Heat pipe Reactor

Whiie the NRPCT deveioped reactor plant concepts for gas reactors, liquid metal reactors, and heat pipe reactors as part of the concept selection in early 2005, the Jet Propulsion Laboratory (JPL) - the NASA lead for the Prometheus program work, and Northrop Grumman Space Technology (NGST) - the selected spacecraft contractor, developed a preliminary spacecraft arrangement, called the Prometheus Baseline 1 (PB1). The PB1 reactor plant concept was a liquid metal reactor with multiple Braytons. Redundant Braytons were assumed for several reasons ... 

The hydrocarbon gas feedstock and Hquid sulfur are separately preheated in an externally fired tubular heater. When the gas reaches 480—650°C, it joins the vaporized sulfur. A special venturi nozzle can be used for mixing the two streams (81). The mixed stream flows through a radiantly-heated pipe cod, where some reaction takes place, before entering an adiabatic catalytic reactor. In the adiabatic reactor, the reaction goes to over 90% completion at a temperature of 580—635°C and a pressure of approximately 250—500 kPa (2.5—5.0 atm). Heater tubes are constmcted from high alloy stainless steel and reportedly must be replaced every 2—3 years (79,82—84). Furnaces are generally fired with natural gas or refinery gas, and heat transfer to the tube coil occurs primarily by radiation with no direct contact of the flames on the tubes. Design of the furnace is critical to achieve uniform heat around the tubes to avoid rapid corrosion at "hot spots."... 

The reactor is a pipe reactor heated with fuel gas, gross calorific value 33.5 MJ/m3. Estimate the quantity of fuel gas required. 

Pulsatile drug delivery systems, 9 57-61 Pulsating heat pipes (PHP), 13 235-236 Pulse combustion heat sources, 9 104-105 Pulse cycles, 9 778 Pulsed baffle reactors, 15 709-710 Pulsed discharge detector (PDD) gas chromatography, 4 614 Pulsed dye lasers, 23 144 Pulsed electrochemical machining (PECM), 9 604-605... 

Powdered niobium metal, 20.0 g. (—200 mesh), and tin(II) fluoride, 52.0 g. (40 mesh),t are mixed in a molybdenum crucible in an Inconel- or nickel-pipe reactor approximately 3 in. in diameter and 10 in. long and heated to 400-500°C. in a stream of dry nitrogen. The niobium(V) fluoride volatilizes from the reaction mixture and condenses on the water-cooled lid of the reactor, which leaves metallic tin in the crucible. The yield of niobium(V) fluoride is 21.1 g., or 95% of theoretical. A very small amount of blue niobium oxyfluoride (composition of variable oxygen and fluorine content) often forms as an impurity because of the presence of minute amounts of oxygen. Anal. Calcd. for NbFs Nb, 49.44 F, 50.56. Found Nb, 49.43 F, 50.2. 

High-intensity inline devices are often used to mix fluids in the process industries. Such devices include simple pipes, baffled pipes, tees, motionless mixers, dynamic mixers, centrifugal pumps, ejectors, and rotor/stator mixers. In addition to their traditional application in physical processes such as mixing and dispersion, such devices can provide very effective environments for mass transfer and chemical reaction to take place. Furthermore, combining effective inline mixing with heat transfer is the basis of combined heat exchanger reactors (HEX reactors). 

Neutralizers may be free-boiling vessels, circulating systems or pipe reactors. The water in the nitric acid is evaporated by the heat of reaction (550 to 620 BTU/lb of AN, depending on the acid strength). At least ten different types and designs of neutralizers are used in Europe. The factors that influence the choice of neutralizer are103 ... 

In an attempt to further simplify DAP plants and reduce the recycle ratio, TVA, CROS S.A., and ERT - Espindesa have tried to use pipe reactors (also called T reactors or pipe-cross reactors) directly releasing slurry in the rotary granulator, instead of applying a preneutralization tank. CROS and ERT -Espindesa report successful operation, but experiences in several U.S. plants were disappointing because of high heat input in the granulator296. 

The pipe reactor processes have been very successful in MAP production. They operate with a very slight ammonia loss, and little or no additional heat is required for drying. In some plants, preneutralizers have been replaced by pipe... 

The heat transfer piping system is not simple. There were three reactors and the heat transfer system is used for both heating and cooling the reactor. The circulating fluid heats the reactor to several hundred degrees Fahrenheit to startup the reaction. Once the very exothermic reaction is under way, the circulating heat fluid removes heat from this reactor. (See Figure 8—1.)... 

The mechanical integrity focus of this section covers stationary existing chemical processing plant equipment and piping. Equipment includes storage tanks, pressure vessels, dryers, heat exchangers, reactors, incinerators, columns, filters, knock-out pots, and so forth. As previously stated, this section assumes the equipment is designed and fabricated to... 

The next sections describe three reactor studies with emphasis on the lithium-structure compatibility. HYLIFE is a liquid metal wall (LMW) ICF reactor considered here for electricity production. It has also been adapted to fissile fuel production ( 5). The Tandem Mirror Reactor (TMR) Cauldron Blanket Module is an MCF concept designed to produce hydrogen. The TMR Heat Pipe Blanket Module is designed to produce either hydrogen or electricity. All three studies emphasize materials compatibility with lithium. Tritium recovery techniques and two aspects of lead-lithium liquids are also discussed. 

Close proximity of multiple heating pipes in larger reactors renders them prone to coking and fouling. 

In continuous processes, the reactants are added and products are removed at a constant rate from the reactor, so that the volume of reacting material in the reactor (reaction vessel) remains constant. Two types of reactors, either (1) a continuous stirred tank or (2) a pipe reactor, are generally used. A continuous stirred tank reactor is similar to the batch reactor described above. A pipe reactor typically is a piece of tubing arranged in a coil or helix shape that is jacketed in a heat-transfer fluid. Reactants enter one end of the pipe, and the materials are mixed under the turbulent flow and react as they pass through the system. Pipe reactors are well-suited for reactants that do not mix well, because the tiu--bulence in the pipes causes all materials to mix thoroughly. 

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