Application of Desiccant Technology for Concentrating Liquid Foods - Experimental Investigation

2007 ◽  
Vol 3 (5) ◽  
Author(s):  
Palanichamy Gandhidasan ◽  
Habib I. Abualhamayel
Keyword(s):  
Flow Rate ◽  
Evaporation Rate ◽  
Food Concentration ◽  
Falling Film ◽  
Liquid Food ◽  
Liquid Desiccant ◽  
Transfer Resistance ◽  
Single Tube ◽  
Film Evaporator ◽  
Liquid Foods

A single tube, stainless steel, liquid desiccant falling film evaporator was built and tested with the calcium chloride solution as the liquid desiccant to concentrate liquid foods. Experiments were conducted in the above setup with sugar solutions as the liquid food. To minimize water vapor mass transfer resistance, non-condensibles were removed from the system by a vacuum pump. No steam was used to drive this evaporator.The liquid food was heated to about 48ºC when the ambient temperature was 40ºC. The single tube double falling film evaporator was tested to determine the effect of desiccant concentration, temperature, and flow rate on the evaporation rate. The effect of liquid food concentration, temperature, and flow rate on evaporation rate was also studied. An uncertainty and error analysis for the experimental data was performed. It was demonstrated that liquid desiccants could provide enough energy, through heat of absorption, to evaporate a liquid food in a falling film evaporator with vapor transfer lines.

scholarly journals Investigation on the Regeneration Performance of a New Mixed Liquid Desiccant Solution in Falling Film Regenerator

Proceedings ◽  
2018 ◽  
Vol 2 (22) ◽  
pp. 1374
Author(s):  
Tao Wen ◽  
Dan Zhong ◽  
Yuanhao Wang ◽  
Yimo Luo
Keyword(s):  
Flow Rate ◽  
Solution Temperature ◽  
Solution Flow Rate ◽  
Mixed Solution ◽  
Falling Film ◽  
Liquid Desiccant ◽  
Solution Flow ◽  
Regeneration Rate ◽  
Air Inlet ◽  
Selection Of

The present study firstly developed a new kind of mixed liquid desiccant for the purpose of causticity reduction on metal based regenerator. The formula of the mixed liquid desiccant is 25% LiCl + 39% hydroxyethyl urea + 36% water. Experimental results show that the causticity of the mixed solution is much less severe than that of conventional LiCl solution. The regeneration rate increases with the increase of air flow rate and solution temperature and decreases with the increase of air inlet humidity. The air temperature and solution flow rate has negligible influence on the regeneration performance. The present study provides a practical alternative for the selection of liquid desiccant and also give useful guidance for the design of regenerator.

scholarly journals Evaporative performance of Single Tube and Multi Tube Falling Film Evaporator Prototypes for Molten Butter: An Experimental Study

2019 ◽  
Vol 72 (1) ◽  
pp. 59-69
Author(s):  
Gaurav S Wale . ◽  
Pradyuman Barnwal . ◽  
Ankit Deep . ◽  
Rahul S Barge .
Keyword(s):  
Experimental Study ◽  
Falling Film ◽  
Single Tube ◽  
Film Evaporator

Heat Transfer in an LTV Falling Film Evaporator: A Theoretical and Experimental Analysis

1968 ◽  
Vol 90 (2) ◽  
pp. 201-210 ◽  
Author(s):  
J. E. Kroll ◽  
J. W. McCutchan
Keyword(s):  
Heat Transfer ◽  
Mathematical Models ◽  
Flow Rate ◽  
Experimental Analysis ◽  
Experimental Results ◽  
Falling Film ◽  
Film Evaporator ◽  
Good Agreement

Two slightly differing mathematical models were developed to describe the heat transfer in the long tube vertical falling film process. The process was investigated experimentally with a 3/4 in. dia tube for various lengths up to 13 ft, for flow rate Reynold’s numbers from 1000 to 13000, for temperature differences of the order of 20 deg F, and for vacuum conditions down to 160 deg F. A comparison of theoretical and experimental results was made and was found to be in good agreement; that is, within 10 percent.

Proposal for modernization of Robert evaporators

2020 ◽  
pp. 51-54
Author(s):  
Hans Joachim Praus
Keyword(s):  
Falling Film ◽  
Film Evaporator ◽  
Heating Steam

It is proposed to convert existing Robert evaporators into Trebor evaporators. Trebor evaporators work as falling film evaporators with the well-known thermal and technological advantages. When converting a Robert evaporator into a Trebor evaporator, the heating steam inlet and the vapour outlet as well as the condensate drain remain in their original positions. If necessary, the positions of the juice inlet and outlet nozzles are changed, and two additional nozzles and a circulation juice pump are required. These changes are cheaper than installing a new falling film evaporator.

scholarly journals EFFECT OF TUBE PITCH ON HEAR TRANSFER IN SPRINKLED TUBE BUNDLE

2015 ◽  
Vol 55 (5) ◽  
pp. 329 ◽  
Author(s):  
Petr Kracík ◽  
Jiří Pospíšil
Keyword(s):  
Flow Rate ◽  
Tube Bundle ◽  
Thin Liquid Film ◽  
Thermal Conditions ◽  
Tube Length ◽  
Falling Film ◽  
Constant Flow Rate ◽  
Physical Conditions ◽  
The Individual ◽  
Tube Pitch

Water flowing on a sprinkled tube bundle forms three basic modes: the Droplet mode (the liquid drips from one tube to another), the Jet mode (with an increasing flow rate, the droplets merge into a column) and the Membrane (Sheet) mode (with a further increase in the flow rate of the falling film liquid, the columns merge and create sheets between the tubes. With a sufficient flow rate, the sheets merge at this stage, and the tube bundle is completely covered by a thin liquid film). There are several factors influencing both the individual modes and the heat transfer. Beside the above-mentioned falling film liquid flow rate, these are for instance the tube diameters, the tube pitches in the tube bundle, or the physical conditions of the falling film liquid. This paper presents a summary of data measured at atmospheric pressure, with a tube bundle consisting of copper tubes of 12 millimetres in diameter, and with a studied tube length of one meter. The tubes are situated horizontally one above another at a pitch of 15 to 30 mm, and there is a distribution tube placed above them with water flowing through apertures of 1.0mm in diameter at a 9.2mm span. Two thermal conditions have been tested with all pitches: 15 °C to 40 °C and 15 °C to 45 °C. The temperature of the falling film liquid, which was heated during the flow through the exchanger, was 15 °C at the distribution tube input. The temperature of the heating liquid at the exchanger input, which had a constant flow rate of approx. 7.2. litres per minute, was 40 °C, or alternatively 45 °C.

Cascade controller design for concentration control in a falling-film evaporator

Food Control ◽  
2006 ◽  
Vol 17 (5) ◽  
pp. 325-330 ◽  
Author(s):  
Huub H.C. Bakker ◽  
Clive Marsh ◽  
Shabeshe Paramalingam ◽  
Hong Chen
Keyword(s):  
Controller Design ◽  
Falling Film ◽  
Film Evaporator

Analysis of Heat and Mass Transfer Between a Desiccant-Air System in a Packed Tower

1987 ◽  
Vol 109 (2) ◽  
pp. 89-93 ◽  
Author(s):  
P. Gandhidasan ◽  
M. Rifat Ullah ◽  
C. F. Kettleborough
Keyword(s):  
Mass Transfer ◽  
Gas Phase ◽  
Heat And Mass Transfer ◽  
Packing Material ◽  
Mass Transfer Resistance ◽  
Liquid Desiccant ◽  
Governing Equations ◽  
Packed Tower ◽  
Transfer Resistance ◽  
Steady State Model

Heat and mass transfer analysis between a desiccant-air contact system in a packed tower has been studied in application to air dehumidification employing liquid desiccant, namely calcium chloride. Ceramic 2 in. Raschig rings are used as the packing material. To predict the tower performance, a steady-state model which considers the heat and mass transfer resistances of the gas phase and the mass transfer resistance of the liquid phase is developed. The governing equations are solved on a digital computer to simulate the performance of the tower. The various parameters such as the effect of liquid concentration and temperature, air temperature and humidity and the rates of flow of air and liquid affecting the tower performance have been discussed.

Sign in / Sign up

Export Citation Format

Share Document