Continuous Evaporation Crystallization

quick overview :

Continuous Evaporation Crystallization

Main characteristics of the pilot.

• Industrial instrumentation.
• Flow switch of the condenser cooling water for operators safety.
• Level and temperature switches to protect heating element.
• Borosilicate glass and stainless steel AISI 316L manufacturing.
• Rigid process pipes.
• Electrical heating.
• Variable speed stirring motor
• Interchangeable stirring rotor
• Mirror polished cooling crystallizer
• AISI 316L stainless steel bag filter (Option)

Principal of Working

Crystallization allows the separation from a solution of one or more solid compounds dissolved in that solution. On separation, the dissolved compounds change to their solid state when the required operating conditions are met (temperature, concentration). The crystals formed are then separated from the liquid phase by filtration. Crystallization is obtained by the partial evaporation of the solvent, then cooling of the concentrated solution thus obtained. The feed of initial solution is continuous, evaporation of the solvent is continuous, crystallization occurs continuously whilst the removal of crystals obtained with the saturated mother liquor is performed in a semi-continuous manner; the separation stage for crystals from the mother liquor is operated using a bag filter under reduced pressure.

Teaching Objectives of Continuous Evaporation Crystallization

• Study of the following experimental parameters:
• Continuous crystallization of a solution through evaporation then cooling.
• Influence of operating conditions on crystallization of a solution.
• Calculations:
• Heat balance.
• Mass balance.

Technical Specifications of Continuous Evaporation Crystallization

• Polyethylene feed solution storage tank; 20 litres nominal volume.
• Feed solution metering pump, AISI 316L stainless steel body, P.T.F.E. diaphragm, manual control.
• Borosilicate glass continuous boiler, electrically heated, fitted with a low level safety switch and high temperature safety switch.
• Incline condenser, borosilicate glass body, AISI 316L stainless steel exchanger with baffle.
• AISI 316L stainless steel solvent cooler.
• Borosilicate glass solvent receiver tank, fitted with AISI 316L stainless steel drain valve.
• AISI 316L stainless steel concentrate cooler with by-pass.
• Borosilicate glass cylindrical crystallization reaction vessel.
• Variable speed stirring assembly made of AISI 316L stainless steel with inclined three-bladed stirrer.
• AISI 316L stainless steel crystallization cooling exchanger, mirror polished.
• AISI 316L stainless steel bag filter operating under reduced pressure.
• AISI 316L stainless steel connecting tubes for the process and PVC reinforced tube for cooling fluid.
• Support framework with AISI 304L stainless steel tubes, aluminium connecting nuts and adjustable feet.

Instrumentation:

• Cooling water feed to condenser fitted with variable area flowmeter with its adjusting valve and water flow switch to turn off heating in case of lack of cooling water.
• Cooling water feed to crystallization reaction vessel fitted with variable area flow meter and adjusting valve.
• Command and control cabinet fitted with emergency stop, operating buttons and the following interfaces:

Boiler heating controller.

• Crystallization vessel stirrer speed controller.
• Two digital temperature indicators with six Pt100 Ω type probes.

Dimensions and weight

• 1350 mm x 600 mm x 2500 mm ~ 180 kg.

Essential requirements

• 230 V / 50 Hz / Single phase : 4 kW.
• Cold water 10°C / 3 bar: 1 m3/h.