Design consideration

Item Maximum Operating Pressure (PSiG) Design Pressure (PSiG) 

1 Vacuum (Full or Partial) 50 PSIG Internal + Full Vacuum 

Item Maximum Operating Temperature (°F) Design Temperature (°F) 

PRESSURE VESSELS WEIGHT 200 Tons WEIGHT 200 to 500 Tons WEIGHT 500 Tons 

Items to be Included in a User s Design Specification (UDS) for ASME Vill-2 Vessels 

The rate equation is fundamental to the design of any chemical reactor. PI This equation describes the rate at which a chemical process takes place with respect to the physical dimensions of the reactor and, therefore, the size of the equipment needed to reach the desired level of cleaning for a given solvent throughput. PI 

The rate equation includes necessary factors for describing the cleaning vessel for either initial design or scaleup operations. 

However, each set of factors entering in to the rate expression is also a potential source of scaleup error. For this, and other reasons, a fundamental requirement when scaling a process is that the model and prototype be similar to each other with respect to reactor type and design. For example, a cleaning process model of a continuous-stirred tank reactor (CSTR) cannot be scaled to a prototype with a tubular reactor design. Process conditions such as fluid flow and heat and mass transfer are totally different for the two types of reactors. However, results from rate-of-reaction experiments using a batch reactor can be used to design either a CSTR or a tubular reactor based solely on a function of conversion, -r  

In addition to flow, thermal, and bed arrangements, an important design consideration is the amount of catalyst required (W), and its possible distribution over two or more stages. This is a measure of the size of the reactor. The depth (L) and diameter (D) of each stage must also be determined. In addition to the usual tools provided by kinetics, and material and energy balances, we must take into account matters peculiar to individual particles, collections of particles, and fluid-particle interactions, as well as any matters peculiar to the nature of the reaction, such as reversibility. Process design aspects of catalytic reactors are described by Lywood (1996). 

The microhotplate design and development was guided by the following considerations  

In view of the above considerations, a circular design of the heated area (300 pm diameter) on a square dielectric membrane (500 x 500 pm ) was chosen, which is shown in Fig. 4.1. 

The design parameters of this microhotplate are summarized in Table 4.1. 

The circular heater design also perfectly matches the shape of the sensitive tin-oxide droplet No excess area is heated, and the heat losses to ambient air are reduced. A SEM (Scanning Electron Microscope) micrograph of a microhotplate coated with a Sn02-droplet is shovm in Fig. 4.1. The grainy structure of the nanocrystaUine oxide material is clearly visible. 

The temperature sensor in the membrane center is made of polysilicon with a nominal resistance of 10 kQ. An additional reference resistor is needed for the control circuitry (Sect. 5.1). For the resistance measurement of the sensitive layer, platinum electrodes are deposited on top of the CMOS aluminum metallization in order to establish good electrical contact to the sensitive metal oxide. 

As in the case of all foundation work, adequate soil investigation is a prerequisite for efficient design. 

Sufficient soil data is also important to assess cost of construction and minimize unforeseen risks. 

The objectives of the soil investigation should include the following  

Determine the founding layer and levelfor the caisson. Assess the depth of excavation required and corresponding practical issues. 

It is common to sink one borehole beneath every caisson, especially where the foundation is expected to carry large loads. In residual soil and rock, it is important that a geologist be employed to ensure that the rock/soil gradings (Grades I to VI) are properly identified before specifying the founding depth. 

Perhaps even more daunting than selecting the actual materials for a particular corrosion conscious design is choosing the corrosion prevention and control technologies that may be needed to protect the system or its components. Some materials require a minimum of corrosion control since they possess surface characteristics that make them resistant to corrosion. Stainless steels are a good example of such corrosion performance. However, most metals (and some other materials) need some form of additional protection from the corrosivity of their operating environment. 

Another approach for reducing corrosion is to employ mechanisms that can modify the electrochemical processes that consume materials. Cathodic protection, either through the use of sacrificial anodes or an impressed current system, can convert a material that normally will corrode quite readily into a material that resists corrosion. This approach, which is the topic of Chap. 13, works very well for protecting fixed assets in contact with potentially corrosive environments such as soils, seawater, or any other electrolytically conducting medium. 

Method of using cooling water defined (open recirculated, salt water, double exchange, ponds, air cooling)  

Tank bottoms protected (cathodically or sealed, depending on type)  

Will hydrotesting corrode the steel or leave chlorides on stainless steels  

3 A Five-Layer Double-Sided Silicon Microstrip Vertex Detector 2.3.1 Design Considerations 

In order to design a detector which provides optimum impact parameter resolution, we must first determine what the most important factors are for this measurement. The impact parameter resolution for a single track has two components. The first is a function of the detector geometry and intrinsic resolution, while the second is due to multiple scattering and depends on the material in the beampipe and detector elements  

In this expression, cTj is the resolution on the impact parainet( r, rlefined as the distance of closest approach to the beamline along the axis for an individual track. We will now discuss each of these contributions to cr- in souk detail. 

For a simplified two-layer system with measurements ri z ) and / 2, 2)1 geometrical term is given by  

111 this expression, cti 2( ) is tiie intrinsic resolution in 2 for the first and second nicasiire-ments and is the intrinsic resolution in r for the first and second measurements. 

Nevertheless, it was essential to launch the products, to secure a position in the market place, and deal with problems as they arose. There was in fact great trouble with this particular design, because of its flexibility. Attempts to improve the flex performance by the use of higher SG foams and better materials failed the problem was essentially mechanical, and its solution was found in the two-shot process already described. 

An example of the close cooperation necessary between designer and technical staff is provided by a newer model ( Mover ). The original plan was to use single-shot moulding. However wear tests of prototype products led to a change to the use of two-shot moulding, i.e. separately injected skin or shell, followed by foam. 

Clearly, experience has elucidated some principles of good mould design some of these are  

Barnatt and Parker, Polyurethanes in the Shoe Sole Industry, paper given at Polyurethanes Symposium, University of Surrey, 1974. 

Assuming that heat is the chosen method of processing the effluent generated by the bioindustrial process, what design considerations are there for the effluent plant itself  

The choice of autoclave or dedicated plant. It is easy both to under- or over-estimate the required processing capacity when designing an effluent disposal facility. Over-estimation may lead to excess capital and perhaps running costs under-estimation may lead to process delays while effluent is treated, and increased risk of escape of agent. To err on the side of overestimation is the safe course, if capital costs allow. 

Small unit volumes of effluent (up to 50 litres) can be treated in a steam autoclave, provided that adequate measures are taken to transfer the material in a safe and contained manner to the autoclave chamber. A Class III cabinet line or contained suite in which the work is performed, and to which the autoclave chamber has direct access provides excellent containment security, but is not conducive to the processing of more than a few litres at a time. Transport of liquid in a leak-proof secondary container permits larger volumes to be handled, but consideration must be given to the logistical problems associated with the transport, especially if the autoclave is situated in a relatively remote location, or is inside another suite. If the autoclave has one door only, procedures must be adopted to ensure that contaminated and safe materials are not mixed. Double door autoclaves permit the uni-directional flow of waste out of the facility, and in the UK are recommended or mandatory for the higher categories of containment.  

Autoclaves vary in their capacity to contain contamination and, depending on the categorisation of the agent of interest, the design of the any disposal plant and its installation must answer the following questions  

What liquids or gases are released or evacuated from the chamber during the sterilisation process, and before the minimum conditions for a safe load have been fulfilled If this happens, is there a risk of release of agent  

Among the 18 TQT studies published in 2012, the majority (/i=14) were conducted in both male and female healthy volunteers, whereas three studies were conducted only in males (Carlson et al. 2011 Hofmann et al. 2012 Vourvahis et al. 2012) and only one in females (Graham et al. 2013). 

Dose A high, supratherapeutic dose of the NCE, which results in plasma levels in excess of what would be observed in patients with impaired clearance of the drug, should be used in the TQT study. The E14 states If not precluded by consideratimis of safety or tolerability due to adverse effects, the drug should be tested at substantial multiples of the anticipated maximum therapeutic exposure. The overriding principle is that plasma levels achieved with the supratherapeutic dose should exceed the worst-case scenario in patients, taking into account both intrinsic (e.g., renal impairment) and extrinsic factors (e.g., drug interactions). As an example, for NCEs that are CYP 3A4 or 2D6 substrates, the achieved exposure must exceed that observed with concomitant administration with potent 3A4 inhibitors, and in 2D6 poor metabolizers (Abbas et al. 2012 Boyce et al. 2012 Chaikin et al. 2005 Dalen et al. 2010 Malhotra et al. 2007 Robert et al. 2007 Tyl et al. 2012 Zhu et al. 2010). For a renally cleared drug, plasma levels that are only 

Adsorption plant operation is very sensitive to the temperature of the incoming gas. Generally, the adsorption efficiency decreases as the temperature increases. 

The temperature of the regeneration gas that commingles with the incoming wet gas ahead of the dehydrators is also important. If the tem perature of these two gas streams differs more than 15°F to 20°F, liquid water and hydrocarbons will condense as the hotter gas stream cools. I hc condensed liquids can shorten the solid desiccant life. 

The temperature of the regeneration gas in the regeneration gas scrubber should be low enough to condense and remove the water and hydrocarbons from the regeneration gas without causing hydrate problems. 

Cic it rally, the adsorption capacity of a dry bed unit decreases as the pressure is lowered. If the dehydrators are operated well below the design presMirc. the desiccant will have to work harder to remove the water and to maintain the desired effluent dew point. With the same volume i i incoming gas, the increased gas velocity, occurring at the lower prcssLiic., could also affect the effluent moisture content and damage the desiccant, 

Most adsorbers operate on a fixed drying cycle time and, frequently, the cycle lime is set for the worst conditions. However, the adsorbent capacity is not a fixed value it declines with usage. For the first few months of operation, a new desiccant has a very high capacity for water removal. If a moisture analyzer is used on the effluent gas, a much longer initial drying cycle can be achieved. As the desiccant ages, the cycle time will be automatically shortened. This will save regeneration fuel costs and improve the desiccant life. 

Moreover, from the packaging and maintenance perspective, an efficient inorganic membrane system in an industrial environment should possess the following characteristics  

Although Manasevit coined the term metal organic chemical vapor deposition (MOCVD) about a quarter of a century ago [6], the basic reactions were known to chemists at least a decade earlier. Strictly defined, MOCVD refers only to those CVD processes which result in thin film growth from a set of precursors possessing metal-carbon bonds. Since this requirement is not met rigorously in many real world systems, CVD is employed as a generic term for all chemically-based vapor phase deposition processes. 

The potential for development of new precursor compounds is tremendous, primarily owing to the rather limited database of the chemistry of some of the elements of interest. It is refreshing to observe the new diseoveries reported over the last few years, and, I anticipate, the subject has been examined only cursorily to this point. 

Many new discoveries should await researchers in this field, particularly in the area of structure-reactivity-volatility correlations. 

In the absence of experimental data, the correlation given by FORSTER and ZUBER may be used to estimate pool boiling coefficients, although the following reduced pre.ssure correlation given by MOSTINSKI is much simpler to use and gives reliable results for h (in W/m2 K)  

One of the most important areas of application of heat transfer to boiling liquids is in the use of evaporators to effect an increase in the concentration of a solution. This topic is considered in Volume 2. 

In the design of forced convection reboilers, the normal practice is to calculate the heat transfer coefficient on the assumption that heat is transferred by forced convechon only, and this gives safe values. recommends that the heat flux should not exceed 

RIM is capable of making parts of up to 50 kg into complex shapes using cheap lightweight moulds. The pressure must be sufficient to ensure rapid, efficient mixing of the reactants and fast filling of the mould. The ability to complete the reaction in situ means that special bond structures can be formed which would not be feasible with thermoplastics. 

The major problems which need to be addressed to ensure good quality products are  

This kind of processing is obviously only suitable for reactions which are very rapid compared with the injection time. In addition, it is also necessary that the resulting mechanical properties are acceptable. Up to now, polyurethanes seem to be the most successful and this depends on the molecular weight and molecular weight distribution, both dependent on temperature and efficiency of mixing. 

Efficient mixing depends on the performance of the high pressure jet impinger. This must give a uniformly continuous stream from the mixing chamber. To achieve this requires  

To further comphcate matters, every surgical robotic tool must comply with the safety requirements that may include anticipating sensor/actuator redundancy, implementing a safe operational speed cap, complying with testing protocols such as ISO 9000, etc. 

One significant aspect of a surgical tool that must be contemplated at the early design stage is sterilizability. Autoclave, gas, and soak are the most common methods for sterilizing surgical instruments of these, gas and soak seem better options for surgical robotic tools. 

Batch centrifuges require frequent cleeming, modifications to their setup, and preventive maintenance. Safety and effectiveness in these procedures require sufficient space with convenient access and easy egress. 

Slurry Charaaeristic Solid Bowl Nozzle- Disk Wall-Valve Disk Manual Disk Manual Tubular Manual Plow, Batch 

Test sediment-condition Firm paste, granular Fluid Flowable, pasty Pasty, firm Pasty, firm Firm 

Liquid clarity (Generally excellent Cfenerally excellent (Generally excellent Generally excellent Generally excellent Generally excellent 

The loads acting on a bonded joint will result in various types of stresses. Stresses are normally expressed in N/mm. In the case of pure tensile and pure compressive loads the stress distribution over the bond line is very even, so that every part of the bond line carries the same load, and to calculate the stresses, the acting forces are simply divided by the bond area. In reality pure tensile and pure compressive loads are very rare and we are confronted more with shear, cleavage and peel loads. The joint stress distribution, i.e., the location of the stresses across the bond line, is less uniform and more complicated to calculate. 

The designer should consider especially the effect of cleavage and peel stresses on the joint. 

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Valdmanis J A and Fork R L 1986 Design considerations for a femtosecond pulse laser balancing self phase modulation, group velocity dispersion, saturable absorption, and saturable gain IEEE J. Quantum. Electron. 22 112-18... 

Design Considerations. For a perforated plate, the pressure drop across the distributor should be at least 30% of the bed pressure drop when operating at the lowest expected gas velocity. The number of holes in the distributor should exceed 10 per square meter. The pressure drop, AP, across the distributor is given by... 

J. E. Kemme, Heat Pipe Design Considerations, T-4221 -MS, Los Alamos Scientific Laboratory, University of California, Los Alamos, N.M., 1969. 

J. N. Chapman and N. R. Johanson, "Design Considerations for a Class of 600 MWe MHD Steam Combined Cycle Plants," 28th Intersociety Energy Conversion Engineering Conference, Adanta, Ga., Aug. 1993. 

Among continuous reactors, the dominant system used to produce parasubstituted alkylphenols is a fixed-bed reactor holding a soHd acid catalyst. Figure 3 shows an example of this type of reactor. The phenol and alkene are premixed and heated or cooled to the desired feed temperature. This mix is fed to the reactor where it contacts the porous soHd, acid-impregnated catalyst. A key design consideration for this type of reactor is the removal of the heat of reaction. 

Design Considerations. The effectiveness of in situ bioremediation is influenced by many factors, including microorganisms, soils, oxygen, pH, temperature, type and quantity of contaminants, and nutrients. 

Raw material usages per ton of carbon disulfide are approximately 310 m of methane, or equivalent volume of other hydrocarbon gas, and 0.86—0.92 ton of sulfur (87,88), which includes typical Claus sulfur recovery efficiency. Fuel usage, as natural gas, is about 180 m /ton carbon disulfide excluding the fuel gas assist for the incinerator or flare. The process is a net generator of steam the amount depends on process design considerations. 

P. E. Glascow and A. A. Murica, "Process and Mechanical Design Considerations for ECC Regeneration Air Distributors," presented at Katalistiks... 

DESIGN CONSIDERATIONS IN FOSSIL FUEL COMBUSTION SYSTEMS... 

Poly(phenylene sulfide) (PPS) is another semicrystalline polymer used in the composites industry. PPS-based composites are generally processed at 330°C and subsequently cooled rapidly in order to avoid excessive crystallisation and reduced toughness. The superior fire-retardant characteristics of PPS-based composites result in appHcations where fire resistance is an important design consideration. Laminated composites based on this material have shown poor resistance to transverse impact as a result of the poor adhesion of the fibers to the semicrystalline matrix. A PPS material more recently developed by Phillips Petroleum, AVTEL, has improved fiber—matrix interfacial properties, and promises, therefore, an enhanced resistance to transverse impact (see PoLYAffiRS containing sulfur). 

When acetylene is recovered, absorption—desorption towers are used. In the first tower, acetylene is absorbed in acetone, dimethylformarnide, or methylpyroUidinone (66,67). In the second tower, absorbed ethylene and ethane are rejected. In the third tower, acetylene is desorbed. Since acetylene decomposition can result at certain conditions of temperature, pressure, and composition, for safety reasons, the design of this unit is critical. The handling of pure acetylene streams requires specific design considerations such as the use of flame arrestors. 

Design considerations and costs of the catalyst, hardware, and a fume control system are direcdy proportional to the oven exhaust volume. The size of the catalyst bed often ranges from 1.0 m at 0°C and 101 kPa per 1000 m /min of exhaust, to 2 m for 1000 m /min of exhaust. Catalyst performance at a number of can plant installations has been enhanced by proper maintenance. Annual analytical measurements show reduction of solvent hydrocarbons to be in excess of 90% for 3—6 years, the equivalent of 12,000 to 30,000 operating hours. When propane was the only available fuel, the catalyst cost was recovered by fuel savings (vs thermal incineration prior to the catalyst retrofit) in two to three months. In numerous cases the fuel savings paid for the catalyst in 6 to 12 months. 

Design considerations for air knives are discussed by Senecal (ibid.). Design procedures for extrusion dies when the flow is laminar. 

Sohds in divided form, such as powders, pellets, and lumps, are heated and/or cooled in chemical processing for a variety of objectives such as solidification or fusing (Sec. 11), drying and water removal (Sec. 20), solvent recoveiy (Secs. 13 and 20), sublimation (Sec. 17), chemical reactions (Sec. 20), and oxidation. For process and mechanical-design considerations, see the referenced sections. 

In rotary devices, reradiation from the exposed shelf surface to the solids bed is a major design consideration. A treatise on furnaces, including radiative heat-transfer effects, is given by Ellwood and Danatos [Chem. Eng., 73(8), 174 (1966)]. For discussion of radiation heat-transfer computational methods, heat fliixes obtainable, and emissivity values, see Schornshort and Viskanta (ASME Paper 68-H 7-32), Sherman (ASME Paper 56-A-III), and the fohowing subsection. 

A knowledge of the properties and behavior of materials used in any ciyogenic system is essential for proper design considerations. Often... 

Auxiliaiy equipment and the special design considerations discussed for batch trays and compartments apply also to tunnel equipment. For size-estimating purposes, tray and truck tunnels and furnaces can be treated in the same manner as discussed for batch equipment. 

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