JP2000203719A - Scrap carrier system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make each scrap amount related to each brand high in accuracy by placing scrap of a brand having little influence on a molten metal component on a most subsequent rank, correcting charging expected weight planned at the beginning and carrying the expected weight. SOLUTION: Repeated scrap 4 is successively carried from a storing place for corresponding brand in a yard for one brand toward a bucket 16. Carrying amount to the bucket 16 for the brand is repeatedingly carried by making a scrap holding function of a lifting magnet 10 into a maximum state. Only when the last carrier for each brand is performed, voltage of the lifting magnet 10 is adjusted to voltage corresponding to weight of insufficient scrap and insufficient scrap is carried. As for scrap of the last brand, scrap of a brand having little influence on molten metal component is selected among plural kinds of brands. This scrap is placed on a most subsequent rank, and charging expected weight planned at the beginning for the scrap is corrected so that scrap within the bucket 16 may be weight corresponding to expected total weight and is carried.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large container used for selecting a plurality of brands of scrap stored in a yard and charging the bucket (the plurality of types of scrap to an arc furnace). A container called a bucket or a container called a hopper used for temporary storage, etc.).

[0002]

2. Description of the Related Art Conventionally, scraps supplied to an electric furnace (arc furnace) are prepared by selectively scraping a plurality of types of brands stored in a yard in an appropriate amount for each brand, with the intention of adjusting the composition. Is transferred to a bucket, and the inside of the bucket is made to have a predetermined total weight with scraps of a plurality of brands. As means in this case, a lifting magnet crane (also referred to as a rif mag in the present case).
This rif mag is also referred to as a lifting electromagnet as also known in JP-A-6-156969, and is used by being mounted on a crane. The rif mag can change the electric power by controlling the voltage or current and change the amount of adsorption.If the rif mag is composed of multiple magnet pieces, the result can be increased or decreased by increasing or decreasing the number of magnet pieces that supply power. The voltage or current with respect to the magnet piece is changed to increase or decrease the amount of adsorption), and the driver can select a plurality of brands from among various brands in the yard 1 shown in FIG. The scrap was selected, and the riff mag was repeatedly transferred for each of the scraps to be transferred, so that the inside of the bucket had the expected total weight.

[0003]

However, according to this conventional method, the scrap is weighed every time the scrap is transported by the rif mag, and the weight charged to the bucket is totaled.
Since it is also artificial, errors in the scrap weight for each brand due to the nature and function of the rifmag and errors due to human error occur. Due to this mistake,
An error occurs in the brand ratio in the bucket, and the molten metal component in the arc furnace becomes unexpected. In addition, there were problems such as an increase in material costs for adjusting the components and an inferior quality.

[0004] This point will be described in more detail. Brands and objectives that need to improve the accuracy of the weight to be conveyed are as follows. It is important that the scrap containing a large amount of expensive alloys (for example, chromium, molybdenum, etc.) adhere to the set weight. If the set value is not maintained, the use of an adjusting alloy (expensive) for obtaining a target component increases, which leads to an increase in cost. Compared to adjusting the composition with an alloy, adjusting with scrap can be adjusted at a lower cost. Example: Chromium molybdenum steel: Chromium component 0.90% <C
r <1.20% Normally, production is aimed at around 1.05%. It is preferable that scrap can cover Cr as much as possible (unless other problems occur). The shortage of components after melting the scrap is compensated for by an alloy additive (expensive). FeCr (ferrochrome)
Etc .: The component ratio of Cr is high. The following brands are problematic in the manufacture of products where the components of impurities are: Scraps that contain many components such as copper, tin, and phosphorus that are difficult or difficult to remove (materials to be removed by chemical reaction, processing time is required) require strict component values for products. If
It is necessary to observe the set weight of the scrap brand. If the set values are not maintained, a large amount of material is required for component adjustment (removing the corresponding component), or a product defect (when removal is not possible) occurs. Example: Spring steel P <0.035%, Cu <0.30% Unless the scrap composition does not exceed the above component values, it becomes difficult to make spring steel. (It takes time and cost to adjust the composition. Also, change to a product with a different standard (change of steel type) etc.) In addition, the brand for adjusting the weight is too low in specific gravity like new cutting (processing waste) and shredder. Scraps that are not small and have relatively stable components are often used for weight adjustment.

[0005] Further, if the scrap weight for each brand is to be made accurate in order to make the mixing ratio of the scraps strict, the transport efficiency by the rif mag deteriorates,
There is a problem that the whole work is delayed.

[0006] In addition, if the scrap in the bucket is not made to have a predetermined total weight, there is a problem in that a shortage of molten metal or a large amount of molten metal is required to produce a product, and unnecessary inventory increases.

[0007] The scrap transport system of the present application is provided to solve the above-mentioned problems of the prior art. The purpose of the present application is to selectively transfer the scraps of a plurality of brands stored in the yard to appropriate buckets for respective brands in an appropriate amount, and to make the inside of the bucket the planned total weight with the scraps of the brands. In this regard, it is an object of the present invention to provide a scrap transport system in which the amount of scraps related to individual brands is set to be higher for each. Another object is that even if the amount of scraps related to individual brands may be slightly different from each other in the process of the transfer, the planned total weight is adjusted with scraps of brands having little influence on the molten metal component. Such a scrap transport system is to be provided. Other objects and advantages will be more readily apparent from the drawings and the following description associated therewith.

[0008]

SUMMARY OF THE INVENTION A scrap transport system according to the present invention transfers scraps of a plurality of brands stored in a yard selectively to appropriate buckets for each brand, and transfers a plurality of types of scraps in the bucket. In the scrap transport system that makes the planned total weight of the scraps of the brands, the total weight of the scraps of the plurality of target brands to be charged into the bucket is the above-mentioned planned total weight, so that the scraps of the plurality of target brands are scrapped. For each of them, the expected loading weight is determined in advance, and in transferring the scrap of each brand, the amount of gripping the scrap changes the voltage or the current, so that the weight is changed in several stages or continuously and held. Using a riff mug with a function, buckets are sequentially stored for each brand from the storage location of each corresponding brand in the yard. The repetitive scrap is transported toward the bucket, and the transport amount of each brand to the bucket is set to the maximum state with the scrap holding function of the riff mag, and is repeatedly transported. The current is adjusted to the voltage or current corresponding to the weight of the missing scrap, and the missing scrap is transported.Furthermore, among the above-mentioned multiple kinds of brands, the scrap of the brand that has little effect on the molten metal component is ranked last. And the planned loading weight originally planned for the scrap
The scrap in the bucket is transported after being corrected so as to have a weight corresponding to the expected total weight.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. 1 to 4, reference numeral 1 denotes one yard (or a plurality of yards) for storing a well-known scrap 4, and scrap containing a large amount of components such as chromium and molybdenum, for example, brand A, copper , Tin, phosphorus, etc. Many kinds of scraps 4 such as brand B, other shapes, specific gravity, stability of components, etc. , 5, and 6 are stored separately. Reference numerals 2 and 3 indicate the presence of side walls provided as necessary and partition walls. Numeral 15 designates a transport carriage reciprocating between an arc furnace (not shown) and the vicinity of the yard, and is used in a known manner to transport a bucket 16 for receiving a plurality of types of scraps 4, 5, and 6. Reference numeral 10 denotes the above-mentioned riff mag, and the amount of gripping the scrap 4 changes the voltage, thereby obtaining a table 31 in FIG.
It shows a riff mag which has the function of changing and holding the weight in several steps or continuously like b. As this type of riff magnet, a lifting electromagnet of a type known in, for example, Japanese Patent Application Laid-Open No. 6-156969 may be used. The rif mag 10 is provided with a yard 1 and a bucket by a crane system controlled using a control device using a computer (not shown) (for example, known from FIGS. 1 and 3 of JP-A-9-323887). The scrap in the yard is conveyed to the bucket 16 by reciprocating along the trajectory of the arrow 11 between 16.

The transport of scrap using the control device will be described with reference to FIGS. Begin with the system 20 of FIG. First, the brand, the order of input, the weight, etc. of the scrap are read out from the table 22 to the system 21 based on the production plan (refer to the table of 22a for the contents of the plan, and more specifically, for example, as shown in the table of 22b of FIG. 4A). Do).
After that, the system 23, 24 and the system 27 of FIG.
Proceeding to 28, 29 and 32, the crane 33 is operated to move the scrap from the yard 1 to the bucket 16 in FIG. Immediately before or at the time of charging the bucket 16 with the scrap, the weight 34 is measured each time using the weighing device 35 and written in the table 25, and the charging result corresponding to the schedule table 22a is corresponded. Create in data 25a. In the system 36, the weight difference between the tables 22a and 25a is determined, and if the charging is not completed, the process returns to the determination system 28 and is repeated. In this way, one brand A is sequentially bucketed from the storage location of the corresponding brand in yard 1.
The repetitive scrap 4 is transported toward 16 and the amount of transport of the brand A to the bucket is set such that the scrap holding function of the rif mag 10 is in the maximum state (V1 level of the table 31a) and is repeatedly transported. Then, only at the time of the last transport of each brand, the voltage of the rif mag is adjusted to a voltage (for example, level 2 to 5) corresponding to the weight of the insufficient scrap, and the insufficient scrap is transported (for example, FIG. 4C).
If the paper is conveyed eight times, the maximum function is seven times
For 1,5 tons, adjust to the corresponding voltage and transport.) The determination as to whether or not each brand is the last transport is performed in the determination system 28, and the answer of "no" is stored in the table 31a in the table 31 (for example, specifically, FIG. 4B).
(Step 30) based on the stored data of the table in which the adsorption weight is changed in response to the voltage level change.
The corresponding voltage level is acquired, and the insufficient scrap is instructed and acquired by the system 32.

As described above, when one brand of scrap is left and the transport operation for brands A to C, for example, is completed, the process proceeds to the next discrimination system 37 (targeting brand D in FIG. 4D). ). Scrap D is one of the above brands,
A brand of scrap that has little effect on the molten metal component is selected. This scrap is placed in the rearmost rank so that the originally planned weight to be charged for the scrap (for example, 7 tons) is adjusted so that the scrap in the bucket has a weight corresponding to the expected total weight (for example, 40 tons). Correct and transport. These are returned to the system 23 of FIG. 2 via * A according to the judgment 37 in FIG. 3 and then to the correction system 26 in the judgment system 24, where, for example, 7 tons of the brand D in FIG. Modified to 6.5 tons and again *
After B, head to 'END' 38 as described above.

The example of FIG. 4 will be repeatedly described with reference to the flowcharts shown in FIGS. It is assumed that 40 tons of scrap are put in the bucket 16 of FIG. 4A, and the breakdown weight and charging order of scrap brands are as shown in Table 22b (corresponding to data 22, 22a). The table 31b in FIG. 4B shows the weight of scrap adsorbed corresponding to the voltage level of the rif mag 10 (corresponding to data 31a). 4B, 16b of brand A is obtained by repeating steps 28 and 29 of FIG. 3 to step 36 of FIG.
Carry at the maximum capacity of Rifmag seven times, and step one for the remaining one
After passing through 28 and 30, the capacity of the rif mag is limited to level 2 and carried, and the overall performance approaches the target value as shown in Table 37b (corresponding to tables 25 and 25a) in Fig. 4 (D). Is shown. The results of FIG. 4D are obtained for brands B and C in the same manner as described above. Fig. 4 (E) changes the initial target value of 7 tons for the last issue D to 6.5 tons (for system 26)
After carrying, carry the full capacity three times, and finally lower the Rifmag ability to level 5 and carry the total to the first 40.
Here is an example of approaching tons (for example, totaling 39.9 tons). The above embodiment shows an example in which the amount of gripping the scrap uses a riff mag having a function of changing the voltage in several steps or continuously by changing the voltage, but the scrap is changed by changing the current. Similar results can be obtained by using a riff mag having a function of changing the gripping amount.

[0013]

As described above, according to the present invention, scraps of a plurality of brands stored in a yard are selectively transferred to buckets in appropriate amounts for respective brands, and scraps of a plurality of brands are stored in the bucket. In order to make the planned total weight, scraps of individual brands are used in the process of repetitive transfer, except for the final transfer, which makes the best use of the rif mag's ability, so the transfer efficiency is increased. Finally, utilizing the performance of the refumag, even if the amount of scrap is slightly insufficient, the corresponding amount is transferred to the bucket by adjusting the voltage or current, and the corresponding brand scrap is loaded into the appropriate bucket. As a result, there is an effect that the scrap ratio of various brands in the bucket can be improved to a good value close to the plan.

[0014] In addition, even if there is a slight charging error in each of a plurality of brands of scrap, finally, a brand of scrap having little adverse effect on the molten metal component is selected and assigned, and the weight is also corrected and adjusted. Therefore, not only can a correct amount of scrap corresponding to the expected total weight be loaded into the bucket, but also there is no adverse effect on the molten metal component, and this is effective in producing high quality molten metal.

[Brief description of the drawings]

FIG. 1 is a front view showing a relationship between a yard, a rif mag, and a bucket.

FIG. 2 is a flowchart showing a process of setting the brand and weight of a loaded scrap from the start of scrap transport to a bucket.

FIG. 3 is a flow chart connected at points marked * A, * B, and * C, and shows a process leading to the completion of bucket loading.

FIG. 4 is a corresponding numerical diagram of data showing a specific example of the data shown in FIGS. 2 and 3;

[Explanation of symbols]

 1 Yard 2 Side wall 3 Partition wall 4 Scrap 5 Scrap 6 Scrap 10 Rif mag 11 Reciprocating trajectory 15 Transport cart 16 bucket

Claims (1)

[Claims] 1. A scrap of a plurality of brands stored in a yard is selectively transferred to a bucket in an appropriate amount for each brand, and a scrap of the plurality of brands in the bucket is adjusted to a predetermined total weight. In the transport system, the planned loading weight is previously determined for each of the plurality of target brand scraps so that the total weight of the plurality of target brand scraps loaded into the bucket becomes the above-mentioned planned total weight. In transferring the scraps of each brand, the amount of gripping the scraps is changed by changing the voltage or current, so that the weight of the scraps can be changed in several stages or continuously using a rifmag which has the function of holding the weight. Sequential scrap is transported from the storage location of each corresponding brand in the yard to the bucket, and the bucket for each brand The amount of transport to the unit is maximized with the scrap retaining function of the rif mag, and repeatedly transported,
Only during the last transport of each brand, the voltage or current of the above-mentioned rif mag is adjusted to the voltage or current corresponding to the weight of the lacking scrap, and the lacking scrap is transported. For scraps of brands that have little effect on the scrap, it is placed in the last place, and the planned loading weight originally planned for that scrap is corrected so that the scrap in the bucket has the weight corresponding to the planned total weight and transported And a scrap transport system.