Mixer vacuum

The audio signal resulting from rf amplification and detection is amplified and detected in a phase sensitive manner by using the original modulation phase as a reference. Both mixer vacuum tubes 6S) and mechanical choppers are used. The resulting DC voltage is fed into a recorder. For sufficiently small audio modulation amplitudes the first derivative of the resonance absorption or dispersion results from the narrow-banding technique. 

High-shear mixer Vacuum/gas stripping/microwave assist—one-pot... 

In a typical commercial dry jet-wet spinning process, PPT polymer of inherent viscosity 6.0 dL/g is added to 99.7% sulfuric acid in a water-jacketed commercial mixer in a ratio of 46 g of polymer to 100 mL of acid. The mixture is sealed in a vacuum of 68.5—76 mL of mercury. Mixing takes place for 2 h... 

These mixers are particularly suited for rapid mixing of powders and granules with liquids, for dissolving resins or solids in liquids, or for removal of volatiles from pastes under vacuum. Scale-up is usually on the basis of maintaining constant peripheral velocity of the impeller. 

Vacuum or Pressure Most tumbling mixers can have provision for vacuum or pressure. Mixers which cannot be adapted to these conditions are iTuulers with rotating pans. Continuous mixers introduce problems of sealing the charge and discharge ends. 

Polycarbonates have proved attractive in domestic appliances. Examples include food processor bowls, coffeemaker cold water reservoirs, vacuum cleaner housings, food mixer housings, power tool housings, hair drier and electric razor housings, and microwave cookware. 

The filtered dough is then returned to a mixer and the alcohol content reduced to 25% by kneading under vacuum. Further reduction in the alcohol content is brought about by rolling the compound on a hooded two-roll mill. The milled product is then consolidated on a two-bowl calender and sheeted off in hides about j in thick. At this stage the solvent content is between 12 and 16%. 

Figure 5. Planetary mixer with a vacuum hood.

Even when the time comes to make a purchasing decision, an energy-efficient motor purchase is not a certainty. Sometimes an energy-efficient motor will be the economically efficient choice at other times, not. The capital investment decision is based on the cost in relation to performance, efficiency and reliability. Moreover, the decision depends on the application and the amount of time the motor is in operation. It can be the major component of a product (drill or mixer), or a minor component (computer disk drive) it can be the major component cost of a product (fan), or it can be a minor component cost (stereo tape deck) it can run almost constantly (fan, pump, and machinery), or only a few minutes a day (vacuums and power tools). For example, contractors purchase circular saws almost solely based on performance and reliability. Time is money, and since the saw is operating only a few minutes a day and the contractor is often not responsible for the electricity costs to run the motor, energy efficiency is not a consideration performance and reliability are what matter most. On the other hand, an industrial user, who runs huge electric motors twenty-four hours a day to work pumps, machinery, and ventilation equipment, is very concerned tvitli energy efficiency as well as performance and reliability. 

For accurate mixing, independent of environmental conditions, vacuum mixers are used as shown in Fig. 6. 

Figure 6. Vacuum mixer for lead paste 1, mixing compartment 2, fast-rotating mixing tools 3, material-deflecting plate 4, discharge opening 5, static, vacuum-sealed enclosure [21J.

In the vacuum mixer, water evaporation is also used for the temperature control, since the evaporation rate can be influenced by the grade of the vacuum. The water vapor, however, does not escape from the mixer, but is condensed and returned into the mix, the composition of which is thus not changed. 

The specimen was prepared by the following method. After mixing HAF carbon black (50 phr) with natural rubber (NR) in a laboratory mixer, carbon gel was extracted from unvulcanized mixture as an insoluble material for toluene for 48 h at room temperamre and dried in a vacuum oven for 24 h at 70°C. We made the specimen as a thin sheet of the carbon gel (including carbon black) by pressing the extracted carbon gel at 90°C. The cured specimen was given by adding sulfur (1.5 phr) to the unvulcanized mixture and vulcanized for 30 min at 145°C. The dynamic viscoelastic measurement was performed with Rheometer under the condition of 0.1% strain and 15 Hz over temperatures. 

Weigh 2.5 or 5 g of crop matrix into a blending vessel. Fortify samples at this point with the appropriate analytical standards. Allow the solvent to evaporate. Add 100 mL of acetone-water (4 1, v/v) and blend the mixture using an Omni mixer equipped with a macro generator for 5 min at 6000-7000 rpm. Filter the sample through a Whatman 934 AFI glass-fiber filter paper on a Buchner funnel/vacuum flask setup. Rinse the blending cup and filter cake with 100 mL of acetone. Transfer the filtrate into a 200-mL TurboVap vessel. 

Rotary vacuum evaporator, with a 40 °C water-bath Round-bottom flasks, 50-, 100-, 500- and 1000-mL Separatory funnels, 250- and 500-mL Ultrasonic water-bath Vortex mixer... 

A further development is the combination of the pin barrel extruder system with that of the Transfermix (see under EXTRUDERS, MIXERS). The combined system is known as Pinconvert and is available with or without vacuum extraction. 

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