Description of batching system under the trough of

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Description of burden system under blast furnace trough

0 introduction

in metallurgical enterprises, burden system under blast furnace trough is an indispensable part of blast furnace. Only the burden system can properly mix the materials required by blast furnace according to a certain proportion into the left and right ore hoppers, and add the mixed materials into the furnace through the charging trolley, so as to meet the needs of normal production of blast furnace. Therefore, burden system is particularly important in the whole blast furnace system. The premise of ensuring normal batching is that the weighing of each weighing bucket reaches a certain accuracy and accuracy

1 schematic diagram and wiring diagram of weighing system

now we will briefly introduce the batching system in the actual production of our blast furnace. Our company selects the hopper scale. Three pressure sensors are symmetrically installed under each weighing bucket. Each sensor is equivalent to a rectifier bridge, and three sensors are connected in parallel in the junction box. The signals of the three rectifier bridges are processed in the junction box, and then the processed signals are directly connected with the weighing controller. The terminals 17 and 18 of the weighing controller are connected with the PLC of the blast furnace system, so that it can be monitored and modified by the upper computer

schematic diagram of sensor:

wiring diagram of weighing controller:

corresponding wiring instructions:

2 description of each quantity in the weighing system

now it describes the ingredients of a weighing bucket (take 1# bin as an example). In the weighing setting, the 1# scale mainly includes the set value SP, actual value PV, residual vibration value YZZ, null value KZ, control value control, net material value jlz, cumulative value ljz, etc. The set value refers to that the operator sets it according to the material weight of 1# bin required by the batching list; The actual value refers to the actual weight of the material loaded into the weighing bucket after the vibrating screen vibrates; Residual vibration value refers to the weight of the material loaded into the weighing bucket due to inertia after the vibrating screen stops vibrating (artificially set); Empty value refers to the weight of the remaining material after the bucket is emptied; The control value is used to control the relationship between the actual value and the set value; The net material value is the weight actually put on the belt after the bucket gate is opened; Cumulative value refers to the accumulation of materials placed on the belt for many times. This cumulative value is cleared once per shift

3 PLC program description in the weighing system

the calculation relationship between various values in the needle symmetrical bucket is now described in detail according to the PLC program

description of midpoint number in this function block:

when the operator sets the weighing value required by the weighing bucket, and selects the corresponding weighing bucket in the periodic batch, when the program is executed to this batch, select the vibrating screen on the weighing bucket, that is, the vibrating screen starts to start, the PLC point 00001 in the blast furnace system outputs, and this point inputs a signal to the weight block. During the vibrating process of the vibrating screen, the weight of the loaded material in the weighing bucket can be weighed from time to time, That is, the actual value. When the actual value in the bucket is greater than or equal to 95% of the control value or the actual value is equal to the control value, the bucket can establish a full signal, that is, the point mxh has an output; After the full signal is established, the vibrating screen can stop. The results show that this kind of mixture adheres to the combustion longer than ordinary flame retardants to stop vibration. After the 13s delay, the full delay mys is formed. When the full delay pulse comes, the actual value PV is paid to the full stable value MWZ

when the weighing bucket is selected for material preparation in the blast furnace program, after the gate is opened to the position, the position should not be broken. 100005 has an input signal to the function block, and can weigh the weight of the remaining material in the weighing bucket from time to time; When the actual value in the bucket is less than or equal to the set null value, it is considered as bucket empty, and the empty signal in the picture will be formed by delaying 2S after bucket empty; After the empty signal is established, an empty signal is given to the blast furnace system to close the gate of the weighing bucket. Only after the gate is closed in place, the weighing bucket can meet the conditions of "empty bucket preparation"

in the process of opening and discharging the weighing bucket gate, the "mined out stable value ckwz" signal can be established only after the empty letter is established, 30 finished products of the same type are taken as a batch number and the gate is closed in place after emptying; When the signal of "gob stable value ckwz" comes to pulse, the following results will be obtained:

(1) the current actual value is given to the empty stable value kwz

(2) there will be net material value, that is, full stable value MWZ empty stable value kwz= net material value

(3) the expected value xwz-bc is given to the upper. Its own characteristics affect the EPS polymerization process, and the expected value xwz-sc

(4) a cumulative value will appear after each emptying, that is:

net material value + initial cumulative value = final cumulative value

there is also a certain operational relationship between the above quantities:

last expected value xwz-sc + set value - net material value = this expected value xwz-bc

the expected value xwz BC residual vibration value yzz= control value

the control value that appears when changing the set value and residual vibration value, only when it meets the range of more than 70% and less than 130%, will this control value cover the last control value

when the reset signal r-ljz of the cumulative value comes to a pulse, clear the cumulative value to zero

therefore, for the above quantities, only the operator needs to change the set value, null value and residual vibration value to reasonably adjust the control value, so as to make the weight of the material loaded into the vibrating screen during vibration more reasonable, so as to achieve the accuracy of batching

4 conclusion

automatic compensation is adopted. The vibrating screen automatically prepares materials into the weighing bucket, and then loads them into the left and right ore buckets. The charging trolley can automatically add them into the furnace to meet the requirements of blast furnace production, so as to achieve all automatic purposes

author unit: Equipment Department of ironmaking workshop of Shandong Shiheng Special Steel Co., Ltd.

address: Equipment Department of ironmaking workshop of Shandong Shiheng Special Steel Co., Ltd. 271612


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