Environmental control equipment

6 ENVIRONMENTAL CONTROL EQUIPMENT Air Pollution Equipment Electrostatic Precipitators 

Electrostatic precipitators are satisfactory devices for removing small particles from moving gas streams at high collection efficiencies. They have been used almost universally in power plants for removing fly ash from the gases prior to discharge. Electrostatic precipitators have the capability of fine particulate control. Resistivity plays an important role in determining whether a particle can be readily collected in this device. 

There are three classes of electrostatic precipitators dry electrostatic precipitators (ESP), wet electrostatic precipitators (WEP), and ionizing wet scrubbers (IWS). 

The dry unit is by far the most popular as it has been used successfully to collect both solid and liquid particulate matter from many operations including smelters, steel furnaces, petroleum refineries, and utility boilers. 

Wet scrubbers have found widespread use in cleaning contaminated gas streams because of their ability to effeetively remove both particulate and gaseous pollutants. Specifically, wet scrubbing describes the technique of bringing a contaminated gas stream into intimate contact with a liquid. The types most widely used for particulate control are spray towers, packed-bed units, ionizing wet scrubbers, and venturi scrubbers. 

To control water pollution, a waste stream can be subjected to at least one, or perhaps a combination, of chemical, biological, and physical treatments. Some of these processes are discussed below. 

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The Isasmelt process uses a simple stationary, cylindrical, refractory-lined reaction vessel. The typical blended feedstock to the vessel is of a moist lumpy consistency and this feature greatly simplifies environmental control equipment requirements. 

In areas where electrical equipment is exposed to contaminants, the selection of equipment whose contacts are oil-immersed or hermetically sealed can increase reliability and equipment life. Similarly, providing environmentally-controlled equipment rooms can greatly increase equipment life at locations where contaminants are prevalent. In offshore and other areas exposed to salt, type 316 stainless steel is often preferred over types 303 and 304, which will pit with time. Likewise, in similar locations, equipment fabricated from galvanized steel will corrode much more rapidly than equipment hot-dip galvanized after fabrication. 

Vapor Collection System A piping system to which vessels are connected, that collects vapors from these vessels and directs them to environmental control equipment snch as flares, incinerators, scmbbers, and activated carbon adsorbers. 

Sterile Products Personnel, Buildings, Air, Environmental Controls, Equipment, WFI, Containers and Closures, Sterilization, Laboratory Controls, Production Records... 

Safety assessment scientists and technicians and even QA personnel sometimes overlook the importance of environmental control equipment to valid study results. Animals stressed by extremes of temperature or humidity may 5ueld spurious data reproductive toxicology studies may be compromised by malfunctioning timers for the control of light/ dark cycles inadequate air filtration may expose experimental animals to environmental contaminants that confound experimental results. 

Heating, ventilation, and air conditioning equipment should be regularly inspected and maintained. Filters on environmental control equipment should be inspected on a regular basis and changed as needed. 

Any information system consists of hardware, software, communications equipment, environmental control equipment, documentation and staff. It manages, i.e., processes, transmits and stores information. All of the above are called the system assets , and must be protected. 

Identify equipment The first step in implementing a condition-monitoring program is to determine what equipment will he monitored. It will he critical equipment and generally is about 10% of the total equipment. All manufacturing and environmental control equipment should he evaluated. 

A safety and environmental manager is employed in an operation that uses a small amount of chemicals in the production of a product that increases the efficiency of environmental control equipment that operates erratically. Occasionally, a spill of a few gallons of a chemical occurs that might get into an adjacent river. Working with engineering personnel, it is determined that mechanical and circuitry design problems should be corrected to avoid the spills. 

It can be seen that a dashed line has been drawn around the block containing the environmental control operations. This identifies the unique role of environmental control operations in a chemical plant conplex. A single environmental control unit may treat the waste from several processes. For exanple, the waste water treatment facility for an oil refinery might treat the waste water from as many as 20 separate processes. In addition, the refinery may contain a single stack and incinerator to deal with gaseous wastes from these processes. Often, this common environmental control equipment is not shown in the PFD for an individual process, but is shown on a separate PFD as part of the off site section of the plant. Just because the environmental units do not appear on the PFD does not indicate that they do not exist or that they are uninportant. 

CFD can provide state-of-the-art models for prediction of combustion and pollutant formation, induding built-in NO prediction. Optimization of environmental control equipment, from incinerators to scrubbers, filters, and collectors, can help ensure compliance and reduce capital costs. 

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