JPH0140936B2 - - Google Patents

Description

Detailed Description of the Invention The present invention is arranged at the tail outlet of a belt conveyor that conveys a powder mixture such as iron ore, and cuts the cutting time of the powder mixture by running across the width of the conveyor to sample a sample. A cutter type sampler with Δt ₂ , a conveyor scale placed upstream of the belt conveyor where the average conveyance time of the powder mixture to the conveyor tail is ₁ , and which detects the flow rate of the powder mixture on the belt conveyor, and a sample sampled by the sampler. The sampler is equipped with a cutter-type condensing machine placed at the tail outlet of the feeder that is supplied with the sample, and the weight of the sample sampled with the cutter-type sampler is measured, and the sample is collected based on this measured sample weight and the number of times of sampling in the above-mentioned condensing machine. Calculating and determining an interval, and measuring the number of times of sampling at this interval, operating the cutter of the reduction machine to reduce the sample and collect the sample for quality characteristic measurement.Measurement of the weight of the sample in the sample collection equipment. It is about the method.

As is well known, when receiving powder mixtures such as imported iron ore, samples are taken during the unloading and transportation process from ore ships, and this sample is further reduced to obtain a sample, and the various characteristic values of this sample are determined. (For example, components, particle size, moisture content) are measured and acceptance inspections are carried out. In this way, in order to measure the quality characteristic values of a powder mixture such as iron ore, the powder mixture is sampled, and this sample is further reduced to obtain a sample using a cutter type reduction machine. The JIS standard has the following provisions. That is, it is specified that the sampling interval is constant, the sampling amount is at least a specified amount, and the number of samples is 4 or more.

Figure 1 shows an overview of a cutter-type reduction equipment 1 (sample collection equipment 1) that satisfies the above JIS regulations as a general receiving and conveying equipment for imported iron ore. Using one or two unloaders (not shown) from
is intermittently supplied to the belt conveyor 3 via the hopper 2. The belt conveyor 3 is operated with a belt moving speed V ₀ (m/sec) as a target value. The iron ore flowing on the belt conveyor 3 is the tail 4 of this belt conveyor 3.
The iron ore is then dropped and transferred onto the next iron ore transport conveyor (not shown). A sample is sampled by a cutter 7 of a cutter type sampler 6 disposed at the tail outlet 5 of the unloading belt conveyor 3. Specifically, for example, a box-shaped cutter 7 of the sampler 6 whose bottom plate can be opened and closed runs across the tail opening in the width direction of the conveyor belt 3 with the bottom plate closed, and samples the sample into the cutter 7. The bottom plate is opened at the end position of the cross-travel, and the sample is discharged onto the sample transport belt conveyor 8 provided below this position. Then, with the bottom plate left open, the vehicle returns to the crossing start position and closes the bottom plate.

Here, to describe in more detail the process from the start of the cross-country travel of the cutter 7 to the end of the cross-traverse travel, as shown in Fig. 2, the width of the cutter 7 is b [mm], and the cross-traverse travel speed of the cutter 7 is V ₇ [mm/sec]. ], the width of the iron ore fall is S [mm], and the cross-traveling distance of cutter 7 is h.
[mm], and the distance between the front of the cutter 7 at the travel start position and the iron ore flow edge on the travel start side is Δh [mm], the iron ore cutting time of the cutter 7 (iron ore crossing time) Δt ₂ , the cutter travel start time The time Δt ₃ from 1 to the start of cutting, and the cutter cross-travel time Δt ₄ until the cutter stops traveling are as follows.

Δt ₂ =S+b/V ₇ Δt ₃ =Δh/V ₇ Δt ₄ =h/V _7The above-mentioned times Δt ₂ , Δt ₃ , and Δt ₄ can be regarded as constant since V ₇ is constant.

The running operation of the cutter 7 of the cutter type sampler 6 was configured as follows. This is done automatically by the control device 15 of the sampler 6. 9 is a conveyor scale disposed upstream from the conveyor tail 4 by a distance Δl ₁ to detect the flow rate (Kg/sec) of iron ore flowing through the conveyor 3. Specifically, the scale 9 outputs a current signal having a magnitude proportional to the flow rate. As mentioned above, the belt transfer speed of the conveyor 3 is operated with V ₀ as the target value, but as will be described later, the belt transfer speed from the hopper 2 to the conveyor belt 3 is
The amount of upward cutting constantly changes, and the weight of iron ore on the belt 3 from the hopper 2 to the tail 4 changes, so the actual moving speed _V3 of the conveyor 3 changes. If the average moving speed of the conveyor 3 that is changing now is V ₃ , the average transfer time ₁ for the iron ore whose flow rate is detected to reach the conveyor tail 4 is Al ₁ / ₃
becomes. The control device 15 is arranged at an upstream position of the belt conveyor 3 where the average conveyance time of iron ore to the conveyor tail 4 is ₁ as described above,
Flow rate of iron ore flowing on conveyor 3 (Kg/sec)
When the flow rate of iron ore is detected by the conveyor scale 9, the flow rate signal 10 of the scale 9 is automatically integrated (integrated in detail), and the initial (first) cutter start is started. When the signal 11 is manually input, the integrated value is cleared and the flow rate signal 10 of the scale 9 starts to be integrated, and thereafter, every time this integrated value reaches a predetermined weight (set value) W. Then, there is a cutter start signal transmitter 13 that clears this cumulative value and starts the cumulative value again, and at the same time transmits a cutter start signal 12. When the cutter start signal 12 is input from , for example, the ore average moving time ₁ (=Δt ), and a cutter automatic control device 14 that automatically operates the cutter 7 for cross-travel operation with a time lag of .) and automatically controls the series of sampling operations.

The initial (first) cutter start signal 11 is transmitted at any timing after the flow rate of iron ore is detected on the scale 9 until the integrated value of the transmitter 13 reaches the set value W for the first time. 13 and device 14 manually.

The flow rate of iron ore detected by the conveyor scale 9 of the control device 15 of the cutter-type sampler 6 configured as described above constantly fluctuates. The reason for this is that iron ore is first supplied from the ore ship to hopper 2 using an unloader, and this supply is intermittent.
This is because the amount of ore cut out from the hopper 2 onto the conveyor belt 3 constantly changes because the ore storage level in the hopper 2 changes. Further, the weight of the sample automatically sampled multiple times by the cutter type sampler 6 differs for each sampling. The reason for this is that the cross-travel speed of the cutter 7 is constant and the amount of cutout constantly changes as described above, so the amount of falling material that flows through the belt 3 and falls from the tail 4 is not always constant but fluctuates. Furthermore, the reason why the conveyor scale 9 is disposed upstream of the belt conveyor 3 is that measurement accuracy cannot be obtained if the scale 9 is disposed close to the tail 4 of the conveyor 3 due to the structure of the scale 9 and the measurement principle.

Now, the samples sampled by the sampler 6 are delivered onto the conveyor 8 every time they are sampled as described above. The sample is then transported by a belt conveyor 8, stored in a hopper 16 of a feeder, for example, a belt feeder 49, and the weight of the sample is measured with a hopper scale 17. Specifically, the scale 17 sends an analog weight signal 18 to an A/D converter 19, and the converter 19 sends a digital weight signal 20. In this way, the scale 17 and the converter 19 constitute a digital weight measuring device 48. Digital weight signal 20 is input to minicomputer 21. Mini computer (hereinafter abbreviated as mini computer) 21
is this sample weight x and the preset JIS
Based on the number of samplings n that is greater than a predetermined number of times, a sampling interval for reduction of the sample by the cutter type reduction machine 25 disposed at the tail 24 of the belt conveyor 23 of the feeder, for example, the belt feeder 22, is determined. The operation interval of the cutter 26 of the separator 25 is determined. For details, sample weight x Kg, belt feeder 22
The sample feeding speed is yKg/sec, and the number of sampling is n.
times (JIS standard: n≧4), the sampling (operation) interval time tsec is expressed as x/ny. For example, when y = 4Kg/sec, n = 5 times, x = 400Kg, t
=20sec.

On the other hand, the sample weighed on the hopper scale 17 is transferred from the hopper 16 to the skip elevator 28 via the conveyor belt 27 of the feeder 49, and further supplied to the hopper 29 of the belt feeder 22. Next, belt feeder 2
The second belt conveyor 23 starts transporting the sample cut out from the hopper 29 at a constant sample feed rate yKg/sec. This transfer start is detected by the conveyor operation start detector 3 of the belt feeder 22.
0 is detected, and this signal 31 activates a timer 32, and when the sample is transferred from the hopper 29 to the tail 24 of the conveyor 23, which is set in advance in the timer 32, the timer 32 activates a sample drop start signal. Send 33.
That is, the detector 30 and the timer 32 constitute a sample fall start detector 34. Upon receiving this fall start signal 33, a random signal transmitter 35 randomly transmits a signal 36 within a predetermined period of time. Upon receiving this signal 36, the minicomputer 21 immediately transmits the first cutter start signal 37 to the cutter automatic control device 38 of the cutter type reduction machine 25, and the cutter automatic control device 38 that received this signal
activates the cutter 26. That is cutter 2
6 is caused to run across the width direction of the belt 23 of the belt feeder 22 at the tail 24 exit.

Furthermore, the minicomputer 21 receiving the signal 36 calculates and determines the sampling (operation) interval time t as described above.
Each time, the cutter start signal 37 is transmitted (n-1) times, and the cutter 26 is operated a total of n times for one sample, that is, is caused to cross-traverse as described above, via the cutter automatic control device 38.

The cutter 26 of the cutter type reduction machine 25 illustrated in the drawing has an intake port 39 at the top and three discharge ports 40, 41, and 42 at the bottom, and the cutter 26 has a receiving port 39 at the top and three discharging ports 40, 41, 42 at the bottom, and the cutter 26 has a receiving port 39 at the top and three discharging ports 40, 41, 42 at the bottom. The sample is divided into three equal parts, and during the traveling process, 1/3 of the sample is transferred to a conveyor belt 44 for subsequent processing via a chute 43 that is opened along the traveling path of the outlet 40 of the cutter 26. 1/3 of the sample is supplied to the Begin-type condenser 46 via a chute 45 that is open along the travel path of the outlet 42 of the cutter 26, and the remaining 1/3 is supplied to the Begin-type fractionator 46 through the outlet 41 of the cutter 26. From there, it falls through the chute 47 and is discarded.

The sample thus sampled by the cutter type sampler 6 is further reduced in accordance with JIS standards, and samples for measuring quality characteristics are collected on the belt conveyor 44 and in the Begin type reduction machine 46.

As described above, in order to measure the quality characteristic values (components, particle size, moisture content) of a powder mixture of iron ore, etc., the powder mixture is sampled with the sampler 6, and this sample is further reduced to obtain a sample. As mentioned above, when carrying out the cutter type reduction method using the cutter type reduction machine 25, in order to keep the sampling (operation) interval constant as specified in the JIS standard, it is necessary to sample with the sampler 6. The sample must be weighed to determine the collection interval time.

Conventionally, the sample weight is measured using the hopper scale 17 as described above, so a belt feeder 49 consisting of the hopper 16 and the belt conveyor 27 is required, and if the height of the equipment is restricted, A skip elevator 28 is required, and the equipment cost of the sample collection equipment 1 becomes expensive. Further, the sample sampled by the sampler 6 is fed through the feeder 49 and the skip elevator 28 to the feeder 22 in which the cutter-type condensing machine 25 is arranged, and the sample is collected by the condensing machine 25. During the process, the moisture in the sample evaporates and the moisture in the collected sample differs slightly from the moisture in the iron ore, making precise and accurate iron ore receiving inspection difficult.

The present invention has been made in view of the above-mentioned circumstances, and a sample is sampled by the cutter type sampler 6 in the sample collection equipment 1 without using the hopper scale 17, and at the same time, the sample is sampled by the cutter type sampler 6 of the sample collection equipment 1 without using the hopper scale 17. The present inventors provide a method for measuring the weight of a sample by which the weight of the sample can be determined with measurement accuracy. Noting that the instantaneous flow rate (Kg/sec) of the mixture is detected by the conveyor scale 9, the present invention was completed by effectively utilizing this.

That is, the gist of the sample weight measurement method in the sample collection equipment of the present invention is as follows.

A cutter-type sampler with a powder agglomerate cutting time Δt ₂ that is placed at the tail outlet of a belt conveyor that conveys a powder agglomerate mixture of iron ore, etc., runs across the width of the conveyor to sample the sample, and has a cutting time of Δt 2. A conveyor scale is placed upstream of the belt conveyor where the average conveyance time of the powder mixture is ₁ , and a conveyor scale is placed to detect the flow rate of the powder mixture on the belt conveyor. It is equipped with a cutter-type condensing machine, which measures the weight of the sample sampled with the cutter-type sampler, calculates and determines a sampling interval based on the measured sample weight and the number of times of sampling in the above-mentioned condenser, and uses this interval to determine the number of samples sampled above. In the sample collection equipment that operates the cutter of the reduction fractionator to reduce the sample and collect a sample for measuring quality characteristics, the flow rate detected by the conveyor scale is used to start cutting with the cutter of the cutter type sampler. The integration starts a predetermined time Δt before
A method for measuring the weight of a sample in a sample collection facility, characterized by integrating the weight for a predetermined time Δt ₅ .

However, Δt= ₁ + Δt ₅ −Δt ₂ /2 Δt ₅ = KΔt ₂ (K>1) ₁ ; Average transfer time from the flow rate detection position to the conveyor tail Δt ₂ ; Cutting time Δt ₅ ; Integral time First, the method of the present invention Explain the principle.

In the sampling equipment shown in Fig. 1, the distance Δl between the conveyor scale 9 position and the conveyor tail 4 position is ₁ , and the average belt speed of the conveyor 3 is ₃ as described above, so the iron ore flow rate detected at the scale 9 position is Average transfer time ₁ for reaching tail 4
is ₁ = Δl ₁ /V ₃ ...(1). Here, as shown in Fig. 2, if the flow rate at the conveyor scale 9 position at any time t is q ₉ (t), and the flow rate at the tail 4 at time t is q ₄ (t), then q ₉ (t) and q ₄ (t), there is a relationship as follows: q ₄ (t)≒q ₉ (t− ₁ ) q ₉ (t)≒ q ₄ (t+ ₁ ) (2). Now, if the flow rate q ₄ (t) does not change over time t and is a constant q, then the flow rate q ₉ (t) will also be a constant q, q ₄ (t) = q ₉ (t) = q ... ( 3) becomes. In this case, the sample weight Q sampled by the cutter type sampler 6 is determined by the width of the cutter 7 being b [mm] and the cross-travel speed of the cutter 7 being V ₇ [mm/mm].
sec], the iron ore falling width is S [mm], and the flow rate is q [Kg/
sec], the falling flow rate per unit width of the falling flow is q/S
If [Kg/sec・mm], then Q=q/S×[(b/2×b/V ₇ )+b×(S-b
/V ₇ ) + (b/2×b/V ₇ )] …(4) Q=q×b/V ₇ …(5) As shown in Fig. 2, the cross-traveling distance of the cutter 7 is h, If the distance between the front of the cutter 7 at the travel start position and the iron ore flow edge on the travel start side is Δh, the iron ore cutting time of the cutter 7 (iron ore crossing time) Δt ₂ and the time from the cutter start of travel to the start of cutting Δt _3. The cutter crossing travel time Δt ₄ from the start of the cutter travel until the cutter stop is Δt ₂ =S+b/V ₇ Δt ₃ =Δh/V ₇ (6) Δt ₄ =h/V ₇ .

As mentioned above, if the flow rate is constant q, the weight Q can be calculated using the above equation (4) or (5), but since q is q ₄ (t) which varies with time t, for example, If cutting is started at t=tu, the true sample weight Q _T is However, t = tu ~ (tu + b / V ₇ ) and b ₁ (t) = V ₇・ (t - tu) t = (tu + b / V ₇ ) ~ (tu + S / V ₇ + b / V ₇ ) and b ₂ (
t) = b-V ₇ (t-tu-S/V ₇ ).

However, since q ₄ (t) cannot be measured and only q ₉ (t) is measured, using the measured value q ₉ (t), the measured sample weight Qm is It can be found by

Now, to describe the relationship between Qm and _QT , as described above, there is a relationship of q ₄ (t)≈q ₉ (t- ₁ ), so Qm≈Q _T. In order to bring the Qm closer to the _QT , the method of the present invention calculates the sample weight using the following equation (9).

[b/V ₇・∫ ^to+ 〓 ^t5 _tp q ₉ (t− ₁ ) dt] ×Δt ₂ /Δt ₅ …(9) However, Δt ₅ =KΔt ₂ (K＞1orΔt ₅ >Δt ₂ )……(10 ) t ₀ = tu−(Δt ₅ −Δt ₂ /2) ……(11) Δt≡tu−(t ₀ − ₁ = tu−(tu−Δt ₅ −Δt ₂ /2)− ₁ 〕 ……(12 ) Δt= ₁ + Δt ₅ −Δt ₂ /2 ……(13) Equation (9) means that the flow rate q ₉ (t) detected by the conveyor scale 9 is as shown in Fig. 3.
The integration starts a predetermined time Δt shown by equation (13) from the cutting start time tn of the cutter 7 of the cutter type sampler 6, and is integrated for a predetermined time Δt ₅ shown by equation (10), and the integrated value is calculated. is multiplied by a coefficient [b/V ₇ ·Δt ₂ /Δt ₅ ].

Assuming that the cutter running start time is now tv, this time tv is different from the above cutting start time tu as tu = tv + Δt ₃ as shown in Figure 4, so if the current time tv is used as the reference, equation (11) is t ₀ = tv + Δt ₃ −
(Δt ₅ - Δt ₂ /2), and the equation (13) obtained by substituting equation (11) into equation (12) is Δt= ₁ + Δt ₅ - Δt ₂ /2 - Δt ₃
becomes.

t ₀ = tv + Δt ₃ - (Δt ₅ - Δt ₂ /2) ...(14) Δt= ₁ + Δt ₅ - Δt ₂ /2 - Δt ₃ ...(15) In this way, based on the cutter travel start time tv, , Equation (9) starts integrating the flow rate q ₉ (t) detected by the conveyor scale 9 a predetermined time Δt shown by Equation (15) from the running start time tv of the cutter 7 of the sampler 6. 10) It means to integrate for a predetermined time Δt ₅ shown in equation 10) and to multiply by a coefficient.

Next, the present invention will be explained in detail using an example device.

FIG. 5 shows a feeder 49 consisting of a hopper 16, a belt conveyor 27, a hopper scale 17, and a skip elevator 28 in the sample collection equipment 1 of FIG. 1 by using a measuring device implementing the method of the present invention. Excluded sample collection equipment 50
The configuration of the sample weight measuring device 51 is as follows.

52 is a current/voltage converter that outputs a current signal 10 from a conveyor scale 9 whose size is proportional to the instantaneous flow rate.
is converted into a voltage signal proportional to its magnitude and output 53. In other words, it outputs a voltage proportional to the instantaneous flow rate. 54 is a voltage/frequency converter which outputs pulses 55 at a period inversely proportional to the input voltage value. That is, pulses are output 55 at a frequency proportional to the instantaneous flow rate.

Reference numeral 56 denotes a counter, which receives the initial cutter start signal 11 and the cutter start signal transmitter 13 which are manually input to the cutter automatic control device 14 of the control device 15 of the sampler 6 described in FIG.
Using the cutter start signal 12 automatically input to the device 14 as a count start signal, the pulses which are the output 55 from the converter 54 are counted for a preset count time ΔS. Then, the count value is outputted 58 to the display 57 and the minicomputer 21 which calculates the operation interval of the cutter 26 of the cutter reduction machine 25 described in FIG. Note that the display 57 displays the count value as weight.

As the set count time ΔS of the counter 56 of the device 51 described above, Δt ₅ determined by the above equation (10) is set, and the cutter automatic control device 14 of the device 15
As the setting time lag Δt, Δt= ₁ + [(Δt ₅ −Δt ₂ )/ ₂ ]−Δt ₃ determined by the above equation (15) is set.

Sample weight measuring device 5 configured as above
1, when the initial cutter start signal 11 or signal 12 is input, the counter 56 outputs a pulse 55 from the converter 54 at a frequency proportional to the instantaneous flow rate q ₉ (t) of iron ore. Starts counting, counts for the set time Δt ₅ , and outputs the count value after counting ends 58
do. On the other hand, the cutter automatic control device 14 of the sampler 6, which receives the signal 11 or 12, operates the cutter 7 to cross the road with a time lag of Δt = ₁ + [(Δt ₅ - Δt ₂ )/ ₂ ] - Δt ₃ . Collect the sample into the cutter 7.

Now, let the traveling start time be tv, the cutting start time be tu, and the transfer speed of the conveyor belt 3 is _V3 .
Assuming that V ₃ = ₃ and the travel time Δt ₁ for the iron ore whose flow rate is detected at the scale 9 position of the belt 3 to reach the tail 4 is Δt ₁ = ₁ , at the timing shown in FIG. 6A, The counter 56 starts counting the counting time Δt ₅ . The counted iron ore reaches the tail 4 of the belt conveyor 3 at the timing shown in FIG. B, and is cut by the cutter 7 at the timing shown in FIG.
In other words, the cutter 7 cuts while the counted iron ore is falling from the tail 4.

Now, suppose that the transfer speed V ₃ is V ₃ =V ₃ mm, and the travel time Δt ₁ is Δt ₁ = ₁ + [(Δt ₅ −Δt ₂ )/ ₂ ] =
Even if the bias is ₁ max, the iron ore counted at timing A will be tail 4 at timing D.
Then, the cutter 7 cuts at the timing shown in E, and while the counted iron ore is falling from the tail 4, the cutter 7 cuts.

Also, suppose that the transfer speed V ₃ =V ₃ max and the travel time Δt ₁ are Δt ₁ = ₁ + [(Δt ₅ −Δt ₂ )/ ₂ ] = Δt ₁ mi
Even if it is n, the iron ore counted at the timing shown in A will be tail 4 at the timing shown in F.
Then, the cutter 7 cuts at the timing shown in G, and while the counted iron ore is falling from the tail 4, the cutter 7 cuts.

As mentioned above, the transfer speed of belt conveyor 3
V ₃ fluctuates from V ₃ min to V ₃ max, and the above transfer time Δt ₁
Even if the flow rate fluctuates from Δt ₁ max to Δt ₂ min, the flow rate detected by the conveyor scale 9 is changed from the start of cutting by the cutter 7 of the cutter type sampler 6 to Δt= ₁ + [(Δt ₅ +Δt ₂ )/ ₂ ] By starting the integration and integrating for a predetermined time Δt ₅ =KΔt ₂ (K>1), the cutter 7 is activated while the accumulated iron ore is falling from the tail 4 of the conveyor 3. At least a portion of the iron ore that has been cut and whose flow rate has been integrated will be sampled.

Note that the coefficient (bΔt ₂ /V ₇ t ₅ ) in equation (9) is determined by the counter 56 of the sample weight measuring device 51, for example.
This can be taken into account by adjusting the counting speed, so the count value which is the output 58 of the counter 56 after adjusting the counting speed indicates almost the true sample weight _QT , and the display on the display 57 indicates the sample weight _QT. It turns out.

〔Example〕

() Sampling equipment 1 in Figure 1 or Figure 5
Alternatively, the conditions of the belt conveyor 3, cutter type sampler 6, and conveyor scale 9 in 50 are as follows.

(1) Concerning conveyor 3; Fluctuation in flow rate q ₉ (t) of conveyor 3; q ₉ (t) = 1000 to 4000 (t/Hr) q ₉ (t) 2777 to 13600 (Kg/sec) Average of conveyor 3 Transfer speed ₃ ; ₃ = 2.6 (m/sec) (2) Conveyor scale 9; Installation position of scale 9; Distance from conveyor tail 4 Δl ₁ = 40
(m) Upstream position Average transfer time from scale 9 to tail 4 ₁ = 15.4 (sec) (3) Regarding cutter type sampler 6; Cutter width b of cutter 7; _b = 450 (mm) Cross-travel of cutter 7 Speed V ₇ ; V ₇ = 800 (mm/sec) Iron ore cutting time of cutter 7 (iron ore crossing time) Δt ₂ ; Δt ₂ = 1.0 (sec) Time from start of cutter running to start of cutting Δt ₃ ; Δt ₃ =0.3 (sec) () The conditions of the sample weight measuring device 51 in the sampling equipment shown in FIG. 5 are as follows.

(1) Set integration time Δt ₅ of the counter 56; Δt ₅ = 4.6 (sec) (2) Timing of integration start of the counter 56; 16.9 seconds before the cutting start time 〃 From the cutting start time
17.2 seconds ago (3) Also, cutter automatic control device 14 of device 15
Set value time lag Δt; Δt=16.9 (sec) () Let Wm be the measured weight obtained as a result of carrying out under the conditions () and () above, and the sample measured by the present invention was placed in the hopper shown in Fig. 1. Measurement error ΔW is the result measured with scale 17 as W _T
= Wm - W _T and the standard deviation σ of this measurement error ΔW were found to be 14.7 kg.

[Comparative example] In the example, the set integration time Δt ₅ is Δt ₅ = Δt ₂ =
1 sec, the measured weight obtained by multiplying the count value of the counter 56 by 4.6 is Wm, and the standard deviation σ of the measurement error ΔW with respect to W _T obtained as above was determined. σ=
It weighed 18.2Kg.

[Comparative example] In the example, the integration start timing was set to ₁ = 15.4 seconds from the cutter travel start time (Δt
= 15.4sec) Standard deviation σ = 16.8Kg.

[Comparative example] In the example, the integrated time Δt ₅ is calculated as Δt ₅ =Δt ₂ =
1.0 sec, the integration start timing is ₁ = 15.4 sec from the cutter running start time, the set time lag Δt is Δt = ₁ , and the count value of the counter 56 is
When Wm was multiplied by 4.6 and the standard deviation σ was determined in the same manner as in the example, it was found that σ=20.3Kg.

Comparing the standard deviation σ of the error between the above embodiment and comparative example, it can be seen that according to the method of the present invention, the cutter type sampler 6 can measure the sample with the same measurement accuracy as the conventional hopper scale 17. It is clear that the sample weight can be known at the same time as it is sampled.

As described above, the method of the present invention is based on the instantaneous flow rate (Kg/sec) of the powder mixture of iron ore, etc., which is generally conveyed by the belt conveyor 3 in which the cutter type sampler 6 is arranged.
is detected by the conveyor scale 9, and basically utilizes this effectively, that is, integrates it. However, in the present invention, the above-mentioned flow rate fluctuation and transfer from the flow rate measurement position to the conveyor tail are By taking into consideration the existence of time and fluctuations in the transfer time mentioned above, and specifying the integration time and integration start timing to predetermined values based on the characteristics of the sampler, transfer time, etc., samples can be processed using a cutter-type sampler without using a hopper scale. As soon as the sample is sampled, the weight of the sample can be ascertained with a measurement accuracy comparable to that of the conventional Hopper scale 17.

As described above, according to the present invention, the sample weight can be ascertained at the same time as sampling with the same measurement accuracy as using a hopper scale without using a hopper scale. Since there is no need to prepare a hopper scale, the cost of sample collection equipment can be reduced, and since the hopper scale and accompanying transfer device are omitted, the time required to transfer the sample to the cutter-type condensing machine is shortened, and as a result, the above-mentioned condensing machine This improves the reliability of moisture measurement data of collected samples.

[Brief explanation of drawings]

Figure 1 is a general explanatory diagram of cutter-type reduction equipment (sample collection equipment) that satisfies JIS standards for general imported iron ore receiving and conveying equipment, and Figure 2 is
3 and 4 are time charts for explaining the principle of the method of the present invention, and FIG. 5 is a sample weight measuring device for carrying out the method of the present invention. FIG. 6 is an explanatory diagram of an example, and is an explanatory diagram of a sample collection equipment whose equipment configuration is simplified by incorporating the above-mentioned example of the weight measuring device. FIG. 7 is an explanatory diagram of the relationship between the transfer speed and transfer time of the belt conveyor. 1... cutter type reduction equipment (sample collection equipment),
2...Hopper, 3...Unloading belt conveyor,
4... Conveyor tail, 5... Tail dropout, 6
...Cutter type sampler, 7...Cutter, 8
... Sample conveyor belt conveyor, 9 ... Conveyor scale, 10 ... Flow rate signal, 11 ... Cutter start signal, 12 ... Signal, 13 ... Cutter start signal transmitter, 11 ... Cutter automatic control device, 15... Sampler control device, 16
...Hopper scale, 17...Hopper scale, 18
...Analog weight signal, 19...A/D converter,
20...Digital weight signal, 21...Mini computer (mini computer), 22...Belt feeder, 23...Belt conveyor, 24...Tail, 25...Cutter type reduction machine, 26...Cutter, 27... Conveyor belt, 28... Skip elevator, 29... Hopper, 30... Conveyor operation start detector, 31... Signal, 32...
Timer, 33...Sample drop start signal, 34
... Sample fall start detector, 35 ... Random signal transmitter, 36 ... Signal, 37 ... Cutter start signal, 38 ... Cutter automatic control device, 3
9... Acceptance port, 40... Payout port, 41... Payout port, 42... Payout port, 43... Shoot, 44...
...transfer belt conveyor, 45...shoot, 4
6... Begin type reduction machine, 47... Shoot, 48
...Digital weighing device, 49...Feeder, 50...Sample collection equipment, 51...Sample weight measuring device, 52...Current/voltage converter, 53...
...output, 54...voltage/frequency converter, 55...
Output, 56... Counter, 57... Display, 5
8...Output.

Claims (1)

[Scope of Claims] 1. A cutter type that is arranged at the tail outlet of a belt conveyor that conveys a powder mixture of iron ore, etc., and runs across the width of the conveyor to sample a sample, and has a cutting time of Δt ₂ for the powder mixture. A sampler, a conveyor scale placed upstream of the belt conveyor where the average conveyance time of the powder mixture to the conveyor tail is ₁ and detects the flow rate of the powder mixture on the belt conveyor, a feeder to which the sample sampled by the sampler is supplied. The sampler is equipped with a cutter-type condensing machine placed at the tail outlet of the machine, and the weight of the sample sampled with the cutter-type sampler is measured, and the sampling interval is calculated and determined based on the measured sample weight and the number of times of sampling in the above-mentioned condensing machine. ,
At this interval, the cutter of the reduction machine is operated to reduce the sample and collect the sample for quality characteristic measurement. Integration starts a predetermined time Δt before the cutter of the sampler starts cutting,
A method for measuring the weight of a sample in a sample collection facility, characterized by integrating the weight for a predetermined time Δt ₅ . However, Δt= ₁ +Δt ₅ −Δt ₂ /2 Δt ₅ =KΔt ₂ (K>1) ₁ ：Average transfer time from the flow rate detection position to the conveyor tail Δt ₂ ：Cutting time Δt ₅ ：Integrated time