T-type Mixers Research Articles

Comparative studies of fluid mixing and heat transfer behaviors in a millimeter scale T-type mixer with triangular baffles

In chemical processes, fluid mixing and heat transfer efficiency are very important. To guarantee high mixing efficiency and heat transfer performance during chemical processes, we designed and embedded triangular baffle structure in millimeter-sized T-type mixers. Through Computational Fluid Dynamics (CFD) simulation and visualization experiments, the influence of triangular baffle on the heat transfer performance of mixing was studied. The results show that visualization experiment verifies the reliability of the model. Compared with T-mixer, the mixing index (M) of the T-mixer with double triangular baffle (DTB) has increased by 88.2% and the Nusselt number (Nu) has increased by 32.9%–65.2%, which shows that DTB has a good effect of enhancing mass and heat transfer. The Performance Evaluation Criterion (PEC) of DTB is within 1.22–2.43, which is 3.1%–24.5% higher than single triangular baffle (STB), indicating that DTB has good hydrothermal performance. The PEC is larger at medium to low Reynolds number (Re < 200). In addition, compared with the mixers reported in the literature, the M and Nu of T-type mixer with DTB have increased by 4.5% and 14.2%, respectively. It indicates the superiority of the structure in enhancing mass and heat transfer. The present study can be used to enhance mass and heat transfer in laminar flow.

Technical and economic evaluation of an engine and irrigation pump using a T-type mixer for natural gas

Energy is regarded as one of the most crucial resources in the industrial process. Numerous measurements were made in the year 2021 in the workshops of the Agricultural Engineering Department, Faculty of Agriculture, Ain Shams University, Egypt, using a gasoline engine (single cylinder with air-cooling) that was used to power an irrigation pump with a discharge diameter of 2 inches, which was manufactured in Egypt. To combine natural gas and air before entering the engine, a variety of mixers were created. Four different types of mixers were employed with iron pipes of various sizes: 90° angle T-mixer (T90), 45° angle T-mixer (T45), 30° angle T-mixer (T30), and venture mixer (VM). The engine shift speeds were set at 1,750, 2,300, 2,900, and 3,500 rpm. The water pump was powered by natural gas and gasoline. The findings in this study focused on the evaluation of technical indicators for several types of mixers that combine natural gas and air to power an irrigation pump, where the actual power (braking power) is superior to all types while operating with gasoline (3.07 kW). A commensurability on every side the report of on the up steam, in the mixer type (T45) (2.83 kW) was 7.8% about than gasoline. The lowest specific fuel consumption (S.fc) for gasoline was 219.025 gm/Kw.h at an engine speed of 2,900 rpm. The T45 mixer had the lowest S.fc of 234.612 gm/KW.h, compared with other types of mixers at an engine speed of 2,900 rpm, an increase of 6.6% compared with gasoline. The T45 mixer had the highest pump discharge of 528.133 L/min, an increase of 2.1% compared with gasoline. Compared with other types of T-mixers, the T45 mixer had the highest actual hydraulic power of 0.6 kW, which was 10.5% lower than that of gasoline. As for the economic indicators, the T90 mixer had the lowest net present value (NPV) of 77219.5, and the T45 mixer had the highest NPV of 106900.7. The mixer-type VM had the lowest benefit–cost ratio (B/C) of 1.38, and the T45mixer had the highest B/C of 1.54.

Preparation of size-controllable monodispersed carbon@silica core-shell microspheres and hollow silica microspheres

Size-controllable monodispersed carbon@silica core-shell microspheres and hollow silica microspheres were prepared in a simple homemade T-type mixer by polymerization of furfuryl alcohol (FA) and hydrolysis of TEOS in H2SO4 water phase microdroplets to obtain polyfurfuryl alcohol (PFA)@silica microspheres, followed by carbonization and calcination. The FA and TEOS diffuse into the water phase from an oil phase. The flow rates of oil and water phase were 4 and 2 ml h−1, respectively. It was found that the concentration of FA has a more significant effect on the diameter of carbon@silica core-shell microspheres than TEOS due to the template effect of the PFA core. However, the diameter of the hollow silica microspheres was influenced by the concentration of TEOS more significantly. The obtained core-shell microspheres and hollow silica microspheres have large surface area of 555 and 769 m2 g−1, respectively. The hollow silica microspheres have both microporous and mesoporous structure, and the percentage of mesoporous volume was as high as 89%. In addition, based on the study results, a rational formation process of the carbon@silica core-shell microsphere and hollow silica microspheres was assumed.

An efficient passive planar micromixer with ellipse-like micropillars for continuous mixing of human blood

In this paper, a passive planar micromixer with ellipse-like micropillars is proposed to operate in the laminar flow regime for high mixing efficiency. With a splitting and recombination (SAR) concept, the diffusion distance of the fluids in a micromixer with ellipse-like micropillars was decreased. Thus, space usage for micromixer of an automatic sample collection system is also minimized. Numerical simulation was conducted to evaluate the performance of proposed micromixer by solving the governing Navier–Stokes equation and convection–diffusion equation. With software (COMSOL 4.3) for computational fluid dynamics (CFD) we simulated the mixing of fluids in a micromixer with ellipse-like micropillars and basic T-type mixer in a laminar flow regime. The efficiency of the proposed micromixer is shown in numerical results and is verified by measurement results.

Microfluidic Devices Fabricated by LTCC Combined with Thick Film Lithography

Low temperature co-fired ceramic (LTCC) process combined with thick film photolithography was employed to fabricate ceramic-based microfluidic devices. To check the applicability of novel process, three types of passive mixers, diffusion-driven T-type mixers with different channel width and convection-driven chaotic mixer, were fabricated and their microfluidic performance was evaluated. It was confirmed that the degree of mixing in ceramic-based microfluidic passive mixers was well matched with the numerical simulation data.

チューブリアクタによるナノシリカ粒子の合成

Monodispersed nano-silica particles were continuously synthesized via the hydrolysis of tetraethyl-orthosilicate (TEOS) in a methanol solution with a small tube type reactor. The tube type reactor consists of a handmade T-type glass mixer and Tygon tube for aging. Reaction was initiated by mixing TEOS methanol solution with a mixture of methanol and ammonia water in the T-type mixer. The morphology of particles formed was dependent on the reaction temperature as well as the water concentration. Monodispersed silica nano-particles were synthesized by stober method using a batch reactor, and they were compared in size with those formed by the tube type reactor. It was found that smaller silica nano-particles are obtained with increasing the reaction temperature and the water concentration. Especially with the tube reactor, the particle size depends mainly on TEOS concentration.