JP3369449B2 - Layer thickness control method for sinter cooler - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the thickness of a sinter cooling machine for efficiently recovering waste heat of sinter in the sinter cooling machine. About. [0002] Exhaust gas from a cooler for cooling a high-temperature sintered ore after sintering is also high in temperature similarly to exhaust gas from a sintering machine.
Heat recovery is also performed from the exhaust gas of the cooler. As shown in FIG. 4, such a sinter cooling equipment has a blower duct 3 below a cooler pan 2 of a cooler 1.
An exhaust hood 4 is disposed above, and an exhaust heat recovery device 7 such as a boiler is installed in a conduit 5 provided between the blower duct 3 and the exhaust hood 4. Ore 9
Is cooled by aeration while the sinter moves to the exhaust ore part of the cooler 1, and air heated to a high temperature by the cooling is introduced into an exhaust heat recovery device 7 such as a boiler to recover the exhaust heat. ing. That is, the high-temperature sinter 9 supplied from the sintering machine 8
Is supplied to the cooler 1 and the cooling air is blown upward from the blower duct 3 from the blower duct 3 while moving to the mining part of the cooler 1 to cool the high-temperature sinter 9 on the cooler pan 2. The air is heated and enters the exhaust hood 4 and is introduced into the exhaust heat recovery device 7 via the conduit 5, and the exhaust gas after the exhaust heat recovery is circulated and used as cooling air. In the figure, 10
Is a crusher for crushing the sintered ore discharged from the sintering machine 8, 11 is a hot screen for sizing the crushed sintered ore, and 12 is a feed chute. In the sinter cooling system having such a configuration, in order to uniformly cool the sinter, it is necessary that the layer thickness of the sinter on the cooler pan 2 is appropriate and constant. However, during operation, the layer thickness of the sinter 9 on the cooler pan 2 varies depending on the sintering machine production base. If the amount of sieve on the screen 11 fluctuates, problems such as a decrease in cooling efficiency, burning of the belt conveyor on the exhaust side, and an increase in power loss of the exhaust fan for cooling are undesirable. FIGS. 5A and 5B show examples of the cooling condition when the layer thickness of the sintered ore on the cooler pan 2 is constant and when the layer thickness fluctuates. FIG. Indicates the case where the layer thickness fluctuates. That is, FIG.
As shown in the figure, when the machine direction direction thickness of the sinter cooler is appropriate and constant, the sinter 9 is cooled uniformly and the amount of heat recovered by the exhaust heat recovery device 7 such as a boiler does not vary. Stabilize. However, for the reasons described above, FIG.
As shown in (B), when the layer thickness in the machine direction of the sinter cooling machine fluctuates, the cooling gas preferentially passes through a region where the layer thickness is small and air permeability is low, and the cooling efficiency of the entire cooling machine decreases. Bring. At the same time, the cooling efficiency of the exhaust heat recovery zone in the cooler also decreases, so that the exhaust gas temperature is lower and the amount of exhaust heat recovery is lower than when the layer thickness is constant. In addition, when the level of the sinter in the cooler becomes extremely low, the cool air generated by the cooling air blower does not pass through the sinter ore layer, resulting in a so-called wind leak, which significantly reduces the cooling effect and the sinter discharged from the cooler. The increase in the temperature of the ore causes burning of the belt conveyor on the exhaust side, and increases the power loss of the exhaust fan for cooling. For this reason,
In the sinter cooling equipment shown in FIG.
Level control to control the thickness of the sinter above is desired. Japanese Patent Application Laid-Open No. Sho 62-89824 discloses that the amount of sinter in a hopper-type sinter cooler is measured, and the amount of sinter from the cooler is reduced so as to eliminate a deviation from the target value. There has been proposed a level control method for a sinter cooler in which the amount of condensate cut is adjusted in accordance with the amount of sinter that is fed from the sinter machine to the cooler. According to this level control method, the sinter ore level in the hopper type sinter cooler can be kept uniform, so that the drop height in the hopper type chiller becomes uniform and the powder generation rate of the sinter decreases. The effect that it can be obtained is obtained. However, since this level control method is intended for a so-called vertical cooler, there is a drawback that it cannot be applied to the belt conveyor type sinter cooler shown in FIG. 4 described above. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been made to prevent a change in the layer thickness of sinter on a cooler pan in a sinter cooling machine of a belt conveyor type. Another object of the present invention is to propose a method for controlling a layer thickness of a sinter cooling machine that can always maintain a proper cooling machine layer thickness. A method for controlling the thickness of a sinter cooler according to the present invention is to automatically control the speed of the chiller in consideration of the thickness of the chiller feeder. This is a method of maintaining the cooling layer thickness at an appropriate level. The gist of this method is to incorporate the sinter cooling machine speed proportional control into the circuit that controls the sinter cooling machine speed from the sinter machine pallet speed, The sinter cooling machine speed P set in proportion to the sintering machine pallet speed Ps by the following equation 1 based on the layer thickness detection signal on the cooler pan detected by the layer thickness meter installed on the feeder side chute of the machine. Is controlled by the speed proportional control to control the layer thickness on the cooler pan to an appropriate level. P = K * Ps P: Sinter cooler speed (m / H) Ps: Sinter machine pallet speed (m / H) K: Speed proportional constant Sinter cooler The layer thickness on the cooler pan is
As is well known, it is determined by the amount of ore supplied to the cooler and the speed of the cooler, so if the layer thickness is lower than the appropriate level, the speed of the sinter cooler is reduced and the layer thickness is adjusted in the ascending direction. If it is higher than the appropriate level, the layer thickness can be maintained at the appropriate level by increasing the sinter cooling machine speed and adjusting the layer thickness in the decreasing direction. As the control means, the present invention is based on layer thickness data detected by a layer thickness gauge installed on a feeder side chute of a sinter cooling machine in a circuit for controlling a cooling machine speed from a sintering machine speed. Incorporating a proportional control for determining a proportional constant K of the sinter cooling machine speed P set in proportion to the sintering machine pallet speed Ps, for example, when the layer thickness is reduced by disturbance, In order to adjust to the level, the proportional constant K was adjusted to be low and the speed of the cooling machine was decreased. On the contrary, when the layer thickness was increased, the proportional constant K was increased. The proportional control means the pallet speed P of the sintering machine.
is a control for determining the sinter cooling machine speed P by the above equation 1, and the proportional constant K of the sinter cooling machine speed P set in proportion to the sintering machine pallet speed Ps is automatically determined. It is adjusted by control. Of course, the adjustment of the proportionality constant K can be performed manually, but in the case of manual operation, the operator adjusts the dial speed while watching the indication of the layer thickness gauge, thereby setting the cooling rate and adjusting the layer thickness. However, in the case of manual operation, it is necessary for the operator to constantly monitor, and if the adjustment timing is delayed when the layer thickness is out of the appropriate range, it takes time to return the layer thickness to the appropriate range. The proportional constant K is adjusted by automatic control. The thickness gauge installed on the chute on the feed side of the sinter cooling machine may be any of an ultrasonic level meter, a non-contact type level meter and a contact type level meter. To adjust the machine layer thickness to an appropriate level,
It is more desirable to install two than one. The layer thickness meter is installed with its height adjusted so that the layer thickness level on the cooler pan is at an optimum level. FIG. 1 is a schematic view showing one embodiment of the present invention, and FIG. 2 is a positional relationship between a sinter cooling machine, a sinter and a layer thickness gauge in the embodiment shown in FIG. FIG. 3 is an explanatory view showing the operation state and the sinter level of the layer thickness gauge in the above embodiment, 13 is a sinter cooling machine speed proportional control device, and A is the upper layer thickness. B is a lower layer thickness gauge. The upper thickness gauge A and the lower thickness gauge B are shown in FIG.
As shown in the enlarged view, a level detection rod A- is rotatably supported on the detector main bodies A-1 and B-1 around the shaft pins A-3 and B-3 in the direction of flow of the sinter. 2. When the ore contacts the tip of B-2 and the level detection rod operates in a pendulum-like manner, contactless detection sensors A-4 and B-4 of the detector bodies A-1 and B-1. The detector operates to output an ON signal, and when the end of the level detection rod is separated from the detection sensor, the detector is installed on the feed chute 12 as if the detector outputs an OFF signal. It is configured to be input to the condensate cooler speed proportional control device 13. According to the upper and lower two layer thickness gauges, the layer thickness levels can be distinguished into three levels as shown in Table 1 below. [Table 1] That is, as shown in FIG. 3, when the upper layer thickness gauge A is ON and the lower layer thickness gauge B is OFF, the appropriate layer thickness level (FIG. 3B) is determined. When both thickness gauges B are OFF and the layer thickness is lower than the appropriate level (FIG. 3)
(A)), the sinter cooling machine speed proportional control device 13 reduces the speed proportional constant K of the above equation 1 to reduce the sinter cooling machine speed, thereby controlling the layer thickness in the ascending direction. When both the thickness gauge A and the lower thickness gauge B are ON and the thickness is higher than an appropriate level (FIG. 3 (C)), the speed proportional constant K is increased to increase the sinter cooling machine speed and increase the thickness. Is controlled in the downward direction. In this way, by automatically controlling the speed of the cooling machine in consideration of the layer thickness on the sinter cooling machine supply side, the cooling machine layer thickness can be maintained at an appropriate level. The results obtained when the present invention is applied to a sinter cooling machine having a capacity of 15000 T / D are shown below. Table 2 shows the operating conditions of the sinter cooler in this embodiment, and Table 3 shows the effect of controlling the thickness of the cooler layer. That is, in the present embodiment, both the upper layer thickness gauge A and the lower layer thickness gauge B
Since the layer thickness became lower than the appropriate level at F, the results are obtained when the speed proportional constant K was reduced and the sinter cooling machine speed was reduced to control the layer thickness in the upward direction. In this example, the appropriate layer thickness level was set to 450 to 500 mm, the low layer thickness level was set to less than 450 mm, and the high layer thickness level was set to 500 mm or more. As is clear from the results in Table 3, before the control of the cooler layer thickness (before adjusting the cooler speed), the exhaust gas temperature was 380 ° C. and the amount of exhaust heat recovery steam was 4 because the layer thickness was lower than the appropriate level.
Although it was 0.2 T / H, the exhaust gas temperature was 390 ° C. as a result of controlling the cooler layer thickness and returning the layer thickness to an appropriate level.
And the amount of exhaust heat recovery steam also increased to 42.4 T / H. In addition, by returning the layer thickness to an appropriate level, air leakage was reduced, and there was no risk of burnout of the belt conveyor on the exhaust side of the cooler, and power loss of the exhaust for the cooler was also reduced. [Table 2] [Table 3] As described above, the present invention maintains the cooling layer thickness at an appropriate level by automatically controlling the cooling machine speed in consideration of the layer thickness on the feeder side of the belt conveyor type cooling machine. Since it is a method of sintering machine, it is possible to sufficiently cope with fluctuations in the amount of sinter ore input to the cooler due to fluctuations in the production base of the sintering machine, and fluctuations in the on-screen amount of the hot screen due to fluctuations in the particle size of the sinter after firing. In the sinter cooler, fluctuations in the layer thickness of the sinter on the cooler pan can be prevented, and the layer thickness of the cooler can always be maintained at an appropriate thickness, thus improving cooling efficiency and improving the belt conveyor on the mining side. This has a great effect on the prevention of burnout and reduction of the power loss of the cooling exhaust fan.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing one embodiment of the present invention. FIG. 2 is an enlarged schematic view showing a positional relationship among a sinter cooler, a sinter and a thickness gauge in the embodiment shown in FIG. FIG. 3 is an explanatory view showing the operation status of the layer thickness gauge and the sinter ore level in the above embodiment. FIG. If lower,
(B) when the upper layer thickness gauge A is ON and the lower layer thickness gauge B is OFF and the layer thickness is at an appropriate level, and (C), when both the upper layer thickness meter A and the lower layer thickness meter B are ON and the layer thickness is Each case is higher than the appropriate level. FIG. 4 is a schematic view showing an example of the entire structure of a sinter cooling machine to which the present invention is applied. FIG. 5 is a diagram illustrating an example of a cooling condition in which the layer thickness of the sinter on the cooler pan of the sinter cooling machine is constant and fluctuates. If (B)
FIG. 3 is a schematic view showing a case where the layer thickness fluctuates. [Description of Signs] 1 sinter cooler 2 cooler pan 3 blower duct 4 exhaust hood 5 conduit 7 waste heat recovery device 8 sinter machine 9 sinter 10 crusher 11 hot screen 12 feed chute 13 sinter cooler Speed proportional controller A Upper layer thickness gauge B Lower layer thickness gauge

Continuation of front page (56) References JP-A-7-138663 (JP, A) JP-A-7-243769 (JP, A) JP-A-5-272287 (JP, A) JP-A-52-117204 (JP, A) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F27B 21/14 C22B 1/26 F27B 21/00

Claims (1)

(57) [Claims] [Claim 1] A sinter cooling machine speed proportional control is incorporated in a circuit for controlling a sinter cooling machine speed from a sinter cooling machine pallet speed to supply the sinter cooling machine. Based on the layer thickness detection signal on the cooler pan detected by the layer thickness gauge installed on the ore side chute, the proportional constant K of the sinter cooling machine speed P set in proportion to the sintering machine pallet speed Ps by the following equation A layer thickness on a cooler pan is controlled to an appropriate level by changing the thickness by the speed proportional control. P = K * Ps P: Sinter cooling machine speed (m / H) Ps: Sintering machine pallet speed (m / H) K: Speed proportional constant