The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform

Bidyut Baran Saha - One of the best experts on this subject based on the ideXlab platform.

  • experimental investigation of the Silica Gel water adsorption isotherm characteristics
    Applied Thermal Engineering, 2001
    Co-Authors: Kim Choon Ng, Hui Tong Chua, C Y Chung, C H Loke, Takao Kashiwagi, Atsushi Akisawa, Bidyut Baran Saha
    Abstract:

    Abstract In designing adsorption chillers that employs Silica Gel–water as adsorbent-adsorbate pair, the overriding objective is to exploit low temperature waste-heat sources from industry. This paper describes an experimental approach for the determination of thermodynamic characteristics of Silica Gel–water working pair that is essential for the sizing of adsorption chillers. The experiments incorporated the moisture balance technique, a control-volume-variable-pressure (CVVP) apparatus and three types of Silica Gel have been investigated, namely the Fuji Davison Type A, Type 3A and Type RD. As evidenced by the experimental results, the Henry-type equation is found to be suitable for describing the isotherm characteristics of Silica Gel–water working pair at the conditions of adsorption chiller. The regeneration of adsorbent depends on the correct allocation of temperature as well as the amount of regeneration time. From the experiments, the isotherm characteristics of Silica Gel–water in the low- to high-pressure regimes and hence, its isosteric heat of adsorption will be determined. Key parameters for optimizing the amount of heat recovery such as the cycle and switching time of chiller can also be implied from the measured results.

Sihli Chen - One of the best experts on this subject based on the ideXlab platform.

  • application of Silica Gel fluidised bed for air conditioning systems
    Applied Thermal Engineering, 2015
    Co-Authors: Chihhao Chen, Gerd Schmid, Chitong Chan, Yuanching Chiang, Sihli Chen
    Abstract:

    Abstract This paper theoretically and experimentally investigates a periodic operating Silica Gel fluidised bed system to adsorb/desorb moisture in air-conditioning systems. First, the theoretical model of a fluidised bed system is utilised to predict the minimum fluidisation velocity, pressure drop, and adsorption/desorption performance of a Silica Gel fluidised bed. Subsequently, the paper experimentally compares the adsorption/desorption performance of the Silica Gel fluidised bed with a packed bed at the regeneration temperature of 40 °C, inlet temperature of 30 °C, inlet relative humidity of 60%, and wind velocity of 2 m/s periodically operating for 40 min. Then it applies two kinds of average diameter (3 mm and 5 mm) Silica Gel particles to the fluidised bed dehumidification system with various filling heights and differing wind velocities. The results show that the fluidised bed system, compared with the packed bed, increases the total amount of adsorption and desorption by 20.8% and 19.8%. It also reduces the pressure drop and outlet temperature by 30% and 36%. Moreover, the adsorption/desorption performance of fluidised bed systems increases with higher filling height and faster wind velocity. The availability of the theoretical modal is verified by 8% relative error between the theoretical and experimental values of the adsorption/desorption performance.

  • Silica Gel polymer composite desiccants for air conditioning systems
    Energy and Buildings, 2015
    Co-Authors: Chihhao Chen, Chihchieh Chen, Sihli Chen
    Abstract:

    Abstract In this study, we developed a composite material to be used in air conditioning systems by combining Silica Gel with both polyacrylic acid and sodium polyacrylate. A test was performed to determine the optimal mixing ratio. The results showed that the optimal composite material was produced at a mixing ratio of 10:1:1. Under a closed environment of 25 °C and a relative humidity of 70%, the material exhibited a sorption capacity 41% higher than Silica Gel on its own. Subsequently, tests were performed to assess the dehumidification performance of the material at varying air velocities, regeneration temperatures, and inlet temperatures and humidity. After 15 min of usage under conditions of an inlet air temperature of 30 °C, a relative humidity of 70%, and a regeneration temperature of 40 °C, the performance of the composite material maintained 80% of its highest dehumidification performance. In addition, the average dehumidification amount reached 2.73 g/min, which was higher than Silica Gel packed bed at 2.46 g/min. Moreover, the airflow design of the composite material facilitated a pressure drop of 149 mmAq/m, which was 0.69 times lower than the Silica Gel packed bed system. Given the above results, application of the Silica Gel/polymer composite desiccant to air conditioning systems has great energy-saving potential.

Mitsuhiko Hida - One of the best experts on this subject based on the ideXlab platform.

  • Thermochromism of dyes on Silica Gel
    Dyes and Pigments, 1998
    Co-Authors: Masahiro Tajima, Masashi Sugai, Katsuji Matsunaga, Tadataka Yamashita, Haruo Inoue, Mitsuhiko Hida
    Abstract:

    1-Hydroxyanthraquinone derivatives and some pH indicators showed thermochromism on Silica Gel, based on the shift in the acid-base equilibrium. In a lower temperature range, the degree of acid dissociation of the dyes increased with a rise in temperature, mainly based on the increase in the basic sites on Silica Gel resulting from the decreasing amount of water adhering on it. In a higher temperature range, on the other hand, the acid dissociation of the dyes with a rise in temperature was promoted by the increase in acidity of the dyes.

  • Thermochromism of dyes on Silica Gel
    Dyes and Pigments, 1998
    Co-Authors: Masahiro Tajima, Masashi Sugai, Katsuji Matsunaga, Tadataka Yamashita, Haruo Inoue, Mitsuhiko Hida
    Abstract:

    1-Hydroxyanthraquinone derivatives and some pH indicators showed thermochromism on Silica Gel, based on the shift in the acid-base equilibrium. In a lower temperature range, the degree of acid dissociation of the dyes increased with a rise in temperature, mainly based on the increase in the basic sites on Silica Gel resulting from the decreasing amount of water adhering on it. In a higher temperature range, on the other hand, the acid dissociation of the dyes with a rise in temperature was promoted by the increase in acidity of the dyes. © 1998 Elsevier Science Ltd. All rights reserved.

Kim Choon Ng - One of the best experts on this subject based on the ideXlab platform.

  • experimental investigation of the Silica Gel water adsorption isotherm characteristics
    Applied Thermal Engineering, 2001
    Co-Authors: Kim Choon Ng, Hui Tong Chua, C Y Chung, C H Loke, Takao Kashiwagi, Atsushi Akisawa, Bidyut Baran Saha
    Abstract:

    Abstract In designing adsorption chillers that employs Silica Gel–water as adsorbent-adsorbate pair, the overriding objective is to exploit low temperature waste-heat sources from industry. This paper describes an experimental approach for the determination of thermodynamic characteristics of Silica Gel–water working pair that is essential for the sizing of adsorption chillers. The experiments incorporated the moisture balance technique, a control-volume-variable-pressure (CVVP) apparatus and three types of Silica Gel have been investigated, namely the Fuji Davison Type A, Type 3A and Type RD. As evidenced by the experimental results, the Henry-type equation is found to be suitable for describing the isotherm characteristics of Silica Gel–water working pair at the conditions of adsorption chiller. The regeneration of adsorbent depends on the correct allocation of temperature as well as the amount of regeneration time. From the experiments, the isotherm characteristics of Silica Gel–water in the low- to high-pressure regimes and hence, its isosteric heat of adsorption will be determined. Key parameters for optimizing the amount of heat recovery such as the cycle and switching time of chiller can also be implied from the measured results.

Chihhao Chen - One of the best experts on this subject based on the ideXlab platform.

  • application of Silica Gel fluidised bed for air conditioning systems
    Applied Thermal Engineering, 2015
    Co-Authors: Chihhao Chen, Gerd Schmid, Chitong Chan, Yuanching Chiang, Sihli Chen
    Abstract:

    Abstract This paper theoretically and experimentally investigates a periodic operating Silica Gel fluidised bed system to adsorb/desorb moisture in air-conditioning systems. First, the theoretical model of a fluidised bed system is utilised to predict the minimum fluidisation velocity, pressure drop, and adsorption/desorption performance of a Silica Gel fluidised bed. Subsequently, the paper experimentally compares the adsorption/desorption performance of the Silica Gel fluidised bed with a packed bed at the regeneration temperature of 40 °C, inlet temperature of 30 °C, inlet relative humidity of 60%, and wind velocity of 2 m/s periodically operating for 40 min. Then it applies two kinds of average diameter (3 mm and 5 mm) Silica Gel particles to the fluidised bed dehumidification system with various filling heights and differing wind velocities. The results show that the fluidised bed system, compared with the packed bed, increases the total amount of adsorption and desorption by 20.8% and 19.8%. It also reduces the pressure drop and outlet temperature by 30% and 36%. Moreover, the adsorption/desorption performance of fluidised bed systems increases with higher filling height and faster wind velocity. The availability of the theoretical modal is verified by 8% relative error between the theoretical and experimental values of the adsorption/desorption performance.

  • Silica Gel polymer composite desiccants for air conditioning systems
    Energy and Buildings, 2015
    Co-Authors: Chihhao Chen, Chihchieh Chen, Sihli Chen
    Abstract:

    Abstract In this study, we developed a composite material to be used in air conditioning systems by combining Silica Gel with both polyacrylic acid and sodium polyacrylate. A test was performed to determine the optimal mixing ratio. The results showed that the optimal composite material was produced at a mixing ratio of 10:1:1. Under a closed environment of 25 °C and a relative humidity of 70%, the material exhibited a sorption capacity 41% higher than Silica Gel on its own. Subsequently, tests were performed to assess the dehumidification performance of the material at varying air velocities, regeneration temperatures, and inlet temperatures and humidity. After 15 min of usage under conditions of an inlet air temperature of 30 °C, a relative humidity of 70%, and a regeneration temperature of 40 °C, the performance of the composite material maintained 80% of its highest dehumidification performance. In addition, the average dehumidification amount reached 2.73 g/min, which was higher than Silica Gel packed bed at 2.46 g/min. Moreover, the airflow design of the composite material facilitated a pressure drop of 149 mmAq/m, which was 0.69 times lower than the Silica Gel packed bed system. Given the above results, application of the Silica Gel/polymer composite desiccant to air conditioning systems has great energy-saving potential.