4 replies to this topic

[ishibabrata]

What will be approximate area requirement to preheat tray dryer inlet air (at 30 deg C) to 110 deg C with outlet exhaust air available at 350 deg C. Approximate air flow is 100 ACFM through the system.

[shan]

What is U (overall heat transfer coefficient) of your preheat tray dryer?

[ishibabrata]

For air-to-air systems, 4 W/m2 K can be assumed for U.

Edited by ishibabrata, 03 October 2018 - 07:33 AM.

[ishibabrata]

Can anyone indicate what are the other factors to be taken into consideration for the subject system.

Edited by ishibabrata, 03 October 2018 - 07:32 AM.

[shan]

1.  Calculate transferred heat duty: Q = H*F*(T2-T1)

2.  Calculate required dryer heat transfer area:  A = Q/(U*LMTD)

 

Q: transferred heat duty

H:  air specific heat

F: flow rate

T2:  dryer outlet temperature

T1:  dryer inlet temperature

A:  dryer heat transfer area

U:  overall heat transfer efficient

LMTD: log mean temperature difference

 

The units of parameters should be consistent.