Treeing vented

Trees originating at a shield—insulation interface are mosdy due to the existence of protmsion from the shields. They are referred to as vented trees if moisture is present, they are called vented water trees. Particulate contaminants present in the insulation, and waterborne ionizable materials that find their way into the insulation, are also causes of tree formation. 

Noise can cause a serious nuisance in the neighbourhood of a process plant. Care needs to be taken when selecting and specifying equipment such as compressors, air-cooler fans, induced and forced draught fans for furnaces, and other noisy plant. Excessive noise can also be generated when venting through steam and other relief valves, and from flare stacks. Such equipment should be fitted with silencers. Vendors specifications should be checked to ensure that equipment complies with statutory noise levels both for the protection of employees (see Chapter 9), as well as for noise pollution considerations. Noisy equipment should, as far as practicable, be sited well away from the site boundary. Earth banks and screens of trees can be used to reduce the noise level perceived outside the site. 

An overview [230] and a decision tree [231] have been presented. Approaches to evaluate the venting possibilities are indicated in Figure 3.26. The following steps must be taken for the design of the relief system ... 

Notice the event labeled Drain/vent valve plugged appears on two branches of the tree. This illustrates the concept of common cause failure. 

The genus Broussonetia L Her. ex Vent, of the Moraceae (mulberry family) is represented by lactiferous trees or shrubs. Broussonetia comprises about 30 species and is distributed throughout various regions of the world including Africa, East Asia, and North America [1,2]. Thus far, only three species of the genus Broussonetia have been studied for their secondary metabolites, namely, B. kazinoki, B. papyrifera, and B. zeylanica. 

The new conditional events can be expanded further. For example, Vapors Present depends on the backflow into the tank and the fact that a direct vent pipe exists. The expanded tree is shown in Figure 11.16. 

Burgoyne discusses containment of a runaway reaction mass and suggests partial containment as a possibility. Here the mass is discharged from the reactor to a closed vessel for disposal later. Particulate solids are allowed to settle, while any gas is flared off or scrubbed. Several reactors can share a common disposal vessel provided that their contents are not incompatible. The same author presents a decision tree (Figure 6.5) for selecting a method of containment or venting. 

Broussonetia papyrifera (L.) Vent. (Japanese name Kajinoki ) is a deciduous tree wldch is distributed throughout Southeast Asia, China, and Japan. B.kazinoki Sieb. (Japanese name Himekouzo ) is also... 

Somewhat earlier Takasugi and his co-workers had reported the isolation and structure determination of a series of antifungal compounds from diseased or wounded paper mulberry trees Broussonetia papyrifera Vent.) (168-172) (Fig. 70). 

Matsumoto, j., T. Fujimoto, C. Takino, M. Saitoh, Y. Hano, T. Fukai, and T. Nomura Constituents of the Cultivated Mulberry Tree XXVI. Components of Bronssonetia papyrifera (l.) Vent. 1. Structures of Two New Isoprenylated Flavonols and Two Chalcone Derivatives. Chem. Pharm. Bull. (Japan) 33, 3250 (1985). 

FIGURE 16.1. Partial fault tree fw vent scrubber. 

FIGURE 7-2. Partial Fault Tree—Chlorine Vent Scrubber. 

---