JP4959121B2 - Granulation method for powder, dehydrated cake, etc. - Google Patents

Description

  The present invention relates to a granulation method for powder, dehydrated cake, and the like, more specifically, a horizontal granulation container into which an object to be processed such as powder and dehydrated cake and a liquid are charged, and a rotating shaft attached to the rotary granule. Desired particle size from powder, incinerated ash, dehydrated cake, etc. using a batch granulator comprising a stirring granulation blade and a chopper blade driven to rotate at a relatively high speed in the horizontal granulation vessel. It is related with granulation methods, such as powder and a dehydrated cake, which obtain the granulated material of this.

The granulating apparatus is well known in the art, without mentioning the literature name. Forced stirring type that agitates the object to be processed in the granulating container with a stirring blade and granulates. There are many types such as rolling granulation type for granulating materials, extrusion type for rotating the screw in the cylinder and extruding from the end of the cylinder, and vibration type for vibrating the tank containing the workpiece Granulators are known. From these granulating apparatuses, a granulating apparatus suitable for the properties of the object to be processed such as dehydrated cake, powder, incinerated ash and the like is appropriately selected and granulated.
The forced agitation granulator is roughly composed of a granulation vessel, a mixing agitating blade that is driven to rotate inside the granulating vessel, and a chopper blade that is driven at a higher speed than the mixing agitating blade. Has been. Therefore, when the object to be treated and water, or water and, for example, an anti-sticking agent are supplied to the granulation container and the mixing stirring blade and chopper blade are rotated for a predetermined time, the lump is crushed and the powder is nucleated. Granulated after production.

JP 2002-153744 A JP 2001-162154 A

  Patent Document 1 discloses a granulating apparatus including a stirring blade and a chopper blade. That is, a horizontally long container is divided into a mixing zone and a granulation zone in the axial direction by a partition wall, and the mixing zone and the granulation zone are respectively provided with first and second rotating shafts equipped with stirring blades. Shows a granulator provided with chopper blades. The granulation apparatus described in Patent Document 1 includes a chopper blade that is rotationally driven at a high speed and an agitation blade that is rotationally driven at a relatively low speed. Mix, shear and disperse in a short time. And it granulates with a stirring blade. Thus, according to the invention described in Patent Document 1, there is an effect that the mixing / granulating apparatus can be obtained at low cost, although both the dispersing / nucleating action and the granulating action are exhibited. Obtained and implemented without problems.

  Patent Document 2 can be cited as a direct prior document of the present invention. The granulation apparatus disclosed in Patent Document 2 includes a horizontal granulation container into which an object to be processed and a liquid are charged, an agitation granulation blade attached to a rotating shaft, and the horizontal granulation container. The chopper blades are driven to rotate at a relatively high speed. The rotating shaft is provided in the horizontal direction inside the horizontal granulation vessel, and the chopper blade can be driven and stopped independently of the stirring granulation blade. Therefore, the stirring granulation blade and the chopper blade are driven, and a predetermined amount of the object to be processed and the liquid are charged. At this time, the timing of adding the object to be treated and the liquid, mixing / kneading time, granulation time, etc. are appropriately determined. Then, nucleation is generated while the particles are repeatedly agglomerated and disintegrated due to mixing, dispersion, shearing, and kneading action in a short time mainly by the chopper blades. Therefore, the chopper blade is stopped. Then, the nuclei adhere to each other and are granulated by the stirring granulation blade.

According to the invention described in Patent Document 2, the object to be treated is mixed, dispersed, sheared, kneaded and granulated in a short time as described above. At this time, the particle size can be controlled by the driving time and speed of the stirring granulation blade, and an excellent effect that a granulated product having a constant particle size can be produced is recognized. However, if the material to be treated itself or the properties of the material to be treated are changed, in order to obtain a granulated material having a desired particle size and strength, the timing of mixing the material to be treated and water or liquid, mixing The shearing time, granulation time, etc. must be determined by repeated trial and error, and there is a problem that it takes time before entering the actual operation. Moreover, the strength of the resulting granulated product may be insufficient.
Therefore, the present invention provides a desired particle size even when the properties of the object to be treated are changed when granulation is performed using a granulation apparatus in which a horizontal granulation vessel is provided with stirring granulation blades and chopper blades. An object of the present invention is to provide a granulation method capable of easily producing a granulated product.

  The granulation apparatus described in Patent Document 2 includes a stirring granulation blade that is driven to rotate at a relatively low speed in a horizontal granulation vessel, and a chopper blade that is driven to rotate at a higher speed than the stirring granulation blade. Since it is provided, it is possible to effectively obtain a granulated product having a desired particle diameter when operated based on the granulation conditions suitable for the physical properties of the object to be processed. Therefore, the present invention also achieves the above object by using a granulating apparatus provided with stirring granulation blades and chopper blades.

  The present inventor has found that this granulating apparatus exhibits unique properties in the granulating action, and has completed the present invention based on the findings. That is, although the objects to be treated are charged all at once, the optimum water content most suitable for granulation can be found by adding water or a liquid obtained by adding an anti-sticking agent to water in a plurality of times. When the nucleus is formed and granulated at the optimum moisture content in this way, the power of the electric motor that drives the chopper blades or the power of the electric motor that drives the rotating shaft to which the stirring granulation blades are attached is as the processing time elapses. When it is found that a specific pattern is shown and the property of the object to be processed has changed or the object to be processed itself has changed, the amount and timing of water or liquid, in other words, water content, so as to indicate the predetermined pattern. It was found that a granulated product having a desired particle diameter can be obtained by controlling the rate.

  Hereinafter, dehydrated cakes, powders, incineration ash and the like are expressed as “objects to be treated”, and water added to the objects to be treated and liquids added by adding an anti-sticking agent such as a polymer-based lubricant to water are Explain in more detail with the expression “water”. The granulating apparatus used in the practice of the present invention is a batch type, but considering the object to be treated and the water to be charged into the horizontal granulation container of this granulating apparatus, the entire amount of the treatment of one batch is treated. Although it is possible to carry out the treatment and water in a horizontal granulation container at once, if all of them are put in at once, the physical properties of the material to be treated will change, and the optimum moisture content for granulation can be accurately grasped. Because there is no, granulation may fail. Therefore, in the present invention, the objects to be treated are added all at once, but water is introduced in a relatively large amount at the time of the first addition, and then added or added in a plurality of times. Thereby, it can throw in so that there may be no excess and deficiency of the moisture with respect to a to-be-processed object, and it may become an optimal moisture content.

   The relationship between the power and time of the chopper blades shown in (a) of FIG. 1 is a relationship diagram when a granulated product having a desired particle diameter is obtained by repeating the test by trial and error. Therefore, as shown in this relationship diagram, if a material to be treated and water are added and stirred and kneaded, a granulated product having a desired particle diameter can be obtained. In FIG. 1 (a), the objects to be processed are charged at a time A. Then, the stirring granulation blade and the chopper blade are driven. The object to be processed is subjected to sufficient mixing, shearing, dispersion and the like. This period T1 is a premixing step that is essential for granulation, which is necessary for obtaining a uniform and small-diameter granulated product, and since water is not added, the power consumption or torque in this period T1 is substantially constant. .

  After premixing for a predetermined time T1, water is added at time B. The amount to be added is, for example, 60 to 90% of the total input amount. Electricity will start to increase. Thereafter, the auxiliary water is added a plurality of times, for example, four times. This period T2 is a nucleation process period in which “nuclei” that become the “core” of the granulated product are formed, and kneading is performed until nucleation generation, that is, “plastic limit point”. When the plastic limit is reached, the increase in power stops. When the amount of auxiliary water to be added at one time is large, the time T2 for reaching the plastic limit point is shortened, and the generation of uniform nuclei is hindered. There is also the possibility of overloading. On the other hand, when the input amount is small, the nucleation process period T2 becomes long and the granulation cycle becomes long. When the plastic limit point is reached, for example, when it is excessively charged, a small amount of the second workpiece is charged as necessary. In the period T3 after the secondary charging, the power is stable and no change is observed. This period T3 can also be said to be a pre-stirring period.

  After this, a granulation process is started in which neither an object to be treated nor water is added. In this period T4, when the stirring granulation blade and the chopper blade are continuously driven and dispersed and kneaded, the nuclei are adhered or combined to be granulated. Electric power decreases rapidly and then decreases gradually. At time E when the decrease is slow, the granule discharge port is opened and the granule is taken out.

Or after that, a chopper blade | wing is stopped and the drive of a stirring granulation blade | wing is continued. As for the power consumption, the power consumption of the chopper blade is adopted in this embodiment, but now the chopper blade is stopped, and this time the driving power of the stirring granulation blade is displayed . As shown in the figure, it grows rapidly . The granulation gradually grows and the power turns to a gentle rise. This period T5 is a particle size control process. In the next period T6, the electric power starts decreasing in the sizing process. The granulated material becomes tight and the strength increases. When no change in power is observed, at time point G, the granule discharge port is opened and the granule is taken out.

  When the plastic limit point is reached, the power consumption starts decreasing as indicated by the dotted line in FIG. Therefore, the pre-stirring step T3 can be carried out as it is without secondly introducing the workpiece. In addition, since the chopper blade is provided in a floating state in the horizontal granulation container, there is little adhesion of the object to be processed, and the power consumption appears as energy consumed for stirring and granulation. Although employed, the drive power of the agitation granulation blade also shows a substantially similar pattern, so the torque of the rotating shaft to which the agitation granulation blade is attached can also be used. In Fig. 1 (b), the driving power uses the average of three points, the maximum value of t seconds and the average value of the minimum value, but the average of three points of 50% of the maximum value in t seconds. You can also

Thus, in order to achieve the above object, the invention according to claim 1 is attached to a horizontal granulation container into which an object to be treated and water are charged, and a rotary shaft provided in the horizontal granulation container. Using a granulating apparatus comprising a stirring granulation blade that is formed and a chopper blade that is driven to rotate at a higher speed than the stirring granulation blade in the horizontal granulation vessel, and the stirring granulation blade, when obtaining the granulated product and the chopper blade from the rotary drive to the object to be processed, the control device, the time and the premix an object to be processed to drive rotating the said agitating granulation blade said chopper blade, plastic It may be stored and a power consumption of the chopper blade or the stirring granulation blade at the limit point, the horizontal granulating container object to be processed collectively put in, and rotated and said agitating granulation blade said chopper blade And when it is remembered Premixed, after premix, and charged with 60% to 90% water of the total input amount expected by kneading, to the power of the chopper blade or the stirring granulation blade reaches the power consumption being the storage Auxiliary water is added to a small amount in several batches, and then a small amount of material to be treated is secondarily charged, and the agitation granulation blade and the chopper blade are rotated and granulated until the decrease in power is slow. In the granulation method according to claim 1, the amount of auxiliary water added at one time is controlled so that the plastic limit point is reached in a predetermined time. Configured to do.

As described above, according to the present invention, the objects to be processed are put into a horizontal granulation container at a time, and the agitation granulation blade and the chopper blade are driven and premixed for the stored time, which is necessary for nucleation. Sufficient dispersion and kneading action. And according to the present invention, after premixing, 60 to 90% of the expected total charge is charged, and then reaches the stored power consumption at the plastic limit point of the chopper blade or stirring granulation blade. Auxiliary water is added several times to a small amount until then, a small amount of material to be treated is secondarily added, and the agitation granulation blade and the chopper blade are rotationally driven until the power decrease is slow. Even if the physical properties of the material to be treated change, water is charged or added without excess or deficiency, and the material to be treated is mainly agglomerated and disintegrated by mixing, dispersing, shearing, and kneading by the chopper blade. is generated uniform nucleation after repeated, and that granulated Ru, unique effects are obtained in the present invention. Moreover, since water is added or added without excess or deficiency, the granulated product obtained in the subsequent granulation step also has a desired uniform particle size. According to the second aspect of the present invention, since the amount of auxiliary water added at one time is controlled so that the plastic limit point is reached in a predetermined time, the nucleation time can be lengthened or shortened. In addition, there is a further effect that uniform nuclei are generated and granulated .

  Hereinafter, the granulating apparatus used for carrying out the present invention will be described with reference to FIG. The granulating apparatus 1 used for carrying out the present invention is a horizontal type horizontal granulation container which is a batch type as shown in FIGS. 2 is provided. And in this horizontal granulation container 2, the rotating shaft 30 is provided in the horizontal direction.

The horizontal granulation container 2 has a substantially cylindrical shape. An air vent 3 and a material supply port 4 for supplying an object to be processed into the horizontal granulation container 2 are provided above the horizontal granulation container 2, and an opening / closing lid 5 is similarly provided below that. The granule discharge port 6 is provided. The material supply port 4 is also provided with a water supply pipe 4 ′. A hopper (not shown) is provided above the material supply port 4, and an object to be processed in the hopper is supplied by a mechanical feeder, and water is supplied in an amount controlled by a flow control valve 8. . Both sides of the horizontal granulation container 2 are closed by side walls 7 and 7, and the lower ends of the side walls 7 and 7 are fixed to the foundation. As shown in FIG. 2B, a heat medium jacket 10 is provided on the outer peripheral portion of the horizontal granulation container 2 configured as described above. The jacket 10 for the heat medium is composed of an outer peripheral wall of the horizontal granulation container 2 and a jacket outer peripheral wall 11 provided at a predetermined interval from the outer peripheral wall. This heat medium jacket 10 is provided avoiding the material supply port 4, the granule discharge port 6 and the like. Although not shown in the figure, the inner walls of the side walls 7 are also provided as appropriate. The inside of the jacket 10 for the heat medium configured as described above is a flow path for steam or cooling water. However, a baffle plate, a guide plate, etc. are provided so that these heat mediums are not short-circuited in the jacket 10. It is provided as appropriate.

  As shown in FIG. 2B, a supply connector 12 is attached to the upper end of the jacket 10 for the heat medium, and is opposed to the supply connector 12 at the lower end of the jacket 10. A discharge connector 13 is attached. A heat medium supply pipe 14 is connected to the supply connector 12, and a return pipe 15 is connected to the discharge connector 13. The heat medium supply pipe 14 and the return pipe 15 are connected to a heating or cooling source 20.

  As described above, the rotary shaft 30 is provided in the horizontal direction inside the horizontal granulation container 2 configured as described above. A plurality of arms 31, 31,... Are fixed to the rotating shaft 30 at predetermined intervals in the axial direction and the rotation angle direction, and the stirring granulation blades 32, 32 are attached to these arms 31, 31,. ... are attached. In this embodiment, the agitation granulation blades 32, 32,... Have a bowl shape, that is, an excavator shape, and are driven along the inner peripheral wall of the horizontal granulation vessel 2. The object to be processed is floated, diffused, mixed and granulated by the stirring granulation blades 32, 32,. The rotating shaft 30 to which such agitation granulation blades 32, 32,... Are attached is rotatably supported by bearings 33, (33) fixed to the side walls 7, 7 of the horizontal granulation vessel 2. The outside is connected to an electric motor 35 via a speed reduction mechanism 34. Therefore, when the electric motor 35 is started, the agitation granulation blades 32, 32,... Are rotated at a relatively low speed in a predetermined direction via the speed reduction mechanism.

  As shown in FIG. 2B, in the horizontal granulation vessel 2, there are chopper blades 40, preferably a plurality of chopper blades 40, in addition to the stirring granulation blades 32, 32,. It is provided in a state where it floats in the horizontal granulation container 2. The chopper blade 40 is provided in the vicinity of the lower part of the horizontal granulation container 2 apart from the wall of the container 2, and is lifted by the stirring granulation blades 32, 32,. Therefore, the electric motor 41 provided outside is rotated and driven at a relatively high speed independently of the stirring granulation blades 32, 32,.

  The granulating apparatus 1 according to the present embodiment includes a control device composed of, for example, a microcomputer. This control device and the electric motor 41 that drives the chopper blade 40 are connected by a signal line, and the power consumption of the electric motor 41 or the electric power value of the electric motor 41 that drives the chopper blade 40 is input to the control device. Yes. The control device and the flow control valve 8 are also connected by a signal line. As will be described below, the control device includes a calculation unit, a comparison unit, a storage unit, a setting unit, and the like.

  Next, a granulation method using the above granulator will be described. The control device stores a power consumption pattern of the chopper blade 40 as shown in FIG. Press the start switch on the control unit. Then, the electric motor 35 is activated and the stirring granulation blades 32, 32,. Further, the chopper blade 40 is also rotationally driven by the electric motor 41. From the material supply port 4, an object to be processed such as a predetermined amount of a dehydrated cake that has been weighed is charged. The charged workpiece is lifted by the stirring granulation blades 32, 32,... And falls and hits the chopper blade 40. As a result, the object to be processed is mixed, sheared, and dispersed mainly by the chopper blade 40 in a short time. That is, it is premixed. The power consumption of the electric motor 41 at this time is input to the control device. In the control device, when the premix time T1 is counted, 60 to 90% of the water amount required for one batch is charged. Thereafter, a small amount is added in several batches. This period T2 is a nucleation process in which “nuclei” that become the “core” of the granulated product are formed, and kneading is performed until nucleation generation, that is, “plastic limit point”. The power consumption during this period T2 increases. Eventually, the maximum power consumption value Max at the stored plastic limit point is reached. Water addition is stopped. Thereby, the nucleation process period T2 ends.

  Although the water is applied in small quantities, it may be too much because it is introduced in several batches. Therefore, if necessary, a small amount of the object to be processed is secondarily charged (T3). In the period T3 after the secondary charging, the power is stable and no change is observed. This period T3 is a period that can be said to be a pre-granulation period.

  After this, a granulation process is started in which neither an object to be treated nor water is added. In this period T4, the object to be processed is agitated and the nuclei adhere or bond together and granulated. Electric power decreases rapidly and then decreases gradually. At time E when the decrease is slow, the opening / closing lid 5 of the granule discharge port 6 is opened, and the granule is taken out. Alternatively, the chopper blade 40 is stopped without taking out the granulated material, and the driving of the stirring granulation blades 32, 32,. The granulation gradually grows and the power turns to a gentle rise. This period T5 is a particle size control process. In the next period T6, the electric power starts decreasing in the sizing process. The granulated material becomes tight and the strength increases. When no power drop is observed, the granule discharge port 6 is opened at time G to take out the granule.

  When granulation is performed as described above, for example, when the temperature is low at the start-up in a cold region, preheat by flowing warm water through the jacket 10 for the heat medium, and when the temperature is too high after entering the operation, flow cooling water, etc. Then, the inside of the horizontal granulation container 2 is kept at a predetermined temperature. Thus, one batch of processing is completed. The granulation is performed by the batch operation as described above.

  Regarding the operation of the above-described embodiment, it has been described that when the power consumption of the chopper blade 40 reaches the maximum power value of the plastic limit point, a small amount of the secondary workpiece is thrown in. However, the secondary workpiece is thrown in. It is clear that the granulation process can be continued without any change. In the above description, only the stirring granulation blades 32, 32,... Are driven during the particle size control step (T5) and the sizing step T6, but the stirring granulation blades 32, 32 are also used during these steps. ,... And both the blades of the chopper blade 40 can be driven. If it carries out like this, a granulated material will be refined | miniaturized by the following particle size control process T5. Further, when the nucleation step T2 is finished, it is clear that the chopper blade 40 can be granulated by reducing the rotation speed of the chopper blade 40 and the speed of the stirring granulation blades 32, 32,.

  Example etc .: The following test 1 shows the granulation conditions when an electric furnace dust collection ash having a moisture content of 2% is used as the object to be processed and a granulated product having a desired particle diameter is obtained. Similarly, the moisture content is adjusted in advance, and the granulation conditions when 10% electric furnace dust collection ash is used are shown in the following test 2. The granulation conditions when a dehydrated cake with a moisture content of 15% is used for the object to be treated are shown in the following test 3.

なお、時間Ｔ３における２.１ｋｗが核化生成完了時、すなわち塑性限界点に達したときの最高電力値Ｍａｘである。 "Test 1"
Granulator: A mixer with ski shovel blades manufactured by Taiyo Kiko Co., Ltd. was used. The capacity of this apparatus is 3.5 m ³ , 6 stirring granulation blades, 8 stages of chopper blades × 3 units, an output of 37 kw of an electric motor for driving a rotating shaft to which the stirring granulation blades are attached, chopper blades 1 The output of the electric motor for driving the table is 11 kW.
Product to be treated: Electric furnace dust collection ash, moisture content 2%, 1 batch processing amount 170kg
Test conditions: The electric furnace dust collection ash was charged with 130 kg of 76% of 170 kg in the first charge, and 40 kg of 24% in the second charge. Water was added in an amount of 40 kg in the primary, and auxiliary water was added in 4 to 5 times and 1 kg per time. Times T1 to T4 such as mixing and dispersion drive the stirring granulation blade and the chopper blade, and T5 and T6 drive only the stirring granulation blade. As the power at that time, as shown in FIG. 1B, an average of three points of the maximum value and the average value of the minimum value for t seconds was adopted. The driving time (seconds) and power consumption (kw) were as shown in Table 1 below.
Table 1

In addition, 2.1 kw at time T3 is the maximum power value Max when nucleation generation is completed, that is, when the plastic limit point is reached.

なお、含水率が１０％で試験１の２％よりも高かったので、プレミックスＴ１時における消費電力は試験１よりも多少高かったが、他のＴ２〜Ｔ６において差は認められなかった。 "Test 2"
Granulator and test conditions: The same apparatus as in Test 1 was used and the same conditions were used.
Product to be treated: Electric furnace dust collection ash, water content 10%, 1 batch processing amount 170kg
The results are shown in Table 2.
Table 2

In addition, since the water content was 10% and higher than 2% in Test 1, the power consumption during premix T1 was slightly higher than that in Test 1, but no difference was observed in other T2 to T6.

脱水ケーキの含水率が１５％と大きかったので、プレミックスＴ１における消費電力は1.5〜1.6ｋｗのように比較的大きかったが、この時間Ｔ１内に電力の変化が認められないので、核は生成されていないと考えられる。他の時間Ｔ２〜Ｔ６において消費電力に格別な差は認められなかった。 “Test 3”
Granulator and test conditions: The same apparatus as in Test 1 was used and the same conditions were used.
Material to be treated: sludge dehydrated cake, water content 15%, 1 batch processing amount 170kg
The results are shown in Table 3.
Table 3

Since the moisture content of the dehydrated cake was as large as 15%, the power consumption in the premix T1 was relatively large, such as 1.5 to 1.6 kW, but no change in power was observed within this time T1, so the nucleus was generated It is thought that it is not done. There was no particular difference in power consumption at other times T2 to T6.

  From the above tests 1 to 3, it can be said that the relationship between the power and the time when a desired granulated product is obtained even when the physical properties of the object to be processed change draws substantially the same pattern.

It is a figure which shows embodiment of this invention, The (b) is a figure which shows the relationship between the power consumption value of the electric motor which drives a chopper blade | wing, and granulation time, The (b) is the sampling method of an electric power value. FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the granulation apparatus used for implementation of this invention, the (a) is a typical perspective view which fractures | ruptures a part, (b) is typical sectional drawing which also shows 1 process of a granulation state It is.

Explanation of symbols

2 Horizontal granulation container 6 Sediment discharge outlet
30 Rotating shaft 32 Agitation granulation blade 35 Electric motor (for agitation granulation blade drive)
40 Chopper feather
41 Electric motor (for chopper blade drive)

Claims (2)

A horizontal granulation container into which an object to be treated and water are charged , a stirring granulation blade attached to a rotary shaft provided in the horizontal granulation container, and the stirring granulation in the horizontal granulation container using the granulating device is composed of a chopper blade which is rotationally driven at a higher speed than the grain blade, when obtaining a granulated product of said chopper blade and the agitating granulation blade from the rotary drive to the article to be treated ,
The control device, the time and the premix an object to be processed to drive rotating the said agitating granulation blade said chopper blade, with the chopper blade or to store the power consumption of the stirring granulation blade in plastic limit point Every
Wherein an object to be processed collectively put into a horizontal granulation vessel, and the chopper blade and the stirring granulation blade driven to rotate, in time premix being the storage,
After premix was poured 60-90% water of the total input amount expected by kneading, the chopper blade or minor amounts of auxiliary water to the power of the stirring granulation blade reaches the power consumption being the storage Add to multiple times ,
After that, a small amount of material to be treated is secondarily charged, and the stirring granulation blade and the chopper blade are rotated and granulated until the decrease in power is slow . Granulation method. The granulation method according to claim 1, wherein the amount of auxiliary water added at one time is controlled so that the plastic limit point is reached in a predetermined time.

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