JPS5910418B2 - How to charge raw materials into sintering machine pallets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a means for charging raw materials in a mobile sintering machine, such as a Dwight Lloyd type sintering machine. This invention relates to automatic control of the charging density of raw materials in the longitudinal direction.

The progress of the sintering reaction in the sintering machine depends on the combustion speed of the coke pleat distributed in the appropriate amount in the sintering raw material, and also on the amount of combustion air supplied to each point of the raw material in the pallet. Therefore, in order to obtain sintered ore of uniform quality, the permeability of the charged raw material against the downward draft from the sintering machine blower must be uniform across the width and length of the pallet. This is an important requirement for sintering, and it also leads to effective use of the sintering machine's capacity and improving its productivity.

The air permeability of this raw material for sintering is influenced by the height of the ore layer, the amount of raw material charged per unit area of the pallet, that is, the charging density, the moisture content of the raw material, the average particle size, and many other factors. Each of these will need to be managed.

Among these factors, the amount of raw material charged per unit area of the pallet, that is, the charging density, has conventionally been calculated from the total amount of raw material cut out of each raw material tank in one day and the average pallet speed. It was determined by calculation from the total area of pallets, and was only used as a guideline for productivity.

Therefore, attempts to stabilize quality by knowing this charging density and controlling it have not been done in the past.

However, variations in the thickness of the ore layer of the sintered raw material charged into the pallet over time lead to quality deterioration and a decrease in yield, so there are no measures to reduce the variation in the layer thickness. Proposed.

For example, as seen in Japanese Patent Publication No. 49-49081, there is a method in which the layer thickness of the charged raw material is detected using a layer thickness meter, and the gate opening of the drum feeder is controlled so that this becomes the set value. However, it is difficult to guarantee uniformity over the entire surface of the pallet using only a layer thickness meter, and even if the layer thickness is made uniform, the filling condition will vary depending on the particle size of the raw material, the moisture content, etc.9, and therefore the air permeability It is difficult to guarantee uniformity.

It was also discovered that the amount of raw material cut out by the surge hopper eli drum feeder over time is greatly influenced by the ore storage level in the key hopper, and by supporting the surge hopper with a known load cell, etc., the total amount of material in the surge hopper can be made uniform. A method for controlling the amount of raw material transported to the surge hopper has also been proposed (Japanese Patent Laid-Open No. 51-151606).
issue).

However, the amount of raw material cut out from the drum feeder is determined by the fact that the ore storage level in the surge hopper is constant, and even if the drum feeder speed and drum feeder gate opening are constant, the raw material for sintering is in the form of fine powder containing considerable moisture. For something,
It is difficult to achieve consistency due to factors such as rough stones adhering to the gate and changes in the cutting speed, and in order to achieve consistency, constant monitoring of the drum feeder gate and frequent cleaning of the gate are required, which requires a lot of labor and effort. The burden of time is on the dog.

This invention solves the above-mentioned problems in charging sintered raw materials into pallets, and by keeping the raw material charging density constant, it improves the quality, yield, and productivity of sintered ore, and saves labor. Therefore, its feature is that when charging the sintering raw material from the raw material cutting device to the pallet, the amount of raw material transported to the raw material cutting device,
The raw material weight change and average pallet speed in the original size cutting device are measured and sent to the computer, which calculates the density,
Hj: Height of raw material layer in pallet, L: Pallet width, V: Pallet speed, WT: Weight of raw material in raw material cutting device at time T, ■T+△r: Weight of raw material in raw material cutting device at time T+ΔT, ωΔT: Unit time The weight of the raw material supplied to the raw material cutting device within ΔT is calculated, and the calculated value is determined based on the deviation from a predetermined charging density setting value, and the drum feeder speed or drum, which is a factor that changes the cutting amount, is calculated. The feeder gate opening degree is automatically controlled to keep the density of raw materials charged into the pallet constant.

The present invention will be described in detail below based on the illustrated embodiments. Fig. 1 shows one example of a sintering machine for carrying out the present invention, and as shown in the figure, the raw material for sintering is The raw material ore is stored in the raw material tank 1 and cut out at a predetermined ratio.
After measuring the cut-out amount, the raw material is conveyed to a drum mixer 4 by a belt conveyor 3, and the moisture content is adjusted to an appropriate level in the drum mixer 4, and the fine powder in the raw material does not impair the air permeability within the pallet. They are turned into pseudo-particles to a certain degree.

The sintered raw materials processed and mixed uniformly in this way exit the mixer 4 and are temporarily stored in the surge hopper 6 supported by the load cell 7 for measuring the weight of the hopper by the belt conveyor 5. The drum feeder gate 9 is opened by the drum feeder 8 provided at the bottom.
The material is charged into a pallet 11 through a sloping plate 10, and under downward ventilation from a wind box 12, the coke pleat in the raw material is ignited by an ignition furnace 13, and as the coke breeze burns, it is charged into a pallet 11. As the sintering reaction progresses, the charging density of the sintered stubs loaded into the pallet 11 at this time is expressed by the following equation.

1 However, each character in the above formula is as described above.

In the present invention, the value of D in the arithmetic expression is controlled by a control method as exemplified in the flow sheet diagram of FIG.

That is, in FIG. 2, the total value measured by the cut-out amount weighers 2 and 2 shown in FIG. 1 is sent to the bulk density calculator shown in FIG. Considering the time difference between the input of the surge hopper 6 and the belt speed, it is given as ωΔT, and the weight of the surge hopper 60 is given as WT, WT + △ via the output of the load cell 7.
The value calculated by this bulk density calculator is calculated by giving the pallet speed V1, the width L of the pallet 11 (constant value), and the height of the raw material layer in the pallet 11 (set value) H, respectively, from the pallet drive device. is sent to the bulk density regulator.The output corresponding to the deviation from the bulk density setting value given to this regulator in advance is sent to the multiplier and inputted to the drum feeder speed controller to control the same. The drum feeder speed is changed through the drum feeder.

When the sintering conditions in the sintering machine are changed significantly, the speed of the sintering machine is changed through a multiplier, as shown by the broken line.

It goes without saying that the object to be controlled in order to keep the charging density D constant may be the drum feeder gate opening instead of the drum feeder speed.

1. When measuring each of the above-mentioned values, the amount of raw material cut out was measured at 20 second intervals, the load cell 7 of the surge press 6 was measured at 1 second intervals, and the sintering machine speed was measured at 1 second intervals. As for the effectiveness of the load cell 7 in the surge hopper 6, the accuracy of the load cell 7 is 0.

2% and the capacity of the surge hopper 6 is 80T, the detection accuracy is about 160 kg.
The amount of cutting out of the machining (the amount of medium material carried in) is about 30T, so it is clear that the accuracy of the load cell 7 can be used effectively.

The present invention is as described above, and by making the charging density constant in the hosopa 6, the density of charging raw materials into the pallet 11 can be increased without being affected by surge hopper level bed drum feeder gate clogging, etc. can be kept constant at all times, making the operation of the sintering machine extremely stable.
Significant effects can be expected, such as significantly reducing the variation in quality of sintered products and improving product yield, and it is excellent as a solution to conventional problems.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an example of a sintering machine implementing the present invention, and FIG. 2 is a flow sheet diagram of the control means in the method of the present invention. 1... Raw material tank, 2... Weigher, 3, 5... Belt conveyor, 4... Drum mixer, 6... Surge hopper, I... Load cell, 8... Drum feeder, 9
...Drum feeder gate, 11...Pallet.

Claims (1)

[Scope of Claims] 1. When the sintering raw material is charged from the raw material cutting device to the pallet, the amount of raw material conveyed to the raw material cutting device and the amount of change in the weight of raw material in the raw material cutting device are measured at fixed time intervals. and the average pallet speed is measured and sent to the computer, and the computer calculates the following: weight of raw material WT + △r; weight of raw material in the raw material cutting device at time T + ΔT; weight of raw material supplied to the raw material cutting device within unit time ΔT), and the calculated value is used to determine the predetermined charging rate. Sintering characterized by automatically controlling the drum feeder speed or drum feeder gate opening degree, which is a factor that changes the cutting amount, based on the deviation from the density setting value, to keep the density of raw materials charged into the pallet constant. How to charge raw materials into machine pallets.