JPS6021636B2 - Coal preheating method combined with coke dry cooling - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preheating coal in which the head heat of gas used for dry cooling of coke is transferred to a coke oven.

As is well known, red-hot coke discharged from a coke oven is extinguished and cooled by water sprinkling in a fire extinguishing tower.

In recent years, in order to effectively recover the head heat of red-hot coke, a method of recovering the head heat of coke by steaming or preheating using an inert gas such as N2 as a heating medium has become a useful means as an energy raising technology. Since then, it has been attracting attention and being implemented. For example, red-hot coke discharged from a coke oven is introduced into a dry coke extinguishing equipment (hereinafter referred to as CDQ), and the coke is cooled by blowing, for example, N2 gas into the extinguishing equipment, and the high-temperature N2 gas is sent to a waste heat boiler. It is introduced to create steam and generate electricity. After completing its work, the N2 gas, now at a low temperature, is introduced into the CDQ again to extinguish the red-hot coke and cool it down. Also, N was blown into the CDQ and became hot.
Coal preheating device (hereinafter referred to as PH) that feeds two gases into the coke oven
) to recover heat.

A method has been proposed for dehumidifying the N2 gas that has completed thermal solidification and then blowing it into the CDQ again. The present invention relates to the latter PH method in combination with CDQ. When the medium gas obtained by replacing with an inert gas at the COQ is directly circulated to the PH system and used, the medium gas is humidified due to the approximately 10% moisture normally contained in coal, and when it returns to the CDQ, it becomes red-hot coke. This has the drawback that the water in the gas undergoes an aqueous reaction, resulting in loss of coke and carbon aqueous reaction, and a portion of the coke is consumed.

The present invention provides a method to overcome these drawbacks.

The gist of this system is to prevent the loss of carbon aqueous reaction of coke by making the CDQ system and the PH system independent circulation systems via heat exchangers. Next, the present invention will be described in detail based on embodiments shown in the drawings.

As shown in FIG. 1, in the CDQ circulation system, red hot coke 2 with an average temperature of 1000° C. is inserted from the upper part of the CDQ cell 1.

From the lower part of the CDQ vessel, N2 gas 3 as an inert gas of 1500 〆/ton of coke is sequentially exchanged with the red-hot coke and reaches the upper part, where it becomes a high-temperature gas of about 800 oo and reaches the heat exchanger 4. The coke cooled during this time is discharged from the lower part of the CDQ vessel 1 at about 2000C. The high temperature N2 gas 3 introduced into the heat exchanger 4 is heat exchanged and cooled from 800q0 to 4500°C in the high temperature side heat exchanger 4', and further heat exchanged and cooled from 450q0 to 170°C in the low temperature side heat exchanger 4''. The gas is again fed into the CDQ vessel 1 by the gas circulation blower 5 to form an open circuit.

On the other hand, in the PH circulation system, approximately 10%
The front and rear wet coals 7 are packed in bags and heat exchanged with the high temperature N2 gas 8 bound from the CDQ Bethel.
〆/t (coal) of high temperature N2 gas 8 with coal 20~4
Parallel air current drying is carried out at a flow rate of 0 h/sec, and Hishiiri wet coal 7 is heated to about 120% by heat exchange with preheated coal of 22000%.
After being cooled down to around 10°C and dehumidifying the green content inside and outside 10% of the wet coal to some extent in the dehumidifier 9, the N2 gas circulation blower 1 sends it to the heat exchanger 4 again from the river, and the low-temperature side heat exchanger 4 '', the heat exchanger 4' on the high temperature side, and the heat exchanger 4' are heated in sequence and then introduced into the PH vessel 6 again to form a closed circuit.

Bypass valve 1 on the CDQ system side controls fluctuations in N2 circulating gas blower 5 and 10 inlet temperature due to the load balance of CDQ and PH.
1 and a PH system side bypass valve 12 for control. The reason why the heat exchanger was divided into two stages, high-temperature side and low-temperature side in this example, is that when heat is exchanged from 80°C to 170°C with a normal shell-tube heat exchanger, the heat transfer area becomes large. The equipment is large, and if it is made smaller to some extent, the pressure loss will be large. Particularly in the low temperature region, a large heat transfer area is required, so for the low temperature side heat exchanger 4, a heat pipe method, which has a proven track record at low temperatures and has high thermal conductivity, was adopted. The high-temperature side heat exchanger 4' adopts an ordinary shell tube type to reduce the size of the equipment. Although the heat exchanger is larger in terms of equipment, a cage heat exchanger can also serve the purpose.

CDQ,P, which has been proposed by such a method,
1 due to carbon aqueous reaction loss due to water entrained in the coal by heat exchange of H with the same inert gas.
The department's coke consumption was completely eliminated. By putting this method into practical use, the thermal efficiency of this method will be approximately double compared to the method of recovering power generation, and a pre-chamber chamber will be installed at the top of the CDQ vessel to prevent power generation load fluctuations. Since there is no need to store red-hot coke, equipment costs are reduced, and by preheating the coal, the productivity of the coke oven improves by about 20%, resulting in approximately lt0,000 Koal/
It has become possible to save 1,000 t (coal) of energy. As explained above, according to the method of the present invention, the sensible heat of red-hot coke can be recovered at low cost and with high efficiency through dry extinguishing of coke, and is an excellent invention useful for energy saving.

[Brief explanation of the drawing]

The drawing is a system flow diagram in an embodiment of the present invention.

Claims (1)

[Claims] 1 In a method of circulating an inert gas to cool red-hot coke and preheat coal for coke oven charging, the coke cooling and coal preheating are independently performed via a heat exchanger installed in between. A method for preheating coal in combination with dry cooling of coke, characterized by circulating inert gas.