JPH0333374B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a stirring device. More specifically, a horizontal cylindrical container has a built-in stirring means in which many paddles are attached to a rotating shaft, and two or more fixed weirs are fixed to the peripheral wall of the container perpendicularly to this rotating shaft. The present invention relates to a horizontal uniaxial stirring device in which the width and attachment of adjacent paddles across a weir are specially configured, and which is suitably used as a polymerization device, a post-processing device, a dryer, etc. [Prior Art] A stirring device in which a horizontal uniaxial stirring means is built into a horizontal cylindrical container has long been known as a stirring device for polymer particles such as polyolefin. As one of these stirring devices, it is used to completely mix polymer particles, catalyst particles, etc. (hereinafter sometimes referred to as powder and granules), improve heat removal efficiency, and further improve the retention of powder and granules in a container. In order to narrow the width of the time distribution (hereinafter sometimes abbreviated as RTD), that is, to make the residence time uniform (hereinafter sometimes referred to as improving RTD), the rectangular flat paddle is placed horizontally. In addition to horizontal uniaxial stirring means installed in large numbers on a rotating shaft, there is also known a stirring device capable of continuous processing in which one or more fixed weirs are fixed to the inner wall of a container in a direction perpendicular to the rotating shaft. There is (Tokuko Akira)
59-21321). [Problems to be Solved by the Invention] However, this type of fixed weir is simply added to the conventional stirring means and is internally installed in each stirring zone (hereinafter sometimes simply referred to as zone) separated by the fixed weir.
Even if mixing or heat removal efficiency could be improved with a stirring device consisting of only 1, a sufficient improvement in RTD could not be obtained. Now, regarding an agitation device that has two fixed weirs and three zones, in one zone, after the powder is stirred for the average residence time in that zone, it is transferred to the next adjacent zone. Assuming that the entire amount is transferred by piston flow, that is, that each zone is batch-operated and transferred sequentially, the greater the number of zones, the greater the stirring effect. This effect is called the tank number effect, and the tank number effect for one zone on this effect is 1,
If the overall tank number effect is expressed as the sum, in the case of three zones as described above, the total tank number effect is three. However, when the above-mentioned conventional stirring device, which is simply equipped with a fixed weir in addition to the conventional stirring means, is operated continuously, short pass particles and long-term residence particles exist in each zone, and the effect of the number of tanks is limited to zone 1.
The number is less than 1 in half, and the total number is less than 3. Furthermore, when the rotational speed is increased in an attempt to achieve complete mixing, even though two fixed weirs are installed, the powder and granules become fluid and the amount of material that exceeds the fixed weirs from both sides becomes fluid. In many cases, the overall effect of the number of tanks approached 1, meaning that the effect of installing a weir was hardly noticeable. In this way, with conventional stirring devices that simply incorporate a fixed weir in addition to conventional stirring means, powder and granule material
There was a problem that it was very difficult to improve RTD. For example, in stirring equipment for olefin polymerization or polyolefin drying,
The presence of pass particles and the like causes nonuniform quality, deterioration of physical properties, poor appearance, etc. in the obtained polyolefin, and therefore, an early solution to the problems of the above-mentioned prior art has been desired. [Means for Solving the Problems] The present invention solves the problems of the prior art as described above, and makes it possible to perform continuous stirring with uniform residence time of powder and granules on an industrial scale for a long period of time. This was achieved as a result of intensive research with the aim of providing a horizontal, single-shaft stirring device that can be used as a stirrer. That is, the present invention provides a horizontal cylindrical container having a supply port for the material to be stirred at one end and an outlet for the powder or granular material at the other end, and one or more sheets at each of a plurality of positions on the horizontal rotation shaft. A horizontal uniaxial stirring device having a built-in stirring means consisting of a plurality of paddle sets each having rectangular flat paddles attached thereto, the stirring device being fixed to the inner wall of the container in a direction perpendicular to the rotation axis. The inside of the container is divided into three or more stirring zones by two or more fixed weirs, and each adjacent paddle set group consisting of two adjacent paddle sets with each fixed weir in between is divided into the following stirring zones for each adjacent paddle set group. A stirring device characterized by satisfying conditions (i) to (iv) and satisfying conditions (vii) to (viii) between adjacent groups of paddle sets; (i) The number of paddles in the two paddle sets is equal. . (ii) β=0゜, (iii) D/100≦l ₁ ≦D/20, (iv) l ₂ /l ₁ ≧1 (v) 1≦S ₂ /S ₁ ≦5 (vi) 1＜W ₁ /W ₂ ≦4 (vii) 1≦W ⁿ⁺¹ ₁ /W ⁿ ₁ <2 (viii) Between all adjacent paddle groups, l ₁ to each other, l ₂ to each other,
S _1s , S _2s , and W _2s are each equal to each other. [Here, β: Phase angle difference formed by each paddle on the projection plane perpendicular to the rotation axis between adjacent paddle sets across the fixed weir, D: Inner diameter of the horizontal cylindrical container (mm), l ₁ : Clearance between the inner wall of the container and the paddle tip of the paddle assembly on the supply port side (mm), l ₂ : Clearance between the inner wall of the container and the paddle tip of the paddle assembly on the extraction port side (mm), S ₁ : Paddle on the supply port side Clearance between the paddles of the group and the fixed weir (mm), S ₂ : Clearance between the paddles of the paddle group on the outlet side and the fixed weir (mm), W ₁ : Paddles of the paddle group on the supply port side of the adjacent paddle group width, W ₂ : Width of the paddle of the paddle group on the outlet side of the adjacent paddle group group, n : All integers from 1 to a number less than 1 than the number of fixed weirs, W ⁿ ₁ : Counting from the supply port side Width of the paddle set on the supply port side of the n-th adjacent paddle set group, W ⁿ⁺¹ ₁ : Width of the paddle set on the supply port side of the (n+1)th adjacent paddle set group counting from the supply port side This relates to the width of the paddle. [Description of Configuration] The stirring device according to the present invention will be explained in detail with reference to the drawings. Fig. 1 shows the device of the present invention, A is a side explanatory view schematically and transparently showing the entirety of one embodiment thereof, and B is a diagram showing two adjacent paddle sets (adjacent) across a fixed weir in another embodiment. A side explanatory view illustrating a part of the configuration including a paddle set) together with an example of the formation state of the powder/granular material deposition surface corresponding to the rotational position of the adjacent paddle set;
The figure is an explanatory view seen in the direction of the arrow from line A-A in FIG.
Figure 3 is an explanatory diagram of the adjacent paddle sets viewed from the same position as Figure 2 when the phase angle difference of the paddles is 90°, and Figure 4 is an illustration of the adjacent paddle sets rotated 90° from the state shown in Figure 3. An explanatory diagram showing the state. Figure 5 is an explanatory diagram showing the height of the powder accumulation surface that changes as the paddle group rotates when stirring the powder. Figures 6 to 10 are illustrations of both adjacent paddles. FIG. 6 and FIG. 7 are explanatory diagrams showing the case where the widths of the paddles in the set are equal, and FIGS. A side explanatory view showing the positions of the paddle sets in two extreme cases corresponding to Fig. 4, and Figs. 8, 9, and 10 show the arrangement of the fixed weir and the adjacent paddle sets on both sides. FIG. 3 is a side explanatory view showing various embodiments and the formation state of a surface on which a powder or granular material is deposited. In the drawings, 1 is a horizontal cylindrical container (diameter D, length L, L/D=3.0), as shown in FIG.
It has a supply port 2 for the material to be stirred at one end and a discharge port 3 for the powder and granular material at the other end. A horizontal rotating shaft (diameter d) 4 is provided at the cylindrical axis position in this horizontal cylindrical container (hereinafter sometimes simply referred to as a container) 1, and a horizontal rotating shaft (diameter d) 4 is provided at each of a plurality of positions on this rotating shaft 4. As shown in FIGS. 1 and 2, a plurality of paddle sets 5 each having one or more rectangular flat paddles (two in the illustrated example) are provided along almost the entire length of the rotating shaft 4. The rotating shaft 4 constitutes a stirring means. This stirring means and the container 1 containing it constitute a horizontal uniaxial stirring device. Although the number of paddles in each paddle set 5 is two in the illustrated example, this is not necessarily necessary; for example, paddle sets 5 consisting of different numbers of paddles, such as one, two, or three, may be mixed. In addition, the width of the paddles does not necessarily have to be unified as shown in the example (excluding paddle sets that are adjacent across the fixed weir), and paddles of various sizes and widths W may be mixed. There isn't. However, as described later, the number of paddles and the widths W ₁ and W 2 of two paddle sets that are adjacent to each other across each fixed weir must satisfy certain conditions (here, the number of paddles and the widths W 1 and W ₂ of two paddle sets that are adjacent to each other with each fixed weir in between) must meet certain conditions. The paddles of all paddle groups other than the above are referred to as general paddles, and their widths are comprehensively indicated by W). 7 is a fixed weir, and as shown in FIGS. 1 and 2, two or more (three in the example) of the fixed weirs extend the length L of the container 1 in the direction perpendicular to the rotation axis 4 to, for example, approximately the same length. It is fixed to the inner wall of the container, leaving a half-moon-shaped (consisting of an arc and a chord, and does not necessarily mean a semicircle) opening 8 between the inner wall and the upper part of the container at the position where the fixed weir is divided into two parts. 7, the inside of the container 1 is divided into one more stirring zone than the number of fixed weirs 7. zone, third zone, etc., and the stirring zones on the supply port 2 side and the outlet port 3 side with respect to one fixed weir 7 are sometimes called the upstream zone and the downstream zone, respectively). By the way, in the device of the present invention, this fixed weir 7
Two adjacent paddle groups (each may be referred to as an adjacent paddle group, and both adjacent paddle groups sandwiching one fixed weir 7 are collectively referred to as an adjacent paddle group group 9), that is, the supply port 2 side (Upstream side)
The adjacent paddle set 5a located at A feature of the present invention is that conditions (vii) to (viii) are satisfied among the paddle set groups 9. The horizontal cylindrical container 1 used in the device of the present invention has a ratio L/D of length L to diameter D.
is preferably 1.0 or more. Further, it is preferable that the area of the opening 8 of the fixed weir 7 is not larger than 30% of the cross-sectional area of the container 1/4πD ² . The shape of the opening 8 is basically preferably a half-moon shape as shown in FIG. 2, but there is no particular restriction other than that the arc of the container peripheral wall is included as part of the periphery of the opening 8. [Function] Hereinafter, the function of the device of the present invention will be explained together with the history of development of the device of the present invention. Even if it is a horizontal uniaxial stirring device in which two or more fixed weirs 7 are provided, if the above conditions for the adjacent paddle groups 5a and 5b are not satisfied for each adjacent paddle group group 9, for example, if the The width W ₁ of the paddle 6a and the width W ₂ of the paddle 6b of the paddle sets 5a and 5b are mutually equal, but the paddles 6a and 5b are equal in width.
If the number of paddles b is different from each other, or if the number of paddles is the same but the phase angle difference β of at least some of the paddles of both adjacent paddle sets 5a and 5b is not 0° (in the former case, the phase angle difference of the paddles is is naturally the same as the latter case), the flow pattern in the axial direction in which the powder and granules pass through the opening 8 above the fixed weir 7 is not unidirectional, but is stirred by the paddle set 5b on the downstream side. In some cases, the lifted powder and granules move backward over the fixed weir 7. At the opening 8 above the fixed weir 7, if the granular material only moves from the upstream zone to the downstream zone, the effect of the number of tanks will appear to some extent, but if the above conditions are not satisfied, the downstream zone There is also a reverse movement from the upstream zone to the upstream zone, and the amount of granular material movement from the upstream zone to the downstream zone increases by the amount of this reverse movement, resulting in an increase in the short pass and making the residence time non-uniform. Further, the amount of reverse movement per unit time increases as the number of revolutions increases, and in extreme cases, even if two or more fixed weirs 7 are installed internally, the effect will hardly be seen. The results of various studies regarding these phenomena will be explained in detail. Although the following explanation is about one adjacent paddle set group 9, it is applicable to any of two or more adjacent paddle set groups 9. First, the process of setting the conditions (i) to (v) will be explained with reference to FIGS. 3 to 7. When setting conditions (i) to (v), first, paddles 6 of both adjacent paddle sets 5a and 5b are set.
Consider the case where the widths W ₁ and W ₂ of b and 6b are equal. Both adjacent paddle sets 5a and 5b sandwiching the fixed weir 7 shown in FIG. The opening angle α° formed by both is set to 180°. Each paddle 6a and 6b1 are provided between both adjacent paddle sets 5a and 5b.
There is a phase angle difference β for each of the two pairs of sheets, but in the above example, the phase angle difference β is set to 90 degrees for both sets as an example of a case where the phase angle difference β is not 0 degrees. These paddle sets 5
When a and 5b are rotated 90 degrees from the position shown in Figure 3, they become the fourth position.
It will be in the position shown in the figure. Generally, when the paddle set 5 is rotated while the stirring device holds a suitable amount of powder (often about 60% by volume of the device), the slope of the surface on which the powder is deposited will change. The height of the top area varies up and down. The state of change is the property of the powder or granule,
Although it varies depending on the rotation speed, amount held, etc., paddle set 5
reaches the angle of repose approximately in the vicinity of the rotational position shown in FIG. 5, and at this time, the entire top area of the powder deposited surface reaches the highest level (represented by HL). Furthermore, the paddle set 5 is moved to 1/2 of the opening angle α from the rotational position shown in FIG.
When rotated (90 degrees in the illustrated example) (the rotational position of the paddle set 5 is not shown), the entire top area of the powder deposition surface becomes the lowest level (represented by LL). Also,
When the paddle set 5 is in the middle of the above two rotational positions, the entire top area of the powder deposition surface is at the average level (represented by AL) between HL and LL. Therefore, the level of the entire top area of the powder and granular material accumulation increases during the rotation of the paddle set 5.
It changes like HL→AL→LL→AL→HL. Here, as shown in Figs. 3 and 4, when the phase angle difference β between adjacent paddle sets is 90°, and the phase angle difference between other mutually adjacent paddle sets is also 90°, based on the above results, Upon examination, as shown in FIGS. 6 and 7, adjacent paddle sets 5a,
When the entire top area of the powder/granular material accumulation surface in one of the areas 5b is at the level HL, the level of the entire top area of the powder/granular material accumulation surface in the other adjacent paddle group 5a or 5b is always at the level LL. Therefore, when stirring the powder by continuously rotating the rotating shaft 4, the adjacent paddle sets 5a and 5b are placed in the position shown in FIG. 3 (the adjacent paddle set 5a is in the position shown in FIG.
), as shown in Figure 6,
The entire top area of the powder/granular material accumulation surface in the adjacent paddle group 5a area is at level HL, and the entire top area of the powder/granular material accumulation surface in the adjacent paddle group 5b area is at level LL. Since the granular material moves in the axial direction from the high level HL to the low level LL direction, in the case of Fig. 6, the granular material naturally moves over the fixed weir 7 from the upstream zone to the downstream zone. do. When the rotating shaft 4 further rotates and the adjacent paddle sets 5a and 5b come to the position shown in FIG. 4, as shown in FIG. The level of the entire top area is shown in Figure 7.
HL and LL are reversed, and the granular material crosses the fixed weir 7 and moves backward from the downstream zone to the upstream zone. This reversal phenomenon of levels HL and LL occurs at equal time intervals in the above example due to the relationship between the phase angle difference β and the paddle opening angle α, but even when it occurs at unequal intervals, the state of movement of the powder and granules may be affected. are basically the same. In this way, when the height of the level of the entire top area is alternately reversed between the powder and granule accumulation surfaces of the adjacent paddle sets 5a and 5b with the fixed weir 7 in between, a reverse movement phenomenon of the powder and granules always occurs. It was found that on the one hand, long-term residence particles were generated, and on the other hand, many short-pass particles were generated, making the residence time uneven.
As a result of further studies in order to reduce this reverse movement phenomenon, it was found that the respective levels of the top area of the powder and granular material accumulation surface scraped up by the rotating paddles 6a and 6b of the adjacent paddle sets 5a and 5b at the same time. Paddle 6 that is the same and does not cause a difference in
We have come to the realization that the arrangement of a and 6b is important. Then, the conditions for that are 5 adjacent paddle groups.
Paddles 6a and 6b of a and 5b have a rectangular shape with the same width, and as shown in FIG. 8, clearances l ₁ and l ₂ with the inner wall of the container 1 (l ₁ and l ₂ in FIG. 8 are ,
Since this is a slightly oblique view of the clearance between the tips of the paddles 6a, 6b and the inner wall of the container, only their positions are shown. The same applies to FIGS. 9, 10, and 1B. ) are equal and the clearances S ₁ and S ₂ with the fixed weir 7 are also equal, and the following conditions were recognized as the basic conditions for equalizing residence time. (i) Paddle 6a between both adjacent paddle sets 5a and 5b,
The numbers of 6b are equal. (ii) Each paddle 6 between both adjacent paddle sets 5a and 5b.
The phase angle difference β between a and 6b is 0°. In other words, condition (ii) means that both adjacent paddle sets 5a,
1 set 2 consisting of one each of paddles 6a and 6b of 5b
This means that the paddles 6a, 6b coincide as shown in FIG. 2 when viewed in the direction of the rotating shaft 4, but it is not necessarily necessary that the opening angles α are the same. In this case, no matter where the level of the top area of the powder accumulation surface in each region of both adjacent paddle sets 5a and 5b is in any state from HL to LL, for example, in the case of HL, as shown in FIG. Unless the powder is supplied from the supply port 2 and flows into the upstream zone, the slope of the powder accumulation surface at the opening 8 above the fixed weir 7 is the same on both sides of the fixed weir 7, and the powder pressure is balanced. The trough P' where the slopes on both sides intersect is formed directly above the fixed weir 7 and is on the upward extension surface P of the fixed weir 7, so that the movement of powder and granules over the fixed weir 7 does not occur. . Such a fixed weir 7 and adjacent paddle set 5a,
In the arrangement 5b, when the powder is supplied from the supply port 2 and flows into the upstream zone, only the increase in the upstream zone results in a slight level difference.
The powder exhibits a flow pattern in which it only moves from the first zone to the second zone. Next, the paddle 6 is moved between both adjacent paddle sets 5a and 5b.
Even if the numbers of a and 6b are equal and the phase angle difference β is 0°, if the area of the opening 8 of the fixed weir 7 is large, the rotation speed is high, or the amount of powder and granular material held is large For example, the degree of scattering of powder particles in the axial direction increases, and prevention of short passes and reverse movement due to scattering is not always sufficient. As a result of various studies on preventing such scattering or reverse movement, we found that the paddles 6a and 6b of both adjacent paddle sets 5a and 5b satisfy l ₂ /l ₁ ≧1 and S ₂ /S ₁ In the case of ≧1, it was recognized that the preventive effect was sufficient.
The case of l ₂ /l ₁ =1 and S ₂ /S ₁ =1 is as seen earlier in FIG. When l ₂ /l ₁ > 1 and S ₂ /S ₁ = 1, the powder and granular material is shown in Figure 9, and when l ₂ /l ₁ = 1, S ₂ /S ₁ > 1, it is shown in Figure 10. The formation state of the entire top area of the deposition surface is shown. In both FIGS. 9 and 10, the trough P' formed by the contact between the powder and granule accumulation surfaces of both adjacent paddle sets 5a and 5b is on the downstream side of the upper extension surface P of the fixed weir 7. It is located on the zone side, and the existence of an axial distance Hs between the valley P' and the plane P is recognized. The existence of this distance Hs on the downstream zone side means that the powder pressure at plane P is directed from the upstream zone to the downstream zone, and Hs
The larger the value, the more difficult it is for the powder to move backwards. Next, we empirically determined in many experiments what range l ₁ should practically be set in relation to the inner diameter D of container 1, and found that the appropriate range for l ₁ is (iii) D/100 It was found that ≦l ₁ ≦D/20. Further, the larger S ₂ /S ₁ is, the more effective it is in preventing reverse movement, but on the other hand, if it is too large, the state of stirring of the powder and granular material in the clearance S ₂ will deteriorate, and if it is too large, it will become a dead space. Regarding this point as well, it has been empirically determined that (') 1≦S ₂ /S ₁ ≦20 is an appropriate range. As described above, first, both adjacent paddle groups 5
For the case where the widths W ₁ and W ₂ of the paddles 6a and 6b of the paddles 6a and 5b are equal, conditions are set that are effective for preventing the powder from moving backwards. The thus obtained stirring device has a significantly improved ability to prevent back movement of powder and granules compared to a stirring device in which the fixed weir 7 is simply installed in addition to the conventional stirring means. Ta. However, after many experiments, the following phenomenon was observed. In other words, as the granular material moves from the upstream side to the downstream side within the stirring device, its properties change due to the effects of heating, drying, etc., and its flow characteristics improve, or its fluidity characteristics temporarily improve. Due to reasons such as an increase in the reaction rate in a certain stirring zone, the average level of powder and granular material accumulation in the subsequent downstream stirring zone may be higher than that in the upstream stirring zone. In such cases, even if the above-mentioned conditions (i) to (') are set to the best, there are still cases where it is insufficient to prevent the reverse movement of the powder or granules. We reconsidered the conditions for solving these problems. As a result, it is very effective to have an average level of particulate material accumulation in the downstream zone lower than that in the upstream zone, so that in each adjacent paddle set 9 It has been found that making the width W ₁ of the paddle 6a of the adjacent paddle group 5a larger than the width W ₂ of the paddle 6b of the adjacent paddle group 5b on the downstream side (that is, W ₁ /W ₂ >1) brings about good results. . Therefore, conditions (i) ~ (′)
Instead, we manufactured and tested a stirring device in which the widths W ₁ and W ₂ of the paddles 6a and 6b were in the above-mentioned size relationship.
As shown in Comparative Example 2 below, there were many cases in which good results were not obtained. As a result of further investigation, this condition of W ₁ /W ₂ > 1 is combined with the condition of W ⁿ⁺¹ ₁ /W ⁿ ₁ ≧1, that is, each W ₁ is directed from the supply port 2 side to the extraction port 3 side. By adding to conditions (i) to (') by increasing the same or sequentially,
The effect of sequentially lowering the average level of powder and granular material accumulation in each stirring zone from the side toward the outlet 3 side is added to the previously obtained effects regarding l ₁ /l ₂ and S ₁ /S ₂ Therefore, compared to a stirring device in which the fixed weir 7 is simply installed in addition to the conventional stirring means, the effect of further improving the ability to prevent the back movement of powder and granules was obtained. This effect was particularly significant when W ⁿ⁺¹ ₁ /W ⁿ ₁ >1. Through numerous implementations, the width W ₁ of the paddles 6a and 6b is determined for each adjacent paddle set group 9.
Regarding the above condition ('), which was once set for the case where W ₂ is equal, (v)1≦S ₂ /S ₁ ≦5,
Also, for W ₁ /W ₂ > 1, (vi) 1<W ₁ /W ₂ ≦4
( _vii ) 1≦W ^{n+ 1} _{1 /} ^W The condition ⁿ ₁ <2 was set. The reason why the upper limit of W ₁ /W ₂ was limited to 4 in condition (vi) is that when considering the torque fluctuation width ΔT (twice the difference between the peak torque and the average torque) of the stirring device, W (general paddle △T is the smallest when the paddle width), W ₁ , and W ₂ are all equal, but if the width of each paddle is large or small, △T becomes large, and W ₁ /
This is because when W ₂ exceeds 4, ΔT tends to increase rapidly. Among the conditions (vii), preferably 1.2≦W ⁿ⁺¹ ₁ /W ⁿ ₁ ≦1.5. Furthermore, even if conditions (i) to (vii) are satisfied, between adjacent paddle group groups 9, _l1 to each other, _l2 to each other, S1 to _each other, S ₂ to each other,
When W ₂ are different from each other, the movement of the powder and granules may be disturbed between the stirring zones and the above effect may be insufficient, so in order to ensure this effect,
Condition (viii) is set that each of the above values is equal among all adjacent paddle group groups 9. Therefore, according to conditions (vi), (vii), and (viii), W ₁ becomes equal or larger from the upstream side to the downstream side, but the adjacent paddle set group 9 with W ₁ /W ₂ = 4 If there is, then each W ₁ is equal in all downstream adjacent paddle group groups 9 and W ₁ /W ₂ = 4
It is. Among all adjacent paddle group groups 9, there are two or more adjacent paddle group groups 9 with different W ₁ /W ₂ , that is, all W ₁
It is preferable that there are two or more types of W ₁ , such as a small W ₁ on the upstream side and a large W ₁ on the downstream side. As described above, the stirring device according to the present invention was constructed. In one embodiment shown in FIG. 1A,
In each adjacent paddle set group, l ₂ /l ₁ >1, S ₂ /S ₁
= 1, and in the other embodiment shown in FIG. 1B, l ₂ /
l ₁ >1 and S ₂ /S ₁ >1. Next, we further investigated l ₂ /l ₁ and S ₂ /S ₁ through many experiments, and found that (iv) 1≦l ₂ /l ₁ ≦3 (vi) 1≦W ⁿ⁺¹ ₁ /W ⁿ If ₁ ≦1.2, it is suitable for stirring powder with a relatively narrow particle size distribution.
In addition, (iv) l ₂ /l ₁ =1 (v) 2≦S ₂ /S ₁ ≦3 (vi) In the case of 1≦W ⁿ⁺¹ ₁ /W ⁿ ₁ ≦1.2, other than the above granular material It has been found that these methods are particularly suitable for stirring powder particles having a shape close to a spherical shape. [How to use] The use of the device of the present invention is not particularly limited, but it can be used as a gas phase polymerization device for gas phase polymerization of α-olefin having 2 to 6 carbon atoms together with a catalyst containing a transition metal compound, and for post-treatment after gas phase polymerization. It is preferably used as a gas phase reaction device, a polymer drying device, etc. When carrying out gas phase polymerization of olefins using the apparatus of the present invention in this way, the rotation is performed so that the Froude number (Fr) shown below is in the range of 0.05 to 3.0, preferably in the range of 0.2 to 2.0. It is better to let Fr=Rω ² /g where R: length from the center of the rotation axis to the tip of the paddle, ω: angular velocity (=2πN, N is the rotation speed rps) g: gravitational acceleration Also, the amount held in the container is 10 to 80% by volume It is preferable to carry out continuous treatment. In this case, it is preferable that the retention levels in each zone be equal, or that the retention level in the downstream zone be slightly lower than that in the upstream zone, in order to further ensure prevention of reverse migration. When the object to be stirred is a polymer, examples of the types include ethylene polymer, propylene polymer, butene polymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, propylene-butene-1 copolymer, propylene-butene-1-ethylene copolymer, etc. can be given. [Effect] If the stirring device according to the present invention is used, in addition to increasing the number of stirring zones by providing two or more fixed weirs, each adjacent paddle set group can be specially controlled for each adjacent paddle set group, and By specially configuring the relationship between polymer particles, the amount of shots and passes of polymer particles, etc. can be extremely reduced, and the residence time of powder and granules can be made uniform. The RTD of granules can be approximated to the RTD of batch polymerization or batch processing, and therefore the quality, physical properties, etc. of the stirred object can be improved. [Examples and Comparative Examples] The present invention will be specifically described below using Examples and Comparative Examples. Example 1, Comparative Examples 1 to 3 Inner diameter D is 430 mm, length L is 1320 mm (L/D = 3)
Various embodiments of the present invention apparatus in which paddles having two or more predetermined widths are attached to a rotating shaft with a diameter d of 110 mm in a horizontal cylindrical container, the presence or absence of a fixed weir, the width of the paddle, and the attachment mode Using a horizontal uniaxial stirrer outside the scope of the present invention, polypropylene inert powder with a relatively narrow particle size distribution with a median diameter of 600 μ and a bulk density of 0.5 g/cm ³ was mixed at 15 kg/hr.
Continuous stirring was performed at a rotational speed of 60 rpm (Fr = 0.826) while continuously supplying the powder, and the amount of powder and granular material held during steady operation was maintained at 60% by volume of the device capacity. In this case, since the actual volume of the device is 179, the average residence time φ is 3.58 hours (215 minutes). During this steady operation, 270 g of the same colored polypropylene powder (equivalent to 0.5% by weight of the amount held) as a tracer was injected into the supply port of the powder and granules, and the tracer in the polymer was extracted at the outlet of the powder and granules. The concentration of was measured over time and its change (hereinafter sometimes referred to as impulse response) was investigated. Based on this impulse response, the uniformity of the residence time of the powder and granular material in each Example and Comparative Example was investigated. Example 1 Three fixed weirs of the same shape are installed in each position that divides the length L of the container into approximately four equal parts, leaving a half-moon-shaped opening with an area of 100 cm ² above, and all paddle sets are The number of paddles is two, the opening angle α is 180°, and the phase angle difference between adjacent paddle sets in each zone divided by each fixed weir is 90°. The clearance l with the tip is all 5.0mm, and the width W of the general paddle
is 40 mm, and three adjacent paddle group groups (n=
1, 2, and 3), l ₁ = l ₂ = 5.0 mm [Therefore, l ₂ /l ₁ = 1, D/100
(=4.3) <l ₁ <D/20 (=21.5)] S ₁ = S ₂ = 8.0mm [Thus, S ₂ /S ₁ = 1] β = 0°W ¹ ₁ = W ² ₁ = W ³ ₁ = 50mm W ¹ ₂ = W ² ₂ = W ³ ₂ = 40mm (therefore, W ₁ /W ₂ > 1,
In the case of the device of the present invention, W ⁿ⁺¹ ₁ /W ⁿ ₁ =1). Comparative Example 1 A stirring device similar to Example 1, except that it does not have a fixed weir and a group of adjacent paddle sets, and the phase angle difference of the paddles between all mutually adjacent paddle sets is 90°. Comparative Example 2 A stirring device similar to Example 1 except that β = 90° between both adjacent paddle sets in any of the adjacent paddle set groups. Comparative Example 3 In each of the second and third adjacent paddle set groups counted from the upstream side, the number of paddles in the downstream adjacent paddle set is 3 and each opening angle α is 120°, and the upstream side For one paddle, β = 0° with respect to the adjacent paddle group, but for other paddles, there is no paddle for which β = 0° (therefore, for each adjacent paddle group, when viewed in the direction of the rotation axis, There is only one set of matching paddles, and in the third and fourth zones, the paddle phase angle difference between the adjacent paddle set on the downstream side of the fixed weir and the adjacent paddle set on the downstream side is not necessarily 90. In the case of the same stirring device as in Example 1 except for Impulse response is sampling time function t/φ
It is shown as the change in the tracer concentration function e/e ₀ with respect to Here, t is the elapsed time (sampling time) from tracer injection until sampling at the powder outlet, that is, the actual residence time of the tracer in the container, φ is the average residence time, and e is the tracer at time t at the powder outlet. Concentration (wt%). e ₀ is the tracer concentration relative to the amount of tracer input to the amount of polymer held in the container.

[Table] Generally, when t/φ is about 0.2 or less, the larger e/e ₀ is, the more short passes there are, and the more the peak value of e/e ₀ is in the relatively large region of t/φ, the more
The number of short passes tends to decrease relatively. From Table 1, it is clear that not only Comparative Example 1, which does not have a fixed weir, but also Comparative Example 2, in which two or more fixed weirs are installed, are In Example 1, where the paddle phase angle difference β between the paddle sets is all 0° and W ₁ /W ₂ in any adjacent paddle set group, the short
It can be seen that the number of passes is overwhelmingly small, and the residence time of the powder and granules is uniform. Further, from Comparative Example 3, it is found that there is no effect when there is one or more adjacent paddle group groups in which only a portion of the paddles between both adjacent paddle groups is β=0°. Examples 2 to 4 Example 2 The device of the present invention is the same as in Example 1 except that l ₂ = 15.0 mm (therefore, l ₂ /l ₁ = 3) in the downstream adjacent paddle set of each adjacent paddle set group. in the case of. Example 3 The device of the present invention is the same as in Example 1 except that S ₂ =24.0 mm (therefore, S ₂ /S ₁ =3) in the downstream adjacent paddle group of each adjacent paddle group. Example 4 Except that l ₂ = 15.0 mm and S ₂ = 24.0 mm (therefore, l ₂ /l ₁ >1 and S ₂ /S ₁ >1) in the downstream adjacent paddle group of each adjacent paddle group , for the device of the present invention similar to Example 1. The impulse response is shown in Table 2.

[Table] From the column of Table 2 and Example 1 of Table 1, if l ₂ /l ₁ (Example 2) or S ₂ > S ₁ (Example 3) in the apparatus of the present invention, the stagnation of powder and granules It can be seen that there is a further effect in making the time uniform, and that there is a further synergistic effect if l ₂ > l ₁ and S ₂ > S ₁ (Example 4). Examples 5 to 7, Comparative Example 4 Example 5 Same as Example 1 except that in each adjacent paddle group, the number of paddles in each adjacent paddle group was 3 and the opening angle α was all 120° (therefore, the above In the case of the device of the present invention where the number of paddles in the paddle set other than the above is 2 and the opening angle α is 180°). Example 6 In each stirring zone, the number of paddles in the paddle sets other than the adjacent paddle sets is 3 and the opening angle α is 120°, and the paddle sets between adjacent paddle sets (excluding between both adjacent paddle sets) are except that the phase angle difference is 60°.
In the case of the device of the present invention similar to Example 5. Example 7 In each adjacent paddle group, the number of paddles in each adjacent paddle group is 3, and each opening angle α1 is 120°.
Same as in Example 4 (therefore, all paddle sets other than the above have two paddles, the opening angle α is 180°, and l ₂
= 5.0mm, l ₂ = 15.0mm, S ₁ = 8.0mm, S ₂ = 24.0mm)
In the case of the device of the present invention. Comparative Example 4 In each of the second and third adjacent paddle group groups counted from the upstream side, the number of paddles and the phase angle difference β of both adjacent paddle groups are the same as in Comparative Example 3 (therefore, the number of paddles and the phase angle difference β of each of the adjacent paddle groups Paddle 1 of each adjacent paddle group in the group
β = 0 for the paddle, but β for the other paddles.
= 0), otherwise the stirring device was the same as in Example 7. The impulse response is shown in Table 3.

[Table] From Table 3, in each stirring zone, when the number of paddles in each paddle group is 3 including the adjacent paddle group (Example 6), as well as in the case of 2 paddles, any adjacent paddle group Also, if β = 0° and W ₁ > W ₂ , there is an effect of making the residence time of the powder uniform.
In addition, the number of paddles and the opening angle α in the adjacent paddle group
Even if the paddle sets are different from those of other paddle sets, as long as the former satisfies the conditions of the present invention (Example 5), it can be seen that the above-mentioned effects of the present invention are achieved. Furthermore, from the comparison between Example 7 and Comparative Example 4, l ₁ and
Even if the relationship with l ₂ and the relationship between S ₁ and S ₂ are in a preferable manner as in Example 4, and W ₁ > W ₂ in all adjacent paddle group groups, both adjacent paddle groups are It can be seen that there is no effect when the paddle phase angle difference β between the paddle sets does not satisfy the conditions of the present invention. Example 8 The same procedure was carried out except that the paddle widths of the upstream adjacent paddle groups in the second and third adjacent paddle groups counted from the upstream side were W ² ₁ = 60 mm and W ³ ₁ = 72 mm, respectively. Same as example 1 (so W ¹ ₁ = 50mm,
W ⁿ⁺¹ ₁ /W ⁿ ₁ = 1.2) in the case of the device of the present invention. Example 9 The area of the half-moon opening above the fixed weir in the second and third adjacent paddle sets counted from the upstream side is 120 cm ² and 140 cm ² , respectively.
In the case of the device of the present invention similar to Example 8. The impulse response is shown in Table 4.

[Table] From the results of Example 8 in Table 4, while keeping the width W ⁿ ₂ of the paddles of the adjacent paddle groups on the downstream side constant, the width W ⁿ ₁ of the paddles on the upstream side is set at the extraction port. It can be seen that reverse movement of the powder can be very effectively prevented by gradually widening the distance as the distance approaches. Furthermore, the results of Example 9 show that this effect is due to the fact that the average level of the powder and granular material in each stirring zone is gradually lowered closer to the outlet, and that the opening above the fixed weir is It has been shown that the effect can be further increased by gradually increasing the area of the section from the supply port side to the outlet side, in other words, by gradually lowering the height of the fixed weir. There is. Example 10 The same stirring device as in Example 1 was used as a gas phase polymerization vessel, and while a mixed monomer of ethylene and propylene was introduced together with a catalyst, a polymerization pressure of 20 kg/
cm ³ , polymerization temperature 60℃, rotation speed 40rpm (Fr=
0.367) was carried out for a long period of time with continuous stirring to produce an ethylene-propylene copolymer (ethylene content 12% by weight). The physical properties of the molded product obtained from this were good, especially the low-temperature impact resistance. Example 11 Using the same stirring device as in Example 4 as a gas phase polymerization vessel, the same mixed monomers as in Example 10 were continuously polymerized for a long period of time under the same conditions to produce an ethylene-propylene copolymer. The physical properties of the thus obtained molded article, particularly the low-temperature impact properties, were significantly improved and were comparable to the low-temperature impact properties of the ethylene-propylene copolymer obtained by batch polymerization.

[Brief explanation of drawings]

Fig. 1 shows the device of the present invention, A is a side explanatory view schematically and transparently showing the entirety of one embodiment thereof, and B is a diagram showing two adjacent paddle sets (adjacent) across a fixed weir in another embodiment. A side explanatory view illustrating a part of the configuration including a paddle set) together with an example of the formation state of the powder/granular material deposition surface corresponding to the rotational position of the adjacent paddle set;
The figure is an explanatory view seen in the arrow direction from line A-A in Figure 1A showing the position of each paddle of adjacent paddle groups,
Figure 3 is an explanatory diagram of the adjacent paddle sets viewed from the same position as Figure 2 when the phase angle difference of the paddles is 90°, and Figure 4 is an illustration of the adjacent paddle sets rotated 90° from the state shown in Figure 3. An explanatory diagram showing the state. Figure 5 is an explanatory diagram showing the height of the powder accumulation surface that changes as the paddle group rotates when stirring the powder. Figures 6 to 10 are illustrations of both adjacent paddles. FIG. 6 and FIG. 7 are explanatory diagrams showing the case where the widths of the paddles in the set are equal, and FIGS. A side explanatory view showing the positions of the paddle sets in two extreme cases corresponding to Fig. 4, and Figs. 8, 9, and 10 show the arrangement of the fixed weir and the adjacent paddle sets on both sides. FIG. 3 is a side explanatory view showing various aspects and the formation state of a surface on which a powder or granular material is deposited. 1... Horizontal cylindrical container (container), 2... Supply port,
3... Extraction port, 4... Rotating shaft, 5... Paddle group, 5a... Paddle group on the supply port (upstream) side of adjacent paddle groups (adjacent paddle groups) across the fixed weir, 5b... Extraction port in adjacent paddle set (downstream)
side paddle group, 6... paddle, 6a... paddle of the supply port (upstream) side paddle group in the adjacent paddle group,
6b... Paddle of the paddle group on the extraction port (downstream) side among the adjacent paddle groups, 7... Fixed weir, 8... Opening, 9... Adjacent paddle group, D... Diameter of the container,
d...Diameter of the rotating shaft, Hs...Distance in the axial direction between the valley of the powder accumulation surface and the upward extension surface of the fixed weir, L
... Length of the container, l ... Clearance between the inner wall of the container and the tip of the paddle, l ₁ ... Clearance between the inner wall of the container and the tip of the paddle of the adjacent paddle group on the supply port (upstream) side, l ₂ ... Clearance between the inner wall of the container and the tip of the paddle Clearance with the paddle tip of the adjacent paddle group on the extraction port (downstream) side, AL
...Average level across the top of the powder/granular material accumulation surface, HL...Highest level throughout the top region of the powder/granular material accumulation surface, LL...Lowest level throughout the top region of the powder/granular material accumulation surface, P... ...Upward extension surface of fixed weir,
P′...trough, S ₁ ... Clearance between the fixed weir and the paddle of the adjacent paddle group on the supply port (upstream) side, S ₂ ...
Clearance between the fixed weir and the paddles of adjacent paddle groups on the extraction port (downstream) side, α...opening angle, β...difference in phase angle of paddles between adjacent paddle groups, W...width of general paddles, W ₁ ...The width of the paddle of the paddle group on the supply port (upstream) side of the adjacent paddle group, W ₂ ...The width of the paddle of the paddle group on the extraction port (downstream) side of the adjacent paddle group, n...Fixed from 1 All integers up to one less than the number of weirs, W ⁿ ₁ ... Supply port (upstream)
Width of the paddles of the adjacent paddle group on the supply port (upstream) side of the n-th adjacent paddle group as counted from the side, W ⁿ⁺¹ ₁ ...
...The width of the paddle of the adjacent paddle group on the supply port (upstream) side of the (n+1)th adjacent paddle group as counted from the supply port (upstream) side.

Claims (1)

[Claims] 1. In a horizontal cylindrical container that generally has a supply port for the material to be stirred and a powder outlet at the other end, one sheet is placed at each of a plurality of positions on the horizontal rotation shaft. It is a horizontal uniaxial stirring device that has a built-in stirring means consisting of a plurality of paddle sets each having the rectangular flat paddles attached thereto, and is fixed to the inner wall of the container in a direction perpendicular to the rotation axis. The inside of the container is divided into three or more stirring zones by two or more fixed weirs, and each adjacent paddle set group consists of two adjacent paddle sets with each fixed weir in between. A stirring device characterized by satisfying conditions (i) to (vi) and satisfying conditions (vii) to (viii) between adjacent groups of paddle sets; (i) The number of paddles in the two paddle sets is equal. (ii) β=0゜, (iii) D/100≦l ₁ ≦D/20, (iv) l ₂ /l ₁ ≧1 (v) 1≦S ₂ /S ₁ ≦5 (v) 1＜W ₂ /W ₁ ≦4 (vii) 1≦W ⁿ⁺¹ ₁ /W ⁿ ₁ <2 (viii) Between all adjacent paddle groups, l ₁ to each other, l ₂ to each other,
S _1s , S _2s , and W _2s are each equal to each other. [Here, β: Phase angle difference between adjacent paddle sets across the fixed weir on the projection plane perpendicular to the axis of rotation, D: Inner diameter of horizontal cylindrical container (mm), l ₁ : Clearance between the inner wall of the container and the paddle tip of the paddle assembly on the supply port side (mm), l ₂ : Clearance between the inner wall of the container and the paddle tip of the paddle assembly on the extraction port side (mm), S ₁ : Paddle on the supply port side Clearance between the paddles of the group and the fixed weir (mm), S ₂ : Clearance between the paddles of the paddle group on the outlet side and the fixed weir (mm), W ₁ : Paddles of the paddle group on the supply port side of the adjacent paddle group width, W ₂ : Width of the paddle of the paddle group on the outlet side of the adjacent paddle group group, n : All integers from 1 to a number less than 1 than the number of fixed weirs, W ⁿ ₁ : Counting from the supply port side Width of the paddle set on the supply port side of the n-th adjacent paddle set group, W ⁿ⁺¹ ₁ : Width of the paddle set on the supply port side of the (n+1)th adjacent paddle set group counting from the supply port side paddle width. ] 2 l ₁ and l ₂ have the relationship (iv) 1≦l ₂ /l ₁ ≦3, and W ⁿ ₁ and W ⁿ⁺¹ ₁ have the relationship (vii) 1≦W ⁿ⁺¹ ₁ /W ⁿ The stirring device according to claim 1, which has a relationship of ₁ ≦1.2. 3 l ₁ and l ₂ are in the relationship (iv) l ₂ /l ₁ = 1, S ₁ and S ₂ are in the relationship (v) 2≦S ₂ /S ₁ ≦3, and W ⁿ ₁ and W ⁿ⁺¹ ₁ have the following relationship: (vii) 1≦W ⁿ⁺¹ ₁ /W ⁿ ₁ ≦1.2. 4 The supply port of the horizontal cylindrical container supplies a mixture of polymerizable monomer and polymerization catalyst that is continuously polymerized in the gas phase inside the container and becomes powder by the time it reaches the first fixed weir. The stirring device according to any one of claims 1 to 3, which is a supply port for.