Vessel-based mechanical mixing involving viscous media is an essential operation in industrial sectors like pharmaceutics, chemistry and oil among many others. In such processes, the quality of the final product depends on the homogenization obtained, which is a consequence of the operating conditions. This topic has been investigated using numerical and experimental methods.[1-3]
In practice, the mixing of viscous liquids in stirred tanks is often made using close clearance impellers such as helical ribbons (HR). Although open impellers are sometimes used for moderate viscosity fluids (less than a few tens of Pa•s), macromixing with HR-type impellers has been well accepted even if the lower side of the mixing vessel is prone to spurious flow phenomena such as segregated and compartmentalized regions that lead to long mixing times as a consequence of the low pumping capacity.
The reports available in the literature investigating the HR mixing performance deals with the geometry of HR mixers as variable quite diverse: single ribbon, double ribbon, impellers with or without an inner screw fixed along the central shaft even used in flat bottom cylindrical tanks or in dished bottom tanks.[4,5]. Beckner and Smith[6] and Brito et al.[7] reported the power drawn for HR agitating both Newtonian and non-Newtonian liquids. Delaplace et al.[8] provided a detailed description of the application of HR in industrial processes emphasizing the geometrical parameters effects like number of ribbons, pitch size (p), blade width (w) or bottomwall clearance effects on the circulation and mixing times.
The study of macroscopic parameters for small mixing volumes (<75 L) have been the main topic of the published reports, even for Newtonian or non-N...
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...e on the mixing of Newtonian viscous flows for industrial purposes. Hence that the goal of the present work is to develop a numerical investigation to describe the hydrodynamics generated by a standard helical ribbon impeller in a stirred tank in comparison with two HR redesigned at the bottom. The analysis focuses the improvement of the axial pumping in the lower side of the tank and discusses on the flow patterns, the power drawn and several distributive mixing criteria such as pumping capacity, shear rate and stretching efficiency. An originality of the present work are the Poincaré maps prepared to compare the mixing performance based on the tracking of a single massless tracer for one hour blending. Such a long period represents a challenge for computation studies. To our knowledge, it has never been performed before for the characterization of HR impellers .
He began experimenting with a cup that would regulate the flow of oil onto moving parts of industrial machines.
The objective of this experiment is to separate a liquid mixture of Ethyl Acetate and Toluene through the process of Fractional Distillation. It is also to determine the mixture composition and the physical properties of the two liquids. Fractional Distillation “is used to separate (purify) the different liquid components of a mixture.”1 This type of distillation differs from Simple Distillation in which the mixture being used “is composed largely of a single liquid component.”1 Both processes use the liquids boiling point for the purification. If a liquid is gathering and the temperature corresponds to the theoretical boiling point of the liquid, then that liquid is what is being collected. The theoretical plate is “Each section of the
Centrifuges were utilized in the lab to separate substances of different densities (i.e. liquid solution and precipitate). Centrifuges separate solids and liquids so quickly because they use high rotational velocity, causing the denser solids to move toward the outer wall of the centrifuge and bottom of the test tube.3 It is vital to balance the centrifuge because the tubes are spun at high rotational velocities, so an imbalance of mass can cause a failure of the centrifuge to work properly and a possible safety
Background: The density of water is 1 g/mL. In order to find density, you must do mass divided by volume. You find solid volume by multiplying the length by width by height or by using displacement. You find mass by weighing the substance. In previous experiments, it is seen that alcohol dissolves faster than water.
The behavior of the viscosity is like pure liquids far from the critical point of a binary liquid mixture, Around the critical point the situation becomes more complicated (Yusur Kittany, 2014). The mode coupling theory is used to study the critical anomaly of the shear viscosity and the coefficients.
Because of the increased motion in the particles allowing it to break down into smaller pieces which the solvent can dissolve.
Compared to the linear peristaltic pump and rotary peristaltic pump, the 360 degree peristaltic pump runs more slowly at the same performance. As a result, the hoses will have longer lifetime which is economic. Furthermore, the 360 degree peristaltic pump produces less friction due to the unique structure, and therefore less thermal. Especially, the 360 degree peristaltic pump has only a single compression per rotation while the ordinary pumps with numerous shoes or rollers have at least two or more compression per revolution. This means that the design of the 360 degree pump will prolong the lifetime of the tube. At the same size, this design will generate more flow volume (55%) at the same
We found that the average density of a full micropipet is 1.03(g/mL). The second table was all about recognizing the density of the unknown. The average density of the unknown is 0.79(g/mL). Table 3 shows the different densities of seven different liquids. Through this table, we discovered that the unknown liquid is ethanol. The density of ethanol is 0.789 which is almost identical to Data Table 2. There could be more options not listed in the table that have a closer density to the unknown.
This chart shows the relationship between the fanning friction factor and the Reynolds number over a wide range of flow rates, from which the roughness parameter (e/D) for the piping system can be estimated.
Journal bearings are some of the most important machine elements used in industrial applications. They are widely used in IC engines, steam and gas turbines, pumps, compressors, etc. When well designed and maintained, they have benefits of supporting high load carrying capacity with a wide range of speeds and unlimited life in comparison with the expense and limited life of ball and roller bearings. Cylindrical journal bearing normally consists of a journal supported by a simple sleeve and sufficient supply of lubricant. The circular hydrodynamic journal bearing becomes noncircular when it was subjected to the wear due to successive starts and stops for a long period of work. This local variation in geometry of the
Particle size influences many properties of particulate materials and is a valuable indicator of quality and performance. This is true for powders, suspensions, emulsions, and aerosols. The size and shape of powders influences flow and compaction properties..
The reason that the water and oil didnt mix, was in fact, fairly simple. The water was more dense than the oil. Density is measured by dividing mass and volume of any substance. Water, by having a higher density, ended up underneath the less dense oil. Another reason is because of the water has polar molecules while the oil is nonpolar, meaning that no matter how hard you try they will never ever mix and end up separate. In the end my hypothesis was correct, but failed to
Firstly, the gas turbine engine operation begins with the air intake process. As of all internal combustion engine, oxygen is required to support the combustion of the fuel and the source of oxygen is from the fresh air that is taken in. Initially, the fan is rotated by a driving shaft that is powered by the turbine of the engine. A negative or vacuum pressure at the intake side is then created by the rotating fan. Next, the surrounding air is drawn towards the inlet and causes it to flow into the gas turbine engine inlet (Cengel & Boles, 2011). At the same time, the pressure on the other side of the fan is increased as it is compressed at a lower pressure ratio and causes the air in the outlet side of the fan to move fu...
Viscosity is the resistance of a fluid to flow. The molecules experience friction due to the molecular interaction among them. Different fluids with different viscosities flow at a different speed the more force the more viscous fluids of a fluid to flow is known to be the amount of thickness in any fluid for, example water would have low amount of viscosity and honey being thicker would have a high viscosity. Although viscosity can be known to be different depending on the density of the liquid. Force is required for any object to to travel the more viscosity that is in any liquid the more force is required
Cornstarch and water is a non-Newtonian, organic fluid. Fluids can fall under different sub groups. They are either Non-Newtonian or Newtonian. They can also be either organic or non organic. NonNewtonian Fluids are a group of liquids that change viscosity when they are stirred, shaken, or otherwise agitated. Cornstarch and water acts differently depending on whether it is still or agitated. This kind of fluid is called a dilatant. It becomes more viscous (has a relatively high resistance to flow) when agitated or compressed. The viscosity of a non-Newtonian fluid is also dependant on temperature. Cornstarch would decrease in viscosity if put in a boiling pot (it would become thinner). Examples of Newtonian fluids include motor oils, mineral oils, gasoline, kerosene, and most salt solutions in water.