Mass flow meter

After the SO converter has stabilized, the 6—7% SO gas stream can be further diluted with dry air, I, to provide the SO reaction gas at a prescribed concentration, ca 4 vol % for LAB sulfonation and ca 2.5% for alcohol ethoxylate sulfation. The molten sulfur is accurately measured and controlled by mass flow meters. The organic feedstock is also accurately controlled by mass flow meters and a variable speed-driven gear pump. The high velocity SO reaction gas and organic feedstock are introduced into the top of the sulfonation reactor,, in cocurrent downward flow where the reaction product and gas are separated in a cyclone separator, K, then pumped to a cooler, L, and circulated back into a quench cooling reservoir at the base of the reactor, unique to Chemithon concentric reactor systems. The gas stream from the cyclone separator, M, is sent to an electrostatic precipitator (ESP), N, which removes entrained acidic organics, and then sent to the packed tower, H, where SO2 and any SO traces are adsorbed in a dilute NaOH solution and finally vented, O. Even a 99% conversion of SO2 to SO contributes ca 500 ppm SO2 to the effluent gas. 

In many cases, problems cannot be overcome by biological means. This is especially true for those related to inhibition by substrate or product. There may, however, be technical solutions to these problems. Nowadays, complicated feed strategies with different substrates can be achieved through the use of flow injection analysis, on-line sensors, mass flow meters and sophisticated computer control. Such control coupled to a fed-batch mode of operation (Figure 2.5) can often eleviate problems caused by substrate inhibition. For some processes, continuous product removal can avoid the problems associated with product inhibition the various options include ... 

The mass flow is continuously detected and controlled in-line by means of modem mass flow meters. The practical accuracy achievable is such as to keep, with a time delay of few seconds, a fluctuation range for the mole ratio of less than 0.5%. 

The mass flow of organic feedstock to the film reactor is detected and adjusted by a mass flow meter, which automatically controls the speed of the gear pump feeding the organic to the reactor. 

The sulfonic acid flow passes through a second mass flow meter. If the mass flow of the sulfonic acid is different from the set point, it means that the S03/ organic ratio is incorrect (i.e., the resulting product may be under- or over-sulfonated) and an automatic controller resets the organic flow controller accordingly. 

Consider now a situation in which the bias limits in the temperature measurements are uncorrelated and are estimated as 0.5 °C, and the bias limit on the specific heat value is 0.5%. The estimated bias error of the mass flow meter system is specified as 0.25% of reading from 10 to 90% of full scale. According to the manufacturer, this is a fixed error estimate (it cannot be reduced by taking the average of multiple readings and is, thus, a true bias error), and B is taken as 0.0025 times the value of m. For AT = 20 °C, Eq. (2.9) gives ... 

The ethylene polymerization was carried out using a 12 OZ glass reactor equipped with a two blade impeller under a constant ethylene pressure of 20 psi. A predetermined amount of solvent (n-heptane), monomer, MAO and embedded catalyst were charged in series into the reactor. Polymerization was carried out at 70"C with agitation speed of 800 rpm. The polymer obtained was washed with excess amount of methanol containing hydrochloric acid solution and dried in vacuo for 24 hrs. The polymerization rate was determined from the amount of consumed ethylene, measured using a mass flow meter. DSC analyses (Dupont V4.0B) was carried out at a rate of 10 C /min, and the results were obtained in the second scan. 

Mass flow meter, Kurz Model 541, Kurz Instruments, Inc. (Carmel Valley, CA, USA)... 

The solvent/water emulsion is heated in its subsystem and flows through a Micro Motion mass flow meter. The emulsion is fed to the POD, where the water and organic phases are separated. Through this contact and separation the impurities are extracted into the aqueous phase. This results in a relatively clean solvent. 

Agitator Turbine, 3.6 HP, 1750 rpm, XP rated motor, variable speed drive Circulating pump Viking series HL124, 2 HP, 1745 rpm, XP rated motor Micro Motion mass flow meter stainless steel 316L, 0-80 lb/min mass flow range, accuracy of 0.4% of range, XP rated with electronics unit mounted separately in nonhazardous area. 

The Wavebag (50 L volume) was placed on the temperature-controlled tray and completely inflated with air using a membrane pump. The airflow was adjusted to 2250 mL using a thermal mass flow meter. 

Nitric oxide at about 50 ppm compressed with very pure nitrogen in gas (flinders is provided for this purpose, and the true concentration is established by comparison with that of a compressed-gas tank that can be obtained from the National Bureau of Standards, as a standard reference material. The nitric oxide meter is calibrated repeatedly at several concentrations of nitric oxide, and the mass flow meters are recalibrated often with absolute bubble meters. 

Different methods used for calibrating samplers include rotometers, wet-test meters, pressure gauges across fixed orifices, mass flow meters, hot wire flow meters and bubble tubes. Each of these calibration devices requires an appropriate correction factor. Some of the devices measure mass flow rather than volumetric flow. Sampling requires volumetric flow calibration. 

Molar carrier flow rate in each line Qn2 is calculated from Equation 3, knowing the volumetric normalized flow rates Qvn2 normalized (Llr1 at 273.15 K, latm) of carrier gas used for saturation, usually obtained by mass flow meters ... 

In such a system, known quantities of the different compounds required to produce the final gas mixture are easily controlled (either by using high-precision metering pumps or mass flow meters) and injected into a flash evaporator (EV01) working at high temperature. Once the vaporization is performed, the gas is... 

Figure 9. Configuration of the DS-IC system A, clean air input B, mass-flow controller C, permeation device chamber D and H, vents E, needle valve-rotameter F, needle valve G, mass-flow meter I, diffusion scrubber Jy scrubber liquid reservoir K, needle valve-rotameter L, suction pump M, injection valve Ny peristaltic pump O, eluent flow F, downstream chromatographic components and Q, sample loop. (Reproduced from reference 96.

Wasson, R. Trans. Inst. Meas. Cont. 5 (12) (1972), 479. Mass flow metering. 

Various methods exist to accurately proportion syrup and water, though the most popular current system uses flow meters. The syrup is usually dosed though a mass flow meter and the water is dosed volumetrically using a magnetic induction flow meter. This allows for density variations within the syrup... 

Two main types of volumetric filler exist. In the first type, a predetermined volume of liquid can be dosed using either a magnetic inductive volumetric flow meter or a mass flow meter. Alternatively, measuring cylinders can be used that incorporate a level probe. The product is fed to a set level in the metering cylinder, at which point the flow valve is closed off from the supply tank. A typical can filler operating at 1,500 cans of 330 ml capacity per minute will fill as per the supply contract within 2.5 ml. However, a standard deviation for a volumetric filler as low as 0.58 ml has been quoted. As with the probe filler, these fillers are fitted with electro-pneumatic valves, enabling accurate control of the... 

A popular series of mass flow meters is available which is based on the use of a thermal sensor in a side stream (Fig. 7.13). Generally, these flow meters are... 

A. Flow Measurement by Displacement. A variety of flow meter designs are based on the positive displacement of a small amount of easily visualized material which does not alter the flow rate. A simple and easily constructed mass flow meter of this type, the soap-film meter, is based on timing the displacement of a soap film up a buret tube (Fig. 7.11). This type of flow meter is often placed at the exit of a gas chromatograph or small flow reactor. It is very... 

Pig. 7.13. Schematic of a mass flow meter. The flow is proportional to (T2 — Tt)1. This type of meter is often employed in an electrically controlled flow regulator. T, and T2 are temperature sensors H is a heater. 

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