Feet per minute

Plutonium solutions that have a low activity (<3.7 x 10 Bq (1 mCi) or 10 mg of Pu) and that do not produce aerosols can be handled safely by a trained radiochemist in a laboratory fume hood with face velocity 125—150 linear feet per minute (38—45 m/min). Larger amounts of solutions, solutions that may produce aerosols, and plutonium compounds that are not air-sensitive are handled in glove boxes that ate maintained at a slight negative pressure, ca 0.1 kPa (0.001 atm, more precisely measured as 1.0—1.2 cm (0.35—0.50 in.) differential pressure on a water column) with respect to the surrounding laboratory pressure (176,179—181). This air is exhausted through high efficiency particulate (HEPA) filters. 

Bars Newtons per square meter 1 X 10 Centimeters per second Feet per minute 1.9685... 

B.t.u. per pound per degree Calories per gram per degree Cubic feet per minute Cubic centimeters per second 472.0... 

Fahrenheit centigrade 1 Cubic feet per minute Gallons per second 0.1247... 

FIG. 10-67 Compressor coverage chart based on the normal range of operation of commercially available types shown. Solid lines use left ordinate, head. Broken lines use right ordinate, pressure. To convert cubic feet per minute to cubic meters per boiir, multiply by 1.699 to convert feet to meters, multiply by 0.3048 and to convert poiinds-force per square incb to Idlopas-cals, multiply by 6.895 ( F — 32)% = C. 

Databy courtesy of Norton Company, Worcester, Mass. To convert inches to centimeters, multiply hy 2.54 to convert feet per minute to meters per second, multiply hy 0.0051. 

FIG. 14-122 Incremental pressure drop in knitted mesh due to the presence of hqiiid a) with the mesh crimps in the same direction and (h) with crimps in the alternating direction, based on the data of York and Poppele [Chem. Eng. Prog., 50, 421 (1954)]. To convert centimeters per minute to feet per minute, multiply hy 0.0328 to convert centimeters per second to feet per second, multiply hy 0.0328. (From Calveti, Yung, and Leung, NTIS Puhl PB-24S050, 1975.)... 

Since this type of conveyor is available in only one standard size, its capacity is determined by the belt speed and the fixed cross-sectional area. Tons-per-hour capacity is figured by multiplying the bulk density in pounds per cubic foot by the speed in feet per minute and a constant of 0.0021. Power requirements are quite low and figured in the same way as those for conventional belt conveyors. 

When 150 SSU at 100°F (38°C) oil is necessary, inlet temperatures should be limited to 110-120°F (43 9° C) to maintain an acceptable viscosity. Oil should be supplied in the temperature and pressure range specified by the manufacturer. Up to a pitch-line speed of approximately 15,000 feet per minute (4572 mpm) the oil should be sprayed into the out-mesh. Spraying allows maximum cooling time for the gear blanks and applies the oil at the highest temperature area of the gears. Also, a negative... 

At more than approximately 15,000 feet per minute, (4,572 mpm) 90% of the oil should be sprayed into the outmesh and 10% into the inmesh. This proeedure is a safety preeaution to assure the amount of oil required for lubrieation is available at the mesh. When the speed ranges from 25,000 to 40,000feet per minute (7,670-12,192mpm), oil should be sprayed on the sides and gap area (on double-heheal) of the gears to minimize thermal distortion. 

ACFM = Actual cubic feet per minute D = Fan diameter, feet... 

From Table 1 and solids rate, estimate duct size and flow in SCFM (standard cubic feet per minute). 

The most important thing to remember in compressor calculations is that compressor flow is a volumetric value based on the flowing conditions of pressure, temperature, relative humidity (if moisture is present), and gas composition at the compressor inlet nozzle. The flow units aix inlet cubic feet per minute (icfm). 

A common method of stating flow is standard cubic feet per minute where the flowing conditions are referred to an arbitrary set of standard conditions. Unfortunately, standard conditions are anything but standard. Of the many used, two are more common. The ASME standard uses 68°F and 14.7 psia. The relative humidity is given as 36%. The other standard that is used by the gas transmission industry and the API Mechanical Equipment Standards is 60°F at 14.7 psia. As can be seen from this short discussion, a flow value must be carefully evaluated before it can be used in a compressor calculation. 

After all the previous statements, it would seem very difficult to select a piston. speed. For someone without direct experience, the following guidelines can be used as a starting point. Actual gas compressing experience should be solicited when a new compressor for the same gas is being eonsidered. These values will apply to the industrial process type of compressor with a double-acting cylinder construction. For horizontal compressors with lubricated cylinders, use 700 feet per minute (fpm) and for nonlubricated cylinders use 600 fpin. For vertical compressors with lubricated cylinders, use 800 fpm and for nonlubricated cylinders use 700 fpm. 

To assist the engineer in making estimates, the curve in Figure 3-6 gives values of efficiency plotted against pressure ratios. The values on the curve include a 95% mechanical efficiency and a valve velocity of 3,000 feet per minute. Table 3-1 and Table 3-2 are included to permit a correction to be made to the compressor horsepower for specific gravity and low inlet pressure. They are included to help illustrate the influence of these factors to the power required. The application of these factors to... 

The SCREEN model uses free format to read the numerical input data, with the exception of the exit velocity/flow rate option. The default choice for this input is stack gas exit velocity, which SCREEN will read as free format. However, if the user precedes the input with the characters VF= in columns 1-3, then SCREEN will interpret the input as flow rate in actual cubic feet per minute (ACFM). Alternatively, if the user inputs the characters VM= in columns 1-3, then SCREEN will interpret the... 

Air Flow Typical gas flow rates for a single cyclone unit are 0.5 to 12 standard cubic meters per second (smVsec) (1,060 to 25,400 standard cubic feet per minute (scfm)). Flows at the high end of this range and higher (up to approximately 50 smVsec or 106,000 scfm) use multiple cyclones in parallel (Cooper, 1994). There are single cyclone units employed for specialized applications which have flow rates of up to approximately 30 smVsec (63,500 scfm) and as low as 0.0005 smVsec (1.1 scfm) (Wark, 1981 Andriola, 1999). 

Standard cubic feet per minute (sefm)). Custom baghouses are designed for speeifie applieations and are built to the speeifieations preseribed by the eustomer. These units are generally mueh larger than standard units, i.e., from 50 to over 500 smVsee (100,000 to over 1,000,000 sefm). 

Air Flow. Typical gas flow rates for dry wire-pipe ESPs are 0.5 to 50 standard cubic meters per second (smVsec) (1,000 to 100,000 standard cubic feet per minute (scftn)). 

The air pollution control solutions that are available to control these emissions are normally dictated by the volume of air that is to be processed. The volume of air flow, measured in cubic feet per minute, is designated as ACFM for Actual Cubic Feet per Minute of SCFM where "S" stands for standard cubic feet per minute, at 70°F, sea level, and one atmosphere. 

Ventilation Rate The rate at which indoor air enters and leaves a building. Expressed in one of two ways the number of changes of outdoor air per unit of time (air changes per hour, or "ACH") or the rate at which a volume of outdoor air enters per unit of time (cubic feet per minute, or "cfm"). 

Engineering Considerations To effect the good engineering design of an activated carbon adsorption system, it is first necessary to obtain information on the following the actual cubic feet per minute (ACFM) of air to be processed by the adsorber, the temperature of gas stream, the material(s) to be absorbed, the concentration of the material to be adsorbed, and if the intended application is air pollution control such as odor control - then the odor threshold of the material to be adsorbed. In addition, data is needed on the presence of other constituents in the gas stream, and whether or not solvent recovery is economical. 

The adsorbers are usually built of steel, and may be lagged or left unlagged the horizontal type is shown in Figure 28. The vapor-laden air is fed by the blower into one adsorber which contains a bed of 6- to 8-mesh activated carbon granules 12 to 30 inches thick. The air velocity through the bed is 40 to 90 feet per minute. The carbon particles retain the vapor only the denuded air reaches the exit, and then the exhaust line. The adsorption is allowed to continue until the carbon is saturated, when the vapor-laden air is diverted to the second adsorber, while the first adsorber receives low-pressure steam fed in below the carbon bed. The vapor is reformed and carried out by the steam. The two are condensed and if the solvent is not miscible with water, it may be decanted continuously while the water is run off similarly. After a period which may be approximately 30 or 60 minutes, all the vapor has been removed, the adsorbing power of the charcoal has been restored, and the adsorber is ready to function again, while adsorber No. 2 is steamed in turn. 

From the standard cubic feet per minute estimate, the linear velocity is as follows ... 

The total releases to air from the facility must be entered m Part III, Section 5 of Form R in pounds per year. The stack test results provide the concentration of metallic lead in each exhaust stream in grains per cubic toot and the exhaust rate in cubic feet per minute. Using the appropriate conversion factors, knowing the scrubber efficiency (from the manufacturer s data), and assuming yourfacility operates 24 hours per day, 300 days per year, you can calculate the total lead releases from the stack test data. Because point (stack) releases of lead are 2,400 pounds per year,-which is greater than the 999 pounds per year ranges in column A. 1, you must enter the actual calculated amount in column A.2 of Section 5.2. 

Flow rate The volume of solution which passes through a given quantity of resin within a given time. Flow rate is usually expressed in terms of feet per minute per cubic foot of resin or as millimeters per minute per millimeter of resin. 

Data from an incinerator indicate a volumetric flow rate of 10,000 scfm (60°F, 1 atm). If the operating temperature and pressure of the unit are 1950°F and I atm, respectively, calculate tlie actual flow rate in cubic feet per minute. 

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