JPS606390B2 - Gas circulation device in vertical molded coke carbonization furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas circulation device in a gas direct heating type vertical molded coke carbonization furnace.

For example, it is known that as a manufacturing method for metallurgical shaped coke, a vertical carbonization furnace is charged with lump coal, and the coal lump is carbonized in the carbonization furnace using hot gas as a medium to obtain the desired shaped coke. There is (Tsubaki Kaisho 52-23107).

This vertical carbonization furnace is equipped with a low-temperature carbonization chamber and a high-temperature carbonization chamber from the top, and is also directly connected to the high-temperature carbonization chamber with a cooling chamber for ripening coke, using the carbonization furnace top gas as a cooling gas. It is known to introduce it into the lower part of the cooling chamber, exchange heat with hot coke, and use it as hot soot gas for heating (Japanese Patent Laid-Open No. 52-23102). In this method, the gas that has passed through the red-hot coke layer in the cooling chamber is sucked by some means from the cooling chamber of the carbonization furnace, the flow rate and temperature are adjusted, and the pressure is increased to the level required for blowing into the tuyere of the low-temperature carbonization chamber. There is a need.

A blower is generally used as a means for raising the pressure, but this has the following disadvantages. {1} The cooling chamber outlet gas to be sucked is at high temperature (800oo or more),
In addition, since it contains a large amount of coke powder generated in the furnace, a special blower with excellent hot wear resistance is required, which is uneconomical in terms of equipment. (2- When lowering the blower suction gas temperature to the maximum operating temperature of a heat-resistant blower (approximately 50,000 ℃), equipment is required to reheat the gas temperature after pressurization to the low temperature carbonization chamber supply gas temperature (600 to 80,000 ℃). It is uneconomical in terms of heat source and heat source unit.

The present invention takes the above-mentioned problems into consideration and provides means for sucking in and pressurizing gas containing a large amount of high-temperature and highly abrasive coke dust.

In other words, in the above-mentioned molded coke carbonization furnace gas circulation system, a part of the furnace top gas is heated by a blower, the temperature is raised by a heating device, this is used as a driving gas, the cooling chamber outlet gas is sucked, and the discharge gas is kept at a low temperature. If an ejector is used to supply the gas to the tuyere of the carbonization chamber, it becomes a gas circulation system that is less expensive and easier to maintain than a blower type.

In addition, both the ejector type and the blower type require a gas heating device, but in the blower type, the entire amount of gas supplied to the low temperature carbonization chamber is heated between the temperature of the heat-resistant blower discharge gas (approx. ), the amount of gas passing through the heating device is large, and the heating temperature is high, making the heating device relatively expensive. On the other hand, with the ejector type, the ejector drive gas amount (less than 1/2 of the gas amount supplied to the low-temperature carbonization chamber) is reduced from room temperature to approximately 550o.
Since the amount of gas passing through the heating device is small and the heating temperature is low because the salt is raised to 100%, the heating device becomes relatively inexpensive. Therefore, even if only the heating device is compared, the ejector type is more economical than the blower type.

By the way, the purpose of the shaped coke carbonization furnace is to produce high-quality metallurgical coke even when the particle size and volatile content of lump coal are varied and when the operating rate is varied. Therefore, in order to adjust the carbonization conditions in response to these fluctuations in operating conditions, it is essential to adjust the temperature and flow rate of the ejector discharge gas (i.e., the low-temperature carbonization chamber supply gas) and the flow rate of the ejector suction gas (i.e., the cooling chamber outlet gas) over a wide range. It is. The inventors of the present invention have developed a device that performs such adjustments using the temperature, flow rate, and pressure of the ejector driving gas.

According to the present invention, by adjusting the state quantities of the ejector driving gas which does not contain coke powder, has a relatively low temperature and a small flow rate, suction gas (cooling chamber outlet gas) and discharge gas (low temperature The suction gas flow rate and the discharge gas flow rate and temperature can be adjusted without having any flow rate, pressure, or temperature adjustment mechanism in the piping for the carbonization chamber supply gas, which is very effective in terms of equipment. However, it is generally known that the essential characteristic of ejectors is that they have low operational efficiency outside the design point, making it difficult to operate over a wide operational range.

Therefore, the inventors of the present invention further developed the following two specific means for controlling the temperature and flow rate of the ejector discharge gas and the amount of suction gas.

The first method is to provide the ejector with a bypass pipe having a flow rate control valve for bypassing a part of the gas circulated from the top of the furnace for driving purposes to the ejector discharge side pipe.

The second type is a multi-tube nozzle for an ejector, which is composed of multiple tubes having two or more ejection ports with different diameters and having the same central axis, and can independently switch the gas ejected from the ejection ports other than the center.

Next, the apparatus according to the present invention will be explained in detail based on embodiments and with reference to the drawings. In Fig. 1, lump coal 1 is first charged into the furnace from the top of an upright carbonization furnace 5, which consists of a low-temperature carbonization chamber 2, a high-temperature carbonization chamber 3, and a cooling chamber 4, and is then lowered through the furnace. The coke is carbonized by the heating medium gas introduced from the vanes 6 and 7, and further cooled by the cooling gas introduced from the cooling gas inlet 8 and discharged from the discharge port 9, and then sent to the lower part of the carbonization furnace as molded coke 10. is discharged from. On the other hand, the gas extracted from the top of the furnace is cooled by the direct cooler 11 and the indirect cooler 12, and the pressure is increased by the circulation blower 13. A part of the gas is led out of the system as recovered gas, and the rest is inside the system as circulating gas. cycle. A part of the circulating gas is introduced into the cooling chamber from the cooling gas inlet as a cooling gas. The remaining part is pressurized by the blower 14 and then introduced into the carbonization furnace through the vane 7 as a heating medium gas for high-temperature carbonization. The remainder of the circulating gas is supplied to the blower 16 and flow control valve 27.
The pressure, flow rate, and temperature of the gas are adjusted by the heating device 17, and the gas is guided to the ejector 18 as a driving gas. The ejector sucks the cooling zone exit gas from the exhaust port 9,
After mixing with the driving gas, the pressure is increased to the required level and introduced into the carbonization furnace through the vane □6 as a heat carrier gas for low-temperature carbonization. Heating device 1
A part of the gas at outlet 7 is bypassed to the ejector discharge side by pipe 19.

A flow rate control valve 20 is disposed in this pipe 19, and by adjusting the bypass flow rate, the amount of gas actually ejected from the ejector nozzle is adjusted, and by adjusting the ejector pressure boosting ability, the amount of gas discharged from the cooling zone is adjusted. The amount can be adjusted. As a result, the amount of gas supplied to the low-temperature carbonization chamber can be adjusted without changing the amount of gas at the outlet of the heating device 17, and without having any flow rate adjustment mechanism between the discharge port 9 and the ejector and between the ejector discharge port and the tuyere 6. The flow rate, temperature, and amount of gas at the outlet of the cooling chamber can be adjusted. By the way, in general, in an ejector, when the nozzle ejection speed is reduced, the boost pressure is significantly reduced.

Therefore, if the amount of ejector driving gas is to be reduced beyond the adjustment range by the bypass valve, the gas introduced into the multi-pipe driving gas nozzle is changed. According to this nozzle,
By sequentially stopping the gas ejected from the outer ejection ports (other than the center ejection port are annular ejection ports), even if the flow rate of all drive gases is reduced, the ejection speed at the nozzle tip will not decrease. It is possible to prevent a significant decrease in ejector boost pressure, and therefore it is possible to respond to a wide range of operating conditions. FIG. 1 shows a double tube nozzle as an example of a multiple tube nozzle.

The ejector driving gas is divided into an inner nozzle pipe 21 and an outer nozzle pipe 22, and is guided to an inner nozzle 23 and an outer nozzle 24, respectively, of a double-pipe driving gas nozzle.

However, the pipe 22 is provided with a cutoff valve 30. The gas blown from the exhaust port 9 by the driving gas blown into the ejector is mixed with the driving gas in the ejector 18 and discharged. When this device is operated, the amount of gas passing through the heating device 17 is set on the inlet side of the heating device, and the heating temperature is adjusted by the regulating thermometer 31.

The amount of gas at the inlet of the cooling chamber is adjusted by the flow rate control valve 27, and the amount of gas at the outlet of the cooling chamber (i.e., the amount of ejector suction gas) is adjusted by adjusting the amount of gas at the outlet of the cooling chamber (i.e., the amount of ejector suction gas) so that this flow rate matches the amount of gas at the outlet of the cooling chamber at the flow rate detection end 33. It is indirectly adjusted by the flow rate control valve 201. When the flow rate in the bypass pipe exceeds a certain value, the shutoff valve 30 is stopped and the ejector is driven only by the inner nozzle 23. Next, examples of the present invention will be described.

The ejector drive nozzle used was of the double tube type, and its dimensions are as shown in FIG.

The components of the driving gas and suction gas are shown in Table 1.
Table 1 Furthermore, the relationship between the difference between the required blowing pressure at the tuyere for low-temperature carbonization and the required suction pressure at the cooling gas outlet, that is, the required rising pressure of the ejector, and the ejector suction gas amount (cooling zone outlet gas amount) is shown in Figure 3. As shown.

As already mentioned, in the formed coke carbonization furnace, it is necessary to independently adjust the flow rate of the cooling chamber outlet gas and the temperature and flow rate of the low temperature carbonization chamber supply gas.

Here, we will first describe an ejector control method for independently adjusting the cooling chamber outlet gas amount and the low temperature carbonization furnace supply gas temperature. FIGS. 4 and 5 show operating ranges that satisfy the required pressure increase shown in FIG. 3 when the drive gas nozzle has an inner diameter of 9 ribs and 70 ribs.

In both cases, the suction gas temperature was set to AS=81000, and the driving gas temperature was set to GM=550°C. In addition, the driving gas source pressure was within 1,500 Yanagi Aq, which was within the pressure increase range of a single-stage blower. The horizontal axis of the figure shows the bypass ratio=VB/VPH (where VB: amount of bypass gas, VPH: amount of preheated gas). Further, parameter 8T in the figure is the ejector discharge gas temperature, and Vs indicates the amount of suction gas.

From Fig. 4, if we use a nozzle with inner d = 90, 8
7=65,000, the boosting force can be adjusted within the operating range of the shaded area A in the figure by adjusting the bypass rate within the range of Vs=1,500 to 3,000 N/day.

However, the operating range of 8T = 69000 (hatched area B in the figure)
is very narrow and has poor controllability.

On the other hand, from Fig. 5, if a nozzle with inner diameter d = 7 mm is used, when aT = 690oo, Vs1500~2800.
The boost force can be adjusted within the operating range indicated by the shaded area A in the figure within the range of N/day.

However, the operating range corresponding to Vs = 2500 to 2800N per day is narrow, and in the case of 8T = 650o0, a bypass ratio of 0.2 to 0.6 is required over the entire operating range, which is not directly related to ejector drive. This is uneconomical because a large amount of bypass gas is pressurized. Therefore, when the suction gas amount and the driving gas amount are each constant as in this example, when 8T is relatively high (for example, 690oo), that is, when the driving gas amount is relatively small, it is necessary to obtain sufficient boost pressure. If a small inner nozzle (inner nozzle only) is used, a wide operating range (shaded area A in FIG. 5) can be obtained.

Conversely, when 8T is relatively low (for example, 65,000), that is, when the amount of driving gas is relatively large, a wide operating range can be obtained by using a nozzle with a large inner diameter (inner nozzle plus outer nozzle).

Above, we have described the ejector control method when the cooling chamber outlet gas amount and the low temperature carbonization chamber supply gas temperature are independently adjusted. The control method is also similar to this.

By the way, as is clear from the above description, when there is little variation in the volatile content of agglomerated coal, the necessary operating conditions for the cooling chamber outlet gas flow rate and the flow rate and temperature of the low-temperature carbonization chamber supply gas are relatively small. This can be done simply by adjusting the gas flow rate through the bypass pipe according to the invention.

As described above, according to the present invention, by combining the adjustment of the bypass flow rate and the switching of the inner diameter of the driving gas nozzle, the suction gas amount (cooling zone exhaust gas amount), the driving gas amount, and the discharge gas (heat carrier gas for low-temperature carbonization) can be adjusted. It is possible to obtain a molded coke carbonization furnace gas circulation system that can follow the changes in flow rate and temperature and ensure a wide operating range, and has excellent thermoeconomic efficiency and maintainability, and its practical value is extremely large.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a gas circulation device in an upright molded coke carbonization furnace which is an embodiment of the present invention, Fig. 2 is a diagram showing the dimensions of an ejector used in the embodiment, and Fig. 3 is a diagram showing the dimensions of an ejector used in the embodiment. A diagram showing the relationship between the required boost pressure and the amount of suction gas used,
FIG. 4 and FIG. 5 are diagrams showing the operating range of the ejector of the embodiment. 1... Lump coal, 2... Low-temperature carbonization chamber, 3... High-temperature carbonization chamber, 4... Cooling chamber, 6... Vertical carbonization furnace, 6... Low-temperature carbonization chamber heating medium gas supply vane Port, 7... High-temperature carbonization chamber heating medium gas supply tuyere, 8... Cooling gas inlet, 9... Cooling gas outlet, 10... Molded coke, 11... Direct Kufu, 12... Indirect cooler, 13...Circulation blower
, 14... Boosting blower, 15... Heating device, 16
... Boosting blower, 17... Heating device, 18... Ejector, 19... Bypass pipe, 21... Inner nozzle pipe, 22... Outer nozzle pipe, 23... Inner nozzle, 24... Outer nozzle, 30 ...Shutoff valve, 25, 28
, 33, 35...Flow rate detection end, 26, 29, 34, 37...
Flow rate regulator, 20, 27, 36...Flow rate control valve, 31, 3
8...Temperature detection end, 32...Temperature regulator. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A method for cooling carbonization furnace top gas in a method of carbonizing lump coal by introducing heating heat medium gas into the lower part and middle part of the carbonization chamber in an upright continuous carbonization furnace to obtain molded coke. Most of the gas that has passed through the cooling chamber is discharged from the upper part of the cooling chamber and is supplied to the inlet in the middle of the carbonization chamber as a heating medium gas. An apparatus for producing molded coke characterized by the following: an ejector driven by part of the circulating furnace top gas is provided, the ejector sucks the gas that has passed through the cooling chamber, and mixes it with the driving gas within the ejector. , a vertical pipe characterized by having a bypass pipe configured to supply the tuyere in the middle part of the carbonization furnace as a heating heat medium gas, and having a flow rate adjustment mechanism for bypassing a part of the driving gas to the ejector discharge side. Gas circulation device in molded coke carbonization furnace. 2. In a method of carbonizing coke by introducing heating heat carrier gas into the lower and intermediate parts of the carbonization chamber in an upright continuous carbonization furnace to carbonize lump coal and obtain shaped coke, the carbonization furnace top gas is used as a cooling gas in the carbonization chamber. The formed coke is introduced into the lower part of the directly connected molded coke cooling chamber, and most of the gas that has passed through the cooling chamber is discharged from the upper part of the cooling chamber and supplied as heating heat medium gas to the inlet in the middle part of the carbonization chamber. In a molded coke manufacturing apparatus, an effluent driven by a part of the circulating furnace top gas is installed, and the effluent sucks the gas that has passed through the cooling chamber, mixes it with the driving gas in the effluent, and generates a heating heat medium gas. It has a bypass pipe with a flow rate adjustment mechanism for bypassing a part of the driving gas to the ejector discharge side, and a pipe with a diameter of A gas circulation device in a vertical coke carbonization furnace, characterized by having a multi-pipe nozzle for driving an ejector, which has two or more different ejection ports and can independently switch the gas ejected from the ejection ports other than the center.