Operation Intercept

October 9, 1992 Russian police operation intercepted the smuggler, Leoni Smirnov, in the Podolsk train station... 

September 21 The U.S. Customs Department launches Operation Intercept. For a period of two weeks every vehicle crossing the border between the United States and Mexico is searched. Traffic bogs down for miles, and businesses on both sides of the border are severely impacted. The operation is stopped, but Mexico agrees to more aggressively pursue marijuana traffickers. 

The signal can be intercepted and used to interface with an operators console using indicator lamps and a two way communication at the off-loading station or at a later date with a sort and marking system. 

Mechanisms of Filter Retention. In general, filtrative processes operate via three mechanisms inertial impaction, diffusional interception, and direct interception (2). Whereas these mechanisms operate concomitantly, the relative importance and role of each may vary. 

Doppler Flow Meters. Doppler flow meters sense the shift in apparent frequency of an ultrasonic beam as it is reflected from air bubbles or other acoustically reflective particles that ate moving in a Hquid flow. It is essential for operation that at least some particles ate present, but the concentration can be low and the particles as small as ca 40 p.m. CaUbration tends to be influenced by particle concentration because higher concentrations result in mote reflections taking place neat the wall, in the low velocity portion of the flow profile. One method used to minimize this effect is to have separate transmitting and receiving transducers focused to receive reflections from an intercept zone neat the center of the pipe. 

The end points of the operating line on an XY plot (Fig. 15-13) are X., Y, andXy, Y., and the number of theoretical stages can be stepped off graphically. The equilibrium curve is taken from the Hand type of correlation shown earlier (Fig. 15-9). When the equilibrium line is straight, its intercept is zero, and the operating line is straight, the number of theoretical stages can be calculated with one of the Kremser equations [Eqs. (l5-14) and (15-15)]. When the intercept of the eqnihbrinm line is not zero, the value of YJK, should be used... 

The concept of a mass-transfer unit was developed many years ago to represent more rigorously what happens in a differential contactor rather than a stagewise contactor. For a straight operating line and a straight equilibrium line with an intercept of zero, the equation for calculating the number of mass-transfer units based on the overall raffinate phase N r is identical to the Kremser equation except for the denominator when the extraction factor is not equal to 1.0 [Eq. (15-23)]. 

The basic operations in dust collection by any device are (1) separation of the gas-borne particles from the gas stream by deposition on a collecting surface (2) retention of the deposit on the surface and (3) removal of the deposit from the surface for recovery or disposal. The separation step requires (1) application of a force that produces a differential motion of a particle relative to the gas and (2) a gas retention time sufficient for the particle to migrate to the coUecting surface. The principal mechanisms of aerosol deposition that are apphed in dust collectors are (1) gravitational deposition, (2) flow-line interception, (3) inertial deposition, (4) diffusional deposition, and (5) electrostatic deposition. Thermal deposition is only a minor factor in practical dust-collectiou equipment because the thermophoretic force is small. Table 17-2 lists these six mechanisms and presents the characteristic... 

It is advisable to start a constant-pressure filtration test, like a comparable plant operation, at a low pressure, and smoothly increase the pressure to the desired operating level. In such cases, time and filtrate-quantity data shoulci not be taken until the constant operating pressure is reahzed. The value of r calculated from the extrapolated intercept then reflec ts the resistance of both the filter medium and that part of the cake deposited during the pressure-buildup period. When only the total mass of diy cake is measured for the tot cycle time, as is usually true in vacuum leaf tests, at least three runs of different lengths should be made to permit a rehable plot of 0/V against W. If rectification of the resulting three points is dubious, additional runs should be made. 

The laboratory studies utilized small-scale (1-5-L) reactors. These are satisfactoiy because the reaction rates observed are independent of reac tor size. Several reac tors are operated in parallel on the waste, each at a different BSRT When steady state is reached after several weeks, data on the biomass level (X) in the system and the untreated waste level in the effluent (usually in terms of BOD or COD) are collected. These data can be plotted for equation forms that will yield linear plots on rec tangular coordinates. From the intercepts and the slope or the hnes, it is possible to determine values of the four pseudo constants. Table 25-42 presents some available data from the literature on these pseudo constants. Figure 25-53 illustrates the procedure for their determination from the laboratory studies discussed previously. 

This type of technology is a part of the group of air pollution controls collectively referred to as "wet scrubbers. Orifice scrubbers are also known as self-induced spray scrubbers, gas-induced spray scrubbers, and entrainment scrubbers. The operating principle is based on the removal of air pollutants by inertial and diffusional interception. 

This equation is a straight line whose slope is 1/n and whose intercept is k at C = 1. Therefore, if straight line will normally be obtained. However, there are occasions, as explained later, when this is not true. The straight and the curved isotherm lines provide valuable information for predicting adsorption operations. 

The use of a drain system permits the quick construction of a collection/removal system which also serves as a barrier for leachate from large, shallow sites. At the Sylvester hazardous waste site in Nashua, New Hampshire, a groundwater interception and recirculation system was installed as a method to retard further spread of the leachate plume until a remedial cleanup action could be implemented. The system was operated for 1 year until a containment wall and cap were constructed over the 20-acre site (McAneny, 1985). 

Which separation operations should be used for interception (e.g., adsorption, extraction, stripping) ... 

In order to synthesize an optimal MEN for intercepting the off-gas condensate, we constnict the pinch diagram as shown in Fig. 4.9. Since the three MSA s lie completely to the left of the rich stream, they are all thermodynamically feasible. Hence, we choose the one with the least cost ( /kg NH3 removed) namely the resin. The annual operating cost for removing ammonia using the resin is ... 

Which separation operations should be used for interception ... 

Based on these results, the optimal single interception for the problem is to use activated Carbon adsorption to separate CE fhim the gaseous stream leaving the reactor (t> = 1) and reduce its composition to y " = 4.55 ppmw CE (which corresponds to removing 4.57 x 10 kg CE/s from v = 1). The optimal solution has a minimum operating cost of approximately 576,250/yr. Several important observations can be drawn from the list of generated solutions ... 

In-plant interception may be superior to terminal-waste separation. For instance, separating CE from the terminal wastewater stream incurs an annual operating cost of 827,820/year, which is 44% more expensive than the optimal solution. 

Mols of component, i, at start of distillation Total mols of liquid in bottoms of still at time, Tj Total mols liquid (not including any steam) in bottom of still at start time Tq (batch charge) y intercept of operating line or constant at fixed pressure for Winn s relative volatility Mols of component, i, in bottoms No. components present, phase rule or no. components, or constant... 

As the boilers are designed for unattended operation, it follows that if a fault occurs and an alarm activated this alarm may need to be duplicated at a secondary location where it will be intercepted and acted upon. 

The principal mechanisms of disposition in dust collectors are (1) gravitational deposition, (2) flow-line interception, (3) inertial deposition, (4) diffusional deposition, and (5) electrostatic deposition. During the initial operating period, particle deposition takes place mainly by inertial and flow-line interception, diffusion, and gravity. Once the dust layer has been fully established, sieving is probably the dominant deposition mechanism. 

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