Exchange nozzles

The following table gives suggested maximum velocities in exchanger nozzles. The pressure drop through nozzles should be checked, especially where pressure losses are a problem such as in low pressure systems. 

Nozzles should be sized with or checked against the sizes of the incoming or outgoing lines. Often the exchanger nozzle must be larger than the pipe in order to keep velocities low to prevent erosion or high pressure drop. 

F. Feed/effluent exchanger nozzle-to-shell weld, cracks in welds and in exchanger tubes. 

Calculations relating to the sizing of the exchanger nozzle inlets and outlets are presented in Appendix H.12. 

Avoid excessive piping strains on exchanger nozzles from the actual weight of pipe and fittings and from forces of thermal expansion. 

Instruments. Locally-mounted pressure and temperature indicators on exchanger nozzles or on the shell or process lines should be visible from the access aisles. 

Carbides SiC, B,C Refractory materials, kiln furniture, varistors, wear parts, heat exchangers, nozzles, abra.sives/grinding wheels... 

EXHIBIT 6-27 Alternative Arrangements for Locating Exchanger Nozzles... 

Nozzle Connections on the side of vessels and heat exchangers. Nozzles come in standard sizes corresponding to standard pipe diameters. 

I ll match up with the piping. If the piping is smaller than my calculated exchanger nozzle sizes, then Til retain my larger exchanger nozzle sizes. 

In order to maintain high energy efficiency and ensure a long service life of the materials of construction in the combustion chamber, turbine and jet nozzle, a clean burning flame must be obtained that minimizes the heat exchange by radiation and limits the formation of carbon deposits. These qualities are determined by two procedures that determine respectively the smoke point and the luminometer index. 

In other useful appHcations, siHcon nitride bearings have been found to offer exceUent performance siHcon nitride cutting tool inserts are a commercial product wear parts such as sand blast nozzles, seals, and die liners are also commercially produced the superior performance of heat exchangers has been demonstrated and there are also military appHcations. 

The pressure difference between the inlet and outiet nozzles on either the sheUside or tubeside of a heat exchanger may be written in the form... 

Figure 12 shows the plan and elevation views of a process unit piping (9). A dmm is supported off the piperack. Heat exchangers are located far enough back from the support columns so that they are accessible and their shell covers can be removed. Pumps are located underneath the piperack, but sufficient room is provided for maintenance equipment to access the motors and to remove the pump if necessary. The motor is always oriented away from the process equipment and located on that side of the piperack. Instmment valve drops are shown supported from the columns. The instmment trays themselves mn on the outside of the support columns. Flat turns are only made from the outside position of the piperack. Nozzle-to-nozzle pipe mns are made whenever possible. Larger lines are located on the outside of the piperack. Connections to nozzles above the rack are made from the top... 

Most of the commercial gas—air premixed burners are basically laminar-dow Bunsen burners and operate at atmospheric pressure. This means that the primary air is induced from the atmosphere by the fuel dow with which it mixes in the burner passage leading to the burner ports, where the mixture is ignited and the dame stabilized. The induced air dow is determined by the fuel dow through momentum exchange and by the position of a shutter or throtde at the air inlet. Hence, the air dow is a function of the fuel velocity as it issues from the orifice or nozzle, or of the fuel supply pressure at the orifice. With a fixed fuel dow rate, the equivalence ratio is adjusted by the shutter, and the resulting induced air dow also determines the total mixture dow rate. 

Process simulators stop generally at the process specifications for the equipment. For the detailed mechanical design of the equipment, such as heat exchangers and distillation columns, stand-alone programs are often used. They make process calculations, size the equipment, calculate thermal and mechanical stresses, design mechanical support of the parts of the equipment, design inlet and outlet nozzles, etc. 

Hydraulic jetting with water forced through spray nozzles at high pressure for cleaning tube interiors and exteriors of removal bundles is reported by Canaday ( Hydrauhc Jetting Tools for Cleaning Heat Exchangers, ASME Pap. 5S-A-2I7, unpublished). 

Tube-Side Passes Most exchangers have an even number of tube-side passes. The fixed-tube-sheet exchanger (which has no shell cover) usually has a return cover without any flow nozzles as shown in Fig. 11-35M Types L and N are also used. All removable-bundle designs (except for the U tube) have a floating-head cover directing the flow of tube-side fluid at the floating tube eet. 

Maximum Recommended Velocities Through Nozzle Connections, Piping, etc. Associated With Sheil and/or Tube Sides of Heat Exchanger... 

The simplest type of shell-and-tube heat exchanger is shown in Eigure 3-1. The essential parts are a shell (1), equipped with two nozzles and having tube sheets (2) at both ends, which also serve as flanges for the attachment of the two channels or beads ( 3) and their respective channel covers (4). The tubes are expanded into both tube sheets and are equipped w nil transverse baffles (5) on the shell side for support. The calculation of the effective heat transfer surface is based on the distance between the inside faces of the tube sheets instead of the overall tube length. 

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