Performance of air blast dewatering machine for lettuce (Lactuca sativa L.) / Jethro Costumbrado Auditor.

Thesis BS in Agricultural Engineering University of Rizal System Tanay 2019

Includes bibliographical references

The air blast dewatering machine was designed to remove the free moisture content on the surface of the lettuce. The air blast dewatering machine for Lettuce is made of stainless steel with an overall dimension of 0.72 m length, 0.74 cm width and 0.65 m height. It has four major parts: fan, gear motor, tray and the baskets. The fan produce the blast of air that removes the free moisture content in the surface and has three speed adjustments. The tray served as the holder of the basket and connected to the gear motor operating at 60 rpm. One basket can accommodate 250 g of lettuce. The data gathered from the experiment were analyzed using Stat-ease Design expert. The statistical analysis used is complete randomized design where three treatments are applied. The 1.6 m/s air velocity with 50 minutes time of operation. The 2.6 m/s air velocity with 45 minutes time of operation. The 3.6 m/s air velocity with 40 minutes time of operation. The air blast dewatering machine can accommodate a total of 4 kg of fresh lettuce in every operation. The visual quality of the lettuce after the dewatering process is generally good. It has only minor broken midribs affecting 1-2 leaves and bruises affecting 1-2 leaves. The highest dewatering efficiency of the machine is 88.12 % when operated at 50 minutes using air velocity of 1.6 m/s. The unit cost of the Air Blast Dewatering Machine is Php. 22,300.00. The total cost of operating the air blast dewatering machine is Php. 30,338.17 annually. The cost of removing the free surface moisture using the machine at 88.12 % efficiency is Php 15.17 per kilogram of lettuce.