Minimum acceptable throughput

Minimum acceptable throughput tests are often conducted when the column is anticipated to operate at low throughput for lengthy periods. The tests supply information on whether column internals should be modified or replaced to improve performance (e.g., reduce energy consumption) during low-rate operation. 

Pipeline length, km Throughput, billion cubic meters p.a. (32 inch high pressure line) Wellhead cost of gas, /l,000 m3 Target rate of return (project discount rate for NPV calculations) Minimum acceptable transportation tariff to secure required NPV and loan coverage ratios, /l,000 m3 Minimum price of delivered gas to secure required NPV and loan coverage ratios, S/l, 000 m3... 

FIGURE 2.6 A plot of the results for the second iteration. Here Z may represent the separation factor, a, between any set of peaks or a parameter that combines the separation with overall retention time. For example, afier designating a minimum acceptable a, the parameter Z = a X (I/O where is the retention time of the latest-eluting peak. Z increases as a increases (resolution gets better) and/or total elution time decreases (sample throughput increases). 

The effect of recycle ratio on coke production is analogous to the effect of pressure. As the recycle ratio is decreased, the production of liquid products is increased. Reduction of recycle also lowers the fuel usage in the furnace because of lowered throughput. Recycle is often reduced to the minimum rate which still produces acceptable product qualities. 

Figure 10.1. Schematic representation of the processing window for the extrusion process. The four curves identify limits to the process Une 1 indicates the maximum screw rotation speed, curve 2 represents the torque limitation of the drive system (region to the right and below of curve exceeds the allowable torque on the drive system), curve 3 represents the maximum temperature allowable to avoid the thermal degradation, and Une 4 shows the minimum screw rotational speed to provide the minimum throughput, acceptable by the process economics.

For best results in a minimum throughput test, it has been recommended (2) to carry out a series of tests at diminishing feed rates (and reflux and reboil in proportion). An efficiency versus throughput curve can then be plotted from which the minimum throughput for acceptable separation can be determined. 

The minimum subunit size depends on the minimum capacity of the plough-share blender. The manufacturer specifies 1 25kg/subunit as acceptable range, covered by three different sizes of equipment. The throughput depends on the process and properties of the raw material. But as the system should be able to run unattended in a semicontinuous way the real throughput is less important if economic aspects are not taken care of... 

In contrast to conventional lead-acid battery constructions, Varta bloc batteries ensure considerably higher energy throughput and also accept a low float charge current, and thereby ensure a minimum electrolyte decomposition of the water during the whole lifespan. 

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