Liquid Trapping

Trapping is an important form of nonsorptive retention of contaminants in the subsurface. Trapping may occur, for example, when spills of water-immiscible fluid compounds (e.g., petroleum products) leave residual ganglia or bulb configurations in the subsurface. 

If the organic liquid saturation is measured as the volume of organic liquid per unit void volume, measured over a representative volume of the porous medium, then S, the fraction of pore space occupied by the organic liquid is 

The extent of trapping is determined primarily by the physical properties of the vadose zone. If the organic liquids are characterized by a low vapor pressure and a low solubility in water, they remain trapped in the partially saturated zone. In this particular case, the porous medium behaves like an inert material and the behavior of the organic liquids depends only on their own properties, with no interaction between the liquid and the solid phases. 

---

Avoid liquid traps in vacuum system piping by never going up after having gone horizontal. 

The piping configuration from the outlet of the drum is important. If possible, there should be no liquid traps in the compressor inlet line. 

Liquid traps in safety valve release lines. 

To avoid injuries of this sort, we should use protective hoods or helmets when breaking joints on lines likely to contain corrosive liquids trapped under pressure, either because the pressure cannot be blown off through a valve or because lines may contain solid deposits. 

Liquid trapped between valves will produee a large rise in pressure as it warms up. 

Figure 9.11 Suction line accumulator or liquid trap...

A burner which utilises a mixture of fuel and oxidant gases and which is attached to a waste vessel (liquid trap) should be provided with a U-shaped connection between the trap and the burner chamber. The head of liquid in the connecting tube should be greater than the operating pressure of the burner if this is not achieved, mixtures of fuel and oxidant gas may be vented to the atmosphere and form an explosive mixture. The trap should be made of a material that will not shatter in the event of an explosive flash-back in the burner chamber. 

There have been several experimental studies of two-phase flow in which the holdup has been measured, either directly or indirectly. The direct method of measurement involves suddenly isolating a section of the pipe by means of quick-acting valves and then determining the quantity of liquid trapped.00111 Such methods are cumbersome and are subject to errors arising from the fact that the valves cannot operate instantaneously. Typical of the indirect methods is that in which the pipe cross-section is scanned by y-rays and the hold-up is determined from the extent of their attenuation.02 13141... 

Connect a vacuum manifold to a vacuum source not to exceed 20 in Hg, and place a 1-L waste liquid trap between the manifold and the vacuum source. To use the manifold, remove the cover, and place a Luer hub solvent guide needle on the male Luer fitting of each flow control valve. Remove the collecting vessel rack, and replace the cover. Close all control valves on the manifold cover. 

Let us consider the behavior of the ith among m trace elements upon partitioning between a homogeneous liquid (labeled liq) and the n phases (labeled j) of the cumulate in a system of finite size. These phases are usually considered as mineral phases but liquid trapped in the cumulate can be handled as an additional phase with partition coefficients equal to unity (Greenland, 1970 Albarede, 1976). 

Hercules trap analychem Water-measuring liquid trap used in aquametry when the material collected is heavier than water. h3r ky3,lez, trap ... 

Fig. 5.7 Illustration of a water immiscible liquid trapped in the vadose zone immediately after a spill. The dashed line represents the water table region (Schwille 1984)...

A conventional flow apparatus shown in Figure 1 was used. It consisted of gas-flow controlling devices, tubular reactor in an electric furnace, Liebig condenser, liquid trap, etc. The temperature profile along the longitudinal axis of the reactor was measured by a thermocouple. The reaction zone is defined here as the part of the reactor above 350°C. The reaction temperature means the highest temperature in the reaction zone. 

The operation of the apparatus for the preparation of keten (1) is as follows. Acetone is placed in the flask which is heated in an electric mantle until the liquid gently refluxes from the condenser M. After a few minutes the U-tube attached to K will fill with acetone and this provides a liquid trap which ensures that all the acetone vapour passes through H. After heating under reflux for a... 

Average results indicate that approximately 24% of the mercury remains in the spent cartridge case/primer cup, approximately 7% of the mercury was recovered from the liquid traps, and only 1.5% of the mercury was present on the filter. Approximately 68% of the mercury appears to be present as large particulate matter, which must have been deposited on the interior of the firing tube. 

The proportion of the discharge residue issuing from the muzzle that has the potential to be detectable by SEM is 12.1%, 11.7%, and 13.5%, respectively. These figures are remarkably reproducible given the scope for experimental error in this type of experiment. The distribution between the filter and the liquid traps, that is, between particulate and vapor, is 17.7%, 17.2%, and 20.2%, respectively, on the filter. 

Finally, breech discharge residue was examined to investigate the occurrence of mercury-containing particles that would be SEM/EDX detectable (Figure 22.3) using the same pump, filter, and liquid traps as the previous experiment. Results are given in Table 22.11. 

Table 22.13 Quantitative Comparison between Filter and Liquid Traps...

---