Collecting Plates

Fig. 11. Types of (a) collecting plate and (b) discharge electrode designs.

A device used to remove fly-ash from boiler exit-gases in order to reduce the atmospheric pollution load. It places an electric charge on the dust particle and removes the particle onto a collecting plate. 

Theoretical approximations of deposition on impactor collection plates can be validated by calibration... 

Electrostatic precipitators are generally used to separate particulate matter that is easily ionized from a gas stream3,8,10. This is accomplished by an electrostatic field produced between wires or grids and collection plates by... 

Some other devices that can be used when the main obnoxious material is large particles are gravity settlers, cyclones, and inertial devices. Gravity settlers rely on gravity to allow the particles to fall into collecting plates. These should not be used on particles smaller than 40/a.25 Cyclones (see Fig. 8-10) depend on centrifugal... 

The deposits on the stainless-steel collection plates of the low-pressure impactor (LPI) were leached with a solution of 1 H HNO3 and the leachate rapidly evaporated on 5.08-cm stainless steel plates (using a hot plate). The concentrations of Pb-212 and Pb-214 in the impactor plate leachates were measured using seven ZnS(Ag) alpha scintillation counters. 

The simplest technique is the use of the 96-well collection plate format (analogous to the format used in SPE) in conjunction with a liquid handling robotic system it follows the same principle as bulk scale LLE. However, immobilization of the aqueous plasma sample on an inert solid support medium packed in a cartridge or in the individual wells of a 96-well plate and percolating a water-immiscible organic solvent to extract the analyte from this medium evoked significant enthusiasm from the pharmaceutical industry. 

Using the Tomtec Quadra 96 workstation, 0.1 mL of the ethyl acetate layer was transferred to a 96-well collection plate containing 0.4 mL of acetonitrile in each sample well. The solution was mixed 10 times by aspiration and dispersion on the Tomtec. The plate was then covered with a sealing mat and stored at 2 to 8°C until LC/MS/MS analysis. The HILIC-MS/MS system consisted of a Shimadzu 10ADVP HPLC system and Perkin Elmer Sciex API 3000 and 4000 tandem mass spectrometers operating in the positive ESI mode. The analytical column was Betasil silica (5 fim, 50 x 3 mm) and a mobile phase of acetonitrile water formic acid with a linear gradient elution from 95 5 0.1 to 73.5 26.5 0.1 was used for 2 min. The flow rate was 1.0 mL/min for the API 3000 and 1.5 mL/min for the API 4000 without any eluent split. The injection volume was 10 jjL and a run time of 2.75 min was employed. 

A coal combustion pilot plant is used to obtain efficiency data on the collection of particulate matter by an electrostatics precipitator (ESP). The ESP performance is varied by changing the surface area of the collecting plates. Figure E2.2 shows the data collected to estimate the coefficients in a model to represent efficiency 17 as a function of the specific collection area A, measured as plate area/volumetric flow rate. 

Collecting plate designs, 26 703, 704 Collective marks, 25 253 Collective works, 7 786 Collector regions, in HBTs, 22 167—168... 

The ability to separate ions spatially is called the dispersion of a mass spectrometer. Dispersion is simply the distance between the centers of two ion beams that differ in mass by Am at the collection plate. A simple sector instrument, where the ion beam enters and exist the magnetic field normal to the pole faces and the object and image distances are the same, is known as a symmetrical geometry analyser. Examples are shown in Fig. 8. In this case, the dispersion, D is given by ... 

For two-stage precipitators with close collecting-plate spacings (Fig. 17-76), the gas flow is substantially streamline, and no electric wind exists. Consequently, with reentrainment neglected, collection efficiency may be expressed as [Penny, Electr. Eng, 56, 159 (1937)]... 

Low resistivity can sometimes be a problem. If the resistivity is below 104 Xcm, the collected particles are so conductive that their charges leak to ground faster than they are replenished by the corona. The particles are no longer electrostatically pinned to the plate, and they may then be swept away and reentrained in the exit gas. The particles may even pick up positive charges from the collecting plate and... 

FCC fine gas laden with catalysts tines enters the ESP in a uniform flow pattern between parallel collecting plates into an area of high voltage. 

When the particles reach the bottom of the collection plate they fall into a hopper for subsequent evacnation into a collection device snch as a dumpster or are pneumatically transported to a storage silo for storage and disposal. Because of their fine natnre, these particles are not typically reintroduced into the FCCU for rense. 

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