Primary Supply

The primary supply is normally thought to be city water. It is water that is available without a prime mover. City water supplies will generally have redundant pumping or gravity supplies for reliability. The disadvantage of city water systems is that the piping installation may not conform to the rigid standards outlined in NFPA 24 Standard for the Installation of Private Service Mains and their Appurtenances.  

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Most applications that use the reverse-flow cleaning system use ambient air as the primary supply of clean gas. 

The second method makes use of the pressure energy of the primary (fresh) air supply to induce room (secondary) air circulation. This air, at a pressure of 150-500 Pa, is released through nozzles within the coil assembly, and the resulting outlet velocity of 16-30 m/s entrains or induces room air to give a total circulation four or five times as much as the primary supply. This extra air passes over the chilled water coil. Most induction units are wall mounted for perimeter cooling, but they have been adapted for ceiling mounting. 

Fire pumps should be solely dedicated to fire protection. They may be used to feed into a backup system for emergency process cooling but not as the primary supply. If such backup is allowed is should be tightly controlled and easily accessible for prompt shutdown in case of a real emergency. 

Unlike other primary energy sources, the global consumption of uranium exceeds its production. Worldwide consumption in 2005 amounted to 66 500 tU (NEA/ IAEA, 2006b).9 As Fig. 4.3 shows, newly mined and processed uranium (primary supply) exceeded reactor-related uranium requirements until 1991. Since 1991, the gap between primary supply and uranium demand has been filled by secondary supply, i.e., material that has been held in inventory (both civilian and military in origin) or has been reprocessed. Besides reprocessed uranium and plutonium of spent... 

Refineries and olefins plants generate the primary supplies of benzene so cyclohexane plants tend to be clustered around refining centers to save transportation costs. 

The use of cooling tower basins and process water pumps as fire water supply is not recommended. This water is usually treated with chemicals or may be contaminated with hydrocarbons that interfere with the use of foam extinguishing agents. At best, this supply could serve as a secondary system, should the primary supply be interrupted, using emergency connections. 

The primary supply of vitamin in humans is not obtained from the diet but rather is derived from the ultraviolet photoconversion of 7-dehydrocholesterol to vitamin Ds in skin. Thus, vitamin Dj synthesis varies with the seasons. D3 is a prohormone and requires further metabolic conversion to exert biological activity in its target organs (Fig. 66.2). The liver and the kidney are the major sites of metabolic activation of this endogenous sterol hormone. The initial transformation of D3 occurs in the liver and is catalyzed by the enzyme 25-OH-D3-hydroxylase... 

The final and perhaps most effective way of delivering a modifier for SFE is by directly adding the modifier as a liquid to the sample matrix before filling the extraction vessel or while the sample matrix is already in the vessel but prior to the extraction. In this respect, the modifier is isolated from the actual primary supply pump thereby not contaminating the pump (and the entire system) with the modifier. 

Some creative approaches to try to match the regular demand of a tapioca production process with the irregular supply of feedstock have been taken. Meuser et al.27 demonstrated that starch could be recovered from either cassava chips or pellets, although the starch is obtained at some sacrifice of quality. Nauta28 has proposed large silos for the storage of tapioca starch, similar to those used in the potato processing industry. At present, the primary supply of tapioca starch remains fresh roots. 

Primary Supply.—In large works, with alternating current locally generated, primary voltages of 2,000 to 2,400 are common. For distribution to substations, 5,000 to 110,000 volts may be used. The losses in transmission are partly constant (corona, core loss of transformers, parts of the losses of all rotating apparatus, meter losses and losses at constant-current devices, if there are any) and partly variable with the load, usually varying as the square of the current carried. 

Potential resources for hydrogen production are large and are more evenly distributed geographically than current oil resources. In many regions of the world, there are potentially large primary supplies that could supply hydrogen fuel via zero or near-zero emission pathways. These include renewable resources and fossil fuels with nearby sites for carbon sequestration. 

In the healthy state, the primary supply of amino adds for endogenous protein synthesis is provided by dietary pro-... 

Unlike gaseous, liquid, or renewable resources, coal can be stockpiled at the power station and stocks drawn on to meet demand without depending on primary supply. Because of the geographical diversity of coal reserves, some power stations can be located at mine-mouth and still be close to the market, thereby minimizing transmission and distribution losses. 

Compressed air to operate ventilation-system dampers comes from two redundant, industrialsized compressors [40 standard ft /min (SCFM) at 125 Ib/in. (psi)], located in Room 222 of B6581. The two compressors operate as a primary supply and as a backup. Downstream of the normal air compressors is miscellaneous support equipment including an air receiver and filters. The air supply is then split into two separate pathways (1) general building compressed air, and (2) dry Instrument air, which is used in the HCF for ventilation system damper positioning. 

Primary Supply predictable demand efficiently at the lowest possible Respond quickly to unpredictable demand in order to minimize stock outs and obsolete... 

Organizational Process Boundaries Areas of primary supply chain process responsibility... 

S.3D. Delivery of Regenerants. Regenerants are HCl and NaOH or KOH. The concentrations used range from 3% to 15%. Dilution of the primary supplies, which are at concentrations above 30%, is necessary. This can be accomplished in several different ways. Three common approaches are... 

Backup supplies are always useful when a utility is lost Spare equipment or multiple-train equipment may be used in order to keep the utility on line even if one part of the system shuts down. An alternative or supplement is to provide backup from a different utility system. The number of different air systems found in a plant provides an opportunity to do this. Moreover, nitrogen can be used to back up some of the air systems. All these tie-ins require careful review during hazard analyses. Usually, the backup supply is activated when the primary supply loses a certain amount of line pressure. If this is done by means of a single pressure regulator and the pressure is also low on the backup system, the flow may be opposite to that intended. It is essential to keep nitrogen out of an air supply to a confined, inhabited space (e.g., the instrument air supply to a control room), and it is essential to keep air out of nitrogen when it is used as an inert gas. 

The electrical hazards of AC supply and distribution also are those faced in industiy in general. We may consider the hazards from the primary supply through the area transformers as conventional. The DC side and the magnetic fields associated with high current are more characteristic of chlor-alkali production. These are discussed in Section 8.5.1. 

Dive-location reserve breathing gas A supply system of air or mixed-gas (as appropriate) at the dive location which is independent of the primary supply system and sufficient to support divers during the planned decompression. 

In addition to these operational benefits, the plant is of a single floor type, thus making it simple to install and easy to locate related machinery nearby. It is worth noting that only three days are required for installation before the plant is ready for operation. There is also no ancillary pipe work reqnired for the machine apart from the primary supply piping. 

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