JPS5820228A - Granulator for sodium percarbonate and method for granulating same - Google Patents

Abstract

PURPOSE:To obtain a granular sodium percarbonate having a proper particle size, hardness and bulk specific gravity, by specifying blade shapes in the feed region, the kneading and mixing region and a breaking region of the screw of a granulator. CONSTITUTION:In the feed region of a granulator, two screws are formed by succeedingly sending trapezoid screw blades 3 to send a material into said feed region and, in the first half of the kneading and mixing region, one screw is formed from a succeedingly sending ribbon like screw blade 4 and the other screw is formed from a reversely sending fragmentary twisted screw blade 5 as well as, in the latter half thereof, both screws are formed from reversely sending trapezoid blades 6. In the breaking region, protruded teeth 7 are attached to both screw shafts to break a small amount of agglomerated particles in granules. When sodium percarbonate is granulated by this granulator, a granular substance with a proper particle size, hardness, bulk density and solubility is obtained without carrying out special pretreatment.

Description

[Detailed Description of the Invention] The ns powder of the present invention is kneaded continuously in a wet state! ! Kneading by marking and granulating into one grain, I! A granulator suitable for granulating powdered soda percarbonate into granules using a Japanese granulator and granulation method. ◎Soda percarbonate is made by reacting soda carbonate and hydrogen peroxide. It is easily obtained by drying and is used as a bleaching agent. Soda percarbonate powder stings the nose if it scatters, making it undesirable for work.Also, it is easy to solidify when stored for a long period of time, and it is extremely difficult to maintain it in a dry state. 1 hour◎Also, soda percarbonate is unstable to moisture.The content of active oxygen in it tends to decrease due to moisture (and it is desirable to reduce the area of contact with moisture). , etc. are generally granulated into granules. Conventionally, soda percarbonate is granulated using a well-known kneader in the presence of an appropriate binder additive and water, Kflh wire, quenching, An extrusion granulator that extrudes even a perforated plate, a Henschel mixer IIJi # type granulator, etc. are generally used.

However, although the extrusion granulation method of extruding through a perforated plate described above yields a granulated product with a relatively uniform shape, the resulting granulated product is hard, and even with the restriction of the pore size of the perforated plate, the particles are large. (The dissolution rate in water is slow. Furthermore, the holes in the perforated plate are easily clogged, which necessitates frequent replacement of the perforated plate, and there are disadvantages such as the need for continuous operation. 0 In addition, the Henschel mixer type granulator has the advantages of granulating in a short time and generating less frictional heat, but on the other hand, the granulated particles are soft and brittle.
On the other hand, as a kneading and lees-pressing device, two screws that rotate in tandem with each other are installed in the container to continuously feed the materials. Knead it! ! Various devices are known that perform summation. Even if soda percarbonate is granulated using this omniscient device, it is not possible to obtain particles that satisfy all of the particle size, hardness, bulk specific gravity, and dissolution rate R. The invention has been made to address these various drawbacks, and the granulator of the present invention is capable of continuously kneading and granulating the supplied sodium percarbonate powder without any special pretreatment. Is it possible to perform granulation? To provide a granulator and a granulation method for preparing granular soda percarbonate which is fully satisfactory in terms of particle size, hardness, bulk specific gravity, dissolution rate in water, etc.・In other words, in the present invention, two screws that rotate once are arranged in parallel in a container, and one end of the container has a material input port that opens upward, and the other end has a material input port that opens downward. Each outlet is provided with a discharge port, which allows the volume to flow! The upper surface KC is a presser lid-type kneading and TE granulator equipped with a presser lid, and the 7 granulators are in the feed area and cross line! ! The feeding area is divided into a merging area and a crushing area, and the feed area is formed with trapezoidal screw blades for feeding both screws, and the above-mentioned crosstalk! ! In the Japanese area, one screw has a reverse-feeding screw blade, and the other screw has a reverse feed.
They are each formed on a screw blade with one shoe feed, and the second reverse feed 1 knee blade is a second 11 knee blade with the twist of a single shoe, and the shoe feed blade is a ribbon-shaped feather II type. These are arranged alternately (at least two new front half parts and a second half part where both screws have trapezoidal screw blades that feed in opposite directions), and the crushing area is connected to the shaft of the companion screw. A plurality of 5I!-shaped crushing teeth are provided, and the holding lid of the container corresponds to the aforementioned front half of the feed area and the kneading lees area. The second half of ## is equipped with a presser lid that can move up and down, and the Zeng crushing area is connected to a granulator with an open structure, and the material input for granulation is J from the mouth
[s] This invention relates to a method for granulating soda percarbonate, which involves supplying soda percarbonate powder, additives, and water, mixing, kneading, granulating, and discharging the granules even from the discharge port. From figure INk'specific Ic1I! I will clarify. FIG.
A vertical cross-sectional side view of I is shown, and a cross-sectional view of IITRM of No. 2 II on line 3111 is shown.In the drawings, 1 is the container of the granulator, 2 is the screw shaft, S is the track-shaped screw blade, 4 9 Bon-shaped vane-shaped screw blade with ball feed, S is a reverse feed screw play with a twist of a single shoe, 6 is a trapezoidal screw blade V with reverse feed, 7 is a crushing tooth, 8 is a material input Mouth, outlet, 10
1 shows a fixed presser lid, 11 movable pressers, and 12, 13, and 14 cooling water inlet or outlet ports, respectively. , Collaboration! !・The summer feed area consists of two screws, each of which has a trapezoidal shape 1 and a shoe blade 8.
In the multi-phase area where the material is fed and kneaded, one screw blade is fed with a ribbon-like blade-shaped play P, and the corresponding other screw blade is fed in reverse. A screw blade 6 with a screw blade 6 is formed and arranged so that these blades are arranged alternately, and two screws, a trapezoidal blade 6 with a reverse feed. The formed second half s12 and the material crosstalk in the band,! ! After sufficient summation, the mixture is granulated. Then, both the crushing area guard and the crushing area number 1 were neglected because multiple central-shaped crushers *7 were attached to the screw shaft.
# Send it to the area! The slightly agglomerated granules are broken up.

In the granulator of the present invention, the screw blades in the feed zone, kneading, and attenuation zone are formed into blades for continuous feeding, reverse feeding for fragments, S-shaped ribbon feeding, and reverse feeding blades, and b Place these in the above-mentioned manner to feed the flies! The materials fed from the above are kneaded, and the material is thoroughly mixed and suppressed by the feeding action of a progressively feeding trapezoidal blade and the return action of a twisted blade and a trapezoidal reverse feeding blade. The feeding force even in the zero granulation feed area where summation is carried out and τ granulation is carried out, the two screws collide, and the above-mentioned crosstalk formed in the blade of reverse feeding,
The reverse feed force applied to the latter half of the multi-phase area is appropriately balanced and sent to the crushing area MIC as appropriate. The granules sent to the crushing zone usually have some agglomeration and some chicken tropism. When the aggregates are crushed in the wrinkle crushing zone, the granules are released at the same time. However, in order to fully accomplish this purpose, it is desirable to leave the granules in the crushing zone for a certain period of time and to perform a kind of agitation. For example, the horseflies that are made to do this are on the side where the granules are input in the crushing area, that is, kneading! ! The crushing teeth on the 12 side of the rear half of the area are shaped like wings with a slight angle so that the granules are fed slightly backwards. One preferred embodiment is to make the inlet and outlet sides of the granules different in the area, and to roughly provide the inlet side with 1 flc and the outlet side.The structure of the crushing area is as specified above. The condition of the material that is kneaded and even sent out in the multi-phase region is 1111y.
For example, if the P partner is a relatively weak particle, it can be a rod-shaped protrusion that mainly has a crushing function, and the opposite K11l)'! In the case of particles with strong force, a feather-like protrusion can be used to feed the particle 11, which mainly has the function of releasing chicken tropism.

In addition, in the granulator of the present invention, a part corresponding to the rear part 12K of the kneading and spasticity area is provided with a presser lid that is movable up and down (J also has a presser lid that can be moved in the reverse direction of the rear part 2). The trapezoidal screw blade is not entirely covered and the outlet side is left slightly open.Such a structure is especially useful when you want to obtain a granulated product with strong multiphase force and relatively large bulk specific gravity. It is sufficient to slightly lower the movable presser foot lid, and conversely, if the multiphase force is relatively weak and you want to obtain a granulated product with a small bulk specific gravity, you may adjust the mechanism by slightly raising the movable presser foot lid. In addition, since the trapezoidal screw blade of the reverse feed is not completely covered and the outlet side is slightly open, it is possible to remove some of the nodules of the extruded granules. Ru.

When the granulator of the present invention requires cooling, cooling water can be passed through designated conduits in the jacket of the granulator vessel and in the screw shaft. The conditions for granulating soda percarbonate powder using the granulation product of the present invention are uniquely different from the size and capacity of the granulator, the particle size of the raw material soda powder, water content, and the s#All1kc of additives. Although it is not possible to decide, for example,
Screw blade 11270m, total top length 2400w
M1 screw rotation speed is 40 to 80 r, p, m, raw material supply rate is 700 to 2000 y/hr, and the amount of additive and water added depends on the water content of the granules. 10-16
◎ The granulated material granulated by the granulation method of the present invention is discharged from the discharge port 9, and then The granules are sized using a sizing machine equipped with a knife cutter that rotates at high speed. ~ 12 sheets are stacked and have a lid equipped with a hopper for introducing granules with a length of 25 to 15011 m, but the cylindrical shape 11112 has no bottom, and there is no visibility between the tip of the blade and the inner wall of the cylinder.
The structure is arranged with ffiTh gaps,
The knife cutter is rotated at a high speed of 1000 to 4000 rpm. When the number of knife cutters is the same, the faster the number of revolutions per rotation and the longer the length of the hooked cylindrical container, the smaller the average particle diameter. For example, the length of the cylindrical container is 25W, the number of knife cutters is 8, and the rotation speed is 400 Or, pom.
In this case, the average diameter of the particles obtained is 410jI, and when the length of the cylindrical container is 15010(r), the average particle diameter vk obtained is 430#'''e. For example, when the number of knife cutters is the same and the number of rotations is the same, the average particle size tends to become smaller as the number of knife cutters increases. Saga 1506 meeting, number of knife cutters-t-1
When 2&, the average particle size is 340μ.0 Of the various physical properties of the granulated lIR crystal obtained by the method of the present invention, the bulk specific gravity, hardness, dissolution rate, etc. of the particles are mainly determined by the granulator IIC. It is affected by the conditions of kneading and holding during granulation, and the particle size is determined by the granulation conditions.

5) Add 8 to 10 liters of raw material soda percarbonate to 20 liters from the material input lower.
kl/hr9, sodium metasilicate 15@dissolved (binder water) 2 J/hr as an additive.

The rotational speed of the screw that supplied 80 r, p, ms
Adjust the height of the movable presser foot lid 1o to 6wl and knead, I! Mark granulation was performed. ◎ Cooling water was passed through the conduit inside the container jacket and screw shaft. One hour after the start of operation, a stable granulated product was obtained. Then, the obtained granules were heated to 400
After sizing using a cylindrical sizing machine with a length of 1508 m equipped with a knife cutter that rotates at Or, p, and m, it is dried.
The physical properties of the obtained product were as follows.

Comparative Example A shell mixer type granulator was used for 1 ml. 20 kg of the same raw material soda percarbonate powder as in the example was introduced into the granulation method, and 15 ml of sodium metasilicate solution (binder water) was added. Add 2J and hold for 3 minutes to granulate L1 The obtained granules were sized using the same granulating machine as in Example 1 Dry-1
I got one item from 1J. The physical properties of this product are as follows: Although the dissolution rate is extremely fast, the bulk specific gravity of the particles is small and the strength is poor, which is not fully satisfactory as a product.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional plan view of the granulator of the present invention, FIG. 2 is a longitudinal side view, and FIG. 3 is a cross-sectional view of the granulator of the present invention. 1 - container, 2 - screw shaft, 3 - progressive trapezoidal screw blade, 4 - progressive ribbon vane screw blade, 6 - screw blade with piecemeal twist, 6 - reverse trapezoidal screw blade , 7--Crushing teeth, 1o-Fixed presser cover 11-Movable presser cover Patent applicant Kazuyoshi Nagano, representative of Mitsubishi Gas Chemical Co., Ltd.

Claims (1)

[Claims] (1) Two scrolls that rotate with each other in the container! knees are arranged side by side, and one end of the container has an upper <, S
A presser foot is provided on the upper surface of the container, with a material input port opening downward and a discharge port opening downward at the other end.
Interference in lI format, I! There is a warehouse granulator, the granulator has a feed area, a kneading area! It has a shape of 1.1 and 1.2, and a trapezoidal wave screw blade is formed in the key record field and the crushing region. On the reverse-feeding screw blade,
The corresponding other screw blades are carved by the screw blades of the forward feed, and the two screw blades of the reverse feed are carved and the screws with the torsion of the backward feed are both ``shi'' - deformed.
The blade wire has a ribbon-like blade shape of the original feed, and the front part is provided in at least two parts so that these are alternately arranged, and the rear part is made of two screws that are both reverse-feeding trapezoidal blades. Both of the crushing zones are provided with a plurality of central crushing teeth on the screw shaft, and the presser lid of the container is in shaft abutment with the front half of the feed zone and the kneading restraint zone. A fixed lid is installed in the area where the kneading is carried out, a movable presser lid is installed in the area corresponding to the latter half of the kneading and holding area, and the crushing area is equipped with a granulator with an open structure (21 containers). There are two screws arranged side by side inside the container that rotate in parallel with each other, and one end of the container has a material injection port that opens upward, and the other end has a discharge port that opens downward. It is a kneading-I phase granulator in the form of a presser lid with a presser lid on the upper surface of the container. In the feed region, both screws have trapezoidal screw blades, and in the kneading multi-phase region, one screw has a backward-feeding screw blade, and the other screw has a forward-feeding screw blade. The two reverse screw blades are screw blades with a fragmentary twist, and the two screw blades are ribbon-shaped blades, and at least two screw blades are provided so that these blades are alternately arranged. The first half of the two screws are shaped like trapezoidal screw blades, and the second half has trapezoidal screw blades that feed in opposite directions. The holding lid of the container is fixed at the portion corresponding to the first half of the feed region and the kneading multi-phase region, and is movable up and down at the portion corresponding to the latter half of the cross-conducting multi-phase region. Using a granulator with a structure in which the crushing area is open and the presser lid is attached, soda percarbonate powder, additives, and water are introduced from the material input port of the granulating area. A method for granulating soda percarbonate, which comprises: supplying sodium percarbonate, kneading and multi-phase granulation, and discharging the granules from a discharge port.