Blockage problems

NOTE Under these circumstances, it is common to provide a time-phased treatment program, whereby the ratio offilmer to neutralizer is gradually increased over time. This reduces the tendency for old deposits to cause blockage problems. 

Many closed-loop hot/cold/chilled water systems are not treated, perhaps due to the mistaken notion that treatment is not required. Only when severe corrosion and fouling/blockages problems occur is something done, by which time it is normally too late to fully recover the situation. Closed-loop systems should always be cleaned, passivated, and treated. Treatment is most usually applied by means of a dosing pot (bypass feeder) installed on a bypass line. Some operators also install sidestream filters to remove suspended iron oxide. This is most probably not necessary if the... 

Because most of the ash is removed as molten slag, addition of a bottom grate is not necessary.7 However, small TDF is required, because much of the combustion must occur in suspension.7 TDF that is too large to combust completely can get carried over into the boiler or dust collection system, and cause blockage problems.9 Therefore, particle size may inversely determine the amount of TDF that can be used in a cyclone boiler.11 Three cyclone-fired boilers at utilities have burned 1M x 1" TDF in test operation, one at the 2 percent, one at the 5 percent, and one at up to a 10 percent level.3,9,12 One pulp and paper mill plans the use of TDF in a cyclone-fired hog-fuel boiler.13... 

Good gravity separation of hoatable oils is mandatory before further treatment in a biological facility. Additional oil removal pretreatment may be required for oil value, prevention of sewer line blockage problems or merely to reduce the size of the biological facilities. 

For basic kinetic studies pure metal foils have been preferred (.2.6.,], 8.) to supported catalysts since with the foils, metal-support interactions, mass transfer limitations and pore blockage problems are practically eliminated. 

Barnacles give birth to planktonic larvae developing in stages till metamorphosis into a small barnacle. Barnacles can settle in much higher water velocities than mussels and may settle on filter screens causing blockage problems. Barnacles are not such a serious problem in Europe as compared to tropical areas. 

Can FIA provide a solution to the automation of precipitation-dissolution and revitalize its function in modem analytical chemistiy The answer to this question came quite late, well after the application of FI techniques to solvent extraction and column separations. The reason for this delay obviously comes from the difficulties in on-line continuous manipulation of a heterogeneous system which could potentially create serious blockage problems in a standard FIA system. However, recent research efforts in this direction have been quite rewarding, and from the achievements described in this chapter the reader will see that the major difficulties in the automation of precipitation and even coprecipitation processes using FI techniques have been overcome. 

A major food company was experiencing screen blockage problems when filtering rapeseed oil for biodiesel production. By installing... 

Tar. Tar is certainly the main impurity present in gasification products. It is corrosive and causes blockage problems. The removal of tar typically takes place via catalytic cracking. For heating applications, in which the quality requirements of the gas are not high, the removal of tar is not necessary. 

In the case of really small cyclones (e.g. 10 mm diameter units), these are sometimes cast into disks and such disks are stacked into columns. Such systems resemble other chemical engineering columns for mass transfer or cartridge systems for filtration. One problem common to all compact multiple hydrocyclone systems is with the operator s inability to see any blockages. He or she must then diagnose any such difficulties from other operating performance such as an increase in pressure drop. Having detected a blockage problem, the only remedy available is to replace the unit or the whole column and clean it off-line. 

Ultrasonication Good for lab scale. micronization, blockage problem, produces Heat High energy requirement. 

The disadvantage of microconcentric nebulizers is that they use an extremely tine capillary, which makes them not very tolerant to high concentrations of dissolved solids or suspended particles. Their high efficiency also means that most of the sample makes it into the plasma, and as a result can cause more severe matrix suppression problems. In addition, the higher level of matrix components entering the interface has the potential to cause cone blockage problems over extended periods of operation. For these reasons, they have been found to be most applicable for the analysis of samples containing low levels of dissolved solids. 

The standard concentric pneumatic nebulizer will give excellent sensitivity and stability, particularly with clean solutions. However, the narrow capillary can be plagued by blockage problems, especially if heavier-matrix samples are being aspirated. For that reason, manufacturers of concentric nebulizers offer modifications to... 

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