Equipment and principles

The second group, loosely called filtration, constrains the particles by a medium and the liquid is allowed to flow freely through the medium. Density difference is not necessary in this group but a truly continuous operation is either not easy or impossible to achieve and the costs might be high. 

Flotation is a gravity separation process based on the attachment of air or gas bubbles to solid (or liquid) particles, which are then carried to the liquid 

Centrifugal Cake filtration Deep bed filtration sedimentation (vacuum, pressure, (sand and coke) centrifugal) 

In electrolytic flotation (electroflotation), hydrogen and oxygen gas bubbles are generated by electrolysis. The bubbles produced can be smaller than 30 microns. Instead of the saturator, an expensive rectifier system is required. The flotation unit is very similar to the dissolved air unit, and in fact the same 

Continuous magnetic separators such as the wet drum separators are widely used for beneficiation of ores and for recycling of magnetite or ferrosihcon from the heavy media pulps used for coal washing , or in the Sirofloc process in water treatment, as discussed in section 1.1.2. Wet drum separators are robust and surprisingly cheap to install and operate. The wet drum separator is the major workhorse but little is published on the efficiency of such devices. Suleski, for example, discusses a specific manufacturer s product.  

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Equipment and principles of soft ionization mass spectrometry... 

Figure 1.5 gives the general classification of equipment and principles of solid-liquid separation. There are two separate main groups of equipment which differ in the way the particles are collected. 

Pressure Equipment Directive. Principles and Requirements Related to Permanent Joining. 

The principles referred to so far are common to all New Approach directives. The individual directives obviously need to be specific on topics such as the scope, the essential requirements, the classification of the products and on the use of modules for conformity assessment. The pressure equipment directive includes some additional sector specific dispositions which relate to recognised third party organisations , the European approval for materials , a committee for pressure equipment and the user inspectorates . 

Reactors are designed to be inherently safe based on physical principles, supplemented by redundant equipment and special procedures. Nuclear power benefits from the appHcation of the concept of defense in depth, ie, by using fuel form, reactor vessel, building containment, and emergency backup procedures to ensure safety. 

The selection of materials to be used in design dictates a basic understanding of the behavior of materials and the principles that govern such behavior. If proper design of suitable materials of construction is incorporated, the eqiiipment should deteriorate at a uniform and anticipated gradual rate, which will allow scheduled maintenance or replacement at regular inteivals. If localized forms of corrosion are characteristic of the combination of materials and environment, the materials engineer should still be able to predict the probable life of equipment, or devise an appropriate inspection schedule to preclude unexpected failures. The concepts of predictive, or at least preventive, maintenance are minimum requirements to proper materials selection. This approach to maintenance is certainly intended to minimize the possibility of unscheduled production shutdowns because of corrosion failures, with their attendant possible financial losses, hazard to personnel and equipment, and resultant environmental pollution. 

General principles for temperature limits in the rating of electric equipment and for the evaluation of electrical installation... 

This chapter describes the basic principles and procedures for the evaluation of overpressure potential in plant equipment, and for the selection, design and specification of appropriate pressure relieving facilities. The design of closed safety valves and flare headers is included in this chapter, but blowdown drums and flares are covered separately. To properly discuss this subject, the reader should become familiar with the following terminology. 

Normally the designer does not try to establish film boiling condidons for the vaporizers or reboilers. However, for systems set by other controlling processing condidons, these film condidons may be imposed. In such cases, they should be recognized and handled accordingly. The principles of design for the equipment are the same as other such equipment, and only the actual value of the coefficient affected needs special attendon. 

A whole range of precautions may be based on the principles summarized earlier. However, general precautions, applicable to the majority of work situations, are listed in Table 5.13, many of which are included in legal requirements. For example, in the UK The Fire Precautions Act 1971 specifies requirements for fire resistance of surfaces and building structure, assessment of risk, means of escape, means for giving warning, firefighting equipment, and fire instruction and drills. 

At the beginning of this chapter, several points were made about general metrics principles that are particularly applicable within the context of equipment and operability. It is worth to revisit them for just a moment to say that good process metrics for these categories are especially dependent on an understanding of the overall process, and optimization of a process should be done from a multivariate perspective. Metrics in these categories should be seen as having considerable dependencies on each other and on the materials and chemicals used in the process. 

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