Stirring paddles

Ruhr-schaufel, /. stirring paddle, -scheit, n. paddle, rake, stirrer spatula, -spatel, m. stirring spatula, -stab, m. stirring rod, stirring pole, paddle, rabble, -stativ, n. stirring stand, -tank, m. ablating tank. 

It 1s not necessary to flame or oven dry this apparatus but a nitrogen inlet on the reflux condenser 1s desirable. The size of the stirring paddle is critical because of the viscous nature of the solution during this protection step. A paddle at least 11 cm in length is recommended to ensure complete mixing. 

Toward the end of the acid chloride addition, TEA hydrochloride precipitated, and the solution became quite viscous, making stirring and removal of reaction heat more difficult. Hence, a large stirring paddle and a strong stirring motor (e.g., an air-driven stirrer) were used. 

Stirring paddles of porcelain, recently introduced, are less fragile and very satisfactory. They are simply attached to a bent glass rod and are available in various shapes and sizes (Fig. la-c). 

We can observe that, with the help of simulation software, we can produce the numerical results which give the effect of the stirrer s number of turns, the position of the stirrer in the tank, the effect of the dimension of the stirring paddles, etc., on the model exits mentioned above. 

A number of rotating components are in common use in process plants, e.g. turbines, compressors, pumps, centrifuges and stirring paddles, and it is important to understand how such pieces of equipment are affected by the conservation of energy. For a rotating component, the principle of conservation of energy states that... 

Stirring Paddle Devices. In an attempt to overcome these problems as well as the temperature limitation (85 °C) of standard oil field equipment, other devices, similar to the equipment used to measure the thickening time, have been developed (20). The cement slurry contained in a cylindrical cup is usually stirred with a paddle under pressure and temperature. This allows the simulation of the shear history encountered by the fluid during placement. Then, the rotational speed is reduced to a very low value—typically 0.003 rpm—and the torque on the paddle is measured as a function of time. The main advantages of such a technique is that measurements are performed under realistic conditions of pressure, temperature, and shear history. On the other hand, the analysis of the data is not straightforward as the stress distribution in these devices is not known, and it is not clear whether or not measurements are affected by wall slip layers. 

The reaction cannot be stirred with a magnetic stir bar as the integrity of the beads will deteriorate. Instead, agitate the beads on a shaker or use an overhead mechanical stirrer, making sure that the stirring paddle does not contact the bottom of the flask. 

Variable-Speed Mechanical Stirrer, a suitable type, equipped with a glass, propeller-type stirring paddle (D in Fig. 1). A propeller with blades 6 mm in radius and set at a... 

Mechanical induced flotation units induce gas bubbles into the system by entrainment of gas in a vortex generated by a stirred paddle. Figure 3.43 shows a cross section of a dispersed gas flotation cell that utilizes a mechanical rotor. The rotor creates a vortex and vacuum within the vortex tube. Shrouds assure that the gas in the vortex mixes with and is entrained in the water. The rotor and draft inducer causes the water to flow as indicated by the arrows in this plane while also creating a swirhng motion. A baffle at the top directs the froth to a skimming tray as a result of this swirling motion. 

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