JP3282694B2 - Powder quantitative feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for quantitatively supplying powder, and more particularly to an apparatus for quantitatively supplying a dry powdery raw material to a smelting furnace.

[0002]

2. Description of the Related Art A preferred example of a method for quantitatively supplying a powder is a method for supplying a powdery raw material to a smelting furnace such as a flash smelting furnace. The flash smelting furnace is basically composed of a reaction tower, a settler and a flue gas. A concentrate burner is provided at the top of the reaction tower, and so-called dry ore and auxiliary fuel are blown into the flash smelting furnace through the concentrate burner together with a reaction gas to cause a smelting reaction in the reaction tower. Has produced a dignified mat. Hereinafter, a method of quantitatively supplying powder will be described by taking an example of a method of supplying dry ore to a flash smelting furnace.

[0003] The composition of sulfide concentrate depends on the type of ore used as a raw material, that is, the brand. Therefore, if a large number of brand products of a specific composition can be secured stably, it is not so desirable in operation. However, in reality, it is difficult to stably secure a large number of specific issues. For this reason,
It is usual to mix various brands of sulfide concentrate and supply them to the flash smelting furnace.

[0004] These sulfide concentrates and fluxes are usually wet and cannot be supplied to the flash smelting furnace as they are. This is because bringing moisture into the flash furnace causes not only energy loss such as removal of latent heat of evaporation, but also various obstacles. For this reason, after mixing the sulfide concentrate and the flux, the mine is dried to a moisture content of about 0.3% by using, for example, a rotary drier and a flash drying device to obtain dry ore. After that, it is dropped and supplied to the concentrate chute of the concentrate burner provided at the top of the flash smelting reactor. The dry mine is blown into the flash smelting furnace from the concentrate burner together with the auxiliary fuel and the reaction gas.

[0005] In order to supply dry ore quantitatively to the flash smelting furnace,
Normally, dry ore is temporarily stored in a drying cabinet located above the flash smelting furnace.
Then, it is cut out from the dry pit by a chain conveyor and supplied to the flash smelting furnace through a chute. In the dry ore supplied to the flash smelting furnace, the moisture content is 0.1% as described above.
It is as low as 3%. In addition, its average particle size is as small as 50 μm,
Dry ore is extremely easy to flush. For this reason, a damper for preventing flashing is provided above the chain conveyor at the outlet of the dry pit.

A damper for adjusting the thickness of the ore layer is provided below the damper for preventing the flushing so as to make it easy to control the amount of dry ore that is cut out while keeping the thickness of the dry ore on the chain conveyor constant. ing. Then, the moving speed of the chain conveyor is controlled to obtain a desired cutout amount. The moving speed of the chain conveyor was determined based on the instantaneous flow rate (t / h) obtained by the impact line flow meter provided in the concentrate chute, or from the raw materials supplied to the rotary dryer and changes in the contents of the dry pit. It is controlled based on the amount of dry ore charge.

[0007] However, in the former method, the falling dry mine adheres to the detection terminal of the impact line flow meter, and the accuracy is easily deteriorated. In the latter method, the measurement error of the supply amount of the wet raw material and the inside of the dry mine warehouse are reduced. The accuracy is poor due to the sudden collapse of the cargo and the effect of shelving. In addition, concentrates have different densities and bulk densities for each brand, and even within the same brand, the bulk density varies depending on the composition. Therefore, the bulk density of the dry ore, which is a mixture for each brand, constantly fluctuates and does not become a constant value. For this reason, it was difficult to control the quantitative supply of dry ore with high accuracy. Therefore, the ratio between the dry mine and the reaction gas is not always stable, and it has been difficult to maintain a good operating state for a long time.

The problems in the quantitative supply of powder have been described above by taking the supply of dry ore to a flash smelting furnace as an example, but such disadvantages are inevitably involved in the quantitative supply of powder. ,
It is not limited to the case where the supplied material is dry mine.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixed-quantity supply apparatus capable of keeping a constant supply amount.

[0010]

An apparatus according to the present invention for solving the above-mentioned problems basically comprises a storage tank, a cutting conveyor, a layer thickness adjusting damper, and a radiographic densitometer.
A cutting conveyor is provided at the lower part of the storage tank, and a layer thickness adjustment damper is provided above the cutting conveyor near the outlet of the storage tank. Is attached. In this apparatus, a flushing prevention damper is provided between the storage tank outlet and the layer thickness adjustment damper as necessary. The bulk density obtained by the radiation transmission type densitometer is input to a drive motor controller of the cut-out conveyor, and the number of revolutions of the cut-out conveyor is controlled according to the input value.

[0011]

Since the accuracy of measuring or estimating the supply amount of powder is poor, it is necessary to consider the quantitativeness of the supply equipment from a different viewpoint in order to stabilize the supply amount.
The present invention has been made from this viewpoint. That is,
The thickness of the powder on the cut-out conveyor after passing through the layer thickness adjusting damper is constant, and the powder amount per unit length of the conveyor can be obtained as long as an accurate bulk density can be obtained. In the present invention, a radiation transmission density meter is used as a means for measuring the bulk density. This is because a densitometer of this type is non-contact, non-destructive, highly accurate and can measure continuously.

When the powder has an extremely low moisture content such as the dry ore and has a possibility of causing fine flushing, a flushing prevention damper is provided in the storage tank to prevent the powder from being flushed. Provided between the outlet and the layer thickness adjustment damper. In this case, generally, the distance between the tip of the flushing prevention damper and the upper surface of the conveyor is equal to the distance between the tip of the layer thickness adjusting damper and the upper surface of the cut-out conveyor (that is, equal to the layer thickness of the powder), or the flushing is made longer by about 10 mm. Install prevention dampers.

[0013]

Next, an embodiment of the present invention will be described.

(Embodiment 1) FIG. 1 is a sectional view of a main part of the present supply apparatus, in which the supply apparatus of the present invention is used for supplying dry ore to a flash smelting furnace. This supply device is provided with a chain conveyor 2 as a cut-out conveyor at a lower part of a dry mine 1 which is a storage tank, and an outlet side of the dry mine 1 and above the chain conveyor 2 for preventing flashing of the dry mine 3. A flashing prevention damper 4 and an ore layer damper 5 for controlling the thickness of the dry ore 3 layer on the chain conveyor 2 are provided. On the lower side of the ore layer tamper 5, a detection unit 6 is provided above the dry ore 3, and this detection unit is provided. 6, a radiation source 8 is provided below the middle partition plate 7 of the chain conveyor 2. The radiation transmission type densitometer 9 includes the detection unit 6 and the radiation source 8. Calculation of the supply amount by this device is as follows.

The rectangular area formed by the casing 10, the middle partition plate 7, and the tip of the mineral layer damper 5 of the chain conveyor 2 is S (m ² ), and the moving speed of the chain conveyor 2 is V (m / h). , The bulk density of the three layers of dry ore is ρ (t /
m ³ ), the cutout amount W by the chain conveyor
(T / h) can be obtained by the following equation (1).

[0016]

W = S × V × ρ As can be seen from Equation 1, when the position of the mineral damper is fixed, S becomes constant. Then, when the chain conveyor moving speed, specifically, the rotation speed of the chain conveyor driving motor is set to a constant value, V also becomes constant. However, as described above, the bulk specific gravity ρ of the dry deposit on the chain conveyor changes constantly and is not constant. Therefore, in order to keep W constant, it is necessary to know the bulk density ρ that changes every moment, and to change V accordingly. In the apparatus according to the present invention, a radiation transmission type densitometer is used as a measuring device for the bulk density ρ, thereby enabling accurate measurement of the bulk density ρ that changes every moment.

The specific operation mechanism of this device is as follows. First, the set value W ₀ defined from relationships such as heat balance and mass balance, the V ₀ from the number 1 with an S obtained by calculation from the position of the ore bed damper and assumptions [rho ₀ determined, chain conveyor The supply speed is manually set to V ₀ and the supply is started manually. After that, when the control is switched to the automatic control, the output (corresponding to ρ _n ) sequentially obtained by the radiation transmission type densitometer is input to an arithmetic circuit (not shown), and the output value (corresponding to V _n ) is obtained according to Equation 1. Is required). The output value is output from the arithmetic circuit to a rotation control circuit (not shown) of the driving motor for the chain conveyor, and the rotation speed of the driving motor changes according to the output value, and the moving speed of the chain conveyor changes. As a result, the supply amount W is always adjusted to the set value W ₀ is maintained.

(Embodiment 2) FIG. 2 shows another embodiment of the apparatus according to the present invention, in which a radiation source 8 and a detection unit 6 are provided in the lateral direction of the chain conveyor 2. The method of using this device is the same as that of the first embodiment, and a detailed description thereof will be omitted.

The mounting positions of the detector 6 and the radiation source 8 of the radiation transmission type densitometer 9 are not limited to those of the first and second embodiments, and the cut-out conveyor is not limited to the chain conveyor.

[0020]

According to the apparatus of the present invention, since the change in the bulk density ρ of the powder layer on the cutting-out conveyor can be quickly and accurately known, the control accuracy of the powder supply amount can be greatly increased. . If this equipment is used to supply dry ore to a smelting furnace, the operating conditions of the smelting furnace (blowing amount, fuel amount) can be changed in response to the change in dry ore supply, thereby stabilizing the operating condition. It is easy to maintain.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of the present supply apparatus, in which a supply apparatus of the present invention is used for supplying dry ore to a flash smelting furnace.

FIG. 2 shows another embodiment of the device of the present invention.

[Explanation of symbols]

 1 ---- Dry ore warehouse 2--Chain conveyor 3--Dry ore 4--Damper to prevent flashing 5--Ore stratum damper 6 ---- Detection unit 7 ---- Partition plate 8 ---- Radiation Source 9 --- Radiation transmission densitometer 10--Casing

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-51-29959 (JP, A) JP-A-63-182716 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01G 13 / G01G 11 /

Claims (2)

(57) [Claims] 1. A storage tank for storing powder, a cutting-out conveyor for carrying out the powder from the storage tank, a layer thickness adjusting damper for keeping a layer thickness of the powder on the cutting-out conveyor constant,
Determination of powder basically consisting of an anti-shinging damper and a radiographic densitometer that measures the bulk density of the powder layer
It is a quantity supply device, a cutting conveyor is provided at the lower part of the storage tank, a layer thickness adjustment damper is provided above the cutting conveyor near the outlet of the storage tank , and a storage tank outlet is provided.
A flashing prevention damper between the layer thickness adjustment damper
A quantitative powder supply apparatus, wherein a radiation transmission type densitometer is provided at a position where the bulk density of the powder can be measured after the layer thickness adjusting damper. 2. The apparatus for quantitatively supplying powder according to claim 1, wherein the number of revolutions of the drive motor of the cutting-out conveyor is controlled based on the output of the radiation transmission type densitometer.