Flow rate jets, orifices, nozzles

Micro-jet arrays are usually associated with lower energy consumption rates than sprays generated by the special (HAGO) nozzle for the same flow rate. The liquid was pushed through a 0.5 mm stainless steel orifice plate to form the jets. The holes in the plate were laser drilled and were arranged in a circular pattern giving a radial... 

In rare ink formulations, the ink may have a non-Newtonian rheology, i.e., high viscosity at low shear rate and low viscosity at high shear rate (shear thinning inks). In such a case, once the ink reaches the orifice it may be jetting well, since the shear rate in the nozzles is very high, but it may not flow properly in the ink supply tubing and the narrow channels of the print head, in which the shear rate is low. 

The flow rate through a Pelton-type hydro unit is controlled by the size of the orifice (jet) in the nozzle... 

The liquid-nitrogen flow rate was measured with a turbine flowmeter. The total pressure of the jet exhaust Ptj was measured at an orifice in the model plenum chamber by a Precision Pressure Balance transducer. The total temperature of the CO2 exhaust was measured by a thermocouple in the line leading into the vacuum chamber. This thermocouple was downstream of the pressure-regulating valve and therefore measured the total temperature of the CO2 after the expansion to near the jet total pressure. The total temperature and the total pressure of the jet were used in a one-dimensional isentropic flow equation for choked nozzles to calculate the mass flow of CO2. The specific heat ratio used was that corresponding to the total temperature and pressure of the jet. 

These authors reported that the jet diameter depends on the nozzle geometry, mainly the orifice diameter D, and the operating conditions, mainly the liquid flow rates. The final droplet diameter can then be written as... 

A water-jet system is mainly composed of a pump, a cutting head, an abrasive feeder, a water-jet orifice, a focussing tube/nozzle, and a catcher with water, as indicated in Fig. 2. The key cutting parameters include pump pressure, traverse rate, abrasive mass flow rate, and standoff distance. 

The other method for collecting small particles, and the method used in the MOUDl cascade impactor, is to employ very small nozzles as described by Kuhlmey et al. (1981). The small dimensions of the nozzle allow for small particles to be collected at relatively low jet velocities, and consequently low pressure drops. By the use of multiple micro-orifice nozzles in the MOUDl cascade impactor (2000 nozzles of 52 pm in diameter in the final stage), the cut-size of the final stage can be as low as 0.056 pm with a total flow rate through the impactor of 30Lmin ... 

Erosion Corrosion Rates at Jets, Nozzles, Orifices and Other Flow Expansions... 

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