Freeze concentration for aqueous solutions

A freeze-concentration and aqueous solution technology, applied in solution crystallization, heat exchange cooling crystallization, general layout of crystallization devices, etc., can solve the problems of non-commercial application, low refrigeration efficiency, and extra energy consumption

Inactive Publication Date: 2002-08-28
梁保民 +1
View PDF13 Cites 30 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this technology is the extra energy consumption of heating the slurry in the column, the driving force for ice crystal growth is small, and the cooling efficiency of the jacketed refrigeration method is low
All of the above techniques, with the exception of the Glencoe / Nirou approach, have not been commercialized due to various issues

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Freeze concentration for aqueous solutions
  • Freeze concentration for aqueous solutions
  • Freeze concentration for aqueous solutions

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0059] This example illustrates subcooling of an aqueous solution without nucleation in a refrigeration heat exchanger.

[0060] Sucrose solutions of varying concentrations, prepared with commercial granulated sugar and water, were cooled in laboratory-scale double-pipe heat exchangers, with the solutions in the tubes and the coolant supplied by a refrigerated water bath in the annulus, operating as countercurrent. The technique described in the "Principles of Supercooling, Metastable Solutions and Instantaneous Nucleation" in the "Best Mode for Carrying Out the Invention" section was used in the experiments to achieve higher degrees of subcooling. The results of the degree of subcooling achieved without nucleation are shown in Table I.

[0061] Table I

[0062] Solution concentration Freezing point Test times Subcooling temperature difference

[0063] (weight%) (°C) (°C) (°C)

[0064] 5 -0.34 8 3.8-6.8 1.0-1.8

[0065] 10 -0.61 9 4.4-6.7 0.8-1.6

[0066] ...

Embodiment 2

[0071] This example illustrates the growth, transformation and aggregation of ice crystals in a lab-scale (1 L) multipurpose crystallizer with cooling jacket. The sucrose solutions with different concentrations are supercooled by a laboratory-scale sleeve-and-tube heat exchanger. The supercooled solution is seeded and nucleated, and the resulting fine ice crystals are separated from the concentrated solution by a filter. For the growth, transformation and aggregation of ice crystals, the obtained fine ice crystal slurry is added to a multifunctional crystallizer containing a suspension of large growing ice crystals. As a starting solution, a 5% sucrose solution was also added to the crystallizer. The mean values ​​and standard deviations of the results obtained through several experiments under different conditions are listed in Table II.

[0072] Table II

[0073] Concentration Range Low Medium Low Medium High High

[0074] Number of trials 4 6 4 6

[0075] C r (we...

Embodiment 3

[0095] This example illustrates a three-stage freeze concentration process for a sucrose solution, operated according to Figure 5 The process shown is carried out. The material balance and operating parameter data of the three freeze concentration stages and the two step combinations of the three-stage freeze concentration process are given in Table III and Table IV, respectively. The mass balance is based on 100 kg of the 5% original sucrose solution to be treated.

[0096] The meanings of the symbols in Table III and Table IV, except those already stated in Table II, are as follows:

[0097] W r - Mix the weight of the sucrose solution in the refrigerated heat exchanger.

[0098] W ri - the weight of the sucrose solution mixed with the circulating solution.

[0099] W rc - the weight of the circulating solution.

[0100] W fc - the weight of the concentrate after separation from the fine ice crystal slurry.

[0101] W fi - the weight of the ice in the fine ice cryst...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
sizeaaaaaaaaaa
Login to view more

Abstract

Investigations on the formation and growth behavior of ice crystallization in aqueous solutions reveal an important phenomenon-ice crystal transformation. It leads to very rapid growth of ice crystals and result in grain-shaped and agglomerated large crystals without inside entrainment of solute. This provides a practical basis for a new technology of freeze concentration. The efficient physical process for freeze concentration of aqueous solutions comprises, mainly, refrigerating solutions to a supercooled status without ice nucleation, or without ice formation on the heat transfer surface, instantaneously nucleating the supercooled solution to generate fine ice crystals and make the solution concentrated, producing large, grain / sphere-shaped ice crystals at high rate by growth, transformation and agglomeration of ice crystals under environment of well-controlled endo / exothermal balances. Apparatus for performing the process including, mainly, refrigerating heat exchangers, nucleators, filters and multi-function crystallizers are described. Single-stage and multistage operations can be used for the process and the major steps can be flexibly arranged.

Description

technical field [0001] The invention provides a physical method for freezing and concentrating various aqueous solutions, especially the aqueous solutions in industries such as food, beverage, dairy products, medicine, nutraceuticals, biochemistry and environmental protection. technical background [0002] Concentration of aqueous solutions is a common technique in many industries. Evaporation is a widely used method of concentration of aqueous solutions. However, an effective evaporation process must be carried out at a higher temperature boiling state, which leads to the loss or destruction of volatile or heat-sensitive substances in the solution. Unlike evaporation, which converts water into vapor, freeze concentration concentrates an aqueous solution by crystallizing water into ice at temperatures as low as the freezing point. The purpose of freeze concentration of an aqueous solution may be to obtain a concentrate, or pure water, or both. Th...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): B01D9/00
CPCB01D9/0013B01D9/0036B01D9/0059
Inventor 梁保民石渝萍
Owner 梁保民
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap