Identification of Suitable Spray Dryer and Fluid Bed Dryer Temperature for Standard Milk Powder in MILCO (Highland) Spray Dryer Milk Factory Ambewela

Abstract

Ambewela MILCO (Highland) Spray Dried Milk Factory produces milk powder under the brand name of “Highland Milk Powder” among five factories belongs to MILCO Company. Moisture content of the final milk powder can hold up to 3.00%. Newly upgraded powder plant produces milk powder with moisture percentage under 2.75%. Spray Drying Inlet Temperature and Fluid Bed Dryer Inlet Temperatures are the main variables that can be controlled in the main process of milk powder production. A study was conducted to find out the possible temperature ranges of both Spray Drying Inlet and Fluid Bed Dryer Inlet in order to select the most suitable temperature range which produces good quality milk powder with acceptable bulk density value (0.56 kg/m3), scorched particles grade (“A” grade) and moisture content value closer to the 3.00%. A trial experiment was conducted to find out the suitable temperature ratio of both Spray Drying Inlet temperature and Fluid Bed Dryer Inlet Temperatures by considering bulk density, scorched particles and moisture content. Possible Spray Dryer Inlet temperatures were 175°C, 176°C, 177°C, 178°C, 179°C, 180°C and 181°C. Possible Fluid Bed Inlet Temperatures were 55°C, 60°C, 65°C, 70°C, 75°C, and 80°C. Based on the trial experiment, T1 (SPI: 175°C, FBD: 75°C), T2 (SDI: 176°C, FBD: 70°C), T3 (SDI: 177°C, FBD: 65°C), T4 (SDI: 178°C, FBD: 60°C), T5 (SDI: 179°C, FBD: 55°C) selected as treatments. Final moisture content, bulk density; scorched particles level and fat levels were taken into consideration for the quality parameters of milk powder. Fat level of the final milk powder indicated that there was no any significant difference (p>0.05) between treatments. Spray Dryer Inlet Temperatures of 177°C, 178°C and Fluid Bed Dryer Inlet Temperatures of 65°C, 60°C ( T3 and T4) produced acceptable bulk density levels and moisture content levels of 0.562 kg/m3, 0.556 kg/m3 and 2.895%, 2.911% respectively. There was no any significant difference (p>0.05) between treatments.