Secondary water

The Bucher-Guyer horizontal rotary press is a highly automated batch process machine that requires no press aid. The press consists of a horizontal hydrauhc ram inside a rotating cylinder containing many flexible rods covered with a knitted synthetic fabric. The rods have serrated surfaces to allow juice which passes through the fabric to flow to the discharge ends. Hydrauhc pressure is apphed for a preset time, the ram is retracted, and the cylinder is rotated to break up the press cake. This cycle is repeated several times before the press cake is removed from the cylinder and the press is cleaned (16). Juice yield for this horizontal rotary press is 84% with secondary water addition it is increased to 92% (15). 

A belt press commonly uses two belts of woven material. Fmit mash is deposited on, and spread out evenly between, the two belts which converge and press the mash between them. The belts wrap around a series of successively smaller cylinders or pass between rollers (less efficient) for the pressing action. Juice yield for the wraparound belt press is 72%, and increases to 92% with secondary water addition (15). 

The flame-space walls are stainless steel and are water cooled. No mechanical coke scraper is required. A water quench cools the cracked gas stream rapidly at the poiat of maximum acetyleae and this is followed by a secondary water quench. The primary quench poiat can be adjusted for variation ia throughput, to accommodate the depeadeace of acetyleae yield oa resideace time ia the flame space. 

PWR Secondary Water Chemistry Guidelines—Revision 3," Report TR-102133, Electric Power Research Institute, Palo Alto, Calif., 1993. 

PWRs operate differendy from BWRs. In PWRs, no boiling takes place in the primary heat-transfer loop. Instead, only heating of highly pressurized water occurs. In a separate heat-exchanger vessel, heat is transferred from the pressurized water circuit to a secondary water circuit that operates at a lower pressure and therefore enables boiling. Because of thermal transfer limitations, ultimate steam conditions in PWR power plants ate similar to those in BWR plants. For this reason, materials used in nuclear plant steam turbines and piping must be more resistant to erosion and thermal stresses than those used in conventional units. 

Until the 1980s, synthetic organic solvents commonly were used in the United States to extract the caffeine, either by direct contact as above or by an indirect secondary water-based system (36). In each case, steaming or stripping was used to remove residual solvent from the beans and the beans were dried to their original moisture content (10—12%) prior to roasting. 

Other paved areas Secondary water treatment—deionization, demineralization, pH and... 

Phosphate is sometimes present in MU water sources (say, 1-2 ppm or more) usually as a result of field and factory run-off or from the deliberate addition as a city water threshold agent to prevent corrosion and deposition in the mains. The steady growth in the reuse of secondary water sources such as municipal and industrial waste waters means that phosphate is increasingly likely to be present in MU. If the phosphate remains undetected, it likely will scale and foul FW lines by forming amorphous calcium orthophosphate [tricalcium phosphate Caj(P04)2] sludge before it reaches the boiler section. 

In this section we link our discussion in two previous sections dealing with structure of water and with ion-water interaction. In the discussion on ion-water interaction it was shown that ions in water arrange their immediate neighboring water dipoles into a local structure of the primary water of hydration. Between this local structure and the bulk water is the nonstructured secondary water of hydration. Thus, the presence of ions in water will change the number of water molecules in both the structured and unstructured regions. Any decrease in the number of water molecules in a cluster will result in a corresponding decrease in the value of g and thus a decrease in the dielectric constant of water [Eq. (2.4)]. 

The process at Three Mile Island involved nuclear fission and subsequent reactor cooling using circulating water. The primary water was kept under pressure to prevent boiling. Heat was transferred to a secondary water system that supplied power to a steam generator. Upon completion of this step, steam condensate was recovered and recycled. All radioactive materials, including primary water, were enclosed in a lined concrete containment building to prevent their escape to the atmosphere. 

The basic design of most nuclear reactors is similar, but several types of reactors are used throughout the world. In the United States most reactors use plain water as the coolant. Reactors using ordinary water are called light water reactors. Light water reactors can be pressurized to approximately 150 atmospheres to keep the primary coolant in the liquid phase at temperatures of approximately 300°C. The heat from the pressurized water is used to heat secondary water to generate steam. In a boiling water reactor, water in the core is allowed to boil. The steam produced powers the turbines directly. Heavy water reactors use water in... 

A rather different reaction of acetylenes is the addition of water, usually catalysed by Hg(II), to give ketones. Terminal acetylenes 41 reliably give methyl ketones 44 as the intermediate vinyl cation 42 is secondary. Water adds to the cation 42 to give the enol 43 which equilibrates to the ketone 44 with the loss of Hg(OAc)2. 

Assemble a simple freezing point (melting point) apparatus. A beaker will serve as a water bath. A hot plate or Bunsen burner will provide the source of heat. A test tube will serve as a secondary water bath in which a thermometer is suspended (Fig. 19.2). 

At 850°C and a molar steam to carbon ratio of 9, the hydrogen yield was 90% of that possible for stoichiometric conversion during eight hours of the catalyst on-stream time. This yield could be 5-7% greater if a secondary water-gas shift reactor followed the reformer. 

Ash pit water reached no well, considering potassium and magnesium—the relatively high values observed exceeded the values in the ash pit water and must be due to some other reason (e.g., secondary water-rock interactions). 

Models may be followed by a discussion of the scientific conclusions reached in the study for example, which elements and compounds tend to behave as conservative parameters which ions participate in secondary water-rock interactions or reliability of isotopically based calculations, such as recharge altitude (section 9.8) or r)l3C values as a tool to correct observed 14C values for water-rock interaction. 

Carbon dioxide produced from ethanol fermentation plants or landfill gas may be recovered with similar processes. Unique to the fermentation plant is the ability to recover the carbon dioxide directly from the ethanol distillation tower, followed by a secondary water wash. Final purification and liquefaction stages then follow the normal process flow. Landfill gas recovery is unique in requiring essentially the removal of the methane and trace impurities.7,17 Several processes exist to... 

Full details of this accident can be found in several major reports. This brief review is focused on the utility hose and the one-minute modification aspects of the accident. Reportedly the trouble started when one of the parallel paths used to treat the secondary water system started plugging. When this resin polisher system, which is designed to remove trace impurities, started to plug, an operator decided to clear the blockage with instrument air. [9]... 

WATER — Secondary Water — So called because Mercury is a species of Aquafortis, but of a mild quality, dissolving, without corroding, metallic natures. 

Insurance companies usually require that a highly reliable secondary water source be provided in-house. This could be in the form of an elevated water tank or a ground level tank or reservoir with a diesel operated pump. The capacity of the reservoir should be at least two hours of the system design flow capacity. The cost... 

The lower CO2 selectivity observed on small pellets (Table V) apparently reflects the transport-limited removal of water, a product of the FT synthesis. CO2 selectivity also increases with increasing site density, CO conversion, and water concentration in the catalyst bed this suggests that CO2 forms in secondary water-gas shift reactions that become significant as intrapellet water fugacities rise because of transport restrictions. Transport rates of CO and H2O in hydrocarbon liquids are qualitatively similar and the reaction stoichiometry requires that one water molecule must be removed... 

In addition to the MCLs listed in Table 8.8, there are secondary standards for water quality in the United States. The National Secondary Water Regulations (NSDWRs) are nonenforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin and tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water. I65 Many in the scientific community argue that the chemicals listed do not merely have cosmetic and aesthetic effects, particularly when they are combined with other toxicants. EPA, however, recommends, but does not require, that water systems comply with these secondary standards. States, however, are permitted to adopt these as enforceable standards. The NSDWRs are listed in Table 8.9. 

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