JPS6253392A - Method of dry quenching of coke - Google Patents

Abstract

PURPOSE:To raise the temperature of a circulating inert gas at the inlet of waste-heat boiler, to contrive increasing and stabilization of an amount of generated steam and to bum sludge, by introducing dehydrated excess active sludge to a prechamber in a stopping period of pushing of coke oven. CONSTITUTION:Firstly, red-hot coke pushed from a coke oven is usually brought into contact with a circulating inert gas (inert gas for short) in a prechamber of a cooling column, quenched, cooled and its sensible heat is recovered as steam by a waste heat boiler. Successively, in a stopping period of pushing of coke oven wherein the amounts of combustible gas components such as CO, H2, etc., in the inert gas are reduced, dehydrated excess active sludge is sprayed on the prechamber, the combustible gas components of the inert gas in the stopping period are increased by the endothermic reaction between coke and water in the sludge and the combustible gas components are burned to raise the temperature of the gas at the inlet of a waste-heat boiler and to increase the amount of generated steam.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a coke dry extinguishing method for extinguishing and cooling red-hot coke using circulating inert gas and recovering the sensible heat of red-hot coke as steam. This invention relates to a coke dry extinguishing method using surplus activated sludge that can stabilize the increase in the amount of steam generated during the interval between kiln discharges.

Background Art] - In the coke dry extinguishing method, red-hot coke discharged from a coke oven is generally stored in a pre-chamber of a cooling tower, and an inert gas is passed through a circulation path provided at the bottom of the cooling tower to extinguish the red-hot coke. The sensible heat is recovered as steam in a waste heat boiler installed in the circulation path outside the cooling tower.

In addition, the circulating inert gas that extinguishes and cools the red-hot coke contains flammable gas components such as Go and H2 generated from the coke, so it is diluted in the flue leading to the waste heat boiler attached to the cooling tower. Air is blown into the system to burn combustible gas components such as Go and H2, thereby raising the temperature of the circulating inert gas at the inlet of the waste heat boiler, allowing more steam to be recovered.

However, the red-hot coke charged into the cooling tower is affected by the batch unloading process of the coke oven, and during the unloading process, the red hot coke is
Charges are made at 0 minute intervals, but no charges are made during interruptions (<60-150 minutes). Therefore, during the interval between unloading from the kiln, combustible gas components such as Co and 82 contained in the circulating inert gas gradually decrease as the extinguishing cooling progresses. In other words, during the interval between unloading of a coke oven, the amount of dilution air blown is adjusted and reduced as the combustible gas component gradually decreases, so the temperature of the circulating inert gas at the inlet of the waste heat boiler decreases, and the steam The amount generated was fluctuating.

Prior art and its problems As a method for solving the fluctuations in the inter-time period between coke ovens and stabilizing the amount of steam generated by the general method described above,
Conventionally, a gas containing moisture in at least one of air and N2 is supplied into the prechamber from the outer peripheral wall or the upper end of the cooling tower to generate gas containing a large amount of Co and H2, which is then combined with the circulating gas. (Japanese Unexamined Patent Publication No. 59-7598
1 @ Publication), ■ Dehydrated surplus activated sludge is blown into the cooling tower from the lower part of the cooling tower or the gas circulation path to release CO2.
A method has been proposed in which H2 is generated by an endothermic reaction and the circulating gas is made into a high-strength atomizer (Japanese Patent Application Laid-open No. 19099/1983, filed by the present applicant).

Purpose of the Invention The present invention proposes a coke dry extinguishing method that can also treat surplus activated sludge in order to stabilize the increase in the amount of steam generated during the intermission period of a coke oven.

Structure of the Invention This invention is a coke dry extinguishing method in which red-hot coke discharged from a coke oven is extinguished and cooled using circulating inert gas, and the sensible heat is recovered as steam. This is a dry coke extinguishing method in which coke is blown into a prechamber during the interval between unloading of a coke oven.

When soft extinguishing red hot coke discharged from a coke oven, the coke level in the prechamber is normally controlled so that it reaches an upper limit at the end of kiln discharge and reaches a lower limit at the start of the next kiln discharge.

For this reason, the combustible gas components such as CO2H2 contained in the circulating inert gas gradually decrease as the red-hot coke extinguishes and cools during the unloading period, and the amount of dilution air blown is adjusted and decreased accordingly. As a result, the temperature of the circulating inert gas at the inlet of the waste heat boiler decreases, and the amount of steam generated fluctuates.

On the other hand, in order to prevent pollution, most of the wastewater from coke factories and the like is treated using the activated sludge method, and excess activated sludge discharged from treatment equipment is dehydrated using a decanter or belt press and then incinerated.

However, even after dehydration, surplus activated sludge still contains around 90% water, which not only requires a huge amount of energy to incinerate, but also causes problems such as the generation of bad odors. .

Further, the coke in the prechamber has thermal energy of about 1000'C even at the lower limit level. This is sufficient thermal energy to incinerate the surplus activated sludge.

Therefore, dehydrated surplus activated sludge is injected into the red-hot coke into the prechamber during the interval between kilns when the combustible gas component in the circulating inert gas is reduced, and the coke and the moisture in the surplus activated sludge undergo an endothermic reaction. (C+820-+COCO2
By increasing the amount of combustible gas components such as CO2H2 in the circulating inert scum during the interval between unloading of the coke oven and burning the combustible gas components without reducing the dilution air, the inert circulation at the inlet of the waste heat boiler is reduced. By increasing the temperature of the active gas, the amount of steam generated is stabilized, and at the same time, excess activated sludge is incinerated.

Embodiment Next, an embodiment of the method of the present invention using the general coke dry extinguishing equipment described in the background art section will be described.

In a prechamber with a capacity of 250 tons, red-hot coke with a temperature of 100 to 1050°C taken out of the coke oven is charged and stored from the charging port at the top of the column for 27T/kiln x 19 kilns in one unloading cycle. , surplus activated sludge with a water content of 92.2% that was dehydrated using a decanter during the interval between kiln discharges was
The red hot coke was extinguished and cooled by blowing in at T/l-1 and circulating inert N2 gas from the lower part of the cooling tower. In addition, the same amount of dilution air was blown in as during unloading from the kiln.

In order to confirm the effectiveness of the method of this invention, the temperature, pressure and amount of steam generated, and the concentration of combustible gas components such as Go and H2 in the circulating inert gas at the inlet of the waste heat boiler were measured.

The results are shown in FIGS. 1 and 2.

Also, various parts inside the cooling tower when implementing the method of this invention,
Figure 3 shows the temperature change at the waste heat boiler inlet.

As shown in Fig. 2, the injection of excess activated sludge increases the concentration of combustible gas components such as Co and H2 at the outlet of the cooling tower, and as a result, as shown in Fig. It was possible to increase and stabilize the temperature and pressure of steam as well as the amount of generation.

In addition, as shown in Figure 3, by injecting excess activated sludge and causing an endothermic reaction, the temperature inside the prechamber decreases slightly, but the inert gas temperature at the annular flue and waste heat boiler inlet hardly changes. I confirmed that it does not.

As is clear from this, the present method of injecting excess activated sludge is effective in stabilizing the increase in the amount of steam generated during the interval between unloading of the coke oven.

Effects of the Invention As described above, this invention aims to stabilize the increase in the amount of steam generated by the waste heat boiler during the interval between unloading of the coke oven by simply injecting the dehydrated surplus activated sludge into the prechamber. Furthermore, surplus activated sludge can also be treated.

[Brief explanation of drawings]

Figure 1 is a graph showing the temperature and pressure of steam in the waste heat boiler, as well as the amount of steam generated. Figure 2 is a graph showing the concentration of combustible gas components in the circulating inert gas at the outlet of the cooling tower. Figure 3 is a graph showing the concentration of combustible gas components in the circulating inert gas at the outlet of the cooling tower. It is a graph showing the inert gas temperature at the annular flue and the waste heat boiler inlet. Figure 1 (1 hour (hr) Time (hr) -G) Time (hr)

Claims (1)

[Claims] 1 In the coke dry extinguishing method, red-hot coke discharged from the coke oven is extinguished and cooled using circulating inert gas, and the sensible heat is recovered as steam. A dry coke extinguishing method characterized by blowing coke into a prechamber during intermittent periods.