The GEA turbulence with draft tube and baffle crystallizer is the typical modern type of crystallizer in the industry. This is a typical model of mixing tank crystallizer. Draft tube is mounted inside, allowing crystals which are growing to be sent efficiently to the evaporation. In a continuous crystallization process employing an evaporative draft tube baffle (DTB) crystallizer apparatus to produce crystal product, the improvement which.

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Growing crystals are brought to the boiling surface where supersaturation is most intense and growth is most rapid. The boiling action is concentrated in the center of the vessel and is well distributed across the surface by means of the vertical draft tube inlet. The practical way is to perform a gravity settling to be able to extract and possibly recycle separately the almost clear liquid, while managing the mass flow around the crystallizer to obtain a precise slurry density elsewhere.

Options include baffling, a conical entrance, and an elutriation step. DE Free format text: Most conventional turbulence crystallizers operate under vacuum, or at slight super atmospheric pressure. Although the DTB crystallizers can produce a high percentage of their production as crystals of size greater than 1.

DTB Crystallizer

It was found that the crystals in the suspension must be a mixture of medium sized crystals 14 to 10 mesh and smaller sized below 14 Tyler mesh. The two-stage crystallizer shown below is used by an agricultural chemical company to evaporate phosphoric acid from a mixture and recover solids.

Crystal slurry is removed via line 17 by the suction of pump 18 and ‘ discharged to a thickener 19 batfle line 17a. Handbook of Industrial Crystallization. Agitated Thin Film Dryer. Method of production of metallic granules, products obtained and a device for the application of the said method.

The forced-circulation crystallizer shown on the left is used to produce sodium sulfate, while that on the right is used in the agricultural industry. Shell and tube heat exchanger Spiral plate heat exchanger. It should be understood that the suspension could enter drxft vessel directly at some other point close to the liquid level 14 or close bafflee the bottom inlet to the draft tube 7 via appropriate piping. Flow is up the draft tube and down along its exterior; and is of sufficient velocity to suspend the crystals in the vessel.


This type of crystallizer is used primarily in the production of a variety of large-size crystalline materials such as ammonium sulfate, potassium chloride and diammonium phosphate for the fertilizer industry.

When destruction of fines is not needed or wanted, baffles are not provided and the internal circulation rate is set to have the minimum nucleating influence on the suspension. The fine crystals are defined as those below 20 mesh 0. Baffling allows slurry density control Swenson DTB crystallizers are especially useful in multiple stage cooling crystallizer applications where cooling of the feed solution in each stage limits the natural slurry density to a few percent.

They are an important piece of chemical processing equipment because they are capable of generating high purity products with a relatively low energy input.

BE Free format text: The crystals are removed and vaporized solvent is condensed and returned to the crystallizer body. The batch vacuum crystallizer is particularly useful when processing materials that tend to grow on the walls of continuous crystallization equipment.

When the crystallizer produces a preponderance of large crystals, removal of mother liquor is expedited and the drying and screening operations are more efficient. FG2A Ref document number: Evaporation of solvent water takes place close to the liquid level 14 induced by a vacuum created in the vapor space Please help us to improve our website Provide feedback. In a continuous crystallization process employing an evaporative draft tube baffle DTB crystallizer apparatus to produce crystal product comprising.

Method of employing elemental zinc for the purification of aqueous solutions of metallic salts. Concentrated ammonium sulfate feed solution from line 10 which is drawn into line 11 via the pump 12 is heated in heat exchanger 13 and enters the vessel via line 11a. A description of a typical apparatus and its normal operation are given below. Inside the pipe, large scrapers wipe the solid deposits from the wall to prevent build up. This invention relates to a process for crystallization in a draft tube baffle crystallizer wherein cycling in the particle size distribution of the product withdrawn is reduced and the rate of production of granular size crystals is increased.


This crystallizer has been named so because it provides for two discharge streams, one of slurry that contains the product crystals, and another, that is mother liquor saturated solvent with a small amount of fines. Frequent flushings required to minimize deposits on the crystallizer wall Cannot effectively handle a high density slurry.

Vaporization occurs at the top surface of the slurry, while nucleation occurs near the bottom of the crystallizer body. Surface-cooled crystallizers combine a draft tube baffle crystallizer body with a heat exchanger. Date of ref document: The description and examples are written for crystallization of ammonium sulfate; but the same type of apparatus may be used for crystallization of potassium chloride, potassium sulfate, sodium chloride and other crystalline materials. DE Date of ref document: Forced-circulation crystallizers are commonly used to produce salts and chemicals in industry.

Forced-circulation crystallization is the most widely used crystallization method in industry.

Draft Tube Baffle Type | Chem Process Systems

Granular crystaplizer crystals, i. Draft tube baffle crystallizers are used to control crystal size and characteristics. Method for producing a coarse-grained ammonium sulfate product by crystallization and facility for performing the method. In the typical operation of the evaporative DTB crystallizer, the vessel is about 24 feet in diameter and is about 50 feet tall.

DTB crystallizers in the chemical industry.

It is desirable to produce large particles for both commercial and process benefits. Production of large crystals has been made easier with tbe introduction of the draft tube baffle crystallizer DTB. Patent 4, teaches a dynamic control method and apparatus for obtaining a uniform particle size. Perry’s Chemical Engineers’ Handbook. These fines are separated from the growing suspension of crystals by gravitational settling in the annular baffle zone.

The GEA turbulence with draft tube and baffle crystallizer is the typical modern type of crystallizer in the industry.