JPS58190607A - Combustion with low nox performing desulfurization simultaneously - Google Patents

Abstract

PURPOSE:To make a low inclusion of NOx together with desulfurization by a method wherein desulfurization agent is supplied while a primary combustion region is applied as a reducing area and is kept at such a temperature as making the complete melting of ash. CONSTITUTION:A reducing combustion is performed in a primary combustion chamber 11 with an air ratio less than 1 and a temperature in the primary combustion chamber 11 is kept at a temperature higher than a point where the ash is melted and fluidized. Desulfurization agent 18 is supplied to the primary combustion chamber 11 from a desulfurization agent supplying nozzle 19 so as to perform the desulfurization process. The melted mixture C of the melted ash and the sulfide generated under the reaction between a sulfer compound and a alkaline substance in the primary combustion chamber 11 is taken out through the melted substance extraction port 20, and the primary combustion discharging gas D containing the non-combustioned substance is guided to a secondary combustion chamber 12 through the communication passage 13. At this secondary combustion chamber 12, a sufficient volume of secondary air 21 is supplied to make a complete oxidation and combustion of the non-combustion substance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to soot and NOx generated when burning a fuel such as coal that simultaneously contains a large amount of ash, nitrogen, and carbon dioxide.

We are excited about the low NOx combustion method that simultaneously performs desulfurization and effectively removes self-reported substances such as SOX.

I
There is a method of directly feeding an alkali (often in powder form) into P and absorbing it as sulfate or sulfite. However, in this method, when the temperature inside the furnace is high, CaO+ Sw + 1/! Ox-1→Ca5O4-=
−(1) NaxO+ SOm +1/m0y---→
Reactions such as Nas SOa (1) are difficult to occur, and as shown in the %IIZ diagram, the desulfurization rate decreases at l..01 or more. On the other hand, low NOx combustion method 1
One known method is the air two-stage combustion method. In other words, simple 2
As shown in the figure, vertical combustion chambers are built in the furnace (1).
A fuel nozzle (4) for supplying the II fuel (3) is arranged at the lower part of the combustion chamber (2), and primary air is supplied from around this fuel nozzle (4). .

Then, the secondary air (
6), and a desulfurizing agent (desulfurizing agent supply nozzle for supplying υ) is arranged opposite to the fuel nozzle 0). In the combustion method, air is supplied in portions;
The reduction combustion is shown below. In such a reducing atmosphere, CaO+ H,S-→CaS+H*0-=
(1m) NhO+ ToS * Nam5+ru0
...-(5) NhO 1 SO Go + I C-> Na Go s
The main reactions are reactions that produce sulfides such as + sco...
Na1S, CaS, FeS, etc.) are stable even at high temperatures. Therefore, the desulfurization agent (1) was added to the -th fIAtI8 region)
If it is supplied to , the desulfurization rate will be high due to the reaction described above. However, if the desulfurization agent (7) is supplied as is in the conventional two-stage air combustion method, the two-stage air combustion method will completely combust and oxidize the unburned matter (reduced substances) by supplying excess air from the downstream. Since the secondary combustion zone (in the secondary combustion zone) is an oxidizing atmosphere, most of the sulfides generated in the fire and smoke incineration (4) are oxidized again and captured, resulting in CaS + s/z. Ox −→ CaO+ SOt
-...(Vl)NazS + 8/20! −→
Because it is released by a reaction such as NaO+50w--61), the results are not much different from conventional desulfurization methods.

Reiro provides a low NOx combustion method that simultaneously performs desulfurization and can eliminate the above-mentioned drawbacks.

That is, the present invention provides a furnace with a primary combustion chamber and a secondary combustion chamber, - performs reductive combustion at an air ratio of 1 or less in the smoke combustion chamber, and - lowers the temperature in the secondary combustion chamber so that the ash melts. After maintaining the temperature above 1 degree to make it linear, supplying alkali, which is a desulfurization agent, into the fire smoke chamber to perform desulfurization, it is produced by the reaction of the melted ash and the potassium compound, Take the molten mixture with disulfide from the primary mm chamber)
The primary combustion exhaust gas containing unburned matter is led to the secondary combustion chamber, where necessary and sufficient secondary air is supplied to completely saponify and burn the unburned matter for desulfurization. At the same time, it provides a low NOx @ @ method. According to the method, F1a1g is
Let's see if it can be done effectively. After extracting the mixture of melted ash and sulfide from the primary combustion chamber, the combustion a# gas is led to the secondary combustion chamber, where secondary air is supplied to completely burn the unburned matter. As a result, reverse reactions such as re-oxidation can be prevented, and the desulfurization rate can be greatly improved. At the same time, the line part that came into contact with the melted ash-ζ is captured by Ash,
Leech - can be reduced once. tr: The reduction of NOx is more effective at high temperatures, and the NOx suppression effect is also greater.

Hereinafter, one embodiment of the present invention will be described based on Figure @8 and Figure 4. In Figure Ayu 8, IQ is a furnace, and inside it there is a downwardly inclined primary combustion chamber (11) and an upwardly vertical secondary combustion chamber. A communication path (to) is formed between the lower ends. *Note: At the upper end of the east side of the fire and smoke combustion chamber, a fuel nozzle that supplies tlA #4 (b) is installed so as to be slanted downward, and the fuel nozzle 4 is connected to the fuel nozzle through a wind box. It is designed to supply Qihan from 8 seconds to 10 seconds.

Furthermore, 0 (
A desulfurizing agent supply nozzle (6) is provided to supply the desulfurizing agent, and a melt outlet for ash and sulfide is provided at the lower end of the shaft.

*A secondary air nozzle 4 for supplying secondary air (b) is provided at the bottom of the secondary combustion chamber (b).

Reductive combustion is carried out at an air ratio of 1 or less in the spinning and firing chamber, and the temperature in the firing chamber (11) is maintained above the humidity at which the ash melts and becomes fluid. Desulfurization material (alkali) is supplied into this fire and smoke combustion chamber shaft from the desulfurization material supply nozzle.
Desulfurization takes place. In this fire-and-smoke furnace casting, the molten mixture of ash and sulfides produced by the reaction of sulfur compounds with alkali is removed from the molten material through a extraction row, and contains unburned matter. Daichi fire smoke exhaust gas I is
j! It is led to the secondary combustion chamber through a four-way shaft. In this secondary combustion chamber, necessary and sufficient secondary air is supplied to completely oxidize and burn the unburned matter.

According to the low dynamic combustion method of the present invention that simultaneously performs desulfurization as described above, the primary combustion zone generated in the secondary combustion chamber is used as the reduction zone, and the desulfurizing agent is supplied while maintaining the temperature at which the ash is completely melted. By doing so, desulfurization can be carried out effectively. In addition, the mixture of sulfide and sulfide is extracted from the primary combustion chamber, and the exhaust gas is led to the secondary combustion chamber, where secondary air is supplied and the unburned components are completely combusted. It prevents reverse reactions such as re-oxidation and greatly improves the desulfurization rate. At the same time, the soot dust that has come into contact with the melted ash is captured by the ash, and the dust concentration can be reduced. Also, Now O reduction is more effective at high temperatures.
The NOx suppression effect will also be great. 1

[Brief explanation of drawings]

Figure 111 is a graph showing the relationship between furnace humidity and desulfurization rate oH, @
The intention is a vertical cross-sectional view showing an example of the conventional example, FIG. 8 is a vertical cross-sectional view showing one implementation of the present invention, and FIG. (2)・Series of passages,
Sakaki...fuel, Ql-fuel nozzle, (to)...wind box,
Medium = - Fire Medium, (To) -- Desulfurizing agent, (6) Desulfurizing agent supply nozzle, (Transfer)... Melt extraction port, (2)
-Secondary air, @...Secondary air nozzle agent Yoshihiro Morimoto Figure 1°°f M ii. . , -4 Temperature inside the furnace (0C) Figure 2~t: Figure 3 4 (%) Written amendment to the procedure (Own ship 1. Indication of the incident 1982 Cantilever Permit Application No. 71979, 2nd of May,
Name of the invention Low NOx combustion method that simultaneously performs desulfurization 3 Relationship with the amended case Name of patent applicant (511) El Ritsuzosen Co., Ltd. 4 Name of agent (680g) Patent attorney Yoshihiro Moto 5
date (shipment date) Showa year month/day 6. Number of inventions increased by the amendment 7. Claims column 8 of the detailed description of the invention in the specification subject to the amendment, content of the amendment as shown in the attached sheet. 2. Kusunoki 0, page 2, line 7 of the detailed description of the invention in the specification rcao+82+1/20zJ t jcao +
Correct it to 502 +1/202 J. On page 2, line 19, "desulfurizing agent supply nozzle" is corrected to "desulfurizing agent supply nozzle." Page 4, line 7, page 6, line 4, ``Desulfurizing agent'' is changed to ``Desulfurizing agent''. 2.1 Scope of HI Permissible Rubbing 1. Configure the furnace with a first fire, smoke, and secondary combustion chamber, - Continuous reduction with an air ratio of 1 or less in the next ship, ImIM, and - Temperature within the fire, smoke, and secondary combustion chamber. is maintained above the temperature at which the ash melts and becomes fluidized, and an alkali, which is desulfurization, is supplied into the combustion chamber to perform desulfurization. # Primary molten mixture with sulfide! A low NOx combustion method is carried out in which the gas is taken out from the continuation chamber, and then the first-flame combustion gas containing unburned components is led to the second-flame smoke**.

Claims (1)

[Claims] L: A furnace includes a primary combustion chamber and a secondary combustion chamber. - Perform reduction combustion with an air ratio of 1 or less in the fire-smoke combustion chamber, and - a! in the fire-smoke combustion chamber. The sulfur compound is maintained at a humidity higher than that at which the ash melts and migrates, and an alkali, which is a desulfurization agent, is supplied into the combustion chamber to perform desulfurization. Melt M with sulfide! The mixture is taken out from the primary combustion chamber, and then the primary combustion exhaust gas containing unburned components is guided to the secondary combustion chamber, where the necessary and sufficient secondary air is supplied to completely remove the unburned components. A low NOx combustion method that simultaneously performs desulfurization through oxidation and combustion.