Ingress

Low pressure. Low pressures are not in general as hazardous as the other extreme operating conditions. However, one particular hazard that does exist in low-pressure plants handling flammable materials is the possible ingress of air with the consequent formation of a flammable mixture. 

Figs. II, 13, 7 and II, 13, 8 depict various set-ups which involve tlio refluxing of a liquid the Liebig condenser may, of course, be replaced by a double-surface condenser. In Fig. II, 13, 7 a calcium chloride guard protects the contents of the flask from ingress of moisture. The... 

Samples to be examined by inductively coupled plasma and mass spectrometry (ICP/MS) are commonly in the form of a solution that is transported into the plasma flame. The thermal mass of the flame is small, and ingress of excessive quantities of extraneous matter, such as solvent, would cool the flame and might even extinguish it. Even cooling the flame reduces its ionization efficiency, with concomitant effects on the accuracy and detection limits of the ICP/MS method. Consequently, it is necessary to remove as much solvent as possible which can be done by evaporation off-line or done on-line by spraying the solution as an aerosol into the plasma flame. 

The primary water specifications for a PWR are given in Table 1 (4). Rigid controls are appHed to the primary water makeup to minimise contaminant ingress into the system. In addition, a bypass stream of reactor coolant is processed continuously through a purification system to maintain primary coolant chemistry specifications. This system provides for removal of impurities plus fission and activated products from the primary coolant by a combination of filtration (qv) and ion exchange (qv). The bypass stream also is used both to reduce the primary coolant boron as fuel consumption progresses, and to control the Li concentrations. 

Before any remedial or preventive actions are implemented, an evaluation should be conducted as to appHcabiUty to the specific plant. The evaluation should continue while the actions are in progress. The main action should be to take measures to reduce the ingress of contaminants into the steam generator by using more rehable materials, such as in the condenser tubes, to reduce leakage. Contaminant control equipment, such as full-flow condensate deminerali2ers, should also be employed. 

Emissions During Disposal and Incineration. The increasing use of modem incinerators to dispose of domestic waste results in complete combustion of plasticizers to carbon dioxide and water. The preponderance of plasticizer going into landfiUs is as plasticized PVC. Once a landfiU has been capped anaerobic conditions prevail and it is biologically relatively inactive. Under these conditions the main route by which organic components are removed from the landfiU contents is by ingress of water, extraction, and subsequent loss of water from the site to the environment. 

In the United Kingdom there are approximately 2000 active landfiU sites with an aimual combined water ingress of 40 x 106 (48,49). The... 

For once-through boilers, the treatment must be without soHd residues, so all-volatile treatment (AVT) is used. AVT, which is also used in some dmm boiler systems, rehes on the feedwater chemical additives, ammonia and hydrazine, to provide water appropriate to the boiler. Because the additives are volatile, they do not accumulate in the boiler and provide only minimal protection during contaminant ingress. Most plants using AVT have some form of condensate poHsher to remove impurities from the condensate. 

Resistance to Chemicals. Different species of wood vary in their resistance to chemical attack. The significant properties are beheved to be inherent to the wood stmcture, which governs the rate of ingress of the chemical and the composition of the cell wall, which affects the rate of action at the point of contact (56). 

The scalping of flavor and aroma by a package can be minimised by placing a barrier material as near as possible to the food. The ingress of undesirable permeants from the environment can be minimised by placing a barrier polymer between the food and the environment, not necessarily near the food. 

The porous carbon rod is often the main pathway of escape for the gases formed in the cell. This pathway also allows ingress of oxygen to the cell limiting the shelf life of the system. The use of shrink tube outer wrapping and other devices have, however, improved the leakage property dramatically over prior generation cells. 

Although equihbrium capacity is the prime concern, few of these closed systems are truly static. Even closed systems have dynamic features or other nonsteady-state aspects, such as temperature fluctuations, moisture ingression, and drydown rates. 

Neither ground-state ethynol (hydroxyacetylene) (80) nor carbenaoxirane (81) appears to be a viable point of ingress to the oxirene-methanoylcarbene system, as both can isomerize to ketene by lower-energy pathways. The limited experimental information available on carbenaoxirane (Section 5.05.6.3.4(f/)) indicates that it is indeed largely isolated from the oxirene-methanoylcarbene manifold (but note the photolysis of ketene in Section 5.5.6.3.4(ff)) appropriate labelling experiments with (the unknown) ethynol have not been performed. 

Flevated or Remote Air Intakes Elevated or remote air intakes for control rooms will help in reducing ingress of dense, flammable vapors into those rooms. Ordinarily, elevating the tip of the air intake duct 9 m (30 ft) above the ground is sufficient. Installing flammable vapor detectors in the air intake ducts provides additional protection. Controls that automatically stop air to control rooms if vapor concentrations reach 25 percent of their LFL should also be considered. 

Ingress of air into reactor containing pyrophoric material. Possibility of fire / deflagration. 

Design equipment layout to accommodate emergency needs—response, ingress, egress... 

Use instrumentation that does not provide an ignition source, and/or minimizes the probability of air ingress into vessel. 

These are an itnprovised version of a totally enclosed motor to protect its live parts from ingress of water, rain, snow or airborne particles etc. This is achieved by providing them with additional protection such as labyrinths at joints such as bearing end covers, centrifugal discs, end shields and terminal box and giving the outer... 

No protection of equipment against ingress of solid foreign bodies. 

Protection against ingress of large solid foreign bodies (diameter greater than 50 mrn). 

Protection against harmful deposit of dust. The ingress of duct is not totally prevented, but dust will not be able to enter in an amount sufficient to harm the machine. 

Industrial Power Engineering and Applications Handbook Table 1.11 Types of Protection against ingress of water... 

Ingress of water in the machine immersed in water under staled conditions of pressure and time will not be possible in a harmful quantity. 

---