Large Installation

More and more global companies extend their CDS to an installation across then-locations over the world. The aim is to harmonize the processes by centralizing the data, in order to reduce costs and expenses for operating the system. A companywide installation has many advantages, where different models can be considered  

With licenses organized bythe concurrent user model, only active user accounts are counted, which are concurrently working with the CDS. By this model, the same licenses could first be used by a site in, for example, Japan and later on in the United States due to the time shift. 

Using licenses according to the named user model, every single active account in the system is counted, no matter if this user has currently registered in the systems or not. Costs for licenses are saved by keeping unused licenses centrally. For example, each single site does not need to keep three spare-licenses, but centrally five licenses are kept that can be offered to any site, if requested. 

A central system demands much more planning for administrating and performing updates. Especially, global installations only offer a few slots, where no user is working in the system, for example, performing a reboot of the server. For the installation of updates that need to be distributed on all servers and clients at the same time, several hours of even days are required, where the system is not available for the daily operation. 

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In the precoat and body feed mode, filter aids allow appHcation of surface filtration to clarification of Hquids, ie, filtration of very dilute suspensions of less than 0.1% by volume, such as those normally treated by deep bed filters or centrifugal clarifiers. Filter aids are used in this mode with pressure filters. A precoat is first formed by passing a suspension of the filter aid through the filter. This is followed by filtration of the feed Hquid, which may have the filter aid mixed with it as body feed in order to improve the permeabiUty of the resulting cake. The proportion of the filter aid to be added as body feed is of the same order as the amount of contaminant soHds in the feed Hquid this limits the appHcation of such systems to low concentrations. Recovery and regeneration of filter aids from the cakes normally is not practiced except in a few very large installations where it might become economical. 

The main advantage of HGMS is high efficiency of separation even at relatively high dow rates and minimum pressure drops across the filter. The capital cost is very high, and only large installations are attractive economically because capacity increases with the square of the diameter of the canister while the weight of copper conductor increases linearly with diameter. 

The cost of the filter station includes not only the installed cost of the filter itself but also that of all the accessories dedicated to the filtration operation. Examples are feed pumps and storage facihties, precoat tanks, vacuum systems (often a major cost factor for a vacuum filter station), and compressed-air systems. The dehvered cost of the accessories plus the cost of installation of filter and accessories generally is of the same order of magnitude as the dehvered filter cost and commonly is several times as large. Installation costs, of course, must be estimated with reference to local labor costs and site-specific considerations. 

Modules Eveiy module design used in other membrane operations has been tried in peivaporation. One unique requirement is for low hydraulic resistance on the permeate side, since permeate pressure is veiy low (O.I-I Pa). The rule for near-vacuum operation is the bigger the channel, the better the transport. Another unique need is for neat input. The heat of evaporation comes from the liquid, and intermediate heating is usually necessary. Of course economy is always a factor. Plate-and-frame construc tion was the first to be used in large installations, and it continues to be quite important. Some smaller plants use spiral-wound modules, and some membranes can be made as capiUaiy bundles. The capillaiy device with the feed on... 

For adequate protection of the machine it is essential to know the amplitude, F, and the rise time, /, of the severest voltage surge (FOW) that may occur on the system. It is recommended that the actual field tests be conducted for large installations according to the recommended simulation test circuits, noted above, to ascertain these surges. 

Since reactive controls are normally meant for large to very large installations, the practice so far has been to use thyristors only for such applications. With the advent of IGBTs. smaller installations can now be switched through IGBTs. 

For ihe proleeiion of series reactors, w hen used t)ii large installations, and are oil cooled, a Buchholz relay may be provided for oil temperature indication once any other proieciion deemed necessary... 

Only local cathodic protection can be used for large installations and old installations with electrical contact to components with low grounding resistances that cannot be isolated (see Section 12.6). The measures necessary for tank installations are described in Ref. 10. 

By far the largest source of phosphorus is phosphate rock, with some use of phosphatic iron ore, from which phosphorus is obtained as a by-product from the slag. Phosphate rock consists of the insoluble tricalcium phosphate and other materials. For use as a fertilizer, phosphate must be converted to the water soluble form, phosphoric acid (H3PO4) which has three hydrogen atoms, all of which are replaceable by a metal. Tricalcium phosphate, is converted to soluble monocalcium phosphate and to superphosphate, A fertilizer factory, typically, a large installation, characterized by large silos produces year round, but peaks with the demands of the growing season. Phosphorus has many uses other than for fertilizer. 

Higher efficiency of electrostatic indicated for large installations especially in residential locations. Often used in conjunction with dry centrifugal. 

Fans are used in parallel to obtain increased capacity in preference to a single large installation, to increase capacity at constant pressure, and for low-resistance systems requiring large capacities. It is important to study the effect of the addition or removal of fens on the system. This is done using the system resistance and the fan characteristics. 

Calculate the test period. On large installations it may be necessary to section the system. 

The usual protection for large installations is to provide a water-spray system. For small bulk storage, fire hoses or monitors are often adequate. However, for installations over 50 tons of storage (and all major cylinder-filling plants) it is accepted that a fixed water-spray system needs to be provided which is automatically initiated by a system capable of detecting a fire threatening the vessels... 

This heat-up procedure is most often adopted in large installations where start-up of the system is an infrequent (perhaps only an annual) occurrence. Large heating systems and chemical processing plants are typical examples. 

If the water circuit temperature rises above about 26°C, the cooling tower comes into operation to reject the surplus. If the circuit drops below 21°C, heat is taken from a boiler or other heat source to make up the deficiency. During mid-season operation within a large installation, many units may be cooling and many heating, so that energy rejected by the former can be used to the latter. With correct system adjustment, use of the boiler and tower can be minimized. 

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