Question: Please complete both problems. Thanks

1) How many flow channels (# of channels shown in sketch are representative and not actual) are available for flow on each side? 2) Calculate (hydrodynamic) equivalent diameter of channel between the plates and flow rate per channel.

Given:

A counter flow plate heat exchanger is being used as regeneration section of a HTST to heat raw (unpasteurized) milk with hot pasteurized milk. The heat exchanger contains 41 plates. Each plate is 1.52 m high and 0.6 m wide. The gap between the plates is 3 mm. The raw milk at 20C enters the heat exchanger at a rate of 2.5 kg/s. The hot milk counter currently enters at 75C. In given temperature range, physical properties of milk are provided in table below:

At 75 C At 20 C 0.001 0.003 Property Viscosity, Pa.s Thermal conductivity, W/mC Heat capacity, J/KgC Density, kg/m3 0.64 0.56 3900 3900 1030 1030 RAW MIX IN, T = 20 deg C, P=? HOT MIX OUT, P = ?, T = ? HOT MIX IN, T = 75 deg C, P RAW MIX OUT, T=?, P = 120 kPa