CN1833747A

CN1833747A - Continuous crystallizing tower

Info

Publication number: CN1833747A
Application number: CN 200510053930
Authority: CN
Inventors: 李群生
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-03-14
Filing date: 2005-03-14
Publication date: 2006-09-20

Abstract

A continuous crystallizing tower is composed of refining segment, recovering segment, purifying segment and fusing segment. The material to be separated is fed in between refining segment and recovering segment, then crystallized to obtain target product, and finally purified. Said purifying segment is based on sweating action, recrystallizing and counter current washing.

Description

Continuous crystallizing tower

Technical field

The present invention relates to a kind of continuous crystalizer, it is a kind of liquid material to be sent in this equipment continuously, and continuous separate is from obtaining high purity product.It mainly is the crystallization process that is used for fields such as chemical industry, petrochemical industry, pharmacy, metallurgy.

Background technology

In the mass transfer apparatus that in the industrial production such as chemical industry, oil, light industry, metallurgy, uses, sometimes need to separate with crystallization process, generally be to adopt crystallizer, at the crystallizer intercrystalline, crystal and mother liquor discharge respectively with material, crystal is realized separating, sometimes for further obtaining high-purity crystal, need crystal is put into crystallizing tank again, be recrystallized or repeatedly be recrystallized (such as Fig. 1, a crystallizer, 3-5 recrystallization tank.)。The continuous crystalizer that the present invention adopts is that material is carried out crystallization in a crystallizer, purifies in rectifying section; Crystallizer has two sections of refining section and exhausting sections, and the former is used for crystal is made with extra care, and the latter is used for reclaiming the target product in the liquid that enters raffinate.Crystal after refining is sent in the rectifying section, and at rectifying section, top-down landing is carried out counter current contacting with from bottom to top liquid, and by perspiration, recrystallization mechanism and countercurrent washing mechanism, crystal further purified the high purity product of purchasing out thus.The length of this section setting, the separation process of a lot of theoretical stages can be provided, promptly can be equivalent to a lot of recrystallization processes intermittently, like this, with these recrystallization processes intermittently, in a tower rectifying section, once finish, significantly shortened purifying technique, save equipment investment, reduced energy consumption and operating cost.And the raising along with product purity requires can design higher rectifying section and reach requirement.

In the tower of rectifying section, crystal forms a crystal bed, and crystal bed is in purifying column, motion in the time of at the bottom of the near tower, is provided with a melt zone and heater at the bottom of tower from top to bottom, with the crystal heating and melting, become melt liquid, at this moment, part melt liquid upwards returns, and with the crystal counter current contacting that moves downward, reaches the purpose of purification, another part fused solution, because the decline process is washed by continuous multi-stage and purified, purity is very high, can be used as product extraction at the bottom of the tower.

The melt liquid that rises, always with the crystal counter current contacting mass transfer that descends, the various impurity such as impurity that adhere in the mother liquor with the impurity that contains between the impurity in the crystal, crystal, plane of crystal, by mechanism and effects such as perspiration, recrystallization mechanism and countercurrent washings, crystal is further purified, and the impurity in the crystal is delivered to from crystal in the fused solution, rise along with fused solution.Be drained into refining section from the rectifying section cat head at last, refining section by the outside by chuck and feed cooling medium cylinder or awl tube form, in the refining section scraper type is set, in refining section, the raw material that to newly import carries out crystal refining on the one hand, on the other hand the raffinate that rises is carried out crystal refining, with the target product in the two, on the wall of refining section, pass through rotating scraper again by refining crystallization, crystal is scraped, simultaneously, scraper is made helical-ribbon type, and the scraper of helical-ribbon type is under self rotates, with being transported in the rectifying section of crystal continuous, make the liquid of crystallization continue to flow to exhausting section.

At exhausting section, it constitutes with refining section similar, also form by cylinder that has chuck or circular cone, the centre has a spiral scraper, and the liquid that refining section is sent here continues crystallization, in order fully to reclaim target product wherein, the temperature of cooling medium in the exhausting section chuck, the refining section of the ratio of control is lower slightly, guarantees that so wherein the content of target product reaches emission request from the liquid of exhausting section discharging.Raffinate discharges from this crystallizer, if be necessary, adopts other methods such as rectifying again, further raffinate is separated.

Summary of the invention

The present invention proposes a kind of continuous crystallisation device, it is by crystallizer, promptly refining section and exhausting section, and purifying column, be that rectifying section and melt zone are formed, material is sent in the crystallizer continuously, and the gained crystal is discharged in the rectifying section, effect of mass transmitting takes place herein, crystal is purified by ascending liquid, and crystal moves down, and meets the requirements of purity at the bottom of tower, be heated fusion, part liquid is discharged outside the tower as product, and another part returns in the tower as phegma, rises, with top-down crystal counter current contacting, carry out mass transfer and separate.

Fused solution and the new raw material that adds in refining stage by crystallization, with the target product crystal refining that wherein contains; Continued crystallization at exhausting section, reclaimed target product wherein.Get rid of at last raffinate from the exhausting section end, be separated into product and raffinate two parts so that enter the raw material of this device.

Description of drawings

Fig. 1 is the structure chart of continuous crystallizing tower among the present invention

The specific embodiment

In paracide and o-dichlorohenzene mixture, paracide content 62%, send between the refining stage and exhausting section of continuous crystalizer, in refining stage, deliver in the rectifying section with the paracide crystallization and with crystal, the liquid scrubbing that crystal is upwards risen and carry out mass transfer, melt zone at the bottom of tower is heated melting, part liquid is discharged crystallizer, another part returns in the tower as phegma, is recovered at refining stage and exhausting section, after the further crystallization recovery of target product paracide, from one section discharge of exhausting section.Paracide content reaches 99.999% in the rectifying section effluent, and the material paracide content that exhausting section is got rid of is reduced to 0.5%-20%, rectifying section height 1m, each 0.5m of length of refining section, exhausting section.

Claims

1, a kind of continuous crystallisation device, it is by crystallizer, i.e. refining stage and exhausting section, and purifying column, i.e. rectifying section and melt zone composition.

2, refining stage according to claim 1 by the outside by chuck and pass into cooling medium cylinder or cone tube form, a scraper type is set in the refining stage, crystal is scraped, scraper is made helical-ribbon type.

3, exhausting section according to claim 1 also is made up of cylinder that has chuck or circular cone, and the centre has a spiral scraper.

4, rectifying section according to claim 1, the length of this section setting can provide the separation process of a lot of theoretical stages, namely can be equivalent to a lot of recrystallization processes intermittently, like this, with these recrystallization processes intermittently, in a tower rectifying section, once finish.

5, in the melt zone according to claim 1, the melt liquid of rising with the crystal counter current contacting mass transfer that descends, is further purified crystal, and the impurity in the crystal is delivered to from crystal in the fused solution always, rises along with fused solution.