RU2179929C1 - Apparatus for concentration of polymeric crumbs - Google Patents

Abstract

FIELD: equipment for working of suspensions of polymeric materials, in particular continues-operation apparatuses designed for raising the concentration of polymeric product, for example, crumb of synthetic rubber in a whirled flow of water. SUBSTANCE: the apparatus has a cylindrical body with a cover and a tapered bottom. The body and the bottom are provided with a coaxial branch pipe for discharge of concentrated polymeric crumb and a pipe for feeding of water for dilution. The apparatus has a tangential branch pipe for feeding of the source mixture and a branch pipe for discharge of clarified water connected to the tapered bottom, installed in the opposite parts of the body, and a gas feed line. The branch pipe for discharge of concentrated polymeric crumb in its lower part is provided with a separator consisting of a set of plates. The latters are made in the form of a truncated cone with a slope of the generating lines exceeding the slope of repose of polymeric crumb. The plates are installed in a spaced relation to one another. The upper diameters of the plates are made variable in the length of the separator and make up an internal duct in the form of a reverse cone. The pipe for feeding of water for dilution is inserted in the internal duct and communicates with the gas feed line. The branch pipe for discharge of clarified water is installed in a spaced relation coaxially to the pipe for feeding of water for dilution. EFFECT: enhanced reliability in operation, prevented interaction of phases in the process of separation, provided an additional differential of densities in liquid and gas-liquid mixture. 1 dwg

Description

 The invention relates to equipment for processing suspensions of polymeric materials, in particular to continuous apparatuses intended to increase the concentration of the polymer product, for example, crumb synthetic rubber in a swirling stream of water. The invention can be used in chemical industries.

 Known hydrocyclone for concentrating polymer chips in the field of centrifugal forces, including a cylindrical body equipped with a tangential nozzle for introducing the initial mixture, with a lid containing a nozzle for removing the light (polymer) phase, and a conical bottom with a nozzle in the lower part for removing the heavy phase / cm ., for example, the book of A. Mustafayev and others. Hydrocyclones in the oil industry. M .: Nedra, 1991, p. 3 /.

 The disadvantage of the hydrocyclone is the limited degree of concentration of the polymer, due to the inevitable clogging of the branch pipe for the removal of the light phase when the yield strength of the concentrated chips is changed. In addition, the functionality of the apparatus is limited only by concentration, and when processing polymer suspensions, there are tasks of washing, replacing the transport fluid, etc.

 Also known is an apparatus for concentrating polymer chips containing a cylindrical body with a lid and a bottom, a tangential nozzle for introducing the initial mixture and a nozzle for concentrating crumb output installed in the upper part of the housing, as well as nozzles for removing clarified water and introducing dilution water placed in the lower part of the housing light phase / cm. e.g. A.S. USSR 1024297, MKI B 29 N 1/00, 1983, B.I. 23 /.

 The disadvantage of this technical solution is the low efficiency of its work.

 This drawback is due to the use of inclined blades and ribs, providing a swirling flow or its straightening, which lead to the formation of stagnant zones and serve as sources of clogging of the devices with polymer chips.

 The closest in technical essence and the achieved result to the invention is an apparatus for concentrating polymer chips, containing a cylindrical body with a lid and a bottom, tangential nozzles for introducing the initial mixture and withdrawing clarified liquid located in opposite parts of the housing at a certain distance from one another, nozzles for the withdrawal of concentrated crumbs and the introduction of water for dilution, installed in the lid and bottom, respectively, with the ends of the nozzles facing towards each other , and the distance between them is chosen equal to 1-4 body diameters / cm. A.S. USSR 2027592, MKI B 29 V 15/02, 1995, B.I. 3 /.

 The disadvantage of this technical solution is the low reliability of the apparatus, due to the influence of the wash liquid flow on the hydrodynamic situation in the zone of concentration of the light phase. Specifying a certain distance between the outlet pipes of the concentrated polymer chips and the inlet of the wash water involves the process at constant operating parameters. Deviation from the established characteristics will lead to a change in the concentration of polymer chips at the outlet of the apparatus: an increase in the flow rate of the washing liquid causes erosion of the formed zone, consisting of a light phase, and the influence of its disintegrated part on the structure of the swirling flow.

 The purpose of the invention is to increase the reliability of the apparatus.

 This goal is achieved by the fact that in the apparatus for the concentration of polymer chips, including a cylindrical body with a lid and a bottom, equipped with coaxial pipe for the output of concentrated polymer chips and a pipe for introducing water for dilution, a tangential pipe for introducing the initial mixture and a pipe for removing clarified water, installed in opposite parts of the housing, according to the invention, it is equipped with a gas supply line, the bottom is conical and connected to the outlet pipe for clarified water, which is installed with a gap coaxial to the pipe for introducing water into the dilution, the outlet pipe for the concentrated polymer chips in its lower part is equipped with a separator consisting of a set of plates made in the form of a truncated cone with an inclination angle exceeding the angle of repose of the polymer chips, and installed with a gap relative to each other, the top diameters of the plates are made variable along the length of the separator and form an inner channel in the form of a inverse cone, while the pipe for introducing dilution water is introduced into the inner enny channel and communicates with the gas supply line.

 Distinctive features of the proposed apparatus is that it is equipped with a gas supply line, the bottom is tapered and connected to the clarified water outlet pipe, which is installed coaxially with a gap for the dilution water inlet pipe, the concentrated polymer crumb outlet pipe is equipped with a separator in its lower part from a set of plates made in the form of a truncated cone with an angle of inclination of the generators exceeding the angle of repose of the polymer chips, and installed with a gap relative to each other friend, the top diameters of the plates are made variable along the length of the separator and form an inner channel in the form of a inverse cone, while the pipe for introducing dilution water is introduced into the inner channel and is in communication with the gas supply line.

 This eliminates the mutual influence of phases in the separation process and provides additional injection of the light phase due to the difference in densities in the liquid and gas-liquid mixture.

 The invention is illustrated in the drawing, which shows a longitudinal section of the apparatus.

 The apparatus consists of a cylindrical body 1, cover 2, conical bottom 3, as well as water supply lines 4 and gas 5.

 The cylindrical housing 1 is provided with a tangential pipe 6 for introducing the initial mixture.

 A nozzle 7 is installed in the lid 2 for withdrawing concentrated polymer chips, which is equipped with a separator in the lower part. The separator is made in the form of a set of plates 8 having the shape of a truncated cone, and installed with a gap 9 relative to each other. The apical diameters of the plates 8 form the inner channel 10 in the form of an inverse cone.

 In the lower part of the conical bottom 3 there is a pipe 11 for outputting clarified water and a pipe 12 for introducing a gas-liquid stream for dilution, coaxially installed with a gap to the pipe 11. The pipe 12 is introduced into the separator and communicated with the water supply lines 4 and gas 5.

 The device operates as follows. After water degassing of the polymerizate, the initial mixture containing about 5% rubber is fed to the apparatus for concentration through the nozzle 6. Due to the tangential introduction, the flow of the initial mixture is twisted. Under the action of a centrifugal field, pulp is separated: the light phase (rubber crumb) is collected in the center, and the heavy phase (water) is discharged to the periphery of the cylindrical body 1 and the conical bottom 3. The light phase, passing through the gaps 9 between the plates 8, enters the inner channel 10 separators. The pipe 12, in communication with lines 4, 5, in the separator serves water and gas. The gas-liquid mixture provides dilution, washing and transportation of rubber crumbs. The rubber crumb exiting from the apparatus through pipe 7 has a concentration of 20-25%.

 By changing the ratio between the flow rates of gas and liquid in the pipe 12, it is possible to control the density of the gas-liquid mixture, and therefore the pressure difference in the central and peripheral parts of the apparatus, which facilitates the injection of crumbs into the inner channel 10 of the separator.

 The interaction of the dispersed material with a gas-liquid flow in the internal channel 10 does not affect the structure of the swirling fluid flow, moving along the periphery down the apparatus.

 The throughput of the inner channel 10, made in the form of a return cone, with an increase in the flow rate of the light phase along the height of the separator provides an increasing cross-sectional area of the cone.

 The clarified water (heavy phase) is removed from the apparatus through a pipe 11 located in the lower part of the conical bottom 3.

 The proposed apparatus is planned for implementation at the butyl rubber plant of Nizhnekamskneftekhim JSC.

 Thus, the introduction of the apparatus will improve the reliability of its operation by eliminating the interaction of phases and providing additional injection of the light fraction created by the gas-liquid mixture.

Claims (1)

 A device for concentrating polymer chips containing a cylindrical body with a lid and a bottom made conical, equipped with coaxial nozzle for withdrawing concentrated polymer chips and a pipe for introducing dilution water, a tangential nozzle for introducing the initial mixture and a clarifying water outlet connecting to the conical bottom, installed in opposite parts of the housing and the gas supply line, characterized in that the outlet pipe of the concentrated polymer chips in its lower part is equipped with a separator a torus consisting of a set of plates made in the form of a truncated cone with an angle of inclination of the generators exceeding the angle of repose of the polymer crumb and set with a gap relative to each other, the upper diameters of the plates are made variable along the length of the separator and form an inner channel in the form of a cone, and a pipe for introducing dilution water is introduced into the inner channel and is in communication with a gas supply line, the clarified water outlet pipe being installed coaxially with a clearance coaxially to the diluting water input pipe.