JPH0227011B2 - - 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 rotating weirs are fixed to the rotating shaft 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 mounted in large numbers on a rotary shaft, there are known stirring devices capable of continuous processing in which one or more rotary weirs are fixed to the rotary shaft in a direction perpendicular to the rotary shaft. There is (Tokuko Showa 60)
-See 48231). [Problems to be Solved by the Invention] However, this type of rotary 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 rotary 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 rotary 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 rotary weir in addition to the conventional stirring means, is operated continuously, shot 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, the powder becomes fluid even though two rotary weirs are installed, and the amount of material that exceeds the rotary weir 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 rotating 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 continuous stirring with uniform residence time of powder and granules stable for a long period of time on an industrial scale. This was achieved as a result of intensive research aimed at providing a horizontal, single-shaft stirring device that can be used. That is, the present invention provides a horizontal cylindrical container having an inlet for supplying the material to be stirred at one end and an outlet for discharging the powder or granular material at the other end. 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 rotating shaft in a direction perpendicular to the rotating shaft. The inside of the container is divided into three or more stirring zones by two or more circular rotating weirs with a clearance of ε (mm) from the inner wall of the container, each consisting of two sets of paddles adjacent to each other with each rotating weir in between. A stirring device characterized in that each adjacent paddle group satisfies the following conditions (i) to (vi) and each adjacent paddle group satisfies conditions (vii) to (viii). (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 all equal to each other. Here, β: Phase angle difference formed by each paddle on a projection plane perpendicular to the axis of rotation between adjacent sets of paddles across the rotating weir, D: Inner diameter of horizontal cylindrical container (mm), l ₁ : Clearance between the container inner wall and the paddle tip of the paddle assembly on the supply port side (mm), l ₂ : Clearance between the container inner wall and the paddle tip of the paddle assembly on the extraction port side (mm), S ₁ : Paddle assembly on the supply port side Clearance between the paddles of the paddle group on the outlet side and the rotating weir (mm), S ₂ : Clearance between the paddles of the paddle group on the outlet side and the rotating weir (mm), W ₁ : Clearance of the paddles of the paddle group on the supply port side of the adjacent paddle group 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 1 less than the number of rotating weirs, W ⁿ ₁ : Number of paddles counting from the supply port side. Width of the paddles of the paddles on the supply port side of the nth adjacent paddle group, W ⁿ⁺¹ ₁ : Paddles of the paddles on the supply port side of the (n+1)th adjacent paddle group as counted from the supply port side It concerns the width of . [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 side view showing two adjacent paddle sets 4 adjacent to each other across a rotary 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 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. FIGS. 6 and 7 are explanatory diagrams showing the case where the widths of a set of paddles are equal, and FIGS. 6 and 7 respectively show changes in height of the surface of the powder and granule accumulation near the rotating weir when stirring the powder and granules. FIGS. Fig. 4 is a side view showing the positions of the paddle sets in two extreme cases, and Figs. 8, 9, and 10 show the arrangement of the rotating weir and the adjacent paddle sets sandwiching it. 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 need to be unified as shown in the example (excluding the adjacent paddle sets across the rotating weir), and there is no problem even if paddles of various sizes and widths W are mixed. do not have. 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 rotating weir must satisfy certain conditions. The paddles of all other paddle groups are referred to as general paddles, and their widths are collectively indicated by W). 7 is a rotating weir, and as shown in FIGS. 1 and 2, two or more of them (three in the example shown) extend the length L of the container 1 in a direction perpendicular to the rotating shaft 4 to, for example, approximately the same length. It is fixed to the rotating shaft leaving an opening 8 corresponding to the clearance ε with the inner wall of the container at the position where it is divided into two parts.
(Hereinafter, the above-mentioned stirring zone may be referred to as the 1st zone, 2nd zone, 3rd zone, etc. in order from the supply port 2 side to the extraction port 3 side. Regarding the rotating weir 7, the stirring zones on the supply port 2 side and the extraction port 3 side may be referred to as an upstream zone and a downstream zone, respectively). By the way, in the device of the present invention, this rotating weir 7
Two adjacent paddle groups (each may be referred to as an adjacent paddle group, and both adjacent paddle groups that sandwich one rotary 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 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, the clearance ε between the rotating weir 7 and the inner wall of the container is preferably such that ε/D is 0.1 or less. Furthermore, it is preferable that the ε/D of each rotary weir be exactly the same, or that the ε/D of the downstream rotary weirs be increased one after another within a range of 0.1 or less so that the downstream zone has a relatively low holding amount. . [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 rotary weirs 7 are provided, if the above conditions for the adjacent paddle sets 5a and 5b are not satisfied for each adjacent paddle set group 9, for example, 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 is not in one direction, but in the flow pattern of the powder particles scraped up by the paddle set 5b on the downstream side. The body moves backwards over the rotating weir 7. In the opening 8, 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 powder will move from the downstream zone to the upstream zone. There is also a reverse movement, and the amount of powder and granular material movement from the upstream zone to the downstream zone increases by this reverse movement, resulting in an increase in shot passes, making the residence time non-uniform. Further, the amount of reverse movement per unit time increases as the number of rotations increases, and in extreme cases, even if two or more rotary 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.
The case where the widths W ₁ and W ₂ of a and 6b are equal was considered. Both adjacent paddle sets 5a and 5b sandwiching the rotating weir 7 shown in FIG. Both α° are set at 180°. Both adjacent paddle sets 5a, 5
There is a phase angle difference β between the two pairs of paddles 6a and 6b, but in the above example, the phase angle difference β is set to 90° for both sets as an example where it is not 0°. When these paddle sets 5a and 5b are rotated 90 degrees from the position shown in FIG. 3, they will be in the position shown in FIG. 4. Generally, a suitable amount of powder or granules is stored in the stirring device (often about 60% by volume of the device), and the paddle set 5
As the particle is rotated, the slope of the surface on which the powder is deposited changes, and the heights of the top and bottom areas change up and down. The state of change varies depending on the properties of the powder, the number of revolutions, the amount held, etc., but the paddle set 5 reaches the angle of repose approximately near the rotational position shown in FIG. The area will be at the highest level (denoted by HL) and the area at the bottom will be at the lowest level (denoted by LL'). More paddle group 5
When rotated by 1/2 of the opening angle α (90° in the example shown) from the rotational position shown in FIG. The lower level (denoted by LL) is reached, and the area at the bottom is at the highest level (denoted by HL'). In addition, when the paddle set 5 is in the middle of the above two rotational positions, the entire top and bottom areas of the powder accumulation surface are HL.
and LL and the average level of HL′ and LL′ (AL
). Therefore, the level of the entire top area of the powder accumulation changes from HL→AL→ during the rotation of the paddle set 5.
It changes like LL → AL → HL, and the level of the whole bottom area changes like LL' → AL → HL' → AL → LL'. 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, When examined, as shown in FIGS. 6 and 7, when the entire top area of the powder accumulation surface of one of the adjacent paddle sets 5a, 5b on both sides of the rotating weir 7 is at the level HL, the other The level of the entire top area of the powder/grain material deposition surface in the area of the adjacent paddle set 5a or 5b is always LL. Similarly, when the entire bottom area of the powder accumulation surface in one of the adjacent paddle sets 5a, 5b on both sides of the rotating weir 7 is at level LL', the bottom area of the other adjacent paddle set 5a or 5b is at level LL'. The level at the bottom of the surface of the granular material is always HL'. 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 Fig. 6, the entire top area of the powder accumulation surface in the area of adjacent paddle group 5a is at level HL, the entire bottom area is at level LL', and the area of adjacent paddle group 5b is at level LL'. The entire top area of the powder accumulation surface is at level LL, and the entire bottom area is at level HL'. Since the granular material moves in the axial direction from the high level HL to the low level LL direction and from HL' to LL', in the case of Fig. 6, the granular material naturally passes through the opening 8 and reaches the top. In one band, it moves from the upstream zone to the downstream zone, and in the bottom band, it moves from the downstream zone to the upstream zone. 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 and HL' and LL' are reversed, and the granular material moves backward from the downstream zone to the upstream zone through the opening 8. In the above example, the reversal development of levels HL and LL occurs at equal time intervals 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 movement state of the powder and granules may be affected. are basically the same. In this way, when the level of the top and bottom areas is alternately reversed between the powder and granule accumulation surfaces of the adjacent paddle sets 5a and 5b across the rotating weir 7, there is always a reverse movement of the granules. It was found that a limiting phenomenon occurred, and 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 non-uniform. As a result of further studies to reduce this reverse movement phenomenon, we found that the respective levels of the top and bottom areas 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. It was realized that it is important to arrange the paddles 6a and 6b so that they are the same at the same time and do not cause any difference. The conditions for this are as follows: paddle 6a of adjacent paddle set 5a, 5b
and 6b have a rectangular shape with the same width, and as shown in FIG. 8, the clearances l ₁ and l ₂ with the inner wall of the container 1 (l ₁ and l ₂ in FIG. Since the clearance between the tip and the inner wall of the container is viewed slightly diagonally, only its position is shown. Clearance with 7
When considering the case where S ₁ and S ₂ are also equal,
The conditions shown below 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, in any state from level HL to LL of the top area of the powder/granular material accumulation surface in each area of both adjacent paddle sets 5a, 5b, the powder/granular material is 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 near the top area is the same on both sides of the rotating weir 7, and the powder pressure is balanced. The trough P' where the slopes on both sides intersect is formed right above the rotating weir 7 and is on the upwardly extending surface P of the rotating weir 7, so that the granular material passing through this opening 8 does not move. Similarly, the level of the entire bottom area of the powder/grain material accumulation surface in each region of both adjacent paddle sets 5a and 5b is from HL' to
In any state up to LL', the slope of the powder accumulation surface at the opening 8 near the bottom area is the same on both sides of the rotating weir 7, and the powder pressure is balanced and the opening 8 is No movement of the passing powder or granules occurs. Such a rotating weir 7 and adjacent paddle set 5
In the arrangement a and 5b, when the powder is supplied from the supply port 2 and flows into the upstream zone, only the increased portion in the upstream zone becomes a slight level difference, and the powder flows from the first zone to the upstream zone. It shows a flow pattern only for movement to the second zone. Next, paddle group 6 is inserted between both adjacent paddle groups 5a and 5b.
Even if the number of sheets a and 6b are equal and the phase angle difference β is 0°, if the area of the opening 8 of the rotating weir 7 is large, the number of rotations is high, or the amount of powder and granules 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 regarding the prevention of such scattering or reverse movement, we found that the paddle groups 6a and 6b of both adjacent paddle groups 5a and 5b satisfy l ₂ /l ₁ ≧1 and S ₂ /S. ₁ ≧1
It was confirmed that the prevention effect was sufficient in the case of 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 state of formation of the top and bottom areas 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 rotating 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 fact that this distance Hs exists on the non-flow zone side means that the powder pressure at the plane P is directed from the upstream zone to the downstream zone, and the larger Hs is, the harder it is for the powder to move backwards. Become. 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 paddle sets 6a and 6b of a and 5b are equal, conditions are set that are effective for preventing the reverse movement of the powder and granular material. 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 rotary 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 rotary 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 paddle width), W ₁ , and W ₂ are all equal; however, if the width of each paddle is large or small, △T increases, 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, l ₁ to each other, l ₂ to each other, S ₁ to each other, S ₂ to each other, W ₂
If they are different from each other, the movement of powder and granules may be disrupted between stirring zones and the above effect may be insufficient. Therefore, in order to ensure this effect, between all adjacent paddle groups 9. Condition (viii) was set that each of the above is equal to each other. 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 subsequent adjacent paddle group groups 9 on the downstream side, and W ₁ /W ₂ =
It is 4. There are two or more adjacent paddle group groups 9 with different W ₁ /W ₂ in all adjacent paddle group groups 9, that is, all adjacent paddle group groups 9 have different W 1 /W 2.
During W ₁ , there is a small W ₁ on the upstream side and a large W ₁ on the downstream side
It is preferable that there are two or more types of W ₁ of different sizes. 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, S ₂ /S ₁ >1. Next, as a result of investigating l ₂ /l ₁ and S ₂ /S ₁ through many more experiments, (iv) 1≦l ₂ /l ₁ ≦3 (vi) 1≦W ⁿ⁺¹ ₁ /W ⁿ When ₁ ≦1.2, it is suitable for stirring powder particles with a relatively narrow particle size distribution; (iv) l ₂ /l ₁ =1 (v) 2≦S ₂ /S ₁ ≦3 (vi) 1≦W ⁿ It has been found that the case of ⁺¹ ₁ /W ⁿ ₁ ≦1.2 is particularly suitable for stirring not only the above-mentioned powder and granular materials but also powder and granular materials 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 manner, 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, and propylene-butene-1-ethylene copolymer. , etc. [Effect] If the stirring device according to the present invention is used, two or more rotating weirs are provided to increase the number of stirring zones, and each adjacent paddle set group is 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 rotating weir, the width of the paddle, and the mounting mode Using a horizontal uniaxial stirrer outside the scope of the present invention, inert polypropylene powder with a relatively narrow particle size distribution with a median diameter of 600 μ and a bulk density of 0.5 g/cm ² was mixed at 15 kg/hr.
Continuous stirring was performed at a rotation speed of 60 rpm (Fr = 0.826) while continuously supplying the powder, and the amount of powder held during steady operation was maintained at 60% by volume of the device capacity. In this case, 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. Using this impulse response, the uniformity of the residence time of the powder in each Example and Comparative Example was investigated. Example 1 Three rotary weirs of the same shape each having an opening with an opening ratio ε/D of 0.04 (ε = 17.2 mm) are installed at each position dividing the length L of the container into approximately four equal parts, All paddle sets have two paddles and their opening angle α
is 180°, the phase angle difference of the paddles between adjacent paddle sets in each zone divided by each rotating weir is 90°, and the clearance l between the inner wall of the container and the tip of each paddle is all 5.0 mm. The width W of the general paddle is 40 mm, and in each of the three adjacent paddle group groups (n = 1, 2, 3) consisting of both adjacent paddle groups sandwiching each rotating weir, l ₁ = l ₂ = 5.0mm [Therefore, l ₂ /l ₁ = 1, D/100 (=4.3) < l ₁ <
D/20 (=21.5)] S ₁ = S ₂ = 8.0 mm [Thus, S ₂ /S ₁ = 1] β = 0° W ¹ ₁ = W ² ₁ = W ³ ₁ = 50 mm W ¹ ₂ = W ² ₂ = W ³ ₂ = 40 mm (therefore, W ₁ /W ₂ >1, W ⁿ⁺¹ ₁ /W ⁿ ₁ =1) in the case of the device of the present invention. Comparative Example 1 A stirring device similar to Example 1, except that it does not have a rotating 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 In the case of 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 counting 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 There is no paddle for which β = 0° with respect to the adjacent paddle group, but β = 0° with respect to the other paddles (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 the following. 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 (% by weight), e ₀ is the tracer concentration relative to the amount of tracer input relative 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/%, the more
The number of short passes tends to decrease relatively. From Table 1, it can be seen that not only Comparative Example 1 which does not have a rotating weir, but also Comparative Example 2 which simply has two or more rotating weirs, there is a difference between adjacent paddle groups in each adjacent paddle set group. 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 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 residence time of the powder It is more effective in making the uniformity of , and l ₂ > l ₁ and S ₂ > S ₁ (Example 4)
If so, it is clear that there is a synergistic effect. 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 Except that in each adjacent paddle group, the number of paddles in each adjacent paddle group was 3 and each opening angle α was 120°.
Same as Example 4 (therefore, all paddle sets other than the above have two paddles, the opening angle α is 180°, and l ₁
= 5.0 mm, l ₂ = 15.0 mm, S ₁ = 8.0 mm, S ₂ = 24.0 mm). 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 uniformizing the residence time of the powder,
In addition, the number of paddles and the opening angle α in the adjacent paddle group
Even if the paddle set is different from that of the other paddle sets, as long as the former satisfies the conditions of the present invention (Example 5), it can be seen that the above 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 aperture ratios ε/D of the second and third adjacent paddle groups counted from the upstream side are respectively
In the case of the device of the present invention, which is the same as in Example 8 except that the values are 0.045 and 0.05. The impulse response is shown in Table 4.

_[ Table] From the results of Example 8 in Table 4, while keeping the width W ⁿ 1 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 powder and granular material in each stirring zone is gradually lowered as it approaches the outlet, and that the aperture ratio ε/D This shows that the effect can be further enhanced by increasing the value from the supply port side toward the extraction port side. 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=
Ethylene-propylene copolymer (ethylene content 12% by weight) was produced by continuous stirring polymerization of 0.367) for a long period of time. 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, especially the low-temperature impact resistance, were significantly improved and were comparable to the low-temperature impact resistance 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 an explanatory side view schematically and transparently showing the entirety of one embodiment of the device, and B is an explanatory side view of two adjacent embodiments with a rotary weir in between.
A side explanatory view showing a part of the configuration including a set of paddle sets (adjacent paddle sets) together with an example of the formation state of the powder deposition surface corresponding to the rotational position of the adjacent paddle set. The first one indicates the position of each paddle.
Figure 3 is an explanatory diagram of the adjacent paddle set viewed from the same position as Figure 2 when the phase angle difference of the paddles is 90°, Figure 4 is an explanatory diagram showing a state in which the adjacent paddle set is rotated by 90 degrees from the state shown in Fig. 3, and Fig. 5 shows the height of the powder accumulation surface that changes as the paddle set rotates when stirring the powder or granule. Explanatory diagrams showing, Figures 6 to 10
The figure is an explanatory diagram showing the case where the widths of the paddles of both adjacent paddle sets are equal, and FIGS. 6 and 7 respectively show height changes of the surface of the powder and granule accumulation near the rotating weir when stirring the powder and granule. Figures 3 and 4
Figures 8, 9, and 10 are side views showing the positions of the paddle sets in two extreme cases corresponding to the two extreme cases, and Figs. It is a side explanatory view which shows the aspect and the formation state of the powder-grain material accumulation surface. 1... Horizontal cylindrical container (container), 2... Supply port, 3
...Extraction port, 4...Rotating shaft, 5...Paddle set, 5a...
A paddle group on the supply port (upstream) side of the adjacent paddle groups (adjacent paddle groups) across the rotating weir, 5b...a paddle group on the extraction port (downstream) side of the adjacent paddle groups,
6... Paddle, 6a... Paddle of the paddle group on the supply port (upstream) side in the adjacent paddle group, 6b... Paddle in the paddle group on the extraction port (downstream) side in the adjacent paddle group, 7
... Rotating 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 upwardly extending surface of the rotating weir, L...Length of the container, l...Inner wall of the container and the tip of the paddle l ₁ ... Clearance between the inner wall of the container and the paddle tip of the adjacent paddle group on the supply port (upstream) side, l ₂ ... Clearance between the inner wall of the container and the paddle tip of the adjacent paddle group on the extraction port (downstream) side,
AL...average level across the top and bottom of the powder/granular material accumulation surface, HL...highest level across the top region of the powder/granular material accumulation surface, LL...lowest level across the top region of the powder/granular material accumulation surface, P ...Upper extending surface of the rotating weir, P'...Trough, HL'...The highest level of the entire bottom area of the powder and granule accumulation surface, LL'...The lowest level of the entire bottom area of the powder and granule accumulation surface, _S1 ...Rotation Clearance between the weir and the paddles of the adjacent paddle group on the supply port (upstream) side, S ₂ ... Clearance between the rotating weir and the paddles of the adjacent paddle group on the extraction port (downstream) side, α... Opening angle,
β...Paddle phase angle difference between adjacent paddle sets, ε...
Clearance between the rotating weir and the inner wall of the container, W... Width of general paddle, W ₁ ... Supply port of adjacent paddle group group (upstream)
Width of the paddles of the side paddle group, W ₂ ... Width of the paddles of the paddle group on the outlet (downstream) side of the adjacent paddle group, n... All integers from 1 to a number 1 less than the number of rotating weirs, W ⁿ ₁ ...Width of the paddles of the adjacent paddle group on the supply port (upstream) side of the n-th adjacent paddle group counting from the supply port (upstream) side, W ⁿ⁺¹ ₁ ...Counting from the supply port (upstream) side width of the paddle of the adjacent paddle group on the supply port (upstream) side of the (n+1)th adjacent paddle group.

Claims (1)

[Scope of Claims] 1. In a horizontal cylindrical container having a supply port for the material to be stirred at one end and a discharge port for the powder or granular material at the other end, a horizontal rotating shaft and a plurality of containers each located at each of a plurality of positions on the horizontal rotating shaft are provided. A horizontal uniaxial stirring device with a built-in stirring means consisting of a plurality of paddle sets each having one or more rectangular flat paddles attached thereto, the stirring device being fixed to the rotating shaft in a direction perpendicular to the rotating shaft. The inside of the container is divided into three or more stirring zones by two or more circular rotating weirs that have a clearance of ε (mm) with the inner wall of the container. The adjacent paddle set groups consisting of the following are characterized in that each adjacent paddle set group satisfies the following conditions (i) to (vi), and each adjacent paddle set group satisfies conditions (vii) to (viii). Stirring device: (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 all equal to each other. Here, β: Phase angle difference between adjacent paddle sets across the rotating weir on the projection plane perpendicular to the axis of rotation, 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 assembly on the supply port side Clearance between the paddles of the paddle group on the outlet side and the rotating weir (mm), S ₂ : Clearance between the paddles of the paddle group on the outlet side and the rotating weir (mm), W ₁ : Clearance of the paddles of the paddle group on the supply port side of the adjacent paddle group 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 1 less than the number of rotating weirs, W ⁿ ₁ : Number of paddles counting from the supply port side. Width of the paddles of the paddle group on the supply port side of the nth adjacent paddle group, W ⁿ⁺¹ ₁ : Width of the paddles of the paddle group on the supply port side of the (n+1)th adjacent paddle group, counting from the supply port side. 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 The stirring device according to claim 1, which satisfies the relationship ⁿ 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 The stirring device according to claim 1, wherein W ⁿ⁺¹ ₁ has 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 rotating weir. The stirring device according to any one of claims 1 to 3, which is a supply port for.