Laboratory Installations

Whenever a ventilation system is available in the laboratories, its exhaust should contain filters all exhaust air from high risk zones must be filtered. The filter should comprise at least a fibre filter for dust and a charcoal filter for vapours. Breakthrough volumes of some carcinogens and solvents through charcoal have been studied by Sansone and Jonas (95). 

Hoods should be installed in all areas where chemical carcinogens are handled and should be equipped with efficient filters, as described above for the ventilation systems. Several suggestions, ranging from 

When installed, glove boxes must be kept under a negative pressure of 15-45 mm of water with respect to the space in which they are located. However, personnel should be made aware of the problems of gloves (see Section 2.5 (4)). 

It is recommended that benches be made of impermeable material, and that trays be available in a material that cannot be attacked by carcinogens or solvents. Stainless-steel trays are preferable, since they can also resist acids and strong oxidants, which might be necessary for their decontamination (see Section 3). Absorbent material with a plastic undercoating must be provided for placing on benches and in trays. 

Eye-wash facilities and safety showers must be installed in every laboratory where chemical carcinogens are used. 

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Work with flammables should be confined to areas where other work that could cause ignition is not performed. This practice must be carefully policed. Extra ventilation may be needed for such an area. Knowing that most flammable fumes are heavier than air, one laboratory installed an explosion-proof exhaust fan at floor level below the bench where flammables were used. To make the area for working with flammables easier to identify, it could be marked off with red lines on the floor. 

Sink traps of resistant plastic are now well accepted. They are easy to install and also easy to clean. Drains of glass pipe are sometimes seen in special installations. Some laboratories install regular thin-walled sink traps designed for kitchen use. The author s experience with them, even in the home, has been poor. 

As with any other project, there were things that could have been done differently and better a second time, but overall it must be said that, in spite of occasional differences of opinion, this laboratory installation worked out well. It was the cooperative effort of fnany people, each one doing his or her best with an eye for the future. No dramatic changes had to be made as work began or when new assignments came in. The laboratory became a place where creative and productive work could be performed with minimum interference. 

Systems (e.g. laboratory installations and full-scale plants) behave similarly, i.e. are similar, if geometric similarity, kinematic similarity, dynamic similarity, thermal similarity, and chemical similarity are preserved. 

Usual device used for mass CVD production of carbon nanotubes is a fluidized-bed reactor [7]. In our laboratory installation we succesfiilly used rotating reactor... 

Do not take a deep breath before blowing. Never blow with all the pressure you can muster blow the glass into shape while it is plastic. A final hard puff when the glass has set will achieve nothing useful. When moulding ground joint cones and stopcock keys, use air pressure from the laboratory installation, controlled with a foot or manually operated valve. 

Fig. 2-36. Scheme of laboratory installation for recording polarisation curves of electronic conductors 1- electronic conductor (mineral or metal) 2- solution of electrolyte A- current electrode B- auxiliary current electrode M- measuring electrode N- non-polarisable measuring (reference) electrode cp- potentiometer CS- electric current source I- ammeter (reproduced with permission from Putikov, 1993). 

Most of the reactions involved in this work, and particularly those with radioactive isotopes, require special laboratory installations and are now, and are likely to remain, the domain of specialists. It should be noted also that they rarely lead to truly homogeneous substances, but rather to mixtures of molecules containing the label at different places and in different proportions, either necessarily—because the pure isotope is not available as starting material or the labeling reaction is not wholly controllable—or intentionally, because economic factors, inconveniently high specific activities and the resulting difficulties of protection against radiation and autoradiolysis, or other considerations leave no other course open. 

An accurate result might not be got without using a silica resistance and operating in a vacuum, he added. The current laboratory installation does not permit us to... 

Figure 21.6. Process of recovery of plasticizer from PVC - laboratory installation. 21 rotating flask (reactor), 22 heating mantle, 23 rotary drive, 24 condenser, 25 feed line, 26 outlet, 27 safety receiver, 28 transfer line, 29 collecting flask, 30 condenser, 31 outlet line, 32 shut-off valve, 33 feed line, 34 gas-washing bottle, 35 gas-washing bottle, 36 offgas line, [Adapted from Lyding Q Pille M, von Plessen H, Semel J, US Patent 5,464,876.]...

A laboratory installation for the thermal degradation of rice husks, equipped with quartz fluidized-bed reactor [93], is presented in Fig. 13.5. 

The air-cooled design and conventional power supply make field or laboratory installations easy. 

Experimental extraction curves have been represented by this model by fitting the kinetic coefficients pf, Df., D x) to the experimental curves, obtained from a laboratory installation. With the optimised parameters it is possible to model the whole extraction curve with reasonable accuracy. These parameters have been used to model the extraction curve obtained from a pilot plant. In Figure 7 experimental and calculated extraction curves are compared the coincidence is sufficient. Therefore, the model can be used to determine the kinetic parameters from a laboratory experiment and they can be used for scaling up the extraction. 

The main part of a laboratory plant for countercurrent gas extraction is the separation column, where the countercurrent contact of liquid and gaseous phase takes place. Equally important is the equipment for establishing the flow of the phases through the column. Other components depend on the size of the column, whether the supercritical solvent is recycled or not, and on the degree of automation. In the following, an example of a laboratory installation is described. It is a non-commercial installation used at our laboratory for separation experiments on edible oils, fats and related compounds, and on mineral oil fractions. 

Electrostatic spinning of fibers based on PHB and titanium dioxide was carried out with original laboratory installation [6]. 

The purchase of a new decanter is very strongly influenced by the Intended process duty, and almost all such purchases are made only after careful analysis by the supplier of the required performance, and, possibly, after some kind of trial with the customer s process liquor. Trials may involve the installation of a temporary test decanter, and ancillary plant, as a static or mobile rig. Such a test may be for an extensive period, to cover all the likely variations in process slurry characteristics. The test rig could be a full size, pilot scale, or laboratory installation. Experience of a particular application by the supplier makes the selection process one which can be approached with confidence, and the potential purchaser would do well to enquire as to the level of relevant experience available. 

If there is no net flow of gas out the cyclone underflow, the captured solids fraction is a pure solids stream, and it may be possible to determine the mass flow of this fraction by collecting the underflow solids for a known time, and weighing. This method can often be applied in both an industrial and a laboratory installation. 

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