Stirring devices

An industrial fermentor of capacity up to several hundred kiloliters equipped with aeration and stirring devices, as well as other automatic control systems, is used. The cultures must be sterilized and aseptic air must be used owing to the high sensitivity to bacterial contamination of L-glutamic acid fermentation. 

Flocculation units should have multiple compartments and should be equipped with adjustable speed mechanical stirring devices to permit meeting changed conditions. In spite of simplicity and low maintenance, non-mechanical, baffled basins are undesirable because of inflexibility, high head losses, and large space requirements. Mechanical flocculators may consist of rotary, horizontal-shaft reel units as shown in Figure 9. 

Into an iron or copper reaction vessel having an efficient stirring device and furnished with a refluxing column and condenser, were charged 330 lb of high quality meta-cresol and 150 lb of glycerol, together with 25 lb of sodium acetate to serve as the catalyst in the reaction. 

The meltings occurred in Pyrex tubes under a vacuum of about 10-5 mm. Hg. The uniformity of the reguli with respect to composition was achieved by two measures first, the alloys were kept in the molten state about 100° C. above their melting-points for more than 2 hr. and secondly, effective agitation was provided by a magnetically driven stirring device. 

An alternative to the rotating disk method in a quiescent fluid is a stationary disk placed in a rotating fluid. This method, like the rotating disk, is based on fluid mechanics principles and has been studied using benzoic acid dissolving into water [30], Khoury et al. [31] applied the stationary disk method to the study of the mass transport of steroids into dilute polymer solutions. Since this method assumes that the rotating fluid near the disk obeys solid body rotation, the stirring device and the distance of the stirrer from the disk become important considerations when it is used. A similar device was developed by Braun and Parrott [32], who used stationary spherical tablets in a stirred liquid to study the effect of various parameters on the mass transport of benzoic acid. 

A liquid flow microcalorimeter, the thermal activity monitor (TAM), is commercially available from ThermoMetric (formerly LKB/Bofors). This instrument consists of two glass or steel ampules with a volume of 3 to 4 cm3 (25 cm3 ampule available with a single detector), placed in a heat sink block. Recently, an injection-titration sample vessel was developed which acts as a microreactor. This vessel is provided with flow-in, flow-out, and titration lines, with a stirring device. The isothermal temperature around the heat sink is maintained by a controlled water bath. Each vessel holder, containing an ampoule, is in direct contact with a thermopile array, and the two arrays are joined in series so that their output voltages subtract. The two pairs of thermopile arrays are oppositely connected to obtain a differential output,... 

Figures 11 and 12 illustrate the flow patterns for the basket and the paddle apparatus, respectively. An undertow can be observed visually in the paddle apparatus for stirring rates exceeding 125 rpm. The hydrodynamic region below the paddle, and, even more pronounced, below the basket, appears to be somehow separated from the region above the stirring device. Diffusion-driven exchange of dissolved mass between these two regions is unhampered, but little...

Figure 13 Vertical (axial) flow (UpJ below the stirring device as a function of stirring rate (to) for paddle (filled circles) and basket (open circles) at the bottom of the hemispheric dissolution vessel filled with 900 mL. Source From Ref. 10.

Batch operation For the design of batch reactors for biphasic conversion the type of stirring device is an essential aspect to generate a narrow distribution with small droplet sizes which is equivalent to high surfaces [36]. Together with the diffusion ability (diffusion coefficient) of the used sol-... 

As illustrated in Figure 22.6, these tanks are approximately 16 ft high and 5ft in diameter. They contain about 0.37 m of bay sediment and 13,000 L of water, which is slowly trickled in from the bay. The outflow rate is set so the water voliune does not change over time. With a stirring device and the top of the tank open, the tanks function much like the neighboring bay. Typical experiments involve monitoring the... 

T-l Raney Nickel Catalyst. To prepare, proceed as follows in a one liter three necked flask containing 600 ml of a 10% sodium hydroxide solution, 40 g of Raney nickel aluminum alloy (50%) is added in small portions. During the addition the temp should be 90-95° and there should be good stirring (do not use a magnetic stirring device). After the addition is complete (25 to 30 min), stir for 1 hour more, and let the nickel settle to the bottom of the flask. Decant the solution off, wash with 5 times 200 ml of water, 5 times 50 ml of ethanol, in such a way to keep the nickel always covered with liquid. The catalyst must be stored under ethanol and refrigerated. It may he stored for three months and remain active. 

This is a fast easy method. If you have a battery powered stirring device it can be performed most anywhere. If you wish to do this formula on a smaller scale then use the following formula. As tetranitromethane is expensive, I suggest you practice on the small scale first. Nitropropenes or nitrostyrenes are not psychoactive, you need to find a reduction. 

Dissolve 175 g of KOH in 1,750 ml of water in a flask of 5 liters volume equipped with a reflux condenser and a gas inlet tube. If a stirring device is not required, it should be removed and the open neck stoppered. Heat the mixture to 80° under a stream of nitrogen and add 500 g of ergotamine tartrate. Hold the temp at 80° for 2Vi hours with bubbling from the nitrogen filled gas inlet tube. Pour the mixture into a 5 gallon polyethylene bucket (made from the same... 

Sulfur trioxide-Dimethylformamide eomplex (SOrDMF). This is a reagent required for this method of LSD production. A completely dry 22 liter flask (round bottom) in an ice cooling bath is fitted with a condenser, stirring device, addition funnel, then is filled with 10-11 liters of... 

Phenylethyl Ketone. 200 g of finely powdered anhydrous aluminum chloride is suspended in 300 g of dry benzene in a flask that is cooled and equipped with a good stirring device. A mixture of 126 g of propionyl chloride and 105 g of benzene is added dropwise, with stirring, over 3 hours. After the 3 hours, the reaction mixture temp is kept at 50°. The contents of the flask are cooled and poured over crushed ice. Add 50 cc of coned HCl acid and remove the phenylethyl ketone and benzene by distillation with steam at 200-220° to yield 152 g of the ketone. 

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