Sulfur steam heated pumps

Molten sulfur has a viscosity (-0.01 kg m 1 s 1, 400-420 K, Fig. 3.2) about ten times that of water (-0.001 kg m 1 s 1, 293 K). Its density is 1.8 kg/m3. It is easily moved in steam jacketed steel pipes (Jondle and Hombaker, 2004). Steam heated pumps much like that in Fig. 9.2 are used. Molten sulfur is an excellent lubricant at 410 K. Sulfur pump impellers need no additional lubrication. 

On the surface, the Hquid sulfur moves through steam-heated lines to a separator where the air is removed. Depending on the mine location, the Hquid sulfur may be pumped to storage vats to be solidified, to tanks for storage as a Hquid, to pipelines, or to thermally insulated barges for transport to a central shipping terminal. 

Portable batch plants have also been built to melt and blend composites on-site. These are useful for larger applications where multiple batches of composite are required. One such unit, built and maintained in Canada, consists of two steam-heated vessels mounted on a common skid. They can be used to convert sulfur into composites or to melt preblended composite delivered to the site in solid form. The vessels have capacities of 1500 and 800 gal. The pump and manifold system has a dual function to transfer sulfur and composite to and from the vessels or to spray-apply composite directly from the tanks via heated hoses. 

The chemical plant consists of a single-effect vacuum evaporator system for regenerating the solution and liberating the sulfur dioxide. Indirect heat is supplied to the forced-circulation evaporator by using exhaust steam from the refinery. The vacuum is supplied by a liquid ring vacuum pump which also pumps the sulfur dioxide back into the front of the Claus plant. 

Solid sulfur is dumped on the grids of the melter and is melted by means of the heat provided through steam coils in the melter. An agitator installed in the melter helps to melt the sulfur at a faster rate. Liquified sulfur is pumped to the pressure leaf filter and the purified sulfur stored in a separate compartment equipped with steam coils. Sulfur pumps are used to feed the liquid sulfur to the sulfur burner at a... 

Steam is also consumed in the plant for keeping the sulfur in the settling and pumping sections in a molten state, for heating the sulfur filter jacket, and for keeping the sulfur pumps and feed lines hot. 

Per kg cathode material, 30-50 kWh energy is required to create process heat for cogeneration, milling, pumps, dryers and furnaces. For lithium iron phosphate (LFP), 50-100% more energy is needed. The ideal energy input mix consists of one-third electricity, one-third natural gas (for heat treatment) and one-third steam (medium/high pressure). Utility and auxiliary materials for cathode production include ammonia, water (condensate), caustic and hydrochloric acid and sulfuric acid. These materials typically account for 1 USD/kg of cathode material. 

Heat generated by the roasting reactions is lost from the hood of the machine and in sinter gases from which heat is not recovered as steam. Otherwise energy input is in the form of electric power to a wide range of fans to supply combustion air and handle sinter plant gases, as well as miscellaneous pumps, conveyors, the drive motors for the sinter strand and product sinter crushers, and feed conditioning equipment. Total electrical power input is related to the sulfur burned, which defines the gas flow and size of the sinter hearth area and is 300 kWh/t of sulfur burned or 90 kWh/t of product lead. 

Rich DMA solution from the bottom of the absorber is heated by indirect exchange with hot, lean DMA and is then fed near the top of the stripping column where it is stripped of its sulfur dioxide content by steam. The resulting hot, lean DMA (with condensed steam) is passed through the exchanger, cooled further, and pumped to a separator from which lean DMA is withdrawn as liquid feed to the absorber. The aqueous stream from the sulfurous acid section of the absorption tower is neutralized with ammonia in this separator, releasing... 

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