Design of Mobile Vertical Burner Machine Integrated with Heat Exchanger for Air Heating System of Tea Dryer Machine

Abstract To enhance the benefit of wood pellet as source of energy for tea production, there is a need to develop an efficient wood pellet burner with high flexibility in use for tea drying process. This research aims to develop a design of a mobile vertical burner wood pellets integrated with a heat exchanger part for tea drying process. The machine was designed to supply the clean heated air for tea drying process using ball tea machine requiring temperature of 105 °C and air flow rate of 890 CFM. The vertical burner type integrated with the multi-layer heat exchanger was provided to enhance the air heating efficiency of the machine. The fin type heat exchanger was used as the primary air heat exchanger and the tube type was used as the pre-heating systems. The blower supplies air for combustion into the burner chamber with a flow rate of 360.75 CFM. The suction blower produces hot air with a flow rate of up to 1103.47 CFM. To optimize the machine performance, 2 process parameters were examined namely wood pellet input feeding rate with 3 levels (5 kg/hour, 7 kg/hour and 9 kg/hour) and output air flowrate (895.23 CFM; 1,028.55 CFM; 1,103.47 CFM). The response parameters used in this research to determine the performance of the machine are the air heating rate and air heating efficiency. The experiment was designed based on the general full factorial design. The results show that proposed design revealed to be able to provide the required air flowrate (up to 1028 cfm) and air heating temperature (up to 105 °C) for the ball tea machine. The analysis shows that the input feeding rate and output air flowrate factors are found to be significant to determine the air heating rate and air heating efficiency parameters. The optimum condition of the process parameter were at air flowrate of 1,028 CFM with input feeding rate of 5 kg/hour wood pellets to obtain the air heating efficiency at 70.83%. The mobile vertical burner design is able to offer an alternative clean hot air solution for drying agricultural products that is cheaper, cleaner, environmentally friendly with high flexibility in use.