Mass Transfer Lab

Natural Draft Tray Dryer is a dryer in which moisture removal takes place by heat under natural condition. The set-up consists of an insulated Stainless Steel chamber fitted with heater. Inside the chamber a tray is attached directly to an electronic weighing balance, which is fitted on the bottom, outside the chamber. Material for drying is placed in the tray and regular loss of weight is monitored. Temperature controller fitted in the set-up maintains the required temperature in the chamber.

Confirming a packed bed of spherical balls of a solid in a vertical tube, and observing its rate of diffusion into stream of air passed across the top of the tube can conveniently study the diffusion of solid into air. The equipment is fitted with a vertical glass column with a mesh near the base of column to hold the spherical balls. Spherical balls of known weight and diameter are filled in the column to make a packed bed. Air is allowed to pass through the silica gel chamber. From the bottom of the column, dry air is allowed to enter in the packed bed.

Using a small sample of the liquid in a narrow vertical tube, and observing its rate of evaporation into stream of air passed across the top of the tube can conveniently be used to study the diffusion of vapour of a volatile liquid into air. The set up consists of a glass tube placed in a water bath. A horizontal glass tube is fixed to the upper end of the tube and air is drawn through this by a small air pump included within the unit. Air flows over this tube maintaining partial pressure difference. A Traveling microscope with sliding vernier scale is provided to measure the rate of fall of solvent within capillary. A stirrer is fitted to maintain constant temperature inside the bath.

The set up is made of Stainless Steel with seven plates for mounting the bubble caps. Each plate is provided with one bubble cap. An electrically heated reboiler is installed at the bottom of the column. The bottom product is collected in the tank. The vapours form the top of column are condensed in the shell and tube type condenser by cooling water supplied by laboratory overhead tank. The condensate is divided into reflux and distillate by automatic reflux divider and R/D Ratio can be varied. Reflux is fed back to the column and distillate is received in a receiving tank. The complete setup is insulated for minimizing the heat loss. Instrumentation provided for pressure & temp. measurement wherever necessary. The present set-up has a facility to interface the system with computer which enables to log the experimental data using computer. The educational software and data-logging package has been developed for unit. This software package provides a comprehensive educational software environment within which the investigations can be performed. This software is capable to tabulate the sample readings according to the requirement of experiment under study and results obtained can be compared. The real time data acquisition can be done by interfacing the set-up with computer using software. Software allows the user to have control on data logging, printing the stored data, preparing spread sheets in Excel etc.

The equipment consists of a distillation still made of stainless steel. the feed in the still is heated externally by heater. The vapours form the top of the vessel is condensed in the type condenser by circulating cooling water. Temperature of the feed mixture is controlled by means of a digital temp. Controller. The condensate is collected in a receiver made of stainless steel.

This setup is designed to study the performance characteristics of Solvent extraction of a particular component from a packed bed of solid material. The apparatus allows study of such systems as water/inorganic salts, water/sugar bed, methylene chloride/vegetable oil etc. The glass column is fitted with SS mesh to support the solid material. The solvent is introduced near the bottom of the column and it flows upward counter-currently to the solids. A pump supplies the solvent and flow rate is monitored by means of a Rotameter. Solvent feed tank is kept in a bath fitted with heater and digital temperature controller is used to maintain the constant temperature.

The set-up consists of a glass column packed with Rasching rings. Continuous counter current contacts between the solvent and solute phases is made, which results into extract and raffinate streams. Flow meters (Rotameters) are used to note the flow of solvent & solute respectively. The continuous and dispersed phase streams are metered and derived from separate containers. The total set-up is housed in a well-designed rigid structure. The structure also supports tanks, piping, Rotameters, panel and other units.