n, so pulverization is necessary, but 6 ash Y1- and coal ash after being heated in a fluidized bed wheeler must be pulverized. Because it is in a state where it is easy to
Cement can be finely pulverized for 1 minute by feeding it to a pulverizer.

Table l Material Balance Table 2
Table 3: Materials to be Tested Mixture and Il Calculation Figure 1 shows a block diagram of an embodiment of the present invention. The waste medium consisting of coal ash after combustion in the fluidized bed boiler as well as lime after desulfurization is taken out at high temperature and conveyed to the heat exchanger i#H in a +1111 heat conveyor.

Here, it is directly cooled with cold air (ordinary crystal is possible) to a temperature below 8'00'' (F culm), and the cement +-h:i
Transported to 1+ crusher. Since the waste medium is still at a high temperature even after passing through the heat exchanger and is in a state where it is easily crushed, an appropriate amount of waste to be supplied to the crusher can be selected depending on the type of crusher. The waste media is pulverized together with the cement raw material and is generally fed to the cement plat via a waste transfer pipe.

Here, even if the heat exchanger is not placed for the convenience of the person handling the high-temperature waste, there is no particular problem in the process.

By combining such a fluidized bed boiler and a cement plant, the fluidized bed boiler solves the problem of disposing of one waste medium, and the cement plant saves cement materials and thermal energy, reducing cement costs. , it is a very effective nostem.

[Brief explanation of the drawing]

FIG. 1 is a flowchart 1 showing one embodiment of the method of the present invention.

Claims (1)

[Claims] A method of utilizing waste fluid media generated from a fluidized bed boiler, characterized in that the fluidized media waste generated from a fluidized bed boiler using limestone, quicklime or slaked lime as a fluidization and desulfurization medium is used as part of a cement raw material.