Showing papers by "Kian Jon Chua published in 1999"

A modular heat pump system for drying and air-conditioning

Abstract: A modular versatile heat pump system for drying and air-conditioning is disclosed. The refrigerating components of the heat pump, comprising the compressor (40a), condenser (41), evaporators (45, 52) and expansion valves, are housed in a chassis with three interface ports (74a, 75a, 76a) for easy integration with any air-handling chamber via flexible industrial couplers. For drying application, the design makes use of conventional import/export transport containers with modification for loading and unloading of products. It adopts the first-in first-out process for loading and unloading of the products. For air-conditioning application, the present design can be coupled to the chamber to provide air-conditioning during system repair and maintenance. The proposed heat pump system has several advantages, namely, easy chamber scale-up to meet increase production, significant reduction of production down time, eliminate thermal discomfort during maintenance of refrigeration components for air conditioning systems.

The contact factor for dryer performance and design

Abstract: We describe an approach using the contact factor (CF) as the dryer performance and design parameter. The CF is calculated using known drying variables with a view to minimizing the drying costs. An algorithm to obtain the 'economic' CF for drying is presented. Besides being a design parameter of single-stage dryers, the CF is a useful parameter in determining the schedule of cascade dryers in multi-stage drying. We demonstrate the dryer component selection process using a set of design charts for heat pump dryers.