|
Passive Aerosol Generator 1. Theory of Operation General Description The aerosol is created from a coating material(s) selected for a specific application. The coating material begins to adhere to the surface being coated and the resulting layer developed is tacky in consistency. This tacky coating encapsulates any loose surface material located in the process area. The types of materials that can be encapsulated can be hazardous or radioactive. The thickness of the applied coating varies based on the type of coating used and the number of coats applied. Nominal thickness is 3 to 5 mils (thousands of an inch). No personnel or equipment is required to enter the area being treated thus greatly reducing the cost, risk, and the liability compared to conventional techniques. In addition, the actual quantity of material used is small per unit surface area, since the material is evenly distributed. The PAG can also be used to introduce chemical agents to neutralize or buffer chemical hazards. This process can be used in areas where it is nearly impossible to have people or equipment enter (vertical /horizontal ventilation ducts, process piping, etc.). The aerosol that enters the process area adheres to the surfaces with the excess exhausted and collected in a recovery system. The recovery system is a spray condensing chamber utilizing a recirculation pump system to supply pump spray. The unused aerosol is recovered prior to exhausting the remaining gases through a HEPA filtration system. By utilizing the spray condensing system, a mass balance calculation can be performed to assist in estimating the amount of aerosol that was consumed in the process area. This allows the PAG operator to estimate the surface thickness of the polymerized capture coating. The HEPA filtration system is a standard design, with specification of removing 99.97% of 0.3 micron Mass Mean Aerosol Diameter (MMAD) particulate material. The process air is then released to a ventilation system duct or to the local air environment. 1 Theory Of Operation This technology mitigates the hazard from airborne contaminants such as radioactive material and other hazardous compounds. The hazards are mitigated by treating an area (referred to as the process area) with an aerosol that encapsulates contaminants in place. The technology does not require entry into the process area and ensures that all surfaces within the process area are treated simultaneously. The technology employs unique coating compounds that are formulated based upon the specific application. 1.1 Passive Aerosol Generator
A detailed description of each of these components is provided in the "Operations and User Manual" for the PK-2000. The frequency generator supplies a selected frequency signal to the continuous wave (CW) power amplifier. The CW power amplifier then boosts this signal, and feeds power to the piezoelectric ultrasonic transducers. The transducers convert the electrical energy from the amplifier to mechanical energy and deliver that energy into a solution. The transducers are submerged in that solution. The mechanical energy that is delivered to the coating solution creates a disturbance at the surface of the solution. Additionally, the mechanical energy shears small droplets of the solution from the surface and knocks the droplets into the air above the surface of the disturbance. A sufficient number of droplets are formed of nominal size such that an aerosol is created. The aerosol is formed in a closed tank. The tank is slightly pressurized forcing the aerosol out through a delivery system. The delivery system directs the aerosol to a process area where the aerosol forms a thin encapsulating film or coating on all surfaces within the process area.
Who we are • What we do • Success Stories • Technical Information • Home
|
