SU1548628A1 - Pneumatic dryer for fine particulate materials - Google Patents

Abstract

The invention relates to a drying technique and can be used in the chemical and related industries. The invention improves the quality of the dried product by increasing the uniformity of drying. The pneumatic dryer contains a spiral channel 1 connected to the central coil through separation 3 and vortex 4 chambers to an unloading cyclone 5 with exhaust pipe 6. Inside the pneumatic dryer, the classifying element 8 is placed along the axis of chambers 3 and 4, consisting of a cylindrical insert 9 with an annular shelf 10 its lower base and mounted on the nozzle 6 with the possibility of vertical movement. The use of classifying element 8 allows a two-stage classification of the particles of the material being dried. First, at the entrance to the separation chamber 3 in the annular gap between the bottom 11 and the outer surface of the cylindrical insert 9, where smaller and dry particles of the material are washed away by the flow of heat carrier and with it enter the inner space of the insert 9 and then into the cyclone 5, and larger wet particles move in a swirling flow on the outer surface of the insert 9. The secondary classification of particles by size is carried out when the material particles enter the vortex chamber 4. With the help of the annular shelf 10, the particles are pushed aside. Well supply of fresh heat transfer fluid, where under the influence of centrifugal force moist and therefore heavier particles are thrown to the wall of the chamber, thus permitting an increase their residence time in the dryer, and the dry and lighter entrainment are immediately to the discharge cyclone. The spent coolant is removed from the dryer through the exhaust pipe 6. 2 Il.

Description

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cyclone 5 with exhaust pipe 6 4 Inside the pneumatic dryer along the axis of the chambers 3 and 4 there is a classifying element 8 consisting of a cylindrical insert 9 with an annular shelf 10 on its lower base and mounted on the pipe 6 with the possibility of vertical movement. The use of classifying element 8 allows a two-stage classification of the particles of the material being dried. First, at the entrance to the separation chamber 3 in the annular gap between the bottom 11 and the outer surface of the cylindrical insert 9, where smaller and dry particles of the material are washed away by the flow of heat-transfer fluid and with it enter into the interior.

the space of the insert 9 and then into the cyclone 5, while larger and wet particles move in a swirling flow along the outer surface of the insert 9. The secondary classification of particles by size is carried out when the particles of material enter the vortex chamber 4. With the help of an annular shelf

, 0 TO the particles are pushed aside into the fresh coolant supply zone, where under the action of centrifugal force, wet and, consequently, heavier particles are thrown to the chamber wall, which

.Ј allows an increase in their residence time in the dryer, and the dry and lighter ones are immediately carried to the discharge cyclone. The spent coolant is removed 1- from the dryer through the exhaust pipe 6. 2 Il.

The invention relates to a drying technique and can be used in the chemical and other industries.

The purpose of the invention is to improve the quality of the dried product by increasing the uniformity of drying.

FIG. 1 shows the dryer, a general view; in fig. 2 is a section A-A in FIG. one .

The pneumatic dryer contains a spiral channel 1 connected on the peripheral coil to the nozzle 2 for introducing a gas suspension of wet material, and on the central through a separating 3 and a vortex 4 chambers to an unloading cyclone 5 with an exhaust nipple 6 taken out through the separating 3 and vortex 4 chambers. The vortex chamber 4 has a tangential nozzle 7 for introducing additional coolant .-

Inside the air dryer, along the axis of the separation 3 and vortex 4 chambers, there is a classifying element 8 consisting of a cylindrical insert 9 with an annular shelf 10 on its lower base.

The classifier element 8 is installed on the exhaust pipe 6 with the possibility of vertical movement and with an annular radial clearance relative to the wall of the bottom 11 of the spiral channel 1.

Air dryer works as follows.

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A gas suspension of the wet material is introduced into the spiral channel 1 through the nozzle 2. In the spiral channel 1 of the air dryer, the wet material is dried in a swirling flow of high-temperature heat transfer fluid in a mode close to ideal displacement.

Then the gas suspension enters the separation chamber 3, where, when particles are removed from the bottom 11, an annular gap between the outer surface of the cylindrical insert 9 is used to first classify the particles of the dried material by size. Smaller and, therefore, drier particles of the material are washed away by the flow of heat-transfer fluid and with it flow into the interior of the cylindrical insert 9 and then into the discharge cyclone 5. And the larger and wetter particles remain outside the cylindrical insert 9 and along it in a swirling flow flow into the vortex chamber 4. At the transition from the separation chamber 3 into the vortex chamber 4. there is a secondary classification of particles of the dried material by size m and drying the material to the desired final moisture in the flow of fresh coolant under conditions close to the ideal blend mode.

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At the same time, heavier and, therefore, wetter particles are pushed aside by the ring shelf 10.

in the peripheral zone of the vortex chamber, where fresh coolant is supplied, where under the action of centrifugal force, heavier particles are thrown against the wall, which allows to increase their residence time in the dryer, while smaller and dry particles of the material are immediately carried away to the discharge cyclone.

The dried material is discharged from the cyclone 5 through the lower nozzle, and the spent coolant is removed from the dryer through the exhaust nozzle 6. Moving the classifying element 8 relative to the exhaust nozzle 6 allows you to adjust the separation effects depending on the dispersion composition of the material being dried.

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Claims (1)

The invention of a pneumatic dryer for dispersed materials, comprising a spiral channel connected on the peripheral coil to a gas feed inlet pipe of a wet material, and on a central coil through a separation and vortex chamber to a discharge cyclone with an exhaust pipe discharged to the outside through a separation chamber that differs that, in order to improve the quality of the dried product by increasing the uniformity of drying, it is additionally equipped with a classifying element made in the form of a cylindrical insert with An end shelf at its bottom end, wherein the classifying element is mounted on the exhaust manifold with the possibility of vertical movement,