JPS6345435B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the utilization of sensible heat of coke during coke cooling and coal preheating in a coking unit in which the heat transfer gas is guided through a coke cooler and a coal preheating unit in sequence. Regarding the method.

German Patent Application No. 2415758 discloses a method for continuously drying and preheating coal, which is combined with a coke drying extinguishing device and utilizes the amount of heat transferred from red-hot coke to a mixed gas, and which is used for extinguishing gas. Devices are known which have a circulation circuit and a drying gas passage containing a drying and preheating device, in which the drying gas passage and the extinguishing gas circulation circuit are combined into a single gas circulation circuit, and the drying gas passage includes a drying and preheating device. The gas circulation circuit has a device for condensing the water vapor liberated during the combustion process, and is guided through the afterburning chamber. This device uses the combusted gases of the combustion chamber as a heat transfer gas that circulates in a closed circulation circuit, which must be continuously generated, and the circulation circuit includes a dust removal device, Necessary and very extensive equipment parts must be added, such as blowers, injection condensers, heat exchangers, and post-combustion chambers for burning the contained water gas leaving the fire bunker. This device is therefore very expensive both from a manufacturing and operational point of view.

From German Patent Application No. 24 34 837 a method is known for energy recovery in gas generation processes, for example in coal vaporizers or coal coking plants for drying or preheating the charging material, in particular pulverized coal for coking plant operations. can be,
In this process, the drying and preheating of the charge material is carried out using waste heat, and during the cooling of solid residues of the process, for example during the dry cooling of coke in a coke plant, the primary gas is shut down with a dedusting device. This waste heat is obtained in a circulation circuit, in which case an inert gas such as nitrogen, flue gas from a coke oven or flue gas resulting from top gas combustion is used as heat transfer medium and drying medium. Used in secondary gas circulation circuits with dust removal equipment. Due to the necessity of two separate circulation circuits, likewise expensive equipment parts such as heat exchangers, dust removers and blowers are required to carry out the method.

From GB 1334373, the sensible heat of the hot coke in the coking process is used for drying and/or preheating the coal by directing an inert gas through the hot coke and coal in a circulating circuit. It is known to do so, and the inert gas can also be part of the combustion products of the fuel gas, which is also used for coking. In this case, the heat transfer gas that is sent to the coke cooler as well as the heat transfer gas that is present in the circuit between the coke cooler and the preheater is pretreated for inertization.

The object of the invention is to eliminate the drawbacks of the known technology mentioned above and to make possible an economical use of the sensible heat of the coke in a process of the type mentioned at the outset.

In order to solve this problem, according to the invention, a coke oven bank is coupled to a dry coke cooler and a coal preheater, which dry coke cooler and coal preheater are not pretreated as a heat transfer gas and are They are coupled together via the flue gas, which reacts to become gas-poor during dry coke cooling, and the steelwork top gas, which is inert to the red-hot coke.

Thus, according to the present invention, the thermal efficiency of the entire coking apparatus can be further improved by utilizing the furnace top gas, which is produced in large quantities in steel plants, for dry cooling of coke and preheating of coal.

At that time, the flue gas from the regenerator or recuperator of the coke oven bank and the top gas of the steelworks are sent directly to the dry coke cooler, where the poor gases generated and the top gas that hardly changes are passed directly to the dry coke cooler. It may also be advantageous for the gas to be sent to a coal preheater.

In the process according to the invention, purification of the flue gas coming from the coke oven bed and which can be used as heat transfer gas is omitted, and lean gases are generated during cooling of the coke. Since the flue gas leaving the coke oven heat storage or recuperator has a significant water vapor content and a balance oxygen content, the
In the temperature range exceeding 100 ml, an endothermic reaction of the water gas occurs in addition to exothermic partial oxidation. However, due to the excess of water gas reaction, the overall reaction is highly endothermic. In addition to the hot flue gases generated at 200°C to 250°C, the endothermic nature of the reaction also greatly aids in cooling the coke. Water vapor and oxygen are therefore not removed from the flue gas.

In the method according to the invention, the heat transfer gas is
It is brought into direct contact with coke or coal in a coke cooling device and a coal preheating device, respectively. In the dry coke chiller, the above-mentioned reactions result in the flue gas becoming lean, which is heated directly in the dry coke chiller and then sent to the coal preheater where it is brought into direct contact with the coking coal. and let it dry, and
Preheat to over 100℃. In the dry coke cooling device, the furnace top gas is in an inert gas state due to the composition of the furnace top gas, and no reaction occurs during the cooling process. The top gas, which is normally available in each steel mill, is sent via this device as cooling gas to a dry coke cooler, where it is heated and then sent to a coal preheating device. Here, this furnace top gas is in direct contact with the coking coal and gives off heat again as it simultaneously absorbs the water extracted from the coal.

Unless it is intended to be sent to another use, at least a portion of the lean gas generated in the dry coke cooler is sent to the combustion chamber, where it is combusted to preheat the coal. It can be an inert heat transfer gas for equipment. If the lean gas produced in the dry coke chiller is combusted and passed through the coal preheater as flue gas, there will be excessive condensation of the moisture content.

After passing through the coal preheater, the moisture content can be removed from the heat transfer gas in a condensation stage and/or dust can be removed from the heat transfer gas in a fine dust cleaning stage.

The condensate formed during condensation can be used for wet post-extinguishing.

The optionally dried and purified lean gas and top gas leaving the coal preheater can be used as bottom gas in the coke oven bank, as heating gas instead of bottom gas, and/or for other heating or heating purposes. Suitable to be used for undercoating.

The top gas leaving the coal preheating device can be returned to the top gas conduit. When the furnace top gas is used as a heat transfer gas in this manner, cooling, purification, or drying by a heat exchanger is not necessary.

If lean gases and furnace top gases are used as heat transfer gases, it is ensured that the lean gases or fuel gases are introduced under pressure, thus ensuring that no oxygen enters the device.

The invention will be explained below with reference to the embodiments shown in the drawings.

A particular advantage of the process according to the invention is that the cooling gas originating from the flue gas 1 of the coke oven bank and used as top gas 2 is passed above the red-hot coke as well as through the coal preheating device 3 and in a closed circuit. This is clear from the fact that the circuit is led as an open circuit. Since the continuously generated flue gas 1 and furnace top gas 2 can also be used at all times and are led through the various treatment stages only once, these gases It is not necessary to procure any alternative, but such an alternative is necessary in known devices which operate with closed circuits that inevitably leak.

Another particular advantage of the solution according to the invention is that the lean gas generated from the flue gas 1 of the coke oven bank and the top gas 2 with a low moisture content impinge on the moist coal in the coal preheating device 3. That's true.

Even during the combustion of the lean gas produced according to the invention and entering the combustion chamber 4 of the coal preheating device 3 at a temperature of 500°C to 800°C, the fuel gas such as coke oven gas, natural gas, etc. An inert heat transfer gas with a much lower water content is also generated.
The concentration gradient between the moist coal and the heat transfer gas is therefore very large in all variants of the process according to the invention, and always much larger than in the known pneumatic coal drying process. This large concentration gradient is very advantageous for the actual drying process.

In the process according to the invention, the waste heat of the solid residue of the coking process is therefore recycled indirectly via the coal preheating 3 in a very economical manner. The liberated heat transfer gas can be used for various plating purposes etc. after leaving the device. By utilizing a common heat transfer gas for all process steps, fine dust separation after dry coke cooling can be dispensed with. The number of necessary equipment parts is therefore reduced for the device according to the invention compared to known devices.

All the features shown in the drawings form the subject matter of the invention in themselves or in any advantageous combination.

[Brief explanation of the drawing]

The drawing shows a method of utilizing sensible heat of coke according to the present invention as a configuration diagram. 1... Flue gas, 2... Fuel gas (furnace top gas), 3
Coal preheating device, 4 Combustion chamber, 5 Dry coke cooling device, 6 Condensation stage, 7 Condensate, 8 Wet post-extinguishing device, 9 Poor gas, 10 Fuel gas (top gas), 11 ... Coke oven, 12 ... Heat storage device, 1
3...Recuperator.

Claims (1)

[Claims] 1. A method in which a heat transfer gas is guided through a coke cooler and a coal preheater in order to perform coke cooling and coal preheating, in which a coke oven bank 11 is connected to a dry coke cooler 5 and a coal preheater. This dry coke cooling device 5 is coupled to the preheating device 3.
and a coal preheating device 3, a flue gas 1 which is not pretreated as a heat transfer gas and reacts to become a poor gas during dry coke cooling, and a steel mill top gas which is inert to red-hot coke. A method of utilizing sensible heat of coke during coke cooling and coal preheating in a coking apparatus, characterized in that the coke is coupled to each other via two. 2 Flue gas 1 from the heat storage device 12 or recuperator 13 of the coke oven bank 11 and furnace top gas 2 of the steelworks are directly sent to the dry coke cooling device 5,
2. A method according to claim 1, characterized in that the lean gases and the almost unchanged furnace top gas generated in this dry coke cooling device are sent to the coal preheating device (3). 3. Process according to claim 1 or 2, characterized in that the heat transfer gas is brought into direct contact with the coke and the coal in the coke cooling device 5 and the coal preheating device 3, respectively. 4. At least a portion of the lean gas coming from the coke cooler 5 is sent to the combustion chamber 4, in which it is combusted to become an inert heat transfer gas for the coal preheater 3. characterized by
A method according to claim 1 or 2. 5. After the heat transfer gas has passed through the coal preheating device 3, the moisture content is removed in a condensation stage 6, and the dust is removed in a fine dust purification stage. The method according to any one of paragraphs 1 to 4. 6 The condensate 7 produced during condensation is extinguished after wetting 8
The method according to claim 5, characterized in that it is used for. 7. The lean gas 9 and top gas 10 coming out of the coal preheating device 3 are used as undercooking gas in a coke oven bank, as heating gas instead of undercooking gas, or for other heating or undercooking purposes. 6. Method according to one of the claims 1 to 5, characterized in that: 8. The method according to claim 1 or 2, characterized in that the furnace top gas 10 exiting the coal preheating device 3 is returned to the furnace top gas conduit. 9. Method according to one of claims 1 to 5, characterized in that the heat transfer gas is guided under pressure.