Plant cells layout

Conventional electrochemical and electrorefining plant cell layouts are schematically shown in Figure 7.3. It is convenient to describe the events that occur in these electrochemical cells in a outline manner. Hence,... 

In a chlor-alkali plant, rectifier specifications are not set in isolation but are part of the larger question of circuit design. Rectifiers are matched with groups of cells or electrolyzers, and conversion efficiency often must be compromised in the interest of safety and an efficient cell layout. The following section discusses this further. 

Safe unit placement enhances the overall safety of a pilot plant. A containment cell or a separate building is not, however, a guarantee of safety. Other measures include Increased process monitoring of safety specific variables, limiting inventories of hazardous feedstocks and products, detailed hazard analysis and risk assessments, and good design practices. One essential element is to ensure that the pilot plant has adequate space to support its operation. This requires a careful evaluation of the required space before the unit is constructed. While a detailed layout and a careful... 

FIG. 21.15. (a) General layout of BNFL Magnox reprocessing plant at Sellafield, UK. (b) Cell top of primary separation plant showing stirrer motors for mixer-settlers below. 

The first two methods require rigid process control except in natural or slightly enriched reprocessing plants before plutonium partitioning. Other features of the layout include a calculated pitch on the process cell floors so that a major spill will not cause the solution depth to exceed criticality. A steam jet and sump pump with alarm devices are located in a geometrically safe sump at the low point in the cell area. To avoid loss of fissionable-fuel material, there should be no gravity connections between the process tanks and the waste storage area. 

Another unique feature of the nuclear plant layout is the requirement for special locker and shower facilities. Personnel coming from a hot area (i.e., processing cells or. other contaminated areas) are generally... 

The typical layout of a mercury cell plant for producing Cl2 and NaOH is presented in Fig. 6. The brine purification procedure is... 

Operation of the Kidd electrolytic zinc plant commenced in 1972 with a cellhouse capacity of 105,000 tonnes of zinc cathode. The original cellhouse layout consisted of 42 parallel rows for a total of 588 cells. As leaching capacity increased, the cellhouse was expanded to 630 cells. Zinc cathode was manually stripped from plant start-up until the development of a mobile automated stripping system in 1994. Machine development continued until a second unit was placed in production in 1996, from which point, 60 % of the cellhouse was being stripped with the automated system. The final phase of the project was implemented in 1999 with the commissioning of two more automated strippers. This paper describes the implementation of the automated stripping system and its impact on cellhouse productivity. 

The conceptual layout of the power island was prepared to facilitate the Factory Cost estimation. As shown in Figure 2, the power island consists of 8 sections each containing 42 fuel cell modules. The module Sections are grouped with 4 Sections on each side of the centralized Power Island equipment. The footprint of the IGFC plant was found to be comparable to an IGCC plant. Recent Factory Cost Estimates have shown an SOFC power island cost of 635/kW in 2007 US dollars, meeting the DOE cost target of < 700/kW. 

As indicated by the terminology of fuel cells, e.g., PEFC, AFC, SOFC, others (see below), the electrolyte is the decisive cell component, which determines operation temperature, the choice the electrodes (electrocatalytic materials), and finally the specifics of the electrochemistry of the reactants. This, on the other hand, has consequences for the layout of the fuel cell design (balance of plant) and possible applications of the respective fuel cell technology, according to the required duty cycle of the application. 

The heart of any fuel cell power plant (electrochemical generator or direct energy converter) is one or a number of stacks built up from individual fuel cells. Such plants include a number of auxiliary devices needed to secure stable, uninterrupted working of the stacks. The number or type of these devices depends on the fuel cell type in the stacks and the intended use of the plant. Below we list the basic components and devices. An overall layout of a fuel cell power plant is presented in Figure 1.4. 

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