Single pressure vessel

In industrial practice, a multiple-bed reactor (Fig. 3.24) is normally used for the synthesis of ammonia, rather than the single-stage reactor illustrated in Fig. 3.22. Because the reaction takes place at high pressures, the whole series of reactions is contained within a single pressure vessel, the diameter of which is minimised for reasons of mechanical design. 

Four to six spiral-wound membrane modules are normally connected in series inside a single pressure vessel (tube). A typical 8-in.-diameter tube containing six modules has 100-200 m2 of membrane area. An exploded view of a membrane tube containing two modules is shown in Figure 3.44 [115]. The end of each module is fitted with an anti-telescoping device (ATD) which is designed to... 

Figure 3.44 Schematic of a spiral-wound module [115] installed in a multimodule pressure vessel. Typically four to six modules are installed in a single pressure vessel. Reprinted from Reverse Osmosis Technology, B.S. Parekh (ed.), Marcel Dekker, New York (1988), p. 81, by courtesy of Marcel Dekker, Inc.

Focusing on spiral wound membrane modules as the most common type of membrane modules used in industry today, an RO array or "skid" or "train" consists of a number of pressure vessels arranged in specific patterns. Figure 5.1 shows an array of 3 pressure vessels. The pressure vessels are arranged into 2 sets, with 2 pressure vessels in parallel followed by 1 single pressure vessel. The 2 sets of pressure vessels are in series. Each set of pressure vessels in parallel (even if there is only 1 vessel) is called a STAGE. 

CPV = common pressure vessel, SPV = single pressure vessel)... 

SMART (System-integrated Modular Advanced ReacTor) is an advanced integral PWR(Pressurized Water Reactor) tihat produces 330MWt at fiill power. Major primary components are housed within a single pressure vessel. New, advanced and innovative features are incorporated in the design to provide the reactor with significant enhancements in safety, reliability, performance, and operability. Major design and safety characteristics of SMART can be summarized as follows ... 

The CAREM NPP is a light water integrated reactor. The whole high-energy primary system and the absorbers rods drive mechanisms are contained inside a single pressure vessel. 

It is economically attractive to provide as many candles as possible inside a single pressure vessel. This will provide the greatest filtration area and hence product flow rate. However, one factor which considerably affects the ease of cake discharge is the occurrence of bridging between the filter candles. If no space exists for the cake to break... 

A dual-stack cell design that enclosed two stacks within the same pressure vessel was developed to reduce the number of pressure vessels required in some power systems. This conflguration was termed a common pressure vessel. These powered the Iridium constellation of 88 satellites (98 satellites, including orbital spares). While these batteries have functioned reasonably well, there are some difficulties in maintaining all the cells at a similar state of charge. However, these single pressure vessel batteries continue to perform well in orbit. 

The SIR reactor is an integral pressurised water reactor, in which all major components are contained in a single pressure vessel. Figure 7.5.1. shows the general arrangement of the RPV and its internal structures. The principal features are ... 

Ni-Hj cells are manufactured in various design configurations. The individual pressure vessel (IPV) cell contains an electrode stack in a cylindrical pressure vessel contained within a common pressure vessel (CPV) cell. Two stacks in a series in a vessel yield 2.5 V. In a single-pressure vessel (SPV) battery, a number of cells (typically more than 20) are connected in a series and are placed in a single vessel. 

Major economic improvements for SMART can be summarized as system simplification, component modularization, factory fabrication, direct site installation of components and reduced construction time. The integral arrangement of the primary reactor systems requires only a single pressurized vessel and removes large-sized pipes connecting primary components. The adoption of simplified passive systems provides a net reduction in the number of safety systems and drastically reduces the number of valves, pumps, wirings and cables, pipes, etc. 

To simplify the design, the whole high-energy primary system (core, steam generators, primary coolant and steam dome) is contained in a single pressure vessel. This reduces considerably the number of pressure vessels needed and simplifies the layout. 

Other advantages of this design inelude the reliability and eeonomies of the use of a single pressure vessel for a battery. In addition, the internal cells, which are not required to be sealed or to withstand pressure, may be of simple design and fabricated with cheaper materials. Individual cells will not require the relatively expensive ceramic-to-metal seals. 

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