Demonstrate the working/SOP tray drier


Most tray dryers used in the food industry comprise a heated cabinet in which a rack of trays is located. These are, however, typically used for the production of dried fruit and vegetables, and include a mechanism by which the lowest tray in the drying cabinet can be removed (once the material on the tray is dry), thus allowing the higher trays to be lowered.

OPERATION:

  • The following procedure should be strictly followed before starting operation.

  • Before starting, clean the dryer and trays properly.

  • Load the granulating materials in the tray and put the loaded trays in

the dryer.

  • Adjust the inlet and outlet air by adjusting the “in” window fitted at the top of the dryer.

  • Adjust the temperature by adjusting the digits thermostat on the left top corner of the panel of

the dryer to the required temperature.

  • Adjust the time

  • from the timer on the panel of the dryer.

  • Switch ON the main supply.

  • ON the machine by pressing the Green Push Button. The air blower will start.

  • Then ON the heaters from the ON/OFF button fitted on the main panel of the dryer pressing the Red Push Button.

  • Switch OFF the main supply. After compilation the process

 

CLEANING:

At the end of each operations ash the trays with hot water and clean all others parts with damp

cloth and then properly dry it.

 

PRECAUTIONS.

  • “ON” the blower and heater and leave it open for a few minutes and then close the dryer.

  • Check the temperature after every 15 minutes

  • When granulation is done with organic solvent, the temperature should not exceed 40 C.

  • When aqueous solvent is used then dry up to 45 C.

  • The door of the dryer will be remain slightly open for the first 5 minutes if organic solvent is

used in granulation.

 

 

PROCEDURE:

  • Charge the material into the product container and spread to form a layer of even thickness.

  • Wheel the product container into the cabinet pushing the container as far back as possible and the wind trolley handle in clockwise direction, until the container rim becomes pressed firmly against the rubber gasket.

  • Close the cabinet door.

  • Close the air control damper.

  • Depress the process timer present button.

  • Alternate  the  air  damper  several  times  between  the  open  and  closed  position,  this  causes air slug to through the bed and break down the agglomerated material. Set the damper lever to the position, which gives the desired turbulence to the bed.

  • The drying cycle will be terminated when either the set drying period has elapsed or the outer temperature reaches the preset value.

  • Operate the filter bag shaker, open the cabinet door lower the container and withdraw it from the cabinet.

 

CHECK POINTS:

  • At the start of the day, run and preheat the dryer by warming it up for about 5 minutes.

  • The inlet air filters should be examined periodically and removed for washing when necessary.

  • The  base  of  the  container  should  be  kept  cleaned,  particular  attention  should  be  paid  to the diffusion holes. Any blockage should be blown or washed away.

  • Before removing the container at the end of drying cycle, shake the filter bag and allow any dust to settle


Construction of Tray Dryer: It consists of a chamber whose wall is insulated by thick glass wool or suitable heat insulating material. Inside the chamber, there are various trays on which wet materials are placed. The number of trays depends on the size of the chamber. For laboratory purposes, a minimum of 3 trays is required. There should be an appropriate distance between the upper, middle, and lower tray. The dryer is also attached to the provision of free: air inlet and air outlet. The fan in the dryer is used to circulate air over the material placed in trays. The heater is also provided inside to facilitate uniform heating. The door of the heater is explosion-proof and is locked with the help of spring-loaded ball latches with suitable pressure. Door lips are having a Neoprene rubber gasket to prevent leakages.

Applications

Tray dryers are used for diverse drying applications like food, electrodes, bakery, plastic & powders and drying of pigments.

Tray dryer is used in the industries where drying and heating are the essential parts of the manufacturing process.

Thermostatic inner chamber of the dryer is fabricated using mild steel and stainless steel and its temperature ranges from 50C to 150C.