Nozzle penetrations

Top nozzles penetrate the shell by 10-50 mm in order to avoid trickling of acid along carbon-steel plate. 

The final steps in the assembly required locating the position of the axial welds and nozzles which were indexed azimuthally in each shell course. A typical PWR RPV was made up of three (upper, intermediate and lower) shell courses. Typically, the RPV beltline spans two of the shell courses. A typical BWR RPV, being substantially larger in height and diameter, had more shell courses depending on the size of the RPV, with nozzle penetrations in almost every shell course. The more complicated geometry of the BWR RPV creates difficulties for RPV weld accessibility during the inspection of these areas. 

The pressurizer has sufficient clearance around the shell weld seams for manual ultrasonic examination of these welds. The insulation is removable at each weld and access is provided for ultrasonic and visual examinations in the area of the bottom head and its nozzle penetrations of the pressurizer. A manway is provided for those inspections which must be made internally on the pressurizer. 

Nozzle penetrations through the end closures can also be screwed into tapped connections in the head. These type of connections should be avoided if the vessel is in cyclic service. 

Jet injectors deliver insulin transcutaneously by an air-jet mechanism. The insulin solution or suspension is forced at high pressure through a fine nozzle, penetrates the skin without a needle, and creates a multitude of small depots. The dispersion of insulin deposited in the tissue explains the more rapid absorption of both rapid- and retarded-acting preparations (Taylor et al, 1981 Malone eta/., 1986 Houtzagerse/a/., 1988). Jet injection seems to affect the action profile of NPH insulin more markedly than that of the Lente t e insulins (Houtzagers et al, 1988). These devices are not painless and, in a European study, not well accepted by patients irrespective of the presence or absence of needle phobia (Houtzagers etal, 1988). However, in a more recent American study, the majority of patients preferred to take insulin by jet injector compared to needle injection (Denne et al, 1992). Jet injection has been found to be associated with a diminished antibody... 

Liquid should be direc ted into the batch materials and not onto bare mixer surface since this could cause buildup. Nozzle spray pressure should be sufficient to penetrate the batch but not so high as to cause heavy splashing. The hquid should be added to the well-mixed... 

Additionally for adequate penetration of the nozzle diseharge across the tank, the exit diameter should be at least as large as that given by (for both heavy and light jets) ... 

They also considered the depth of penetration of the igniter jet into the motor. They found that the motor L/Dp ratio had little effect on the heat transfer provided L exceeded the depth of penetration of the igniter jet. Their results also showed that high penetration is desirable and can be achieved by the use of high igniter mass-flow rates in conjunction with supersonic igniter-exhaust nozzles. 

Vertical jet penetration in fluidized beds increases significantly with system pressure as shown in Fig. 18. Vertical jets fluctuate in the vertical direction between a minimum and a maximum value. Most jet penetration correlations are given in terms of the maximum jet penetration length which is designated Lmax (Hirsan et al. 1980). Over a pressure range of 1 to 50 bar with jet nozzles up to 3.8 cm in diameter, Hirsan et al. (1980) developed the following empirical correlation for the maximum jet penetration. 

Yates et al. (1986) varied system pressure up to 20 bar with jet nozzles of 2 and 4 mm diameter, and also found that the maximum jet penetration varied significantly with pressure. They then developed the following correlation for the maximum jet penetration ... 

The solids circulation patterns were investigated with a force probe developed in-house. Typical force probe responses are presented in Figs. 43 and 44 for a probe located at 0.13 m from the jet nozzle and with different penetrations into the bed for an air tube velocity of 45.7 m/s. Sincetheforce probe is directional, the upward solids movement will produce a positive response from the probe and vice versa, the magnitude of the response being an indication of the magnitude of solids circulation rate. The number of major peaks per unit time is closely related to the actual bubble frequency in the bed. 

Figure 43. Force probe responses for probe penetration from 0.05 m to 0.30 m— 0.13 m from jet nozzle elevation, 46 m/s jet velocity, no solid feed.

There are a variety of nozzles that can be provided to hoses and monitors. They are capable of projecting a solid, spray or fog stream of water depending on the requirements and at varying flow rates. Straight stream nozzles have a greater reach and penetration, while fog and water sprays will absorb more heat because the water droplets absorb more heat due to greater surface area availability. Fog and water spray nozzles are sometimes used to assist in the dispersion of vapor releases. 

The first task was to produce carriers from different recipes and in different shapes as shown schematically in Fig. 8. The raw materials diatomaceous earth, water and various binders are mixed to a paste, which is subsequently extruded through a shaped nozzle and cut off to wet pellets. The wet pellets are finally dried and heated in a furnace in an oxidising atmosphere (calcination). The nozzle geometry determines the cross section of the pellet (cf. Fig. 3) and the pellet length is controlled by adjusting the cut-off device. Important parameters in the extrusion process are the dry matter content and the viscosity of the paste. The pore volume distribution of the carriers is measured by Hg porosimetry, in which the penetration of Hg into the pores of the carrier is measured as a function of applied pressure, and the surface area is measured by the BET method, which is based on adsorption of nitrogen on the carrier surface [1]. 

Break-up of the jet occurs as follows. Ligaments of liquid are tom off, which collapse to form drops. These may be subsequently blown out into films, which in turn further collapse to give a fine spray. Generally, this spray has a small cone angle and is capable of penetrating far greater distances than the pressure nozzle. Small atomisers of this type have been used in spray-drying units of low capacities. 

In these equations, C is the humidifier solids concentration in ppm, Q is the total air-conditioned flow rate in CFM, F is the total, single path penetration efficiency of the air-handling equipment, p is the density of water (= Igm/cm ), GPM is the humidifier flow rate in gallons per minute, N is the number of humidifier nozzles or heads, W is the weight rate in pounds per hour emitted by each humidifier unit, and x, as above in Equation 3, is the humidifier on-time fraction. 

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