JP2728590B2 - Raw material feeder for closed furnace - 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 automatically charging a predetermined amount of a raw material into a closed furnace such as an atmosphere furnace used for metallurgy.

[0002]

2. Description of the Related Art In magnesium smelting by the magnetotherm method, tantalum smelting by the sodium reduction method, or smelting of rare earth elements by the electrolytic method, etc., since the reduced metal has a strong affinity for oxygen, it is required to use an inert gas atmosphere. Operation is performed. As a furnace (or called a reaction vessel) used for smelting, a closed furnace is used to shut off the inside from the atmosphere. Raw materials required for smelting must be supplied continuously or intermittently as the reduction reaction proceeds. Conventionally, when supplying raw materials to such a closed furnace, work is performed to release the sealing of the temporary furnace at the time of supplying the raw materials, to finish supplying a predetermined amount of raw materials as soon as possible, and to restore the sealing. Alternatively, a necessary amount of raw material is previously stored in a large-capacity closed raw material tank integrally connected to a furnace, and a means for cutting and reacting the raw material in small amounts is adopted (Japanese Patent Application Laid-Open Nos. 50-96413 and 6-164).
1-87888).

[0003]

It is not preferable to break the cutoff with the atmosphere during the reduction operation because it causes intrusion of oxygen, oxidation of the produced metal, and oxidative consumption of the furnace structure. Also,
Providing an airtight large-capacity raw material hopper is disadvantageous in terms of equipment cost, and the production volume of one batch is naturally limited. Performing the manual operation while controlling the atmosphere, such as the conventional weighing operation, the charging operation to the raw material hopper, and the raw material charging operation into the furnace as in the related art, is inefficient and disadvantageous in terms of cost. In addition, there is a problem that the raw material may not be cut out smoothly due to pressure fluctuations in the furnace, and when a powder raw material is used, trouble frequently occurs.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide an apparatus for feeding a required amount of raw materials at predetermined intervals while maintaining the airtightness of a closed furnace. The apparatus of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram for explaining a main configuration of the present invention. In FIG. 1, 1 is a weighing hopper, and 2 is a charging hopper. The weighing hopper 1 is mounted on the load cell 3 via a frame 9 so that the weight of the raw material (not shown) stored in the weighing hopper 1 can be measured from time to time.

The weighing hopper 1 is provided with a raw material receiving hatch 8 and a fixed amount feeder 4 for discharging the raw material.
The fixed-quantity feeder 4 sends out the raw material in the weighing hopper 1 at a fixed rate or a predetermined amount to the charging hopper 2. The quantitative feeder is not particularly limited as long as it is a rotary feeder, a screw feeder, a vibration feeder, or the like. Depending on the weighing range, load cell 3
Therefore, the accuracy of the fixed-quantity feeder 4 does not need to be very high. Usually measurement range 0-5
Those having a size of about 00 kg and a minimum scale of about 10 g are used. A gate valve 5 is connected to the fixed-quantity feeder 4. The gate valve 5 is for preventing the raw material spilled after the fixed-quantity feeder 4 is stopped from being measured as a weight loss.

A gate valve 6 and a gate valve 7 are provided in the charging hopper 2, and when the raw material is received from the measuring hopper or when the raw material is supplied into the furnace, the inside of the furnace is shut off from the atmosphere to maintain airtightness. It is. The gate valve 6 and the gate valve 5 are connected by a flexible tube 11. Since the flexible tube 11 connects the weighing hopper on the load cell and the fixed-type charging hopper, it is preferable that a flexible material be used. If a hard material is used, accurate measurement cannot be performed. Usually cloth,
Rubber or the like is used.

After closing the gate valves 5, 6 and 7 to shut off the inside of the furnace and the raw material charging device, the raw material is supplied to the measuring hopper 1 from the raw material receiving hatch 8. Next, after the gate valves 5 and 6 are opened, a predetermined amount of the raw material is cut out to the charging hopper 2 using the fixed amount feeder 4, and then the gate valves 5 and 6 are closed. After the inside of the charging hopper 2 is replaced with an inert gas (usually argon gas is used), the gate valve 7 is opened when the temperature reaches a predetermined time or the furnace temperature, and the raw material in the charging hopper 2 is reduced. It is charged into a reaction vessel (not shown). After charging the raw materials into the reaction vessel, the gate valve 7
Is closed to start weighing the next raw material. Usually, raw materials are replenished intermittently at a fixed rate.

In this type of reduction furnace, it is necessary to keep the inside of the furnace in a non-oxidizing atmosphere. Therefore, in the apparatus of the present invention, a gate valve 7 is provided between the inside of the reduction furnace and the charging hopper 2 to prevent the invasion of the atmosphere. When charging the raw material from the charging hopper 2 into the reduction furnace, it is necessary to make the internal pressures of the charging hopper 2 and the reducing furnace substantially equal. If the pressure fluctuation acts on the weighing hopper 1, an error occurs in the detected weight of the load cell.
A gate valve 6 is provided so that the pressure in the charging hopper 2 can be adjusted. The inside of the measuring hopper 1 is at the atmospheric pressure, while the inside of the charging hopper 2 is at the atmospheric pressure when the raw material is supplied from the measuring hopper to the charging hopper, and the same as in the furnace when the raw material is charged from the charging hopper into the reduction furnace. You have to pressure. Therefore, as shown in FIG. 2, the gas holder and the gas pipe are connected via the control valve.

When the raw material is supplied from the measuring hopper 1 to the charging hopper 2, the control valve 12 connected to the charging hopper 2 is opened to make the pressure in the charging hopper 2 atmospheric.
When replacing the inside of the charging hopper 2 with the inert gas, the control valves 12 and 13 are opened. When charging the raw material from the charging hopper 2 into the reduction furnace, the control valves 12 and 13 are closed and the control valve 14 is opened. Since the pressure in the gas holder 16 is adjusted to be substantially equal to the pressure in the reduction furnace, the pressure in the charging hopper 2 and the pressure in the reduction furnace are substantially equal. The gas holder 16 is provided with a gas introduction pipe 20 for replenishing inert gas. The inside of the reduction furnace is usually operated at a pressure slightly higher than the atmospheric pressure. The magnetotherm method operates under reduced pressure. In such a case, the gas discharge pipe 17 may be connected to an exhaust pump, or the pressure in the gas holder 16 may be reduced by using the gas introduction pipe 20.

When the present apparatus is applied to an actual reduction furnace,
As shown in FIG. 3, it is convenient to install the camera on a pedestal movable vertically and horizontally. As the vertical mechanism 21 shown in FIG. 3, for example, a hydraulic jack or a screw jack can be used. Also,
In FIG. 3, reference numeral 22 denotes wheels, which may move on rails. By mounting the apparatus on a gantry as shown in FIG. 3, it is possible to supply raw materials without hindering other furnace operation.

[0011]

According to the present invention, a weighing hopper and an airtight charging hopper are provided, and both hoppers are connected by a quantitative hopper and a gate valve so that the raw material can be supplied to the furnace while preventing air from entering the furnace. did.

[0012]

According to the present invention, the raw material can be charged into the closed furnace by remote control or automatic operation while maintaining the airtightness of the furnace.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main configuration of the present invention.

FIG. 2 is a diagram showing a means for pressure adjustment.

FIG. 3 is a diagram showing a mode in which the apparatus of the present invention is mounted on a gantry.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 weighing hopper 2 charging hopper 3 load cell 4 fixed-quantity feeder 5 gate valve 6 gate valve 7 gate valve 8 hatch 9 frame 10 gantry 11 flexible tube 12 control valve 13 control valve 14 control valve 15 control valve 16 gas holder 17 gas discharge pipe Reference Signs List 18 gas introduction pipe 19 gas introduction pipe 20 gas introduction pipe 21 vertical mechanism 22 wheels 23 rail 30 raw material container 31 gate valve 32 hatch 40 response vessel

Claims (5)

(57) [Claims] 1. A weighing hopper and a confidential charging hopper are provided. The weighing hopper is supported on a load cell.
The fixed-quantity feeder is connected to a charging hopper via a flexible tube, and gate valves are arranged on the raw material inlet side and the discharge side of the charging hopper so that confidentiality in the furnace can be maintained. A raw material charging device for a closed furnace, wherein the raw material charging device is configured as follows. 2. The raw material charging device for a closed furnace according to claim 1, wherein the charging hopper is provided with an internal pressure compensating device comprising a gas holder and a control valve. 3. The material feeder for a closed furnace according to claim 1, wherein the fixed-quantity feeder is a rotary feeder. 4. The raw material charging apparatus for a closed furnace according to claim 1, further comprising a confidential gate valve on the discharge side of the charging hopper. 5. A raw material charging apparatus for a closed furnace, wherein the raw material charging apparatus for a closed furnace according to claim 1 is mounted on a pedestal having wheels and capable of moving up and down.