Preheating process parameters

In chemical plants, in steam and gas turbine powered compressor and power stations and pressure control facilities for natural gas, combustible fluids and gases need to be preheated in order to comply with the process parameters,... 

Oldfield, D.J. Taylor, M.W. Singh, H. Effect of preheating and other process parameters on whey proteins reactions during skim milk powder manufacture. International Dairy Journal, 2005, 75,501-511. 

In Fig. 7.2 a thermoplastic filament winding process consisting of a material rack, a tension controller, a preheating zone, a main heater, a consolidation roller and a mandrel is shown schematically. Beside the material used, the most adjustable process parameters are winding velocity (which is defined by mandrel rotation and crosshead movement), roving tension, temperature, winding angle and mandrel/liner (material and temperature control). 

Figure 22.6. Exemplariiy iiiustrated machine settings for the process parameters of the preheating, hot-compaction and cooling sequence for manufacturing of SR-PP composites...

The shown start-up example did not include an optimization or exploration of optimizing the start-up time. But several parameters can be adjusted to affect the dynamic characteristics of the initial preheating process of the reformer in question fuel flow, air-to-fuel ratio, oxidant supply control, and steam-to-carbon ratio. 

Different mandrel rotational speeds, consolidation pressures, and preheating and consolidation temperatures were used to manufacture pipes from towpregs and to verify the influence of these processing parameters on the mechanical properties. The circumferential tensile strength of the pipes was tested in an Instron 4505 machine using the split disk test method according to ASTM 2290 at a crosshead speed of 1 mm/min. 

A DoE was performed containing two alloys SACX and Sn/Cu/Ni three substrates Immersion Tin (ImSn), Immersion Silver (ImAg), and CuOSP two fluxes and three process parameters for the solder pot, conveyor speed, and preheat temperatures. 

The pure carbon dioxide is pumped to the desired pressure and preheated to extraction temperature using a heat exchanger. The supercritical fluid is then percolated through the extraction unit packed with one or more substrates. In the precipitation unit, the supercritical solution is expanded through a nozzle that needs to be heated in order to avoid plugging by substrates precipitation. Typically used expansion nozzles are capillaries of diameter < 100 p,m or laser drilled nozzles of 20-60 p,m in diameter. The process allows control over several parameters affecting... 

One unique reactor is the preheater in the DCL process. It is a long coiled tube where the slurry is heated to the reactor temperature and as described later, for swelling coals, it may possess a peculiar thermo-hydraulic behavior. While, as described later in Table 5, available literature for various hydrodynamic, mixing, and transport parameters can be applicable to the reactors, their applicability to the preheater is questionable. More work is needed in understanding the hydrodynamic, mixing and transport characteristics of the preheater. 

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