JPS6241635B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cutting control method that enables uniform cooling of grain agglomerates in dry cooling equipment.

[Prior Art] In the fields of steel manufacturing and chemical industry, there is a dry cooling method for the purpose of recovering sensible heat from high-temperature granules. This is a method in which high-temperature agglomerates are put into a tower, cooling gas is circulated to recover the sensible heat of the agglomerates, and then converted into steam energy in a boiler. Dry extinguishing equipment for red-hot coke is also a type of this method. However, the explanation will be given below using coke dry extinguishing equipment as an example.

As shown in FIG. 1, the coke dry extinguishing equipment includes a cooling tower body 1 having a red-hot coke inlet 2 at the top and an outlet 3 at the bottom for discharging cooled coke. The upper part of this tower body 1 is connected to the upper part of the boiler 5 via a communication pipe 4,
The bottom of the boiler 5 and the lower part of the cooling tower body 1 are connected to the fan 6.
They are connected by a connecting pipe 7 with an interposed one, and cooling gas such as inert gas can be circulated by driving a fan 6. A cutoff valve 8 is installed at the cutout port 3 to cut out coke in batches.
By this operation, a downwardly moving bed of coke can be formed in the column body 1. Therefore, the moving bed of coke flows countercurrently to the cooling gas, and the coke is cooled while the cooling gas is heated to a high temperature. According to this, the coke can be cooled and the boiler 5 can be heated by the sensible heat of the coke via the cooling gas, so that an energy saving effect can be achieved. In addition, 9 is an upper bunker, and the upper gate 10 is attached so that it can be opened and closed, and 11 is a lower bunker, and the lower gate 12 is attached so that it can be opened and closed.

However, this dry cooling tower has a problem in that red-hot coke is not cooled uniformly due to uneven flow of cooling gas caused by particle size segregation of coke, non-uniform fall of granules, and the like. If the non-uniformity became noticeable, high temperature coke would be mixed in the coke cut out from the cutout port 3 by the cutoff valve 8, which was dangerous.

For this reason, conventionally, multiple temperature detection ends were placed on the circumferential wall of the cooling tower 1 to operationally monitor the non-uniform cooling of coke, and when a large difference occurred in the temperature distribution on the circumferential wall, In this case, the cut-out valve 8 was closed to stop the discharge of coke based on the approximation and correlation with non-uniform cooling.

However, it is not preferable to stop discharging coke. In order to deal with the non-uniform cooling of coke without stopping the coke discharge, it is possible to assume in advance the non-uniform flow of cooling gas and coke and design the shape of the cooling tower body 1 to match this.
However, in this case, there is a margin in the cooling capacity, and the shape of the column body 1 becomes large, which impairs economic efficiency as a facility for recovering the sensible heat of coke. On the other hand, for non-uniform cooling of coke, a method can be considered in which the supply amount of cooling gas is changed in response to non-uniform cooling. That is, the cooling gas supply equipment is divided and provided, and the supply amount is increased to the under-cooled portion and decreased to the over-cooled portion, thereby uniformly cooling the coke. Furthermore, there is also a method of dividing the outlet of the cooling gas and appropriately limiting the amount of each gas discharged, thereby making coke cooling more uniform. There is also a method of increasing the amount of cooling gas supplied as a whole in order to supply the minimum amount of cooling gas required for cooling to the non-uniform cooling section. According to these methods of changing the supply amount of cooling gas, due to the unevenness of the particle size distribution of coke in the column body 1, the rising speed distribution of the cooling gas is compared to both wall surfaces 1a and 1b as shown in FIG. Even if the speed is slow at the center 1c, the speed distribution can be made uniform by increasing the amount of gas supplied to the center 1c,
This makes it possible to uniformly cool the coke.

[Problems to be Solved by the Invention] However, the inside of the column body 1 is a moving bed of coke, and if the coke descending speed is high, there is a limit to the method of changing the amount of cooling gas supplied. In other words, as shown in FIG. 3, the descending velocity distribution of coke in the column body 1 is such that the velocity is slowest at the center 1c, fastest between the center 1c and both wall surfaces 1a and 1b, and has a maximum value. If the conventional method is used to cool coke uniformly when the difference in minimum values is large, it is necessary to send a large amount of cooling gas to ensure that sufficient cooling gas is distributed even to areas where the falling speed is high. However, this required an increase in the size of the equipment, such as increasing the size of the fan 6, which had the disadvantage of impairing economic efficiency.

In addition, there is a method in which a plurality of gas pressure sensors are attached to the wall of the column body corresponding to each cutting port, and the cooling status of the agglomerates is indirectly estimated based on the pressure (Japanese Patent Laid-Open No. 136087/1987). ), but the pressure is controlled by the temperature of the gas in the furnace, but it is not the temperature of the agglomerates itself, and the difference in pressure has almost no effect on the temperature of the agglomerates. The problem is still not resolved.

An object of the present invention is to provide a cutting control method in dry cooling equipment for grain agglomerates, which can uniformly cool grain agglomerates without stopping the discharge of grain agglomerates, and can improve the economic efficiency of the equipment. It is.

[Means and effects for solving the problems] In order to achieve the above object, the configuration of the present invention is as follows:
A radiation-type temperature sensor that directly and continuously detects the surface temperature of the agglomerates cut out from the cutting opening at the bottom of the cooling tower, discharged to the outside of the tower, and conveyed in a line on a belt conveyor outside the tower; A cutting number sensor that detects the number of times the agglomerate is cut out of a plurality of cutting valves provided in the agglomerate cutting device at the lower part of the cooling tower, and a signal from the temperature sensor and the cutting number sensor is provided. is input into the calculator, the amount of agglomerates cut out within a certain period of time is calculated from the signal of the cutting number sensor, the agglomerate cutting speed is calculated, and the agglomerate temperature from the signal of the temperature sensor and inside the cooling tower are calculated. Calculates the temperature difference between the cooling gas temperature before entering the system or a preset reference temperature, calculates the optimum interval for the cutting operation from the temperature difference and the agglomerate cutting speed, and controls the operation of each cutting valve. The granules are cooled to a uniform temperature.

[Example] Hereinafter, a preferred example of the present invention will be described with reference to FIG. 4.

As shown in FIG. 4, reference numeral 1 denotes a cooling tower body, and a cutout port 3 is provided at the bottom of the cooling tower body for discharging cooled granules, that is, coke in this embodiment.
A plurality of cutting ports 3 are provided, and here, a case in which two ports are provided will be explained, and coke can be discharged from each of the cutting ports 3a and 3b. Cutoff valves 8a, 8b are installed in each cutout port 3a, 3b, and each cutout port 3 is
A and 3b are designed to open and close. Each cutting valve 8a, 8b is provided with cutting number sensors 13a, 13b for detecting the number of coke cuttings. Further, 15 is coke discharged from the lower gate 12, and 16 is a belt conveyor for conveying the coke. Reference numeral 17 denotes a radiation type temperature sensor that directly and continuously measures the surface temperature of the coke 15 placed on the conveyor 16 and moving. This one temperature sensor 17 and multiple cutting number sensors 13
a, 13b are electrically connected to the computing unit 18, and input the temperature signal and the cutting number signal to the computing unit 18. The calculator 18 includes a coke cutting speed setting device 1.
9 is connected, and inputs a coke cutting speed set value to the calculator 18. The output side of the calculator 18 is connected to each of the cutoff valves 8a and 8b, and controls the operation of each of the cutoff valves 8a and 8b by issuing an operation command signal 20.

To explain the functions of the calculator 18, firstly, the coke cutting speed is calculated from the cutting number signal.
That is, the normal coke cutting speed V is calculated by the following equation.

V=Z×Q/t [tons/hour] ...(1) Here, t is the elapsed time [hours], Z is the number of times the coke is cut out within the elapsed time [times], and Q is the coke per time Cutting amount [tons/number of times].

On the other hand, the coke cutting speed V' during the transient period is calculated by the following equation.

V'=V ₀ ×t ₀ /t' [tons/hour] ...(2) Here, V ₀ is the coke cutting speed setting value [tons/hour], and for t ₀ and t', t ₀ = Q/V ₀
[time/times], t'=t/C [time/times], C is the integrated value [times] of the number of times of coke cutting within a certain elapsed time. The period corresponding to the transition period refers to the period from the start of coke cutting or the time when the coke cutting speed setting value V ₀ is changed until a predetermined period of time has elapsed.
This is the period until the change in coke cutting rate stabilizes at the minimum necessary level.

Second, the computing unit 18 continuously measures the coke temperature θi of the cutoff valve 8a from the temperature sensor 17.
Calculate the temperature differences Δθi and Δθj between the coke temperature θj of the cutoff valve 8b and the cooling gas temperature _θ0 while entering the column body 1, and also calculate the temperature differences Δθi and Δθ
Calculate the average value and for j.
This calculation formula is shown below.

Here, N and M are the number of times the cutoff valves 8a and 8b are cut out within the set time.

Note that the temperature of the cooling gas before it flows into the tower body 1 is a value measured by a temperature sensor (not shown), but instead of this cooling gas temperature, it may be a reference temperature determined in advance for design purposes.

Thirdly, the calculation unit 18 calculates the intervals T ₁ , T ₂ , T _{1 ' of the cutting times of the cutting valves 8a and 8b from the temperature difference Δθi, the average temperature difference Δθj, and the coke cutting speeds V, V', etc.} , T ₂ ′. That is, the cutoff valves 8a and 8 in normal times
b The interval T of the coke cutting time is calculated by the following formula.

On the other hand, the interval T' of the coke cutting time during the transient period is calculated by the following equation.

Next, the operation of the apparatus shown in FIG. 4 will be described.

The cutting speed set value V ₀ is set in the cutting speed setting device 19, and each cutting valve 8a, 8b is set via the calculator 18.
The coke cutting time intervals T ₁ , T ₂ ,
Adjust T ₁ ′ and T ₂ ′. At this time, each cut-off valve 8a,
The cutting speeds V ₁ , V ₂ , V ₁ ′, and V ₂ ′ at 8b change, and the descending speed of coke within the cooling tower body 1 changes.

If non-uniform cooling of coke occurs under normal conditions,
When the unevenly cooled coke is cut out, the temperature difference Δ is determined by the temperature signal from the temperature sensor 17.
θi, Δθj and average value,,
is calculated by the computing unit 18, and it is possible to easily determine that the cooling is uneven. Further, the coke cutting speed V at the cutting valves 8a, 8b of the cutting ports 3a, 3b is measured by each cutting number sensor 13a, 13b.
The coke cutting speed is calculated by the computing unit 18 based on the number of coke cutting signals from the coke cutting speed, but since the opening and closing of the cutting valves 8a and 8b are also performed by the computing unit 18, the coke cutting speed corresponding to the temperature difference Δθi and Δθj may be either. It can be easily identified. From these calculated values determined in this way, each cut-off valve 8a,
The calculator 18 calculates the optimal intervals T ₁ and T ₂ of the cut-out times of the cut-out valves 8b, and sends an operation command signal 20 that causes the cut-out valves 8a and 8b to operate at the intervals T _{1 and T2} . Output. Therefore, for each valve,
If the average value of the temperature difference, The operation interval T will be increased. As the interval T increases, the coke cutting rate V decreases (V=Q/T) because the coke cutting amount Q is constant, and the coke descending speed slows down. As a result, the residence time in the furnace is extended, so the coke cooling effect increases and coke cooling becomes more uniform. On the other hand, the temperature difference,
is smaller than the average value, the interval T of the cutting time of the cutting valves 8a, 8b corresponding to the cutting ports 3a, 3b from which low-temperature coke is cut is reduced, and the coke cutting speed V
increases, and the coke fall rate becomes faster. As a result, the residence time in the furnace is shortened, so the coke cooling effect is reduced and coke cooling is made more uniform.

Even when non-uniform cooling of coke occurs during a transient period, the temperature difference, its average value, and the coke cutting rate can be calculated in the same manner as described above.
The computing unit 18 calculates V ₁ ′, V ₂ ′, and calculates the intervals T ₁ ′, T ₂ ′ of the coke cutting time of each cutting valve 8a, 8b as shown in the above equation (6) from these values. vessel 18
The calculation unit 18 outputs an operation command signal 20 such that each cutoff valve 8a, 8b operates at the interval T ₁ ′, T _{2 ′} . As a result, the coke cutting speeds V ₁ ′ and V ₂ ′ of the respective cutting valves 8a and 8b change, and the coke descending speed is changed, so the residence time in the furnace is adjusted, and coke cooling is made uniform. It turns out.

By appropriately repeating the above operations, coke can be uniformly cooled both during normal times and during transient times.

Note that the radiation type temperature sensor 17 is not installed inside the cooling tower body 1 like a thermocouple, but is installed inside the cooling tower body 1.
One coke is provided outside, and the coke is cut out from each cutoff valve 8a, 8b, falls from the lower gate 12 onto the belt conveyor 16, and immediately detects the temperature of the coke as it is conveyed in batches on the conveyor 16.

That is, when a thermocouple is installed inside the cooling tower body 1, the thermocouple must be buried in the tower wall bricks to prevent wear, which makes it impossible to accurately measure the temperature of coke inside the tower body 1. The coke inside the column body 1 is still in the process of being cooled, and cannot be called cooled coke. Furthermore, the thermocouple detects the temperature of the gas within the tower body 1 due to the influence of the gas, and the response is also slow. However, if the radiation type temperature sensor 17 is installed outside the tower body 17 as shown in FIG. 4, it is possible to measure the true temperature of the coke after cooling without any disturbance. The installation environment is better, a longer life can be expected, maintenance is easier, and the response is faster than in the case where changes in process values are detected quickly and can be easily used to control the cutoff valves 8a and 8b.

[Effects of the Invention] In summary, the present invention exhibits the following excellent effects.

(1) Directly measure the surface temperature of the agglomerates discharged outside the tower using a radiation temperature sensor, and also continuously measure the temperature of the large amount of agglomerates that are conveyed in a line on the belt conveyor. Unlike the conventional method, which measures the gas temperature and gas pressure inside the tower and indirectly estimates the temperature of the agglomerates, this method detects the true temperature of the coke after cooling without any disturbance. However, since the response is faster, the cooling effect can be fully confirmed. Based on this temperature, the intervals between opening and closing of each cut-off valve are controlled with high accuracy, ensuring uniform cooling of the granules. This makes it possible to effectively prevent belt conveyor burnout. In addition, the installation environment is good, a long life can be expected, and maintenance is easy.

(2) According to the method of installing thermocouples in the furnace to determine the temperature of the agglomerates, at least as many thermocouples as there are cut-out valves are required. Since the cut-out valve never opens or closes, if it is linked with the cut-out number sensor, even if there are multiple cut-out valves, one radiation temperature sensor can detect the cut-out granules for each cut-out valve. Can detect temperature.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional elevational view showing an example of a conventional granular dry type fire extinguishing equipment, Fig. 2 is an explanatory diagram showing the distribution of the cooling gas rising speed ratio in the cooling tower body of Fig. 1,
FIG. 3 is an explanatory diagram showing the descending velocity ratio distribution of the particles in the cooling tower body of FIG. 1, and FIG. 4 is a longitudinal sectional elevational view showing an example of the apparatus for carrying out the present invention. In addition, in the figure, 1 is a cooling tower, 3a, 3b are cutting ports,
8a and 8b are cutting valves, 13 and 14 are cutting number sensors, 15 is coke, 17 is a temperature sensor, and 18 is a computing unit.

Claims (1)

[Claims] 1. A radiation-type temperature sensor that directly and continuously detects the surface temperature of the agglomerates that are cut out from the cutting opening at the bottom of the cooling tower, discharged to the outside of the tower, and conveyed in a line on a belt conveyor outside the tower. , and a cutting number sensor that detects the number of times the agglomerate is cut out of a plurality of cutting valves provided in the agglomerate cutting device at the lower part of the cooling tower, and the signals from these temperature sensors and the cutting number sensor are provided. is input into the calculator, the amount of agglomerates cut out within a certain period of time is calculated from the signal of the cutting number sensor, the agglomerate cutting speed is calculated, and the agglomerate temperature from the signal of the temperature sensor and inside the cooling tower are calculated. Calculate the temperature difference between the cooling gas temperature before entering the system or a preset reference temperature, and use the temperature difference and the agglomerate cutting speed to calculate the cut-off valve operation interval so that the agglomerate temperature is below the desired temperature. A method for cutting out grain agglomerates in a dry cooling equipment, characterized in that the operation of each cutting valve is controlled to cool the grain agglomerates to a uniform temperature.