Simple retrofitting

For the NaCI electrolysis, finite-gap operation proved initially to be the most promising way to realise good and reproducible cell voltages. Predominantly the reasons were a proper control of the membrane water content, the relatively simple retrofit of existing membrane electrolysers and the ongoing utilisation of the peripheral caustic equipment with the ODC technique. 

Figure 7.8 Comparison of Pareto fronts for simple retrofitting via 15% area additional various generations with population size of 100 diamonds, circles, triangles and crosses are the solutions at 100, 250, 500 and 1000 generations, respectively. The solution selected for discussion is in the oval. Dots are the front for simple retrofitting with up to 30% area addition.

Figure 7.9 HEN after simple retrofitting according to the selected optimal solution in figure 7.8.

Figure 7.14 Comparison of Pareto fronts for simple, moderating and complex retrofitting of HEN in the case study diamonds and pluses are the solutions for simple retrofitting with 15% and 30% area addition, respectively and circles and triangles are the solutions for moderate and complex retrofitting, respectively.

Retrofitting directly to a SUVA MFC Refrigerant can of course be done, but takes longer and costs more than the simple change to a SUVA S Blend. 

This table is intended as a guide, to cover the situations most likely to be encountered. The equipment owner may request the use of the permanent or New System refrigerant in a retrofit, usually to ensure the lowest ODP. Retrofitting directly to a SUVA HFC Refrigerant can of course be done, but takes longer and costs more than the simple change to a SUVA Blend. 

The approach leads to simple and practical retrofit designs and has the major advantage that it allows the designer to assess modifications one at a time and to keep control over the complexity of the retrofit. Its disadvantage is that different combinations of modifications can be taken and there is no guarantee that this will lead to an optimum network retrofit. However, it is almost impossible to say that any retrofit is optimal or nonoptimal. The features of each retrofit are unique and it is difficult to formulate all the constraints for a retrofit in order to guarantee the very best retrofit. 

Apart from not requiring filtering aids, such as a-cellulose, membrane filters are very simple to automate, since they can be immediately brought on-line after back-pulsing. Registers that are suitable for retrofitting have been developed by Permas-cand and Akzo Nobel and are employed by many other plants, such as those at Bayer Uerdingen. Their operation at these plants has been successful. 

Methanol would allow a transitional phase where some fuel cell vehicles use methanol, which is relatively simple to reform and would not present too big a change from our current system. However, methanol is toxic and very corrosive. Gas stations would need to be retrofitted to operate with it (new fuel tanks and fuel lines.) But, many gas station tanks are already methanol- compliant. 

One industrial facility that has done exhaust system retrofit is the Eldec Corporation, an aerospace electronic manufacturer. With the help of the local utility, Eldec implemented a control project to reduce exhaust air by up to 30% for the first shift and 60% for the rest of the time and achieved great savings with one year simple payback. The project closed the exhaust inlets with dampers and controlled the exhaust fan speeds with variable frequency drives (VFD). The exhaust fans are now monitored and controlled by the building direct digital controls (DDC) system to ensure proper operation and save energy. 

The most frequently used lamp for UV curing processes is medium-pressure mercury lamp. Its emission spectrum can be used to excite the commonly used photoinitiators. Moreover, this type of lamp has a relatively simple design, is inexpensive, can be easily retrofitted to a production line, and is available in lengths up to 8 ft (2.5 m). Power levels in common use are in the range 40 to 240 W/cm, and even higher levels are available for special applications. ... 

In small facilities an individual pipeline may be run from outside the facility to the point of use. In large facilities a utility chase (Figure 19) that enables major utility lines to be brought to the vicinity of process tools may be provided. Final hook-up between the chase and point of use then becomes a relatively simple, minimally intrusive procedure. The utility chase concept is also beneficial in facilities that undergo frequent retrofit or upgrade. 

Recent experience has shown that these machines tend to process whole soybean more efficiently if the material is preconditioned with steam prior to extrusion. This finding, together with other recent work, has shown that simple extruders can be made more versatile and efficient in the context of producing compounded feed products (such as aqua feeds and pet foods) if raw materials are preconditioned with steam before extmsion. This has led to the retrofitting of many of these dry extenders with steam conditioners and has hence blurred the distinction between dry and wet/steam extenders (8). It has thus become a little confusing to continue to call these simple machines dry extmders. A typical dry extmder with a preconditioner is shown in Figure 2. 

The external modifications to retrofit the distillation system are considered as starting steps for the retrofit procedure. Simple modifications requiring little or no capital investment are implemented to improve the match between the heat exchanger networks (HEN) associated with the column and the available utilities. The external modifications do not change the column hardware and its internals [4]. 

The Gas-Solid-Solid Trickle Flow Reactor appears to offer considerable potential for reduced energy costs in conventional methanol plants. If the claims made by the inventors are realised, it would be a simple matter to retrofit plants by replacing existing converters with reactors using this novel contacting method. 

Retrofit. Use of adipic acid in an existing lime or limestone system does not require modification of process flow configuration or absorber design therefore, it is particularly suited for retrofit applications. The fact that it may be added at any point in the slurry circuit provides a greater flexibility in the location and installation of a simple solids storage and feed system, a minimal capital investment. 

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