Pressure, types atmospheric

Magnetic filters have been used to clean paint sHps and Hquids. Filters that are open to the atmosphere or closed, ie, pressure type, are available where the filter inlets are matched to standard pipe connections from 10 to 50 mm, for low capacity appHcations. 

Several descriptions have been pubUshed of the continuous tar stills used in the CIS (9—11). These appear to be of the single-pass, atmospheric-pressure type, but are noteworthy in three respects the stills do not employ heat exchange and they incorporate a column having a bubble-cap fractionating section and a baffled enrichment section instead of the simple baffled-pitch flash chamber used in other designs. Both this column and the fractionation column, from which light oil and water overhead distillates, carboHc and naphthalene oil side streams, and a wash oil-base product are taken, are equipped with reboilers. 

Mechanical Pressure Gauges The Bourdon-tube gauge indicates pressure by the amount of flection under internal pressure of an oval tube bent in an arc of a circle and closed at one end. These gauges are commercially available for all pressures below atmospheric and for pressures up to 700 MPa (about 100,000 Ibfliu") above atmospheric. Details on Bourdon-type gauges are given by Harland [Mach. Des., 40(22), 69-74 (Sept. 19, 1968)]. 

The term Fp is a dimensionless dry packing factor, specific for a given packing type and size. Values of Fp are given in Table 14-7. For operating pressures above atmospheric, and for certain packing sizes, Lj and Gj a.re calculated differently ... 

Size an end-of-line deflagration flame arrester for the normal vent nozzle of a 126,000 gallon API-type atmospheric pressure storage tank for the following conditions ... 

The way in which the active microzone is retained also depends on its relationship to the detector (Fig. 2.6) and the type of interaction with the analyte or its reaction product. If the microzone is an integral part of the probe, an additional support (usually a membrane) is often required, so contact with the sample is hindered to some extent. On the other hand, a microzone located in a flow-cell can be retained in various ways. Thus, if the microzone consists of a porous solid or particle, the flow-cell is simply packed with two filters in order to avoid washing out (e.g. see [21]). Too finely divided solids (viz. particle sizes below 30-40 pm) should be avoided as they require pressures above atmospheric level, which complicates system design and precludes use of microzones with a high specific surface. Placing a separation membrane in a flow-cell is... 

PRESSURE. If a body of fluid is at rest, the forces are in equilibrium or the fluid is in static equilibrium. The types of force that may aci on a body are shear or tangential force, tensile force, and compressive force. Fluids move continuously under the action of shear or tangential forces. Thus, a fluid at rest is free in each part from shear forces one fluid layer does not slide relative to an adjacent layer. Fluids can be subjected to a compressive stress, which is commonly called pressure. The term may be defined as force per unit area. The pressure units may be dynes per square centimeter, pounds per square foot, torr. mega-Pascals, etc. Atmospheric pressure is the force acting upon a unit area due to the weight of the atmosphere. Gage pressure is the difference between the pressure of the fluid measured (at some point) and atmospheric pressure. Absolute pressure, which can be measured by a mercury barometer, is the sum of gage pressure plus atmospheric pressure. 

Chemical vapor deposition (CVD) of thin solid films from gaseous reactants is reviewed. General process considerations such as film thickness, uniformity, and structure are discussed, along with chemical vapor deposition reactor systems. Fundamental issues related to nucleation, thermodynamics, gas-phase chemistry, and surface chemistry are reviewed. Transport phenomena in low-pressure and atmospheric-pressure chemical vapor deposition systems are described and compared with those in other chemically reacting systems. Finally, modeling approaches to the different types of chemical vapor deposition reactors are outlined and illustrated with examples. 

Bourdon gauges are used on gas cylinders and are also considered a type of aneroid gauge. These devices have a coiled tube (shown in Figure 3.5) and are used to measure the pressure difference between the pressure exerted by the gas in a cylinder and the atmospheric pressure. The coiled tube is mechanically coupled to a pointer (shown in red). As a gas at a pressure above atmospheric pressure enters the coiled tube, it causes it to slightly uncoil, kind of like those New Year s Eve paper noisemakers. This causes the pointer to move over a numerical scale, thereby indicating the gauge pressure in the tank. 

Obviously, a multidisciplined safety review committee may have detected the problems of the ill-advised use of a combination vent/overflow line, but this type of collapse is viewed as somewhat of an oddity. Several variations of this type of collapse have been reported on low-pressure and atmospheric tanks. Another incident occurred when a company requested the operating team to fill a tank as high as possible for storage needs, so they ignored the high-level alarm. After the tank level reached the overflow, the liquid started pouring out of the overflow faster than it was being pumped in and the tank collapsed. [4]... 

Kyung, S., et al. (2006), Deposition of carbon nanotubes by capillary-type atmospheric pressure PECVD, Thin Solid Films, 506-507,268-273. 

This procedure can be applied to all types of pressure and atmosphere tanks and... 

---