Jetting operation

Constant flow jets operate by passiag a stream of charged particles contiauously through an electric field. In order for these to hit the substrate the drops have to be deflected by electrical force. Nondeflected drops fall iato a gutter. By changing the electrical field, drops can be deflected different distances and directions, so it is possible to obtain designs usiag a relatively few number of jets. Both techniques have been used widely for paper. 

It collides with the gas communicating a large downward momentum to the gas molecules. The top jet operates at the lowest pressure. The body of the pump is typically cooled by water or air. When the vapour reaches the cooled walls, it condenses back into a fluid which drops into the pump boiler for reboiling. 

Sallack (1955) was the first to publish a study of dissolver-tank explosions. He was motivated by incidents which occurred in a soda pulp operation with a dissolver tank 4.3 m in diameter and 3.7 m tall. Molten smelt entered the tank at the top and was to be broken up with a jet of recirculating green liquor. Agitation of the bulk liquid was also accomplished by air jets. Operation was normally smooth, but if a boiler upset led to a sharp increase in smelt flow, then the smelt-green liquor breakup operation was inefficient and unbroken slugs of smelt could enter the bulk green liquor in the tank. Explosions could then occur. 

Wishart, D.P. 1995. The structure of a heated supersonic jet operating at design and off-design conditions. Ph.D. Thesis. Tallahassee, FL Department of Mechanical Engineering, Florida State University. 

T-type (initial flow before plugging) 2000 ml fr1, mixer type 6. Top right device plugged after some minutes of T-type jet operation 2000 ml h mixer type 2. Bottom left stable jet, Y-type 2000 ml h mixer type 5. 

The backwash system used by Zum, for instance, employs two header pipes one operates continuously at 20 psi, while the other operates at 40-55 psi. Under normal operating conditions, these jets operate at 35 psi. Once a day they are operated at 50 psi for 30 min to keep the jets free of slime buildup. Should this procedure fail to keep the jets clean, the pressure is raised to 55 psi. At this pressure the spring-loaded jet mouth widens to allow for more effective cleaning. 

As discussed in Section 9.1.2, reverse addition has been a time-honored method of producing small crystals. It typically suffers from broad size distribution and high impurity content (if present in the mother liquors) because of the excessive supersamration gradients encountered by the inlet solution. In the present example, the final product contained too much of an undesired impurity. This product will also be compared to that from the impinging jet operation in the discussion below. 

Product from the impinging jet operation had excellent X-ray diffraction patterns, equal in peak intensity to the most highly crystalline large particles crystalhzed in a growth-dominated process. 

Impurities rejection for solid crystallized with the impinging jets was good at 25°C and excellent at 50°C. For an undesired contaminant required to be <0.5 wt%, the impinging jet operation at 50 C... 

Nevertheless, caution must be taken in selecting an effective spray jet operating strategy and design. The violent action of the cleanout jets can develop turbulent flows sufficient to reform emulsions. 

BEM can be extended to compute interior fluxes by taking the derivative of the velocity potential from the governing equation (18.4). Yoon et al. [3] computed the interior fluxes of the electrostatic field outside an electrified jet whose symmetric sector configuration is shown in Fig. 18.14. Assuming symmetry, they computed a sector of the multi-jets, which can produce extremely small (a few or sub-micron) droplets. The multi-jet mode enables multiple cone-jet operation (about 5 10 jets), which in turn increases the flow rate without sacrificing basic features of the eletrospray s cone-jet mode [82]. 

Thus, for example, one of the new entrants involved in a fatal accident in the database of Barnett and Higgins, World Airlines, was a former charter carrier with extensive experience in jet operations (TRB, 1991,pg. 178). Since the number of accidents in that database was so small, re-categorizing even one of the carriers involved in an accident from a new entrant to a trunkline would substantially affect the results. 

Behr A, Becker M, Dostal J. (2008) cf Behr et ah, 2009. Hydrodynamic and lapsed time response of jet operation reactors and for the adoption in polyphase catalyst. Chem. Ing. TechnoL, 80(10) 1501-1508. 

Test Procedure If a jet operates steadily, but fails to produce the required vacuum ... 

Spindle regulated jets are usually not acceptable except for thermocompressors. A discussion of their application is given in Chapter 18. For critical vacuum pumps, regulating spindles are an ineffective means of control and can lead to unstable jet operation. 

It is customary to obtain fluorescence excitation spectra rather than absorption spectra in jets, where the total fluorescence intensity is monitored as a function of excitation laser wavelength. In cases where the fluorescence quantum efficiency (defined as fluorescence photons emitted/laser photons absorbed) is independent of excitation wavelength, the fluorescence excitation spectrum coincides with the absorption spectrum. Part of the fluorescence excitation spectrum of an Na2 jet operated with vibrational and rotational temperatures of 50 and 30 K, respectively, is shown in Fig. 4.3. The four intense bands arise from electronic transitions from v" = 0 in the ground state to v = 25... 

Thus, we are in the foam regime. Note that that correlation of Jeronimo et al. [JER 73] gives a smaller value for but that value corresponds to a jet operation of only 70% of the holes. 

Figure 14.34 Water-jetting operation (a) and pressurizing equipment (b). (Courtesy of Termarust Technologies)...

In fasciated spinning long staple sliver without twist is introduced into a limited space and subjected to a torque jet operating at right angles to the flow of the sliver thereby imparting a fal se twist to the sliver. As the sliver exits the torque jet it rapidly untwists, and the... 

Airlines are a widely used mode of transportation throughout the world. Currently, over 16,000 jet aircraft are being used around the world, with over 17 million departures per year [6]. A study of worldwide scheduled commercial jet operations during the period 1959-2001 indicates that there were a total of 1,307 accidents, resulting in 24,700 onboard fatalities [6,14], By type of operation, these 1307 accidents can be classified as follows [6] ... 

Most iron scales can be treated with acid with varpng degrees of success. Greater care must be taken to maintain soluble material in solution. A properly selected iron control agent is imperative. Iron sulfide is partially soluble or slowly soluble in HCl, but that is the only viable treatment option. It may be safer to remove iron scales mechanically by drill-out, milling, or high-pressure jetting operations. 

Figure 6.3 The BTRC UHP water jetting process for removing rubber from end-of-life large tyres (a) cutting operation and (b) jetting operation. Reproduced with permission of Big Tyre Recycling Corporation, Martelaarslaan, Belgium. 2014, Big Tyre Recycling Corporation...

British Ministry of Supply. Kerosene used world wide in civil jet operations (1956). 

The first aircraft to be used routinely for infrared observations was a Lear jet operated by NASA from the Ames Research Center. It was equipped with a 12-inch telescope that looked out from the side of the aircraft. The aircraft was modified to accommodate the telescope and for high-altitude performance, with flights typically reaching 50,000 feet. It could accommodate two observers and a pilot. With this platform observations of roughly 1 hr could be taken at high altitudes. 

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