Growth rates, provided they are measured using liquor containing the correct impurities, are simple to scale-up from bench measurements. Scale up is a very complex procedure for crystallizers, and several points should be noted. For further information, consult Söhnel and Garside (1992), Myerson (1992) or the SPS Crystallization Manual. Equipment selection is dependent upon system kinetics and product requirements.
Precipitation processes are often carried out in agitated vessels of some kind, or by techniques such as impinging jets.
Product purity can be increased by "sweating" impurities out of the solidified crystals before recovery.įor further information on melt crystallizers, refer to Myerson (1992) or the SPS Crystallization Manual. The third has crystals building up on a cooled wall when crystallization is complete, residual mother liquor and impurities are drained off and the temperature raised to melt and recover the product. The second has crystals forming on the outside of a cooled rotating drum or belt, with a scraper removing crystals directly as product. A melting zone can be added to increase purification of the crystals. The first has crystals in suspension within the vessel crystals form on a cooled wall and are removed by a scraper. Melt crystallizers fall into three general categories. The Oslo-Krystal unit has a fluidized bed of crystals, suspension and agitation being provided by an external circulation loop of either crystal magma or relatively crystal-free solution.įor further information on industrial solution crystallizers, refer to Myerson (1992), Mullin (1993) or the SPS Crystallization Manual. Both evaporative and cooling versions are found. The Swenson DTB has the main recirculation provided by a propeller inside a draft tube, with a settling zone to allow fines to be removed and dissolved, and a product elutriation leg, where large crystals are extracted against an upward flow carrying small crystals back into the vessel. A draft tube and baffles are often added to improve suspension characteristics, and this leads to designs such as the Swenson Draft Tube Baffled (DTB) and Oslo-Krystal crystallizers. Although simple, it is far from optimal in terms of hydrodynamics, with poor crystal suspension. We have the experience and the technology to provide you with the mixer or agitator that you need.For solution crystallizers, the simplest equipment is an agitated, cooled vessel. We have aligned ourselves with multiple commercial gearbox manufacturers, so we can find the best-fit drive at the lowest cost for any application. Our efficient design method ensures that our mixers are both economical and robust. The different specialities of each Mixtec office allows us to quickly tap into a wealth of design experience and expertise, expanding our overall knowledge base and enabling us to confidently satisfy our customer’s needs no matter where they are located. In addition to our worldwide Mixtec Branches, we also have agents who cater to markets in which we do not have a physical presence.Įvery Mixtec office has its own research and development department as well as design, engineering and commissioning personnel who are trained to apply the latest fluid mixing technology for every application and installation. Our partners are based in the United States, South Africa, Australia, United Kingdom, Malaysia, Chile and New Zealand. The Mixtec group currently has seven manufacturing plants worldwide. Today, Mixtec is one of the world’s premier manufacturers of industrial agitators and mixers.