Stacks discharge rate

When one takes a sample at the rate of 0.3 liter min from a stack discharging 2000 m min to the atmosphere, the chances for error become quite large. If the sample is truly representative, it is said to be both accurate and unbiased. If it is not representative, it may be biased because of some consistent phenomenon (some of the hydrocarbons condense in the tubing ahead of the trap) or in error because of some uncontrolled variation (only 1.23 gm of sample was collected, and the analytical technique is accurate to 0.5 gm) (1). 

Average concentrations of a contaminant downwind from a stack are directly proportional to tlie discharge rate. An increase in discharge rate by a given factor increases ground level concentrations at all points by the same factor. 

The blast furnace operates continuously although the individual particles see a batch mode of reaction. The actual reaction conditions must be based on the batch reactor sequence for the particles since complete conversion is desired. This requires control of the mass throughput in the furnace, but primarily it requires accurate temperature control. Control of the solids is maintained at the bottom discharge port. Gas flow rate is controlled by blowers or by a stack discharge fan. 

This evaluation of the potential impact od solid waste incineration on the neighbouring environment involves the measurement of pollutant stack discharge, ambient air concentrations and atmospheric deposition rates. 

The primary collection system, where the bulk of the cell fluoride loss is captured, may simply discharge to a tall stack [24]. This aids in dispersal, which may be sufficient for a small smelter. But it neither decreases mass discharge rates nor allows recovery of fluoride for reuse. In some cases, a stack has been found to cost more to operate than abatement methods, which employ fluoride capture. 

In engineering terminology, the stack draft often is expressed in pounds per second, since this quantity is invariable for different atmospheric pressures and effluent densities. The effluent velocity (V2) varies considerably with such values, however, for any fixed discharge rate and stack diameter. 

Two Li-ion battery banks, 10 Ah and 40 Ah, respectively, with the OCV around 55 V were incorporated into the fuel cell system as the internal power. The 40 Ah battery bank was directly connected to the DC buss of the load (i.e., it is connected in parallel between the fuel cell system s DC-EXZ converter and the load). During the startup of the fuel cell system, this battery bank supplied DC power to the load directly without DC-DC conversion because it was connected to the DC buss directly. This battery bank itself can supply 2500 W power output for more than 40 minutes at a discharge rate of 1.25 C in case the fuel cell stack fails to start. The system set a 5-second delay for starting the stack, because if the grid power was back within 5 seconds, the stack would not start in order to reduce its start-stop numbers, and thus lengthen its lifetime (the performance decay caused by one start-stop cycle... 

Figures 5.8 and 5.9 show the discharging processes of the 53 V/40 Ah and 53 V/10 Ah battery bank at 2350 and 2300 W constant power output with discharge rates at 1.25 and 5 C, respectively. The voltage of the 40 Ah battery bank was around 47 V, above the load s lower voltage limit of 43 V for telecommunications stations. However, the voltage of the 10 Ah battery bank dropped to 41.9 V in one minute, so this battery bank could not provide power by itself to the load with the lower input voltage limit of 43 V. Since the 10 Ah battery bank worked together with the stack to supply power to the load through the system s main DC-DC converter, tests showed that it was enough.

The programmes of radiation monitoring substantially depend on the characteristics of the release source, release medium and release rate, radionuclide composition and physical and chemical form of the released radionuclides, and on environmental parameters in the area contaminated with radionuclides. They also depend on the possibilities of control of the release in cases of practices and interventions. Different techniques and programmes are applied for the monitoring of a release source (stack, discharge pipe, etc.) or radioactive contamination of the environment. 

Cell or stack aging is indicated by a loss in overall performance due to diminishing capacitance, slower charging and discharging rates, and increased series resistance. In addition, these signs can also be associated with macroscopic phenomena, for example, localized detachment of electrode materials from the metallic collector through electrode swelling, gas evolution, and loss of elements involved in faradic reactions. 

FIGURE 39.3 Charge-discharge profile for 50-cell stack. 80% electrolyte utilization 30°C 90-mAh/cm zinc loading 20-mA/cm or C/4.5 charge rate 20-mA/cm or C/4 discharge rate. Courtesy of Scmdia National Laboratories.)... 

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