For achieving rapid drying rate in a spray dryer, the diameter of the particles in the feed should be in the range of _______________ microns (1 mm = 1000 microns)?

Related Mcqs:

1. A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids)) ?

   A. M(Xo – XF)
   B. M(Xo/XF)
   C. M ln(Xo/XF)
   D. MXo ln(Xo/XF)

2. A solid is being dried in the linear drying rate regime from moisture content Xo to XF. The drying rate is zero at X = 0 and the critical moisture content is the same as the initial moisture Xo. The drying time for M = (Ls/ARc) is (where, L = total mass of dry solid, A = total surface area for drying Rc = Constant maximum drying rate per unit area X = moisture content (in mass of water/mass of dry solids))_____________?

   A. M(Xo – XF)
   B. M(Xo/XF)
   C. M ln(Xo/XF)
   D. MXo ln(Xo/XF)

3. For continuous drying of granular or crystalline material, the dryer used is the _______________ dryer?

   A. Tunnel
   B. Tray
   C. Rotary
   D. None of these

4. A 25 cm × 25 cm × 1 cm flat sheet weighing 1.2 kg initially was dried from both sides under constant drying rate conditions. It took 1500 seconds for the weight of the sheet to reduce to 1.05 kg. Another 1m × 1m × 1cm flat sheet of the same material is to be dried from one side only. Under the same constant drying rate conditions, the time required for drying (in seconds) from its initial weight of 19.2 kg to 17.6 kg is ____________________?

   A. 1000
   B. 1500
   C. 2000
   D. 2500

5. On moving the feed line (q-line) from saturated liquid feed (vertical position) to saturated vapor feed (horizontal feed), if the slope of both the operating lines are to be increased, then it will result in______________________?

   A. Greater degree of separation with a fixed number of trays
   B. Increased reboiler load
   C. Increased reflux ratio
   D. None of these

6. Occurrence of ‘case hardening’ during drying of a high moisture solid cake _______________ the drying rate?

   A. Increases
   B. Decreases
   C. Does not affect
   D. Exponentially increases

7. During constant rate drying period, vaporisation rate per unit drying surface area _____________________?

   A. Decreases with time
   B. Increases with time
   C. Does not change with time
   D. Does not affect the moisture content of the wet solid

8. In the constant rate period of the rate of drying curve for batch drying,_________________?

   A. Cracks develop on the surface of the solid
   B. Rate of drying decreases abruptly
   C. Surface evaporation of unbound moisture occurs
   D. None of these

9. Large scale drying of sugar is done in a _______________ dryer?

   A. Spouted bed
   B. Tray
   C. Rotary
   D. Truck

10. Dryer widely used in a textile industry is ______________ dryer?

    A. Festoon
    B. Cylinder
    C. Conveyor
    D. Tunnel