Design and development of a two-stage evaporative cooler for short term storage of tomatoes (Lycopersicon esculentum)

Date

5-2010

Degree

Bachelor of Science in Agricultural Engineering

Major Course

Major in Agricultural and Bio-Process Engineering

College

College of Engineering and Agro-Industrial Technology (CEAT)

Adviser/Committee Chair

Kevin F. Yaptenco

Committee Member

Edgardo V. Casas, Arnold R. Elepaño

Abstract

Postrharvest losses can constitute up to 40% of the local losses in agriculture. These losses are primarily brought by inappropriate postharvest handling procedure and storage practices. One way of reducing such losses is by temperature management and the most effective means on temperature management id refrigeration. However, some perishables have low selling that cannot compensate the high cost of refrigeration. With this problem at hand, there is an urgent need in developing or improving non- refrigerated facility and one of which is evaporative cooling. This study aimed to design and develop a two-stage evaporative cooler that can be used for short-term storage of tomato. A car radiator served as a heat exchanger to precool the air before it enters the cooling pad. The area of cooling pad and the size of the radiator were determined using the computed heat load. Water pumps recirculated the water to the cooling pad and radiator. Storage trial conducted determined the effectiveness of the evaporative cooling in reducing the moisture loss in tomato. Modification on the cooling pad were done to increase its humidification efficiency which consist of increasing the number of perforations of the water above the cooling pad and reducing the size of the charcoal in the cooling pad to improve uniformity of wetting. After the modifications the relative humidity rise and temperature drop of the air is compared with the data obtained during storage trial. Results of the study showed that before any modifications were done to the cooling pad. it can raise the relative humidity of the air of an average of 11% while decreasing its temperature of an average of 2.12°C. It can also reduce the moisture loss of tomato from an average of 4.9% per day to 3.0% per day. ANOVA showed that there is no significant difference between the moisture losses between the tomatoes that are stored using the evaporative cooler. Modifying the cooling pad increases the potential cooling and humidifying effect of the evaporative cooler. The cooling pad increases the relative humidity and temperature drop of the air at an average of 20% and 4.6°C. Economic analysis showed that storing tomato in the storage chamber with the evaporative cooler has a computed benefit-cost ratio of 1.326, a payback period of 1.67 years and cost of storage of 2.45PhP/kg of tomatoes.

Language

English

LC Subject

Tomatoes, Tomatoes--Storage.

Location

UPLB College of Engineering and Agro-Industrial Technology

Call Number

LG 993.5 2010 A2 R89

Document Type

Thesis

This document is currently not available here.

Share

COinS