Solvents centrifugal cleaning

Core cleaning was done with an overnight Dean-Stark toluene extraction followed by 6 hours in a chloroform solvent centrifuge. Cleaned cores were equipped with stainless steel headers and had a pressure tap 0.5 in. [1.3 cm] from the inlet face. 

About 1920, a tumble dryer was used for drying the dry cleaned textiles. Fresh air was heated up, blown through the dryer, where the air was saturated with solvent vapor and then blown out to be exhausted into the environment The used solvent was cleaned to be recycled by separation of solid matter by centrifugal power with a separator and to be cleaned from dissolved contamination by distilling. 

The methodology used to analyze these compounds in plant-based materials, generally, includes a series of steps ranging from exhaustive solvent extraction, clean-up of extracts, and preconcentration procedures to simple filtration and centrifugation in liquid samples. After the extraction procedures, the phenolic compounds are characterized and quantified [7, 8]. Various complex analytical methods have been used for the determination of these compounds in natural samples and the most important of them are described in detail in this chapter. 

Materials of Construction and Operational Stress. Before a centrifugal separation device is chosen, the corrosive characteristics of the Hquid and soHds as weU as the cleaning and saniti2ing solutions must be deterrnined. A wide variety of materials may be used. Most centrifuges are austenitic stainless steels however, many are made of ordinary steel, mbber or plastic coated steel. Monel, HasteUoy, titanium, duplex stainless steel, and others. The solvents present and of course the temperature environment must be considered in elastomers and plastics, including composites. 

Initially, this method utilized 5-mL conical centrifuge tubes as the collection device for final elution of the extract from the Cig tubes. In practice, these tubes were found to be very difficult to clean and in few instances were the cause of cross-contamination when low-concentration samples were extracted following samples with very high concentrations. Since no commercial graduated tubes were available, disposable culture tubes are used as the receiver. These tubes are individually calibrated before use. A solvent blank sample may be processed through the method from extraction to quantification to determine if contamination from glassware occurs. 

In many cases, extraction of organic compounds requires that the extract be cleaned up before analysis. This may be as simple as centrifugation, but it may also involve concentration or evaporation of the solvent. Another approach is to absorb the analyte of interest on an absorbant and subsequently to extract it into another solvent. This may be necessary to ensure that the extract is compatible with the analytical procedure to be used. 

In the conventional method, the shard powder (or visible residue, or soil) is extracted with three separate aliquots of c. 0.5 ml DCM MeOH (dichlor-omethane methanol 1 1, v/v), with ultrasonication for 5 minutes to break up any particle aggregates and to aid dissolution. The solvent is separated from any insoluble material (including the ceramic) with centrifugation (5 minutes at lOOOrpm) and each of the three solvent aliquots is combined into a new clean vial. The solvent is then removed by placing the sample under a stream of nitrogen on a warm hotplate to aid evaporation, leaving the extracted... 

Centrifuge for 1 min at 2000 rpm (470 xg). Pour the solvent phase to a clean appropriately labeled glass tube. 

After the item has been cleaned and treated, paint can be applied depending on the size, shape, complexity, and quantity of items to be painted, different application methods can be employed. When it is desired to paint a large number of very small items, the most commonly used methods are tumbling, barreling, or centrifuging. For all three methods, the parts are placed inside a barrel, solvent-based paint is poured onto the items, and the barrel is then rotated. After a short time and at the correct point of tackiness, the parts... 

Paraffin. Separator operation can be adversely affected by paraffin accumulation. Coalescing plates in the liquid section and mesh pad mist extractors in the gas section are particularly prone to plugging by paraffin. If paraffin is an actual or potential problem, use of plate type or centrifugal mist extractors should be considered. Manways, handholes and nozzles should be provided to allow steam, solvent or other types of cleaning of separator internals. 

Dry-cleaning machines are usually provided with a centrifugal pump to force the liquid through a filter, and with a blower to move and filter the solvent vapour phase also. After the cleaning cycle, the solvent is drained from the cleaning chamber and may be reused, provided that the level of dissolved contaminants is not approaching saturation, otherwise it is regenerated by distillation or cleaned by mechanical filtration. 

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