Papers by Keyword: Bubble Absorption

Abstract: The treatment of NH₃ releasing concentrated rubber latex to air was studied using skim serum in laboratory scale of bubble absorption reactor. The skim serum (pH 2.5 to 3) is a liquid waste from concentrated rubber latex. The concentration of NH₃ in air (300 to 1500 ppmv) and air flow rate (0.5 to 1.5 l/min) feeding into the reactor were measured for the effect of the treatment efficiency. At lower NH₃ concentration and air flow rate have resulted to higher NH₃ removal efficiency. Bubble absorption reactor can be effectively used and applied to remove NH₃ releasing from the concentrated rubber latex process to the air without any plugging of the skim rubber in the system. Skim serum waste liquid has the result in higher efficiency in NH₃ removal comparing to pure water usage. This study would be practically used as a guidance for the further design and operate to minimize waste and emission control in rubber industrial-scale system.

Abstract: The objective of this paper is to analyze the enhancement mechanism of ammonia bubble absorption performance by nanofluid. In this paper, the process of ammonia bubble absorption is divided into three different steps: the bubble growing, the gas absorption in liquid phase and the interface phase transfer. According to the analysis, nanofluid can enhance the diffusion coefficient or the absorption performance in each step, and enhance the whole absorption performance resultly; the gas mass transfer during the bubble growing is enhanced by nanofluid for the surface tension decrease; the main cause for the enhancement of the gas absorption in liquid phase is considered as the transport effect of nanoparticles carrying ammonia gas molecule and the vortex transfer effect arising from Brownian motion of nanoparticles; the main cause for the enhancement of the transfer at phase interface is considered as the Marangoni convection and the vortex transfer effect due to nanoparticles.

Abstract: The main objectives of this work are to experimentally examine the enhancing mass transfer performance of FeO nanofluid on the bubble absorption and to find the optimal method to design highly effective compact absorber for NH₃/H₂O absorption refrigerator. Based on the microcosmic analysis of the factors affecting the stable performance of nanofluid, FeO nanofluid was prepared by using the ultrasonic dispersion method. The ammonia bubble absorption experiments with FeO nanofluid were carried out and the data of absorption height were acquired. The results showed that FeO nanofluid had an enhancing effect on mass transfer performance, and the absorption height was 2mm higher than that of the water based solution in 2 minutes of the experiment conditions. The curves of the solution temperature in absorption were also given. According to the data of the absorption height and the solution temperature, it is pointed out that there are two factors which might have negative influences on the mass transfer enhancing process.

Abstract: Absorber is a key component of absorption refrigeration system, in which there is a complicated heat and mass transfer. To improve the performance of absorber, the magnetic field was used as a enhancing way, the experiments of NH₃/H₂O bubble absorption in magnetic field were carried out. The results showed that the NH₃/H₂O bubble absorption can be strengthened by the magnetic field. Both AR(absorption rate) and EAR(effective absorption ratio) increase with the increase of magnetic intensity within the range of 0~280mT. The EAR is always higher than 1 when the external magnetic field exists. The EAR reaches the maximum 1.069 when the initial ammonia concentration is 20wt% and the magnetic intensity is 280mT. The primary strengthening mechanisms are also explained.

Abstract: The object of this paper is to study the effects of nanofluid on NH₃/H₂O bubble absorption performance under adiabatic and non-adiabatic conditions. Mono nano Ag with the concentration of 0.02wt% was used as the enhancement medium, and the absorption performance experiments under the heat insulation and water cooling for absorption test section were respectively conducted and contrastively analyzed. The results showed that the absorption rate with mono nano Ag in bubble absorption process is higher than that without any nanoparticles; in adiabatic case, when the initial temperature of NH₃/H₂O solution is gradually increased within 6～18°C, the absorption rate decreases correspondingly, and so does the effective absorption ratio; in non-adiabatic case, with the cooling water temperature rising within 10～25°C, the absorption rate decreases but the effective absorption ratio increases. Therefore, it is concluded that the heat transfer enhancement of nanofluid can promote the NH₃/H₂O bubble absorption performance to a certain degree, and the enhancement of the absorption is not completely dependent on heat transfer.