JPS63173934A - Quantitative reduction of primary specimen - Google Patents

Abstract

PURPOSE:To accurately collect a primary sample within a short time, by such a simple mechanism that the wt. of the primary specimen reduced by drawing out said specimen by a feeder is continuously weighed by a weighing machine and a cutter is driven at each time when predetermined quantity is reduced. CONSTITUTION:The primary specimen sampled by a primary sampling apparatus is fed by a conveyor 9 to be charged in a hopper 1 and, after the charging of the specimen is finished, the net wt. M kg of the primary specimen is inputted to an operator 14 from a weighing machine 4. This operator 14 operates M/n kg on the basis of the cutting number (n) set by a cutting number setting device 13 and subsequently generates a random wt. value within a range of 0-M/n kg. after the completion of this operation, a belt feeder 2 is started and the wt. of the specimen is reduced by the random value after a predetermined time to transmit the cutting start signal of the first cutting and a cutter 6 is operated to sample the specimen of the first cutting. From the second cutting, the cutting start signal is outputted each time when M/n kg is reduced to operate the cutter 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a quantitative reduction method for a primary sample in a sample preparation facility for a powder mixture of coal, ore, etc.

[Conventional technology]

As a conventional technique, there is a quantitative reduction method in a sample preparation facility described in Japanese Patent Application Laid-Open No. 58-24834. This conventional method involves weighing the primary sample using a vibrating feeder equipped with a weighing device, setting the amount of secondary sample to be collected each time and the number of sampling times using a setting device, and inputting these values into a calculator to calculate the amount of divided sampling each time. The discharge amount is calculated each time, and the condensing machine and feeder are operated according to the signal, and each time the vibrating feeder discharges the divided sampling amount, this vibratory feeder is stopped, and the switching damper type condensing machine calculates the divided sampling amount each time. This method collects a sample into a sample collection box.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, there is a problem in that the reduction operation takes too much time because it is necessary to stop the vibrating feeder each time the discharge amount is discharged and each time the divided collection amount is discharged.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a reduction method for collecting an accurate primary sample in a short time using a simple mechanism.

(Means for Solving the Problems) In order to solve the above problems, the present invention uses a belt feeder equipped with a weighing machine, and after weighing the entire weight of the primary sample, the belt feeder pulls out the primary sample. At the same time, the weight loss of the primary sample is continuously weighed by the weighing machine, and the
The value obtained by dividing the total amount of the next sample by the number of cuts is set as the sample cutting interval, and every time the amount of the sample decreases by this value, the counter is operated to cut the second sample, and the first cut is the value of the cut interval. It starts randomly within a range.

〔Example〕

FIG. 1 shows an example of an apparatus for carrying out the method of this invention.

In this figure, 1 is a hopper, 2 is a belt feeder below the hopper, 3 is a surface structure that supports the hopper 1 and the feeder 2, and this surface structure 3 is suspended by a weighing device 4 such as a load cell.

5 is a chute at the lower end of the belt feeder 2, 6 is a chute-shaped cutter below the chute, and 7 is a driving portion thereof.

A container 8 for receiving the sample taken by the cutter 6 and a belt conveyor 10 for carrying out the rejected sample are provided below the cutter 6.

In addition, FIG. 12 shows the scale 1i! ! 1 a control device, 13 a cut number setting device, 14 a calculator, 15 a cutter control device, 1
6 is a feeder control device.

In the above apparatus, a primary sample collected by a primary sampling device (not shown) is conveyed by a conveyor 9 and placed into a hopper 1. At this time, since the belt feeder 2 is stopped, the sample fed from the conveyor 9 is stored in the hopper 1.

When the completion of loading the sample into the hopper 1 is detected by some means, the detection signal is input to the weighing machine 4 as a primary sample weighing command signal as shown in FIG. The weight of the primary sample including the hopper 1 and the feeder 2, which are known in advance, is subtracted by taring, and the net weight Mkg of the primary sample is input to the calculator 14.

Since the number of cuts n set by the cut number setting device 13 is stored in this calculator 14, M/n kg is calculated by this calculator 14, and then Okt=M/
Generate random weight values in the range n kg.

As shown in the block diagram of Fig. 2, the random generation mechanism consists of a preset counter 18 that repeats counting in the range of 0 to 99, and a pulse generator 19 (usually about 60m5/1 pulse). This pulse is input to the preset counter 18 to repeatedly count from 0 to 99. That is, when the count reaches 99, it is reset to 0 by a reset signal and the above process is repeated from 0 again, but the counting time for one cycle from 0 to 99 is about 60 m5 x 100-6 seconds.

This 0-99 count signal is always input to the AND circuit 20, and the primary sample weighing command signal is also input to the AND circuit 20.
At the same time as the next sample weighing command signal is input to the weighing machine 4,
This signal is also input to the AND circuit 20, and the count value (referred to as m) between 0 and 99 input at that time is stored in the random numerical value memory 21.

A random weight value (referred to as MRan) can be calculated using the following formula using the above value of m, the set number of cuts n, and the weighed value Mk1.

When the above calculation is completed, assuming the counter value is m-40, the belt feeder 2 is started and after the timer (from the time when the feeder is started until the sample falls, the cutter moves from the stroke end to the stroke center) After the time subtracted)
When the amount is reduced by the random value MRan calculated above, a cutter activation signal for the first cut is transmitted, the cutter is operated, and a sample for the first cut is collected. From the second cut,
Every time MZnkg is reduced, a cutter activation signal is issued and the cutter is activated. Kaftaro performs kafta n times until the weighing value of the weighing machine 4 reaches Okg. When the weighing value reaches Okg, the feeder 2 is stopped and the feeder 2 waits for the next primary sample to be input.

By the above method, the first cut is within the sampling interval (0 to
Collect any part of the layer length of the primary sample drawn by the belt feeder by starting randomly at M/nkIr) and operating the second force transfer at constant sampling intervals (M/n kg). Have a chance.

In order to ensure that the cycle of the preset counter (6 seconds in the above example) and the cycle of the weighing command signal of the primary sample match and randomness is not lost, when the cutter start signal for the first counter is issued, the current count value of the preset counter 18 is Regardless of the value, send a reset signal to the counter 18 as shown in Figure 2 a.
Make sure to clear it. Of course, the value stored in the random memory 21 also returns to 0. The cutter 6 is stopped at the stroke end as shown by the chain line or solid line in FIG. The sample inside becomes the reduced sample. Collection of 1 cut l S kg
is the pull-out amount Q kg/S of the belt feeder 2, the cutter width Ass, the canter speed Vsm/5ecS:= □ ■ Figure 3 shows the length of the layer drawn by the belt feeder 2, and the thickness of the layer is determined by the gate 11. The shaded area in Figure 0, which is a constant layer, indicates the area to be collected using a canter as a reduction sample. The first cut is made at random from 0 to M/n kg stored in the random numerical value memory 21, and the second cut is made at intervals of M/n kg.

It should be noted that the present invention can also be applied to the case where the secondary samples obtained in the above manner are reassembled and used as a primary sample, and subjected to quantitative reduction (secondary sample collection) by the method of the present invention.

〔effect〕

As described above, this invention draws out the primary sample with a feeder, continuously weighs the decreasing weight with a weighing machine, and sends a signal to the cutter drive unit every time the weight decreases by M/n kIF. Since the sample is collected by moving the cutter, the set force is always cut reliably regardless of the bulk specific gravity or the layer thickness of the sample on the belt feeder, and there is no risk of missed shots. Moreover, since the feeder can be operated continuously, the processing time can be shortened compared to the conventional technique in which the feeder needs to be stopped every time a sample is collected. Furthermore, since the start of the first cut is performed at random, there is a chance of sampling any part of the primary sample, which has the effect of allowing an unbiased representative sample to be sampled.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinal side view showing an example of an apparatus for implementing the method of the present invention, FIG. 2 is a block diagram of the same, and FIG. 3 is a plan view showing a collection area of a reduction sample. 1...Hopper, 2...Belt feeder, 4...Weighing machine, 6...Cutter, 7...
...Cutter drive unit, 13...Cut number setting device, 14...Arithmetic unit. Figure 2

Claims (1)

[Claims] After weighing the entire weight of the primary sample using a belt feeder with a weighing machine, while pulling out the primary sample using the belt feeder,
The weight loss of the primary sample is continuously weighed by the weighing machine, and the value obtained by dividing the total amount of the primary sample by the number of cuts is set as the sample cutting interval, and the cutter is operated every time the weight loss is by this value to remove the secondary sample. A quantitative reduction method for a primary sample in sample preparation equipment, characterized in that the first cut is started randomly within the value range of the cut interval.