Electrostatic separator particle-charging device

The two-stage electrostatic precipitators used in light-industry applications are compact devices which can be fitted into the ventilation system. These air cleaners are normally used to clean air from dusts, smokes, and fumes in industrial workplaces. The basic features of these devices are the separate sections for particle charging and collection. The charging section consists of thin metal wires installed between grounded metal plates. The distance... 

In general, all electrostatic separator systems contain at least four components (i) a chargingdischarging mechanism (ii) an external electric field (iii) a nonelectrical particle trajectory device and (iv) feed and product collection systems. Depending primarily on the charging mechanism involved, the electrostatic separator systems are classified into three categories (i) free fall separators (ii) high tension separators and (iii) conduction separators. 

Another device used to separate particulate and vapor phase PAHs is an electrostatic precipitator, consisting of a conducting surface to which an electric field has been applied. A corona is produced, which charges particles and allows them to collect on an oppositely-charged surface. A sorbent is placed downstream of the electrostatic precipitator to collect gaseous PAHs. The electrostatic precipitator is often referred to as an EA method (electrostatic precipitator-adsorbent). EA methods are less susceptible to sorption/desorption. The corona has the potential to destroy PAHs and create other artifacts by reactions with corona-generated ozone. ... 

The drug output increases with spacer volume, while the ratio between line and coarse particles is dependent on the balance between spacer volume and pMDI vapor pressure. Electrostatic charges in plastic spacers cause a clinically significant reduction of lung dose thus, nonelectrostatic devices should be used in the future. Drug delivery is reduced by the proportion dead space to tidal volume. Differences in spacer construction may change drug delivery several-fold. Therefore each pMDI-spacer combination should be considered a separate entity and the use of a universal spacer for different pMDIs should be avoided. 

Electrostatic charge can however cause too many dust particles to adhere to the plastic. The air separator (Figure 6.18) is then the more suitable device to use. Lighter-weight dust is carried out of the unit by the opposed directional air stream. 

The basic principles of thermal ionization mass spectrometry (TIMS) operation were described in Chapter 1 a drop of the liquid sample is deposited on a filament, a low electric current heats the filament, and the solution is evaporated to dryness. The filament current (temperature) is then raised and atoms of the sample are emitted and ionized (either by the same filament or by a second electron emitting filament). The ions are accelerated by an electric field, pass through an electrostatic analyzer (ESA) that focuses the ion beam before it enters a magnetic field that deflects the ions into a curved pathway (in some devices, the ions enter the magnetic field before the ESA—referred to as reverse geometry). Heavy and light ions are deflected by the field at different curvatures that depend on their mass-to-charge ratio. A detector at the end of the ion path measures the ion current (or counts the ion pulses). There are many variations of ion sources, ion separation devices, and detectors that are used in TIMS instruments and specifically adapted for ultratrace or particle analysis. 

Electrostatic devices were developed in Australia to process beach and mineral sands. The sand ore is fed to a conducting and grounding rotor and is exposed to ionization. The particles, which have certain electrostatic properties, are attracted by the electric charge and are separated from the other particles. The nonconducting particles drop on the rotor and are brushed away into a separate container (Figure 1-13). 

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