Expansion chamber

An effective way of preventing vent loss is to use one of the many types of variable-volume tanks. These are built under API Standard 650. They may have floating roofs of the double-deck or the singledeck type. There are hfter-roof types in which the roof either has a sldrt moving up and down in an annular hquid seal or is connected to the tank shell oy a flexible membrane. A fabric expansion chamber housed in a compartment on top of the tank roof also permits variation in volume. 

Water hammer arrestors, if correctly sized, placed, and maintained, will reduce water hammer by providing a controlled expansion chamber in the system. As the forward motion of the water column in the pipe is stopped by the valve, a portion of the reversing column is forced into the water hammer arrestor. The water chamber of the arrestor expands at a rate controlled by the pressure chamber and gradually slows the column, preventing hydraulic shock. 

The part that marries the plasma to the mass spectrometer in ICPMS is the interfacial region. This is where the 6000° C argon plasma couples to the mass spectrometer. The interface must transport ions from the atmospheric pressure of the plasma to the 10 bar pressures within the mass spectrometer. This is accomplished using an expansion chamber with an intermediate pressure. The expansion chamber consists of two cones, a sample cone upon which the plasma flame impinges and a skimmer cone. The region between these is continuously pumped. 

There are two primary types of settling chambers the expansion chamber and the multipletray chamber. In the expansion chamber, the velocity of the gas stream is significantly reduced as the gas expands in a large chamber. The reduction in velocity allows larger particles to settle out of the gas stream (EPA, 1982 Wark, 1981 Perry, 1984 Mycock, 1995 EPA, 1998). A multiple-tray settling chamber is an expansion chamber with a number of thin trays closely spaced within the chamber, which causes the gas to flow horizontally between them. While the gas... 

The sizing of pulsation drums is based on the National Advisory Committee for Aeronautics (NACA) Technical Note 2893. The single expansion chamber type has been chosen because of cost, ease of installation, and effectiveness. 

Qe = mass fraction of vapor phase in the expansion chamber... 

The separation of the expansion chamber (with cold finger) from the compressor by a capillary ( 30cm) reduces vibration. Typical small split-cycle single-stage units have a cooling power of 1W near 80 K, a cool-down time of 5-10 min and a life of over 5000 h. 

The sample is converted into an aerosol in an atomizer. It then passes through an expansion chamber to allow a fall in the gas pressure and the larger droplets to settle out before passing to the burner, where the solvent evaporates instantly, the atoms remaining as a finely distributed gas. Atoms in the sample that are bound in molecules should be decomposed at the flame temperature so rapidly that the same effect is achieved. In practice only a small proportion of the sample (approximately 5%) is effectively atomized because the drop size of the remaining 95% is so large that the water is never effectively stripped away. In low temperature flames, for instance, only one sodium atom in about 60000 is excited but despite this apparently low efficiency the technique is very sensitive. 

EXPANSION CHAMBER PELLET RETAINER DELAY PELLET PELLET CONTAINER ACCELERATING CAVITY... 

The aerosol then passes along the plastic expansion chamber. Large droplets collect on the walls of the chamber and, to ensure that only the smallest particles reach the flame, spoilers or baffles may be placed in the path of the gases. The chamber also allows for mixing of the gases and tends to damp fluctuations in nebulization efficiency. Some loss of solvent by evaporation will also occur. The chamber requires a drain tube which must be sealed to provide a back-pressure for the flame. This is usually... 

The efficiency of this kind of indirect nebulizer and expansion chamber arrangement is usually about 10-15%. It is favoured because only very small droplets reach the flame, but clearly it would be useful to improve its... 

Schematic diagrams of (a) the ICP-MS interface and (b) the supersonic expansion formed in the expansion chamber, showing the barrel shock and position of the Mach disc.

Typical fluid-bed processor elements can be seen in Figure 1. The fluidizing gas enters the bed at the bottom through an air distributor. The gas passes up through the bed of solids, causing it to fluidize. This gas/solid mixture behaves much like liquid of similar bulk density. Above the fluidized bed, a freeboard section (expansion chamber) is provided to slow down the... 

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