Laboratory units

Table 6. Laboratory Unit, Pilot-Plant, and Commercial Scale-Up Ratios...

Commercial samplers are available that combine a traversing-type sampler and an unacceptable table sampler. An alternative design is the radial cutter or Vezin sampler. These samplers vary in size from a 15-cm laboratory unit to a 152-cm commercial unit. 

It is estimated that the worldwide clinical chemistry diagnostics market is about 3 biUion. This amount includes an estimated 700 million in instmment sales, and 2.3 bUHon in sales of reagents and consumables. Some of the principal instmment manufacturers are Hitachi (Japan), Miles Laboratories/Technicon Instmments (United States), E. I. du Pont de Nemours (United States), Beckman Instmments (United States), Eastman Kodak (United States), Abbott Laboratories (United States), Olympus (Japan), Toshiba (Japan), Hoffmann-La Roche (Switzerland), and Ciba Corning Diagnostics (United States). 

In 1966, in a paper that now is considered a classic, Danckwerts and Gillham [Tmns. Inst. Chem. Eng., 44, T42 (1966)] showed that data taken in a small stirred-ceU laboratoiy apparatus could be used in the design of a packed-tower absorber when chemical reactions are involved. They showed that if the packed-tower mass-transfer coefficient in the absence of reaction (/cf) can be reproduced in the laboratory unit, then the rate of absorption in the l oratoiy apparatus will respond to chemical reactions in the same way as in the packed column even though the means of agitating the hquid in the two systems might be quite different. 

There are a number of different types of experimental laboratory units that could be used to develop design data for chemically reacting systems. Charpentier [ACS Symp. Sen, 72, 223-261 (1978)] has summarized the state of the art with respect to methods of scaUng up lab-oratoiy data and tabulated typical values of the mass-transfer coefficients, interfacial areas, and contact times to be found in various commercial gas absorbers as well as in currently available laboratoiy units. 

The laboratory units that have been employed to date for these experiments were designed to operate at a total system pressure of about 100 kPa (1 atm) and at near-ambient temperatures. In practical situations, it may become necessaiy to design a laboratory absorption unit that can be operated either under vacuum or at elevated pressures and over a reasonable range of temperatures in order to apply the Danckwerts method. 

U.S. EPA, Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Ground Water, National Risk Management Research Laboratory, United States Environmental Protection Agency, Washington, DC, October 1998. 

Yang and Kearins (1987) describes the experiments carried out in a 30-cm diameter laboratory unit to study the fines residence time... 

Experiments were conducted with the use of compact laboratory unit... 

Calsinter A process for extracting aluminum from fly ash and from flue-gas desulfurization sludge. The ash is sintered with calcium carbonate and calcium sulfate at 1,000 to 1,200°C and then leached with sulfuric acid. Developed at Oak Ridge National Laboratory, United States in 1976, but not known to have been piloted. 

Data of the behavior of chemical reactions are obtained from laboratory units designed for or adapted to the purpose, or from pilot plant or commercial units. The larger units have the advantages of more instrumentation and controls but have less flexibility. Fundamentally what is determined is the time dependence of composition or pressure, or some measurement that can be related to these properties, and of the temperature. 

The laboratory unit was based on a ElectroCell MP cell with an elec-trode/membrane area of 0.01 m2. A DSA (Dimensionally Stable Anode) anode served as oxygen electrode, Ni as cathode. Anion exchange membranes = Neosepta ACM (Tokuyama Soda) AMH cation ex-change membranes = Nafion 324 Nation 902. 

Expert systems create value for groups of people, ranging from laboratory units to entire companies, in several ways, by ... 

Laboratory Unit Fire Hazard Class Flammable and Combustible Liquid Class Maximum per 100 fP (9.3 m") of Laboratory Unit gal (1) Maximum per Laboratory Unit gal (1) Maximum per lOOfP (9.3 m ) of Laboratory Unit gal (1) M[Pg.308]

Laboratory Unit Fire Hazard Class Fire Separation-Fire-Resistive Partition Rating ... 

All laboratory units should be provided with fire protection appropriate to the fire hazard, as follows ... 

Class A and Class B laboratory units should have a manual fire alarm system installed and maintained in accordance with NFPA 72, National Fire Alarm Code. The fire alarm system, where provided, should be designed so that all personnel endangered by the fire event should be alerted. The fire alarm system should also alarm to an attended location to alert emergency responders or the public fire department. 

Portable fire extinguishers should be installed, located, and maintained in accordance with NFPA 10, Standard for Portable Fire Extinguishers. For sizing and placement purposes. Class A laboratory units should be rated as extra (high) hazard, and Class B, Class C, and Class D laboratory units should be rated as ordinary (moderate) hazard. 

Since the oxidation of SO to SO is a step in the operation of SOx catalysts, an increase in oxygen concentration should favor the reaction, and thereby increase the efficiency of SOx catalysts. The evidence indicates that this occurs. Baron, Wu and Krenzke (9) have shown that an increase in excess oxygen from 0.9% to 3.4% resulted in a 20% reduction in SOx emissions. This was for a steam-deactivated catalyst in a laboratory unit at 1345 F (no combustion promoter). 

REST need not necessarily involve any animals at all. If electronic sensors of adequate sensitivity are developed, they can replace the animals. Certainly, the history of electronic instrument development shows that the earlier generations of any device are more suited for laboratory than field use, and that laboratory units can normally be expected to show better performance than portable ones. Calibration of an electronic instrument, which corresponds to training of a mammal, should become more precise and dependable than that training. 

PACT systems have achieved commercial status abroad. Retech has designed on-site PACT-6 and PACT-8 units, a portable PACT-2 unit, and PACT-1 laboratory unit. This technology is commercially available. 

Sample analyses were carried out by a number of laboratories. We are grateful to Mr. Mark E. Peden and Ms. Loretta M. Skowron of the Water Survey s Analytical Chemistry Laboratory Unit for atomic absorption spectrophotometry, Mr. L. R. Henderson of the Illinois State Geological Survey for X-ray Fluorescence specto-scopy, and Dr. T. A. Cahill of the University of Califomia-Davis for elemental analysis. Mr. R. G. Semonin reviewed the manuscript. This material is based upon work supported by the National Science Foundation under Grant No. ATM-7724294, and by the Department of Energy, Division of Biomedical and Environmental Research, under Contract No. EY-76-S-02-1199. 

J. O. HAWTHORNE, K. A. SCHOWALTER, A. W. SIMON, and M. H. WILT Applied Research Laboratory, United States Steel Corp., Monroeville, Pa. 

Since our laboratory frequently uses HPLC for the final determination step, those assays were first chosen for automation. Each procedure was subdivided into discrete laboratory unit operations for final inclusion into the Zymate program. Each of these operations was also assigned to a module such as hand, master lab station, or blender. The sequence of operations and modules was then merged to arrive at a final procedure. This final procedure was then "taught" to the robot using a series of user-defined terms which could then be coupled into a program for that sample preparation. Since many of the laboratory operations are the same for many assays, an analyst needs to define only a limited number of terms to be intermixed into a variety of programs. 

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