JPH0758254B2 - Measuring device for measuring particle size or concentration and particle size of powder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of simply measuring the particle size of powder or granules, carrying the powder or granules in a gas and transporting them as a mixed fluid through a transport pipe, Fields that use powders and granules, such as the ceramics field and the pulverized coal combustion field, the ratio of the volume (weight) of the powders to the gas flow rate (volume) of the mixed fluid to be transported, that is, the concentration of the powders and the volume of the powders. The present invention relates to a measuring device for measuring the concentration and particle size of a powder or granular material, which requires simultaneous measurement of the particle size of the granular material for measuring the particle size distribution.

Conventional technology Generally, powders and granules are crushed by a crusher, loaded into a gas and mixed into a fluid to be transported by a transport pipe. The concentration and particle size of the transported powder or granules are simply collected from a pipeline. It is measured based on the materials.

Problems to be Solved by the Invention In the measuring device for measuring the particle size, it was difficult to classify the particle size of the powder and granules in a continuous manner in a series of classifiers to measure the particle size. It is to provide a compact and low-cost measuring device that continuously performs classification.

Further, regarding the measuring device for measuring the concentration and the particle size, it is to provide the following measuring device.

In the simple data collection described above, the difference between the time of sampling and the time of measurement is different from that of a control system in which the method of using powder and granules is controlled as one system, that is, continuously controlled. It was unsatisfactory because it was large, the accuracy of sampling was poor, and it required manpower each time.

The problem to be solved by the present invention is that there is no gap between the time of collection and the time of measurement, very short time intervals and continuous measurement can be performed, and no manual labor is required for data collection and measurement. It is to provide a low-cost measuring device that has a simple structure that is easy to maintain, and is compact in terms of piping as a control system.

Means for Solving the Problem The present invention, in the case of measuring the particle size, arranges classifiers so that multistage classification of two or more stages can be continuously measured, and supplements the intake side of the classifiers. The air blower is provided with a suction blower on the exhaust side, and these are controlled by the controller for steady classification, and the classifier can perform constant-speed suction to solve the above problems and measure the concentration and particle size. In some cases, the return pipes are placed in parallel with the transport pipes, and classifiers that reduce the classification particle size range sequentially are placed in parallel in two or more stages in parallel with the transport pipes. Even if there is a change in the flow of the mixed fluid inside, a replenishing device is installed on the intake side of the classifier and a suction blower is installed on the exhaust side so that the classifier can perform constant velocity suction.
These are controlled by a steady classification controller, and a weighing hopper is installed in parallel on each of the classified particle discharge sides of each classifier to continuously measure the measured change of each classified particle. The above problems are solved by arranging the whole so as to return to the transport pipe via the return pipes and enabling the flow rate in the transport pipe to be measured by the steady classification controller.

Effect In the present invention, uniform speed suction makes the selection condition of the classification particle size range of the classifier of two or more stages in series in a steady state,
The respective weighing hoppers of the respective classifiers operate so as to continuously perform the respective weighings corresponding to the classified particles at the same time, so that the particle size of the powder or granular material can be measured or the concentration and the particle size can be measured simultaneously.

Example FIG. 1 shows that the concentration and the particle size are measured at the same time, and the concentration and particle size of the granular material according to the present invention can be applied to a pulverized coal combustion control system when it can be transported at the same concentration even under partial load as at full load. It shows an embodiment to which a measuring device for measuring is applied.

The combustion system has, for example, a predetermined number of burners B ₁ , B ₂ ... B _n as boiler burners. Each of the burners B ₁ , B _2, ... B _n has a predetermined particle size distribution in the crusher 14, for example 70 μm or more, 25%, 30
It is crushed to have a particle size of 60 μm or more and 60% or more and 10 μm or more,
It is mounted on air as a mounting gas and supplied to each of them as a mixed fluid by the transport pipe 1.

These mixed fluids make the ratio of the amount of pulverized coal (weight) to the amount of air (volume), that is, the pulverized coal concentration, within a predetermined range for automatic point extinguishing of the coal type and each burner, and stable combustion. Must be within the specified distribution range.

The concentration is usually in the range of ^{300g / m 3 ~1000g / m 3} , particle size,
The above examples are the main ones.

Further, the required flow rate of the mixed fluid fluctuates because the number of burning burners fluctuates according to the fluctuation of the load of the boiler or the like, for example, 30% to 100% load. It requires a great deal of measure to continuously measure the concentration according to all. In addition, the particle size tends to change due to the deterioration of the capacity of the crusher.

The measuring device according to the present invention is configured as follows in order to measure the concentration and the particle size at the same time with respect to such a varying flow rate, and to make it possible to measure almost continuously.

A return pipe 13 having a forced blower F ₃ is juxtaposed to the transport pipe 1, and the return pipe 13 is connected to the transport pipe 1 via an opening / closing valve V ₃ .

An outlet pipe 2 is provided on the transport pipe 1 so that the amount of air discharged from the outlet pipe 2 will be the same even if a partial load of up to 30% is reached based on the above 100% full load. is the provided Hoki device F _1, the flow rate of the transport tube 1 as measured by the pressure value input of the pressure gauge P ₂ of the pressure gauge P ₁ and the lead pipe 2 of the transport tube 1, Hoki device F according to the measured value Yes and stationary classifier for controller C ₁ to control the ₁ provided, at the outlet of the take-out tube 2 is provided with a outlet valve V _1. The air supplement device F ₁ may be an air supplement blower,
If there is a pressure air source, the pressure air may be replaced with a control valve that supplies the pressure air as supplementary air.

In the illustrated one, four-stage classifiers (S ₁ , S ₂ , S ₃ , S ₄ ) are installed in parallel in series, and the first and second stage classifiers (S ₁ , S ₂ ) are a louver classifier, third and fourth-stage classifier (S _3, S ₄₎ are those without moving parts so is a cyclone classifier comprising not limited to this good in terms of maintenance. The classification particle size is 70 μm for the first-stage classifier S ₁ , 30 μm for the second-stage classifier S ₂ , and 10 μm for the third-stage classifier S _3.
Although the m-cut, fourth stage, that is, the last stage classifier S ₄ has the ability to collect all fine powder, generally, the first to third stage classifying ability ranges are not limited to this. Further, the number of stages of the classifier is not limited to four, and two or more stages can be considered.

The inlet of the first-stage classifier S ₁ is connected to the outlet of the take-out pipe 2, and the inlet of the second-stage classifier S ₂ is the exhaust of the upper-stage classifier, that is, the first-stage classifier S ₁ . The connection relationship between the inlets of the third and second stages, the fourth and third stages, and the exhaust side is the same as described above. _On the exhaust side 3 of the last-stage classifier S ₄ , a suction fan F ₂ whose on / off operation is controlled by a steady-state classifier C ₁ , an opening / closing valve V _2, and a suction fan
A flow meter (FM) for measuring the flow rate from F ₂ and keeping the flow rate constant is provided, and is connected to the atmosphere by the exhaust pipe 4. The replenishing device F ₁ and the suction blower F ₂ are for performing constant velocity suction on each classifier even if there is a flow fluctuation of the transport pipe 1 to make the selection condition of the classifying particle size range of the classifier steady.

Each classification particle emission side of the first to fourth-stage classifier (S ₁ ~S _4), first to fourth weighing hopper (H ₁ ~H ₄₎ are provided, to each of the weighing hoppers Is the inlet valve (V ₁₁ , V ₂₁ , V ₃₁ , V ₄₁ ) of the inlet pipe (5,6,7,8) and the outlet pipe (9,10,11,12)
The outlet valve and _{(V 12, V 22, V} 32, V 42), the exhaust valve of the hopper top _{(V 13, V 23, V} 33, V 43) and is provided, their outlet pipes (9, 10, 11, 12) are connected to the return pipe 13 arranged in parallel in the transport pipe 1, and each set of the distributor and the weighing hopper is arranged in parallel in the return pipe 13.

The command controller C ₀ receives the power generation load, the boiler load, and the coal feeder load, and inputs the command to the main controller C ₂ , the burner controller C ₄ , and the grinding regulator C ₅ .

The main controller C ₂ inputs the flow status of the mixed fluid in the transport pipe 1 from the steady classification controller C _{1 in} addition to the load command from the command controller C ₀ , and each of them from the burner controller C ₄ Burner B ₁ , B ₂ ...... Bn _n
Enter the combustion status of automatic point extinction. Also, the main controller C ₂
Controls the opening and closing of each valve of the measuring device, and each weighing hopper (H ₁ ~
The measurement output from H ₄ ) is also input and calculated to measure the concentration and particle size, and whether the concentration and particle size are appropriate for each load is compared.

The return controller C ₃ is connected to the main controller C ₂ by each weighing hopper (H ₁ ~
H ₄ ) command to discharge classified particles and check whether each valve of the measuring device is opened and closed as necessary to control the operation of the forced draft fan F ₃ . If there is a pressurized air source, the forced draft fan F ₃ may be replaced with a control valve that supplies the pressurized air as forced draft.

The burner controller C ₄ receives the command from the command controller C ₀ and controls the automatic point extinction of each of the burners B ₁ , B ₂ ... B _n .

The crushing adjuster C ₅ operates the crusher 14 in response to a command from the command controller C ₀ , inputs from the main controller C ₂ whether the concentration and particle size are appropriate, and if the particle size is not appropriate, the crusher is crushed. The crushing condition of the machine 14 is adjusted, and if the concentration is not proper, the amount of air as the on-board gas and the crushing amount are adjusted.

The measuring device in this example is used as follows.

When there is a command from the command controller C ₀ , the crushing machine C ₅ operates the crusher 14, and the burner controller C ₄ causes the burners B ₁ , B _2, ... B _n to perform automatic ignition. Also, the stationary classification controller C ₁ operates. Main controller C ₂ which inputs these situations
Opens the valve required for measurement and the measurement device starts measurement.

That is, when the outlet valve V ₁ of the take-out pipe 2 is opened,
Off valve V ₂ of the suction fan F ₂ becomes open, each weighing hopper (H ₁
~ H ₄ ) inlet valves (V _{11 to} V ₄₁ ) and exhaust valves (V _{13 to} V ₄₃ ) are opened, and the open outputs of these valves are input to the return controller C ₃ . Further, if necessary, the air supplementation device F ₁ and the suction blower F ₂ are operated under the control of the steady-state classification controller C ₁ , and the measurement of concentration and particle size is started. At that time, the valves other than the above remain closed.

Now, assuming that the burner controller C ₄ is at full load,
Since that is input to the main controller C ₂ , the weighing output of each weighing hopper (H _{1 to} H ₄ ) and the flow output of the steady classification controller C ₁ are compared so that the concentration and particle size in that state are compared. And is the main controller C ₂
Entered in.

When the partial load occurs, that is input from the command controller C ₀ and the burner controller C ₄ to the main controller C ₂ , and the above is performed in that state.

The adjustment for crushing that is appropriate as a result of comparison has been described above.

When the weighing of each weighing hopper (H _{1 to} H ₄ ) exceeds the specified time,
The classified particles accumulated in these weighing hoppers must be returned to the transport pipe 1 via the return pipe 13.

At that time, the command from the main controller C ₂ is input to the return controller C _3, and the outlet valve V ₁ of the take-out pipe 2 is closed to deactivate the refueling device F ₁ and the suction blower F _2. Along with closing the open / close valve V ₂ of the suction blower F ₂ , opening the open / close valve V ₃ of the return pipe 13, and leaving the exhaust valves (V _{13 to} V ₄₃ ) of the respective weighing hoppers (H _{1 to} H ₄ ) open. The inlet valve (V _{11 to} V ₄₁ ) is closed, the outlet valve (V _{12 to} V ₄₂ ) is opened, and the return controller C ₃ confirms the opening and closing of these valves and operates the forced draft fan F ₃ . Meanwhile, the measurement of the measuring device is interrupted, but the time is only a short time. After that time, the measurement is started again.

However, if you want to measure continuously, each weighing hopper (H ₁
~ H ₄ ) are installed side by side, and each of the weighing hoppers is equipped with an inlet valve (V _{11 to} V ₄₁ ) and an outlet valve (V _{12 to} V ₄₂ ) as a switching valve. The other weighing hopper may be used for returning. In that case, the outlet valve V ₁ of the take-out pipe 2 and the open / close valve V ₂ of the suction blower F ₂ are continuously open, and the open / close valve V ₃ of the return pipe 13 and the operation of the forced blower F ₃ are switched valves. Return controller so that it lasts only for a certain period of time after switching
C ₃ also needs to be modified.

Fig. 2 shows the pulverized coal combustion control in the case where it is necessary to proportionally increase the amount of air or change the flow rate for each burner because the amount of air in transport becomes insufficient when the concentration is the same as that of full load under partial load. The Example which applied the measuring apparatus which measures the density | concentration and particle size of the granular material of this invention to the system is shown.

Only the control mode of the combustion control system is different from that of FIG. 1, and the measuring device itself is not particularly different.

The main difference is that the transport pipe 1 belongs to each burner, and therefore the measuring device is also provided for each.

The command controller C ₀ , the stationary classification controller C ₁ , and the returning controller C ₃ are the same.

The main controller C ₂ measures the concentration and particle size of each transport pipe 1 by each measuring device.

The burner controller C ′ ₄ inputs the concentration value from the main controller C ₂ and controls the burner controller C ′ ₄ so that the burner has a concentration suitable for combustion.

The crushing adjuster C ₅ adjusts the crushing amount and the air amount for mounting it by the load command from the command controller C ₀ , and the main controller
The particle size value from C ₂ is input to adjust the crushing status of the crusher 14.

The distribution controller C ₆ is one in which the main controller C ₂ inputs the concentration value from each transportation pipe 1 and adjusts the distribution amount between the transportation pipes 1 by the distribution adjustment valve V _x .

The distribution amount is adjusted so that the transport pipes 1 are uniform with each other, or different when the boiler load is different for each burner.

The way of using the measuring device in this embodiment is not particularly different from that in FIG.

When using this measuring device as a particle size measuring device,
An inlet for the powder to be measured is provided on the outlet pipe 2, and air required for classification is fed by the air supplementing device F ₁ and mixed with the powder fed from the inlet and taken out as a mixed fluid. Tube 2
The take-out / return pipe 13 may be simply the inclined pipe and the discharge pipe 13.

EFFECTS OF THE INVENTION The present invention has a configuration described in each claim. Even in a control system, steady measurement can be performed in consideration of the fluctuation of the system and a certain classification particle size range of powder and granules. Since it is used in combination with a hopper, it does not require manual labor for measurement, maintenance is easy, and a compact and low-cost, highly reliable measuring device can be obtained.

[Brief description of drawings]

FIGS. 1 and 2 show schematic views of examples in which the measuring apparatus for measuring the concentration and particle size of the granular material of the present invention is applied to each pulverized coal combustion control system. 1 …… Transport pipe 2 …… Extraction pipe 5,6,7,8 …… Weighing hopper inlet pipe 9,10,11,12 …… Weighing hopper outlet pipe 13 …… Return pipe or discharge pipe F ₁ …… Complement Air device F ₂ …… Suction blower F ₃ …… Pressing blower H ₁ , H ₂ , H ₃ , H ₄ …… Weighing hopper S ₁ , S ₂ , S ₃ , S ₄ …… Classifier

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kim, Hirohiro 7-4-1-201 Waseda, Misato City, Saitama Prefecture (72) Inventor, Hiroshi Tomiyasu 1028 Kaminakazato, Isogo-ku, Yokohama City, Kanagawa Prefecture 10-16 (72) Invention Person Koichi Iitani 105 Kamikamo Motoyama, Kita-ku, Kyoto City, Kyoto Prefecture (56) References JP-A-56-124035 (JP, A) JP-A-49-119690 (JP, A) JP-A-48-48155 (JP, 48-155) A)

Claims (8)

[Claims] 1. A measuring device for measuring the particle size of a granular material, an inlet for the measured granular material, a discharge pipe (13) for discharging the measured granular material, and a refueling device (F ₁ ), An extraction pipe (2) for taking out the powder or granular material as a mixed fluid of gas and powder, and a plurality of stages of two or more stages arranged in parallel so that the classification particle size range is gradually reduced to a fine powder. Classifier (S ₁ , S ₂ ,
S ₃ ......), the take-out pipe (2) is connected to the inlet of the first-stage classifier (S ₁ ), and the lower-stage classifiers from the second stage onward ( Each exhaust side of the upper classifier (S ₁ , S ₂ ......) is connected to the inlet of S ₂ , S ₃ ......) and each classifier (S ₁ , S ₂ , S ₃ ......) The exhaust side (3) of the classifier (S ₄ ) at the final stage is connected to a suction blower (F ₂ ) at a constant flow rate by a flow meter (F, M) and connected in series in the order of stages. On each of the classified particle discharge sides of the classifiers (S ₁ , S ₂ , S ₃ ......), the inlet valves (V ₁₁ ,
V _21, V ₃₁ ......) and the respective outlet valve of the outlet pipe _{(9,10,11 ......) (V 12,} V 22, V 32 ......) and with weighing hopper (H _1,
H ₂ , H ₃ ......) are connected, and the outlet pipes (9,10,11 ...) of these weighing hoppers are arranged side by side in parallel with the return pipe (13).
A measuring apparatus, which is connected to the air conditioner and is provided with a controller (C ₁ ) for steady classification for controlling the refueling device (F ₁ ) and the suction blower (F ₂ ). 2. A multi-stage classifier is a four-stage classifier (S ₁ , S ₂ ,
S _3, consists S _4), the first-stage classifier (S ₁₎ is 70μm cut, second-stage classifier (S ₂₎ is 30μm cut, third-stage classifier (S ₃₎ Has a capability of cutting 10 μm, and the classifier (S ₄ ) at the final stage has a capability of collecting all fine powder. 3. A main controller (C ₂ ) for inputting a measured value from each measuring hopper (H ₁ , H ₂ , H ₃ ...) And calculating the particle size of the powder or granular material.
The measuring device according to claim 1 or 2, further comprising: 4. Each of the weighing hoppers (H ₁ , H ₂ , H ₃ ...) is provided in parallel with each other, and the inlet valves (V ₁₁ , V ₂₁ , V of each weighing hopper are provided.
₃₁ ......) and the outlet valves (V ₁₂ , V ₂₂ , V ₃₂ ......) are switching valves, and one of the two units can be continuously metered. The measuring device according to 1. 5. A measuring device for measuring the concentration and particle size of a powder or granular material in a transport pipe for carrying the powder or granular material in a gas and transporting it as a mixed fluid, wherein the transport pipe (1) whose flow rate is measured A return pipe (13) equipped with a forced air blower (F ₃ ) and an extraction pipe (2) for taking out the mixed fluid in a transportation pipe (1) having a supplemental air supply device (F ₁ ).
And a multi-stage classifier (S ₁ , S ₂ , S ₃ ...) with two or more stages arranged in parallel so that the classification particle size range is gradually reduced to fine powder. The take-out pipe (2) is connected to the inlet side of the classifier (S ₁ ), and the upper side of the classifiers (S ₂ , S ₃ ...) at the _second and lower stages is connected to the inlet. Step classifier (S ₁ ,
Each exhaust side of S ₂ ……) is connected and each classifier (S ₁ , S ₂ , S ₃ …)
…) Are connected in series in the order of stages, and a suction blower (F ₂ ) is used to make the flow rate (F, M) constant at the exhaust side (3) of the final classifier (S ₄ ). Are connected to each of the classifiers (S ₁ , S ₂ , S ₃ ......) on the classified particle discharge side, and the inlet valves (V ₁ , V ₂₁ , V ₃₁ …
…) And outlet pipes (9,10,11 ……) with respective outlet valves (V ₁₂ , V ₂₂ , V ₃₂ ……) and hoppers (H ₁ , H ₂ , H ₃
......) are connected to the outlet pipes (9,10,1) of these weighing hoppers.
1 ...) are connected in parallel to the return pipe (13), and pressure gauges (P ₂ ) and (P ₁ ) are provided on the transportation pipe (1) and the extraction pipe (2), respectively. Enter that pressure value,
As a result, a steady classification controller (C ₁ ) for controlling the refueling device (F ₁ ) and the suction blower (F ₂ ) is provided, and the steady classification controller (C ₁ ) is used for the transportation pipe. A measuring device characterized by measuring the flow rate of (1). 6. A multi-stage classifier is a four-stage classifier (S ₁ , S ₂ ,
S ₃ and S ₄ ), the first stage classifier (S ₁ ) cuts 70μm, the die second stage classifier (S ₂ ) cuts 30μm, 3rd
The measuring apparatus according to claim 5, wherein the classifier (S ₃ ) at the stage has a capacity of 10 μm cut, and the classifier (S ₄ ) at the stage of the final stage has a capability of collecting all fine powder. 7. The concentration of powder and granules is inputted by inputting the flow rate measurement value from the steady classification controller (C ₁ ) and the measurement value from each weighing hopper (H ₁ , H ₂ , H ₃ ...). 7. The measuring device according to claim 5, further comprising a main controller (C ₂ ) for calculating the granularity. 8. Each of the weighing hoppers (H ₁ , H ₂ , H ₃ ...) Is provided in parallel with each other, and the inlet valves (V ₁₁ , V ₂₁ , V of each weighing hopper are arranged.
₃₁ ......) and the outlet valve (V ₁₂ , V ₂₂ , V ₃₂ ......) are switching valves, and one of the two units can be continuously metered. The measuring device according to 1.