Discharge flow

Discharge Flow Regimes Upon developing a puncture in either the vessel or a line attached to the vessel, as in Fig. 26-62, the subsequent depressurization can cause a volatile liqmd to flash and develop bubbles in the liquid. These bubbles cause an expansion, or. 9well, which raises the two-phase, or frothy, level. If the puncture is in the vapor space of a vessel or on a line from the vapor space, the discharge will be at least initially all vapor. This is the simplest discharge case and is treated here as a special case. 

Composite samples can be collected over an 8- or 24-hour period at half-hour or one-hour intervals from the regular effluent discharges such as from the pretreatment tanks. The volume of each sample will depend upon the variation in the discharge flow rate. 

This is a low flow condition where the discharge flow of the pump is restricted and the product cannot leave the pump. The liquid is forced to re-circulate from high-pressure zones in the pump into low-pressure zones across the impeller. 

This condition cannot be corrected on pumps with an enclosed impeller. You need to relax the restricted discharge flow on the pump. The problem could be a clogged downstream filter, a closed discharge valve, an over-pressurized header (back-pressurizing the pump), or a... 

The way that a pump receives the liquid into the impeller determines the available combination of discharge flow and head that the pump can generate. Hssentially, it determines the operating window of the pump. 

This would be induced or caused by operation, if the plant operators strangle valves to control production tlow. Any other discharge flow restriction (clogged filter, pipe obstruction, or tin-calibrated automatic valve) would produce the same evidence. Talk with the plant engineer about this situation and show him the evidence on the pump. 

Not enough discharge flow Excessive discharge Head Not enough NPSHa Worn or damaged impeller Inadequate foot valve size. Air aspiration or air pocket in the suction line. Plugged impeller or piping... 

Place the measuring tube on the top of the basket holding with one hand. Be careful not to block the discharge flow at the open top of the reactor. 

A forward pressure regulator (FPR) reduces the pressure and keeps the reactor at 7.5 psig. Reactor pressure is Indicated and recorded by (PIR) and temperature by (TIR). Discharge flow from the reactor is measured by a flow transmitter (FT) and after correction for temperature and pressure the Flow is Recorded on (FR). 

First it is important to study how the gradual conversion of soda will influence the rate of reaction. Initially, keep all other conditions constant that can influence the rate oxygen and water concentration, and the mole fraction of TCE in the reactor. This last is the same as the TCE in the discharge flow from the reactor. 

The experiment should be conducted at constant TCE concentration of 250 PPM. For this purpose, discharge enough flow from the reactor to maintain the concentration of TCE in the discharge flow at 250 PPM level. The forward pressure regulator keeps the reaction pressure constant. The difference between 500 and 250 PPM multiplied with the molar flow rate gives the moles per hour converted that may change continuously as the soda is consumed. 

Expander performance will shift as plant conditions—such as gas flowrate, gas inlet, and discharge pressure—gas composition, and inlet temperature change. Calculation of expander diermal efficiency from field data is not accurate because expander discharge flow normally consists of two phases, gas and liquid. Efficiency calculations should always be cross-checked with the shaft power produced before any decision on expander performance is made. 

Eckhardt, D., Instantaneous Measurements in the Jet-Wake Discharge Flow of a Centrifugal Compressor Impeller, ASME Paper No. 74-GT-90. 

The correct flow to use is the compressor suction. However, a flow element such as an orifice in the compressor suction can rob inordinate horsepower. Therefore, sometimes the discharge flow is measured and the suction flow computed within the controller by using pressure measurements. Other times the compressor intake nozzle is calibrated and used as a flow element. The correct AP to use is the discharge minus the suction pressure. 

Step 9.1 Identify the Effluent Discharge Points. Determine the points at which wastewater leaves the site. Wastewater may go to an effluent treatment plant, directly to a public sewer, or directly to a watercourse. One factor that is often overlooked in audits is the use of several discharge points. It is important to identify the location, type, and size of all discharge flows. Identify where flows from different unit operations or process areas contribute to the overall flow. In this way, it is possible to piece together the drainage network for the site. This can lead to startling discoveries of what goes where ... 

Pumping Capacity the amount of discharge flow from an impeller. It is frequently correlated on the basis of the dimensionless impeller discharge coefficient, Nq = Q/ND, where Q == volumetric discharge rate. 

If the calculated blending time is longer than desired, nozzle discharge flow rate can be increased or, nozzle diameter increased. Consideration of nozzle recirculation line pressure drops and pump characteristics is required to select the parameter to change. 

Excessive Built-up Back Pressure - Built-up back pressure resulting from discharge flow through the outlet system of a conventional PR valve results in a force on the valve disc tending to return it to the closed position. If this returning force is sufficiently large, it may cause the valve to close, only to reopen immediately when the effect of built-up back pressure is removed. Chattering results from the rapid repetition of this cycle. 

Sano, Y. and Usui, H., Interrelations among mixing time, power number and discharge flow rate number in baffled mixing vessels, J. Chem. Eng., Japan, 18 47-52, 1985. 

Fully adjustable air diffuser An air diffuser that has the provision of adjusting the discharge flow direction through a wide angle. 

If tv o-phase flow situations are not recognized, pressure drop problems may develop which can prevent systems from operating. It requires very little percentage of vapor, generally above 7% to 8%, to establish volumes and flow velocities that must be solved by two-phase flow analysis. The discharge flow through a pressure relief valve on a process reactor is often an important example where two-phase flow exists, and must be recognized for its back pressure impact. 

Figure 3-68. Reciprocating pump discharge flow patterns. (Courtesy the Aldrich Pump Co.)...

R, = Reynolds number = No = d np/H Nqd = discharge flow number = qu/nd p - pressure qq = discharge flow rate ejq = mixing time... 

Significant Features in Reciprocating Pump Arrangements, 215 Performance, 217 Discharge Flow Patterns, 218 Horsepower, 218 Pump Selection, 221. 

The discharge flow may have some pulsing characteristics depending upon the blower speed the lower speed exhibits more pulsing. 

Four characters are utilized in a prescribed order (Figure 4-156) to indicate seven fixed cutter bit design features cutter type, body material, bit profile, fluid discharge, flow distribution, cutter size, and cutter density. These design traits were selected as being most descriptive of fixed cutter bit appearance. 

Figure 4-164. Example of steel body impregnated core bit with face discharge flow [54]. (Courtesy SPE.)...

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