4. To avoid the tearing off the plate of an edge, the margin (i.e., the minimum distance from the centre of the rivet hole to the nearest edge of the plate) should be equal to
6. Normally, the length to diameter ratio of rotary dryers varies form 4 to 10 and for its economic operation, the number of transfer units (NTU) for such dryers varies from
7. Large process vessels operating under extreme temperature and pressure conditions are normally clad/ lined with materials like stainless steel, aluminium, nickel & its alloys, copper & its alloys and titanium. The cladding thickness is generally about __________ percent of the total thickness.
Correct Answer: ratio of true temperature difference to the LMTD.
9. The clearance between two tubes in a shell and tube heat exchanger is known as 'ligament', whose minimum value is __________ the outside diameter of the tube, but in no case it should be less than 4.5 mm.