Buss reactor

Several changes to the initial conditions were tested in the laboratory and directly applied to the BUSS reactor... 

The concept of a circulating flow reactor was further developed in the Buss reactor technology (Figure 1.26). Large quantities of reaction gas are introduced via a mixer to create a well dispersed mixture. This mixture is rapidly circulated by a special pump at high gas/liquid ratios throughout the volume of the loop and permits the maximum possible mass transfer rates. A heal exchanger in the external loop allows for independent optimisation of heat transfer. For continuous operation, the product is separated by an in-line cross-flow filter which retains the suspended solid catalyst within the loop. Such a system can operate in batch, semi-continuous and continuous mode. 

For the theory of neutralization of the magnetic effect on the conductor in a non-magnetic shielding, refer to the continuous enclosures for isolated phase bus systems discussed in Section 31.2.2. As a result of non-magnetic shielding there will be no saturation of the iron core and the V-I characteristic of the reactor will remain almost linear. 

Determining the size of reactor Consider a three-phase bus system as shown in Figure 28.27. If and X are the inductive reactances of each phase on account of skin and proximity effects respectively, then the impedances of each of the three phases can be expressed as... 

Consider a bus duct having a rated current of 4000 A and an unbalanced current in the middle phase of 4400 A. Determine the size of the reactor to achieve a balanced voltage system. 

Figure 28.27 Design of a reactor for a power distribution bus system. Illustrating Example 28.10...

The Imbalance for this length and rating of bus system is not substantial, yet it we assume that a balanced supply source is desirable, then we must make up the lost inductance in phase Vby inserting a reactor into this phase, as discussed in Section 28.8.2 of an equal value of X, i.e. 

Markowz G, Schirrmeister S, Albrecht J, Becker F, Schiltte R, Caspary KJ, Klemm E (2005) Microstructured reactors for heterogeneously catalysed gas-phase reactions on an industrial scale. Chem Eng Technol 28 459 -64 Muller A, Cominos V, Hessel V, Horn B, Schiirer J, Ziogas A, Jahnisch K, Hillmann V, GroBer V, Jamc KA, Bazzanella A, Rinke G, Kraut M (2005) Fluidic bus system for chemical process engineering in the laboratory and for small-scale production. Chem Eng J 107 205-214 Pennemann H, Watts P, Haswell S, Hessel V, Lowe H (2004) Org Proc Res Dev 8 422... 

The concept presented here in much detail as an example of cooperative project work in micro structured reactor plant development is based on the bus system and simultaneously handles a number of tasks such as mechanical stability, fluidic flow and signal transmission. A key feature of the so-called backbone interface is its open architecture. It does not rely on standardized reactors or devices, thus allowing the combination of devices from various suppliers. A robust interface was developed which withstands high pressures and temperatures. Thermal cross-talk was minimized through the use of different heat-conducting materials. 

MEMS technology also allows embedding of actuators and sensors in single reactor channels. Despite problems with temperature robustness, a solution must be found to transport the signals from the micro channels to the central process control system. To avoid a confusing cable set-up ( spaghetti conditions ), it is desirable to process the sensor data on-site, for example in an A/D converter, and to feed the digital data in a common bus system [13]. 

Fig. 29. Origin of systematic errors in spite of potentially error-free analysis. On-line sampling setups (top) and time trajectories of limiting substrate concentration during sample preparation in the two paradigmatic setups depending on the actual culture density (bottom). Either a filter in bypass loop is used for the preparation of cell-free supernatant (upper part in top insert) or an aliquot of the entire culture is removed using an automatic sampler valve and a sample bus for further inactivation and transport of the samples taken (lower part). Both methods require some finite time for sample transportation from the reactor outlet (at z = 0) to the location where separation of cells from supernatant or inactivation by adding appropriate inactivators (at z = L) takes place. During transport from z = 0 to z = L, the cells do not stop consuming substrate. A low substrate concentration in the reactor (namely s KS) and a maximal specific substrate consumption rate of 3 g g h 1 were assumed in the simulation example to reflect the situation of either a fed-batch or a continuous culture of an industrially relevant organism such as yeast. The actual culture density (in g 1 1) marks some trajectories in the mesh plot. Note that the time scale is in seconds...

Baier, F.O. Mass Transfer Characterization of a Novel Gas-Liquid Contractor. The Advanced Bus Loop Reactor Ph.D. thesis, Swiss Federation Institute-ETH Zurich, Switzerland, 2002. 

In order that reactor operation may be as free as possible from the effects of transient disturbances or outages on the purchased-power lines, electrica1.power for the control system is obtained from a special supply, labeled "Energy Conversion and Storage". in Fig. 5.1.A. This supply consists of two alternators operated from storage batteries. In normal operation one alternator would supply "instrument bus voltage" and the other alternator would supply "relay bus voltage."... 

The instrument bus furnishes power to those instruments most sensitive to disturbance while the relay bus (also called the "control bus") furnishes power to the less sensitive components, such as relays and motors, which not only are less sensitive to disturbance but are themselves actual sources of disturbance. If one of the alternator supplies breaks down or otherwise becomes unavailable, the relay bus would be switched to purchased power. To permit operation with the "rougher" purchased power, the relay circuits include a 2-sec timer and a number of time delay relays so that reactor shutdown does not ensue unless the r.elay bus voltage is off for 2 sec or longer. 

Figure 2.1 Preliminary flow sheet for a 2000 ton yr benzaldehyde plant using electrolytic oxidation of Ce to Ce in HCIO/ and two-phase chemical oxidation, i,e, aqueous Ce with toluene in hexane, in a second reactor. From Kramer, K., Robertson, P. M. and Ibl, N. (1980) J. Appl. Electrochem., 10, 29. Key 1, electrolysis cells (proposed 31 undivided tubular cells, radius 91.4 cm, height 86.4 cm I = 113 mA cm ) 2, rectifier 3, bus-bars 4, chemical reactor (proposed 5 x 20 m reactors) 5, pump 6, heat exchanger 1, valve 8, extraction column (with hexane) 9, electrolyte stripper 10, solvent extractor using heat pump principle with compressor(s) 11, distillation column to remove remaining hexane 12, condenser 13, distillation to separate toluene and benzaldehyde. Process streams a, aqueous HCIO4 with Ce Ce b, aqueous HCIO4 with Ce c, toluene d, hexane e, benzaldehyde.

Backbone interface based on the bus concept where the flow passes through a central spine has been developed [12]. The modular backbone allows both commercial and demonstration type of microstmctured devices to be coupled in all three dimensions in a flexible and easy manner. Microstmctured heat exchangers, reactors, and mixers made of different manufacturers are surface-mounted on this backbone. The backbone itself consists of elements which can be combined individually and flexibly in all directions, according to the demands of the plant to be built. The backbone provides the flow paths for fluids and electrical conduits for power supply and signal transmission of sensors and actuators as shown in Fig. 5. With this united microreactor system, sulfonation of toluene with gaseous SO3 was successfully conducted to give... 

Another switchboard fault was presented in this plant. The evidence showed that there was an arc flash between CT s connection bars to the switchboard wall. A few minutes before the fault occurred in the 115 kV transmission line in the pniblic network which was feeding the load plant, then it was produced an overvoltage in the 13.8 kV network of the plant. Due to the principal transformer is connected through a reactor to the synchronizing bus the transient was spread to the feeder circuits connected to the bus. Due to the disturber in the 115 kV line service, the interrupter was operated. Immediately after, the load segregation system was operated. 

The network consists of 24 hus locations (numbered in bold in the Figure) connected by 34 hnes and transformers. The transmission lines operate at two different voltage levels, 138 kV and 230 kV The 230 kV system is the top part of Figure 1, with 230/138 kV tie stations at Buses 11, 12 and 24. Buses 1, 2, 7, 13, 15, 16,18, 21, 22 and 23 are the generating units. The system is also provided with voltage corrective devices in correspondence of Bus 14 (synchronous condensers) and Bus 6 (reactor). 

The requirement for reducing the probability of reactor trip in the event of a loss of a single safety-related bus (criterion 2) is met by the System 80+ Standard Design, also as described in detail in CESSAR-DC, Section 8 3.2. As shown in CESSAR-DC, Figure 8.3.2-2, the safety-related (Class IE) DC power supply system consists of four separate isolated channels. The DC bus from each channel can be isolated from its battery bank and alternately supplied from its division s DC bus. For typical Class lE DC and AC instrumentation and control power supply systems, either the Channel A or Channel C DC bus can be supplied from the Division I, also a IE DC bus. Similarly, either the Channel B or Channel D bus can be supplied from the Division II, also a IE DC bus. Cross-ties between buses, however, are isolated through two sets of manually operated fusible disconnects. 

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