Construction Options

Figure 1 indicates a typical nitroglycerin facility "inside out" wood frame construction at a concrete floor slab. Note that the exterior cant strip, the lead conductive floor cant and the wood cap are all sloped to discourage product build-up and facilitate cleaning. This assembly also indicates spray-on foam insulation as an optional construction item. At Radford AAP this is a safety approved insulation system. The insulation at Radford AAP received a chlorinated rubber paint coating for weathering. 

In this paper, the characteristics and economics of these three solar options constructed in five different locations in the world are evaluated and compared. 

With the deposits Talvivaara was assigned the right to use all exploration data and research documentation relating to various process options studied. Bioheapleaching seemed to be the most economical option. Construction of a 17,000 tonnes on-site pilot heap was started in May... 

Each of the main facility types, e.g. steel jacket, gravity structure, tension leg and floating platform, have different options for decommissioning. The main factors which need to be considered and which will impact on costs are type of construction, size, distance from shore, weather conditions and the complexity of the removal, including all safety aspects. The following options are available ... 

Straight-lobe compressor casings, also called housings or cylinders by different manufacturers, are furnished in cast iron by all vendors. There is an optional aluminum construction available for special applications. Inlet and outlet are suitable for a 125 pound standard ANSI flanged connection. 

Corrective Measures Implementation (CMI) -those activities associated with the design and construction of the technology options selected and with performance monitoring. 

Another option is to use open filters, which are generally constructed in concrete. They are normally rectangular in configuration. The filter mass is posed on a filter bottom, provided with its own drainage system, including bores that are needed for the flow of filtered water as well as for countercurrent washing with water or air. 

Any one of the above may require a specific building to be designed and constructed due to the unsuitability of available facilities falling into the option (1) and (2) categories. 

Mechanical strength becomes an important criterion, because wound cells (spiral-type construction), in which a layer of separator material is spirally wound between each two electrodes, are manufactured automatically at very high speed. Melt-blown polypropylene fleeces, with their excellent tensile properties, offer an interesting option. Frequently two layers of the same or different materials are used, to gain increased protection against shorts for button cells the use of three layers, even, is not unusual. Nevertheless the total thickness of the separation does not exceed 0.2 - 0.3 mm. For higher-temperature applications (up to about 60 °C) polypropylene fleeces are preferred since they offer a better chemical stability, though at lower electrolyte absorption [ 114"]. 

Pretreatment Requirements for RO In addition to CIP and other fouling control systems constructed within the main body of the RO frame, it is vital that all due consideration be given to providing the correct kinds of RO RW pretreatment, in order to further reduce risks of membrane fouling. Options for pretreatment include ... 

Two options are being developed at the moment. The first is to produce 1,2-propanediol (propylene glycol) from glycerol. 1,2-Propanediol has a number of industrial uses, including as a less toxic alternative to ethylene glycol in anti-freeze. Conventionally, 1,2-propanediol is made from a petrochemical feedstock, propylene oxide. The new process uses a combination of a copper-chromite catalyst and reactive distillation. The catalyst operates at a lower temperature and pressure than alternative systems 220°C compared to 260°C and 10 bar compared to 150 bar. The process also produces fewer by-products, and should be cheaper than petrochemical routes at current prices for natural glycerol. The first commercial plant is under construction and the process is being actively licensed to other companies. 

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