JPH06299154A - Method for increasing recovered heat quantity of cdq facility - Google Patents

Abstract

PURPOSE:To increase the recovered heat-quantity without causing the problems of moisture condensation, etc., in a CDQ facility to charge red-hot coke into a chamber, quench the coke with an inert gas blasted into the chamber, introduce the heated inert gas from the chamber to a boiler to recover the thermal energy by heat-exchange and introduce the cooled inert gas again into the chamber to recover the heat-energy of the red-hot coke while recycling the inert gas. CONSTITUTION:Water is supplied to a chamber 1 through a blasting device 6 at the bottom of the chamber 1 to effect the water gas reaction with C in the coke. Air is supplied to the inert gas exhausted from the chamber 1 to burn CO and Hz formed by the water gas reaction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for increasing the amount of heat recovered in coke dry fire extinguishing equipment (CDQ equipment).

[0002]

2. Description of the Related Art Red hot coke produced by carbonizing carbon in a coke oven has a high temperature of about 1000 ° C. or more at the time of being extruded from the coke oven, and as it is, it reacts with oxygen in the atmosphere and burns. Therefore, it is necessary to quench it. Conventionally, a method of directly pouring water was adopted as a quenching method, but this requires a large amount of water,
In addition, there was a problem that heat energy could not be reused. Recently, coke dry fire extinguishing (C) in which red hot coke is rapidly cooled using an inert gas and then heat is recovered from the gas.
The DQ) method has been put to practical use.

FIG. 2 shows an example of CDQ equipment. The red hot coke transferred from the coke oven by a coke bucket is put into the chamber 1 from the upper part, an inert gas is blown from the lower part to cool it, and the cooled coke is discharged from the lower part. On the other hand, the inert gas heated to a high temperature by cooling the red hot coke is discharged from the upper part of the chamber 1 and supplied to the boiler 2 via the dust catcher 3. Then, by exchanging heat with the boiler 2, the sensible heat of the red hot coke can be effectively used. The inert gas after the heat exchange is passed through the cyclone 4 and the blower 5 again to the chamber 1
It is recycled by blowing into the lower part of.

The component of the gas thus circulated is mainly nitrogen, but contains several% of CO and H ₂ . Since there is a danger of explosion when the concentration of CO and H ₂ becomes high, an air supply pipe 7 is provided at the chamber outlet part of the gas circulation path to blow air to burn CO and H ₂ and stabilize the components. ing. Moreover, since the temperature of the gas rises due to this combustion, the amount of heat recovered in the boiler 2 also increases.

Since the coke in the chamber 1 tends to flow in the center and is hard to flow near the wall, a blasting device 6 is provided in the lower portion of the chamber 1 to prevent the deviation from falling. A gas is blown into the blasting device 6 by providing a nozzle.

In order to increase the coke cooling capacity in such a CDQ facility and make the enriched gas produced during cooling more rich, Japanese Patent Laid-Open No. 58-136688 discloses a gas circulation path in front of the chamber inlet. A CDQ facility with means for supplying water or steam into the gas is described. In other words, if cooling with only gas, the amount of gas must be increased in order to increase the cooling capacity, but if water or steam is supplied into the gas, the red hot coke is cooled with water or steam in addition to the gas. If the water or steam reduces the temperature of the gas to improve the cooling capacity and the water or steam reacts with C in the coke, this water gasification reaction is an endothermic reaction, That is, the enriched gas becomes rich due to the water gasification reaction.

[0007]

However, in the CDQ equipment described in Japanese Patent Laid-Open No. 58-136688, since water or steam is supplied before the chamber inlet of the circulation path where the temperature of the circulation gas is the lowest, the inside of the circulation path is reduced. There is a problem in that water is accumulated on the inside of the duct or the like, which causes corrosion or damage, etc. Further, only a part of the supplied water or steam is blown into the chamber and contributes to the water gasification reaction. These problems are mainly due to the fact that the device described in the publication lowers the temperature of the gas blown into the chamber in order to enhance the cooling capacity of the red hot coke, and makes the supply location of water or steam the location where the circulating gas temperature is the lowest. This is a problem that arises from the need.

It is an object of the present invention to provide a method for increasing the amount of heat recovered in CDQ equipment without causing such problems as dew condensation.

[0009]

Means for Solving the Problems The gist of the present invention is to charge red hot coke into a chamber, blow inert gas to cool it, and guide the hot inert gas from the chamber to a boiler for heat exchange. When recovering the heat energy of the red hot coke while recovering the heat energy and introducing the low temperature inert gas into the chamber again and circulating it,
Moisture is supplied into the chamber from the blasting device at the bottom of the chamber to cause a water gasification reaction with C in the coke, and air is supplied to the inert gas discharged from the chamber. C, which is characterized by burning CO and H ₂ generated by the chemical reaction
This is a method for increasing the amount of heat recovered from DQ equipment.

[0010]

[Action] In the present invention, CO by causing the water gas reaction upon cooling of the red-hot coke, which both generates and H _2, is introduced into the boiler by the CO, for burning of H ₂ in the chamber exit side It was decided to raise the temperature of the circulating gas and increase the amount of heat recovered by the boiler.

Then, first, there is a problem in which part of the gas circulation path the water is supplied to efficiently cause the water gasification reaction. Specifically, three types are considered: inside the chamber, between the chamber and the boiler, and between the boiler and the chamber. Of these, there is no high-temperature coke, and it is only possible to react by contacting dust floating in the circulating gas at best, and since the water gasification reaction is an endothermic reaction, the reaction occurred. On the contrary, there is a problem that the temperature of the gas supplied to the boiler is lowered, which is inappropriate. Further, was used in the device described in Japanese Patent Laid-Open No. 58-136688, but this has to be adopted when the main purpose is to lower the temperature of the gas blown into the chamber as in the same publication. However, if it is not, the temperature of the circulating gas is low as described above, which causes problems such as dew condensation. Therefore, in the present invention, water is supplied into the chamber.

The inside of the chamber is at a high temperature, and when water is supplied to it, the water abruptly evaporates and rises in the chamber to come into contact with red hot coke charged from above, causing a water gasification reaction. Above all, since the blasting device is located in the center of the lower part of the chamber, attaching a water spray nozzle to this will not only make it easier to supply water to the center of the chamber, but also when the supplied water evaporates. Has a rapid volume expansion, and there is a problem that if it evaporates in a narrow circulation path such as a duct, it will disturb the pressure balance in the system, but it is safe because it can absorb the rapid volume expansion in the center of the chamber. It is also excellent in that respect.

Moisture supplied to the chamber is about 600
When it comes into contact with a coke having a high temperature of ℃ or more, a water gasification reaction represented by the formula 1 is caused, and CO and H ₂ are generated by this reaction. Further, since this reaction is an endothermic reaction, it also contributes to the cooling of coke. At this time, the powder coke having a large surface area mainly reacts with the water, and the coke coke suitable for the blast furnace pig iron method is not consumed.

[0014]

## EQU1 ## C + H ₂ O = CO + H ₂ -2350 kcal / kg

Next, CO and H generated in this way
_In No. 2, combustion is performed by supplying air on the outlet side of the chamber of the gas circulation path, and the temperature of the circulation gas is raised by the amount of combustion heat as shown in Formula 2.

[0016]

[Equation 2] CO + (1/2) O ₂ = CO ₂ +3020 kc
al / Nm ³ H ₂ + (1/2) O ₂ = H ₂ O + 2570 kcal / N
m ³

In the device described in Japanese Patent Laid-Open No. 58-136688, air is supplied to the circulating gas on the outlet side of the chamber, but the device also aims to recover rich enriched gas. However, it is not possible to burn all of the CO and H ₂ generated by the water gasification reaction, but to burn some of them, and it is not the pursuit to increase the amount of heat recovered.

Then, the circulating gas is introduced into the boiler, and heat energy is recovered by heat exchange. The gas whose temperature has become low due to heat exchange is introduced again into the chamber and is circulated for reuse.

[0019]

FIG. 1 shows an example of a CDQ facility for carrying out the present invention. This is provided with a nozzle 8 for supplying water to the blasting device 6 of the conventional CDQ equipment shown in FIG. 2, and the nozzle 8 is connected to a water pipe 9.

Using the 100 t / h class CDQ equipment shown in FIG. 1, 100 H ₂ O is supplied from the nozzle 8 to the chamber 1.
kg / h was supplied. When 100 kg of H ₂ O causes a water gasification reaction with C in the coke, CO and H ₂ are generated by the formula ^{3 by} 124 Nm ³ / h each. Heat of combustion of CO and H ₂ O is because as 3020kcal / Nm ³ and 2570kcal / Nm ³ shown in Formula 4, a total of from several 5 69
A combustion heat of × 10 ⁴ kcal / h is obtained. The sensible heat of the circulating gas before the boiler is 4921 × 10 ⁴ kcal from the number 6
/ H, and the heat of combustion by supplying 100 kg / h of H ₂ O corresponds to 1.4% of the sensible heat of the circulating gas. That is, the amount of recovered heat could be increased by 1.4%.

[0021]

[Equation 3] C + H ₂ O = CO + H ₂ −2350 kcal / kg 100 kg / h of H ₂ O generates CO 22.4 × 100/18 = 124 Nm
Generated amount of ³ / h H ₂ 22.4 × 100/18 = 124 Nm
³ / h

[0022]

[Equation 4] CO + (1/2) O ₂ = CO ₂ +3020 kc
al / Nm ³ H ₂ + (1/2) O ₂ = H ₂ O + 2570 kcal / N
m ³

[0023]

[Equation 5] CO combustion heat 124 Nm ³ / h × 3020k
cal / Nm ³ = 37 × 10 ⁴ kcal / h H ₂ combustion heat 124 Nm ³ / h × 2570 kcal /
Nm ³ = 32 × 10 ⁴ kcal / h Total 69 × 10 ⁴ kcal / h

[0024]

[Equation 6] Sensible heat of circulating gas 140000 Nm ^{3 /} h × 0.37 kcal / Nm ³ ° C
× 950 ° C. = 4921 × 10 ⁴ kcal / h

In this case, the amount of coke consumed to cause the water gasification reaction with 100 kg / h of H ₂ O was 67 kg / h, which was very small from several 7, and was mainly powder coke.

[0026]

[Equation 7] 12 × 100 kg / h / 18 = 67 kg / h

The endothermic amount due to the water gasification reaction caused by 100 kg / h of H ₂ O is 1.3 × 10 ⁴ k from the equation 8.
cal / h, and the sensible heat of the coke at the chamber outlet is 420 × 10 ⁴ kcal / h from the number 9,
The effect of coke cooling by the water gasification reaction was not so large as 0.3%.

[0028]

[Equation 8] C + H ₂ O = CO + H ₂ −2350 kcal /
Because kg from H ₂ O is 2350Kcal / kg at 18 kg, the H ₂ O is 100kg 2350 × 100/18 = 1 .
3 × 10 ⁴ kcal / h

[0029]

[Equation 9] Sensible heat at the discharge part of coke 100 t / h × 0.21 kcal / kg ° C. × 200 ° C. =
420 × 10 ⁴ kcal / h

[0030]

According to the method of the present invention, it is possible to increase the amount of recovered heat without causing problems such as dew condensation in the CDQ equipment.

[Brief description of drawings]

1 shows an example of a CDQ facility for carrying out the method of the invention.

FIG. 2 is a diagram showing an example of a conventional CDQ facility.

[Explanation of symbols]

 1 Chamber 2 Boiler 3 Dust Catcher 4 Cyclone 5 Blower 6 Blasting Device 7 Air Supply Pipe 8 Nozzle 9 Water Pipe

Claims (1)

[Claims] 1. A chamber is charged with red hot coke, and an inert gas is blown into the chamber to cool it. The hot inert gas is introduced from the chamber to a boiler to recover heat energy by heat exchange, resulting in a low temperature. When recovering the thermal energy of the red-hot coke while introducing the inert gas into the chamber and circulating it, moisture is supplied from the blasting device part at the bottom of the chamber to the inside of the chamber to form a water gas between it and C in the coke. While causing a chemical reaction,
A method for increasing the amount of heat recovered from a CDQ facility, which comprises supplying air to an inert gas discharged from a chamber to burn CO and H ₂ generated by the water gasification reaction.