Vobis specializes in designing and manufacturing a broad range of different crystallizer systems designs to fulfill diverse client requirements. We provide the design, engineering, manufacture, and implementation of complete evaporative crystallizer systems, and we have the decades of successful experience necessary to meet our clients’ specific needs throughout their process development.  As our clients require, we help them implement our production-scale crystallizers.  Our crystallizers are capable of yielding solids from a vast spectrum of waste and product feed streams; our process solutions enable our clients to cost-effectively reduce waste stream volumes, create landfill-ready solid crystals or produce product crystals, and provide ZLD (Zero Liquid Discharge) processing solutions.  We achieve these goals through building and delivering a variety of required crystallization processing systems.

To achieve the first client goal, cost-effectively reducing waste stream volumes, we manufacture single or multiple-stage brine crystallizers.  One of our single-stage pilot crystallizers in some cases constitutes the final step of the client solution, and in other cases is implemented to produce data which facilitates scale-up design.  We utilize either our experience in fulfilling multiple crystallizer applications or pilot data generated during testing to design and manufacture a production-scale single or multiple effect crystallizer (increasing efficiency with mechanical or thermal vapor compression) with the goal of highly energy efficient operation.

Second, creating landfill-ready crystals involves additional crystallization specific and post crystallization processing steps.  For many of our crystallizers, the feed stream is first concentrated by evaporation, until the saturation point is passed and crystal nucleation begins, during the process the precipitating solids remain suspended in liquid through the use of high pumping recirculation velocities.  This heavy slurry of crystals and saturated solution is circulated at a high rate within the system also to minimize fouling in the heat exchanger.  Crystal growth is promoted onto the developing crystals, while growth is retarded on the interior of the system chambers.  At this stage, a continuous heavy slurry stream of crystals is drawn from the crystallizer; often to a cooling chamber for completion of the crystallization process; and next through centrifugation (or a filter press), where it is further concentrated into its final, landfill-ready dry crystal form at over 95% solids.

Third, Zero Liquid Discharge (ZLD) can be achieved by crystallizing dissolved solids from wastewater as dry crystals, and returning distilled water.  First, falling film or forced circulation evaporation processes concentrate the wastewater to the saturation point.  Then, the crystallization process yields crystals (which can be dried for landfill or pelletized for other uses) and distilled water is produced, thus eliminating the wastes to realize the goal of zero liquid discharge.

These are three significant goals for our clients, and an overview of the processes by which we accomplish them; however, while the concepts involved in crystallization (heat, mass transfer and crystal growth) are reasonably universal, each feed material’s specific characteristics does significantly influence the system’s design.  The application specific appropriate design is determined according to established principles and experience, which Vobis applies in providing the following range of crystallizer systems:

 

Crystallizers which Vobis designs and builds

  • Cooling Crystallizers
  • DTB Crystallizers (Draft Tube Crystallizers)
  • Evaporative Crystallizers
  • Forced Circulation Crystallizers
  • Oslo Type Crystallizers (classified suspension crystallizers to grow specific size crystals)
  • Vacuum Crystallizers
  • MVR Crystallizers

Also taken into account during the design process, is the range of applications which the client wishes the system to be capable to accommodate as well as the extent the client wants the system’s users to be able to customize the process.  The crystallizer design effects the nucleation, crystal size, and crystal yield; considerations and specific considerations such as “what will aid in keeping heat transfer surfaces clean,” also fall into the realm of concerns addressed by the crystallizer design appropriate for the application. 

 

Vobis crystallizers accomplish diverse client requirements:

While each Vobis crystallizer involves a customized and specific process (such as supplying a specific capacity multiple effect forced circulation crystallizer), the purpose of our crystallizers overall is to provide an easily operable and energy efficient full scale production crystallizers.  With our crystallizers as with all of our systems, Vobis innovates purpose-driven systems that will enable you to accomplish your process and economic goals.  

For information regarding our pilot crystallizers, please follow this link.