CN101712013B - Method for classifying calcium alginate plastic beads - Google Patents

Abstract

The invention relates to a method for classifying calcium alginate plastic beads. In the method, the plastic beads to be classified are put into a fluidized bed and are used as solid phases; solution of calcium chloride is used as a mobile phase; the solution of the calcium chloride flows into the fluidized bed from a fluid inlet on the lower part of the fluidized bed through a peristaltic pump, flows through the inside of the fluidized bed, and finally flows out of the fluidized bed from a fluid outlet on the upper part of the fluidized bed; and the plastic beads are classified by changing the flow velocity of the ascending fluid according to the different sedimentation velocities of the plastic beads with different grain sizes in the fluid. The method classifies the calcium alginate plastic beads according to the grain sizes, the used device is simple, is easy to amplify and can separate the plastic beads of which the average grain size difference is 200 microns, and the classification range is between 100 and 1,000 microns.

Description

A kind of method for the classification of calcium alginate glue beads

technical field

The invention relates to the classification of gel-like bead-like microspheres, specifically a method for classifying them according to particle size by using the principle of fluid mechanics in a liquid-solid fluidized bed.

Background technique

Calcium alginate gel beads (hereinafter referred to as gel beads) are a kind of gel microspheres, with a density of 1.02-1.03g/cm ³ , and have been widely used in the fields of microcapsule preparation, drug controlled release, cell immobilization, and in vivo transplantation. Extensive research and application. The particle size range of the rubber beads prepared by electrostatic titration is 200-1000 μm. In order to obtain rubber beads with a relatively uniform particle size, the commonly used classification method is sieve screening, which has low classification efficiency and is easy to cause blockage. People such as Zhang Qizhou invented a kind of beaded agarose gel band sieve classifier (patent publication number CN2043135), this device has improved the classification efficiency on the basis of sieve screen, but the classification of this method is still limited by the screen .

Contents of the invention

The purpose of the present invention is to provide a new method for grading calcium alginate rubber beads. The difference in settling velocity makes the rubber beads be graded by changing the flow velocity of the ascending fluid (see accompanying drawing 5). The equipment used in the method is simple, not limited by the pore size of the sieve used in traditional classification, can realize continuous classification, and can classify rubber beads with a minimum particle size difference of about 200 μm, and the classification method is easy to scale up and has high classification efficiency.

To achieve the above object, the technical solution adopted in the present invention is:

A method for grading calcium alginate glue beads, the glue beads to be classified are placed in a fluidized bed, the glue beads are used as a stationary phase, the calcium chloride solution is used as a mobile phase, and the calcium chloride solution is transferred from the fluidized bed through a peristaltic pump The lower fluid inlet flows in, passes through the interior of the fluidized bed, and finally flows out from the upper fluid outlet. According to the different sedimentation velocities of the rubber beads with different particle sizes in the fluid, the rubber beads are graded by changing the flow rate of the ascending fluid;

The fluidized bed is a cylindrical fluidized bed with a height-to-diameter ratio of 5-20, a fluid inlet at the lower end, a fluid outlet at the upper end, and a material outlet on the side wall of the upper part, and the material outlet is located at The height of the fluidized bed is 2/3-5/6, and a fluid distribution plate is arranged under the inside of the fluidized bed.

Its specific operation process is as follows,

1) Put the rubber beads to be classified in the fluidized bed, and the volume of the rubber beads is 1/10-2/5 of the volume of the fluidized bed.

2) Turn on the peristaltic pump, slowly pump the calcium chloride solution from the fluid inlet at the lower end of the fluidized bed, and at the same time open the fluid outlet at the upper end of the fluidized bed, and control the surface velocity of the fluid at 0.01-0.1cm/s until the fluid fills the entire the inner cavity of the fluidized bed;

3) Increase the speed of the peristaltic pump to increase the flow rate of the fluid until the bed expansion height of the rubber beads is consistent with the height of the material outlet on the side wall of the fluidized bed, open the material outlet, and close the upper fluid outlet at the same time to maintain a constant flow rate Stable for 5-30 minutes, the rubber beads flowing out of the fluidized bed are the first batch of graded rubber beads;

4) If you want to continue to classify the rubber beads remaining in the fluidized bed, then continue to increase the fluid flow rate until the bed expansion height of the rubber beads is consistent with the height of the material outlet on the side wall of the fluidized bed. Stable at a constant flow rate for 5-30 minutes, the rubber beads flowing out of the fluidized bed are the second batch of graded rubber beads; by performing the above operations in sequence, calcium alginate beads with different particle sizes can be obtained in equal parts.

The concentration of the calcium chloride solution is 0.05-0.3mol/L. The surface velocity of the fluid during classification is usually 0.1-0.6 cm/s.

The present invention has the following advantages:

1. The equipment is simple and easy to operate. Not limited by the screen used in traditional classification, the mechanical equipment used is only a liquid-solid fluidized bed, and the classification of rubber beads can be realized only by adjusting the flow rate of the fluid.

2. Compared with screen screening, this classification method will not cause damage to the rubber beads, and the separation effect is good.

3. It can realize continuous classification, and can classify rubber beads with a minimum particle size difference of about 200 μm, and this classification method is easy to scale up and has high classification efficiency.

In a word, compared with the traditional screen screening, the method of the present invention has the advantages of simple equipment, convenient operation, high classification efficiency and large-scale application.

Description of drawings

Fig. 1 is the particle size distribution figure of rubber beads before and after classification of embodiment 1;

Fig. 2 is the particle size distribution figure of rubber beads before and after classification of embodiment 2;

Fig. 3 is the particle size distribution figure of rubber beads before and after classification of embodiment 3;

Fig. 4 is the schematic diagram of fluidized bed of the present invention;

Figure 5 shows the influence of the flow rate of the fluid on the fluid dynamics of rubber beads with different particle sizes in the fluidized bed.

Detailed ways

As shown in Figure 4, the fluidized bed used in the present invention is a cylindrical fluidized bed with an aspect ratio of 5-20, a fluid inlet 1 is provided at the lower end, a fluid outlet 2 is provided at the upper end, and the side of the upper part A material outlet 3 is arranged on the wall, and the material outlet is located at 2/3-5/6 of the height of the fluidized bed, and a fluid distribution plate 4 is arranged under the inside of the fluidized bed.

The present invention realizes the classification of rubber beads in a fluidized bed according to the principles of fluid mechanics, and the fluidization characteristics of the rubber beads in the fluidized bed depend on the size, shape and density of the particles and the flow rate of the fluid. Under the condition of certain factors, the fluidization characteristics of rubber beads mainly depend on their particle size. As shown in Figure 5, the expansion height of rubber beads with different particle sizes in the fluidized bed.

The equipment used in the method is simple and easy to scale up, and can separate rubber beads with an average particle diameter difference of 200 microns, and the classification range is 100-1000 microns.

Example 1

1) Detect the particle size distribution of the rubber beads to be classified on the particle size analyzer (see the blue distribution line in Figure 1), the particle size range of the rubber beads includes two parts, the minimum particle size of the first part is 185 μm, and the maximum particle size 270μm, with an average particle size of 225±15μm; the second part has a minimum particle size of 356μm, a maximum particle size of 471μm, and an average particle size of 412±19μm.

2) Put the rubber beads to be classified in the fluidized bed, and the volume of the rubber beads accounts for 1/5 of the volume of the fluidized bed.

3) Turn on the peristaltic pump, and slowly pump the calcium chloride solution with a concentration of 0.05mol/L from the fluid inlet 1 of the fluidized bed, and simultaneously open the fluid outlet 2 of the fluidized bed, and control the surface velocity of the fluid at 0.05cm/s, Until the fluid fills the entire cavity of the fluidized bed.

4) Slowly increase the speed of the peristaltic pump to increase the flow rate of the fluid until the bed expansion height of the rubber beads is consistent with the height of the material outlet 3, open the material outlet 3, and close the fluid outlet 2 at the same time, continue to slowly increase the fluid flow rate To 0.10-0.12cm/s, keep the flow rate stable for 10 minutes. After treatment, the first part of the rubber beads flows out of the fluidized bed, and the second part of the rubber beads remains in the fluidized bed (see the red distribution line in Figure 1), and the particle size analyzer detects the average amount of the rubber beads remaining in the fluidized bed. The particle size is 419±17 μm, and the range of particle size distribution is consistent with that of the second part before separation. The results show that this method can completely separate the two parts of rubber beads with different particle sizes.

Example 2

1) Detect the particle size distribution of the rubber beads to be classified on the particle size analyzer (see the blue distribution line in Figure 2), the particle size range of the rubber beads includes two parts, the minimum particle size of the first part is 391 μm, and the maximum particle size 471μm, with an average particle size of 429±20μm; the second part has a minimum particle size of 517μm, a maximum particle size of 751μm, and an average particle size of 623±39μm.

2) Put the rubber beads to be classified in the fluidized bed, and the volume of the rubber beads accounts for 1/5 of the volume of the fluidized bed.

3) Turn on the peristaltic pump, and slowly pump the calcium chloride solution with a concentration of 0.1mol/L from the fluid inlet 1 of the fluidized bed, and simultaneously open the fluid outlet 2 of the fluidized bed, and control the surface velocity of the fluid at 0.1cm/s. Until the fluid fills the entire cavity of the fluidized bed.

4) Slowly increase the speed of the peristaltic pump to increase the flow rate of the fluid until the bed expansion height of the rubber beads is consistent with the height of the material outlet 3, open the material outlet 3, and close the fluid outlet 2 at the same time, continue to slowly increase the fluid flow rate To 0.15-0.18cm/s, keep the flow rate stable for 15 minutes, the rubber beads flowing out of the fluidized bed are the first batch of rubber beads that are classified (see the red square distribution line in Figure 2), and the average particle size is 451 ± 21 μm, The rubber beads staying in the fluidized bed are the second batch of classified rubber beads (see the red star-shaped distribution line in Figure 2), with an average particle size of 649±30 μm. Although some changes have taken place in the particle size range of the rubber beads after classification, the results show that the method can separate the rubber beads in the two particle size ranges.

Example 3

1) Detect the particle size distribution of the rubber beads to be classified on the particle size analyzer (see the blue distribution line in Figure 3). The particle size distribution of the rubber beads has a wide range, the minimum particle size is 293 μm, and the maximum particle size is 815 μm.

2) Put the rubber beads to be classified in the fluidized bed, and the volume of the rubber beads accounts for 1/10 of the volume of the fluidized bed.

3) Turn on the peristaltic pump, and slowly pump the calcium chloride solution with a concentration of 0.3mol/L from the fluid inlet 1 of the fluidized bed, and simultaneously open the fluid outlet 2 of the fluidized bed, and control the surface velocity of the fluid at 0.06cm/s. Until the fluid fills the entire cavity of the fluidized bed.

4) Slowly increase the speed of the peristaltic pump to increase the flow rate of the fluid until the bed expansion height of the rubber beads is consistent with the height of the material outlet 3, open the material outlet 3, and close the fluid outlet 2 at the same time, continue to slowly increase the fluid flow rate to 0.15cm/s, keep the flow rate stable for 25 minutes, the rubber beads flowing out of the fluidized bed are the first batch of rubber beads to be classified (see the red square distribution line in Figure 3), the average particle size is 398±22μm, and the The size distribution range is narrow; the rubber beads staying in the fluidized bed are the second batch of rubber beads that are classified (see the red star-shaped distribution line in Figure 3), and the average particle size is 593±78 μm. From the results, This method can divide the rubber beads into two parts according to the particle size.

Claims (3)

1. a method for calcium alginate glue beads classification, it is characterized in that: put the glue beads to be classified in fluidized bed, glue beads are as stationary phase, calcium chloride solution is as mobile phase, and calcium chloride solution passes through peristalsis The pump flows in from the fluid inlet of the lower part of the fluidized bed, passes through the interior of the fluidized bed, and finally flows out from the upper fluid outlet. Grading; The fluidized bed is a cylindrical fluidized bed with an aspect ratio of 5-20, a fluid inlet (1) at the lower end, a fluid outlet (2) at the upper end, and a fluid outlet (2) at the upper side wall. The material outlet (3), the material outlet (3) is located at 2/3-5/6 of the height of the fluidized bed, and a fluid distribution plate (4) is arranged under the inside of the fluidized bed; Its specific operation process is as follows, 1) Put the rubber beads to be classified in the fluidized bed, and the volume of the rubber beads is 1/10-2/5 of the volume of the fluidized bed; 2) Turn on the peristaltic pump, slowly pump the calcium chloride solution from the fluid inlet (1) at the lower end of the fluidized bed, and simultaneously open the upper fluid outlet (2) of the fluidized bed, and control the surface velocity of the fluid at 0.01-0.1cm/ s, until the fluid fills the entire cavity of the fluidized bed; 3) Increase the speed of the peristaltic pump to increase the flow rate of the fluid until the bed expansion height of the rubber beads is consistent with the height of the material outlet on the side wall of the fluidized bed, open the material outlet (3), and close the upper fluid outlet ( 2), keep stable at a constant flow rate for 5-30 minutes, the rubber beads flowing out of the fluidized bed are the first batch of classified rubber beads; 4) Continue to classify the rubber beads remaining in the fluidized bed, and then continue to increase the fluid flow rate until the bed expansion height of the rubber beads is consistent with the height of the material outlet on the side wall of the fluidized bed, maintaining a constant flow rate Stable at high temperature for 5-30 minutes, the rubber beads flowing out of the fluidized bed are the second batch of graded rubber beads; by performing the above operations in sequence, calcium alginate beads with different particle sizes can be obtained in equal parts. 2. according to the described method of claim 1, it is characterized in that: the concentration of described calcium chloride solution is 0.05-0.3mol/L. 3. according to the described method of claim 1, it is characterized in that: the superficial flow velocity of calcium chloride fluid is 0.1-0.6cm/s during step 3) classification.

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