Process Engineering Equipment Handbook Episode 2 Part 5 pps

are easily dropped and lost. For example, a 60-in ID vessel made by this information source has only 20 removable parts (not counting the filter cartridges) as opposed to 235 parts in a conventional design. There are no support arm threads to become stripped, and no support arms. This avoids the difficult job of removing a collapsed filter cartridge from a support arm. The design of the retainer assembly allows all maintenance work to be done through a small closure (below), with substantial savings in first cost as well as in man-hours in removing and resealing the closure. Gas filters are designed for both operating efficiency and clean-out efficiency. To make the cartridge replacing operation as quick and simple as possible, a quick- demountable filter cartridge retainer assembly is used in all vessels of 30-in shell diameter and larger. The result is a substantial saving in both man-hours and down-time whenever cartridges are replaced. Not all foreign matter from the gas stream is deposited on the filter cartridges. In any gas filter there is a gradual buildup of rust, scale, and other gas line dirt on the inner surfaces of the shell, especially at the bottom. This phenomenon is used by directing the incoming gas into a generously sized inlet chamber (① in Fig. F-13), where the abrupt drop in velocity allows the heavier particles to fall out of the gas stream by gravity before they reach the filter cartridges. Thus the filter cartridges’ dirt-holding capacity is used to best advantage in trapping the hard-to-catch fine particles. The material collected in the shell is removed from gas filters. There are no longitudinal support arms for the filter cartridges, so that when the cartridges are removed, the filter chamber (② in Fig. F-13) is empty of all structural parts. The standpipes that connect to the cartridge outlets are arranged in a square rather than a diagonal pattern, with plenty of room between them for dirt to fall through to the bottom of the shell. In addition, the cartridges and standpipes are positioned well above the bottom, clear of accumulated dirt. Because of the design of the cartridge retainer assembly and location of the cartridges themselves, all of this servicing can be done by one person, standing outside the vessel. Sizing and performance For this original equipment manufacturer’s (OEM) product range, for instance, series MT multitube filters are built in sizes from 6-in through 144-in shell diameter. They are usually selected for a pressure drop of 1 / 4 to 2 psi (clean), although they can be selected or designed for other pressure drops. Filters F-9 FIG. F-13 Series MT horizontal multitube filter. (Source: Peerless.) Multitube filters remove 100 percent of all particles larger than 3 microns in diameter and 99 1 / 2 percent of all particles 1 / 2 to 3 microns. Construction Each filter cartridge consists of a small-diameter tube made up of closely packed glass fibers and covered with a knitted cotton sock. A perforated metal liner stiffens the cartridge and maintains its inside diameter against the inward-acting pressure of the gas. The shell is constructed in accordance with the latest edition of the ASME Code— with stamp. A resident National Board licensed inspector is on hand at all times to check each phase of construction. Optional features Customized construction can be provided to meet various state codes and customer specifications. An external bypass with rupture disc can be added. A davit can be installed to facilitate removing the closure head. Alternative metals can be used instead of the standard carbon steel. In-line Gas Filters* In-line gas filters (see Fig. F-14) generally provide the same gas-handling performance as (series MT for this information source) multitube filters. They are built in two configurations—vertical (VGF) and horizontal (HGF). (VGF and HGF are both model designations specific to this manufacturer.) The inlet and outlet nozzles are opposite each other, on a common centerline, near one end of the vessel. This arrangement simplifies connections and allows installation in piping runs that are too short for other filter designs. Sizing and performance VGF and HGF filters are built in sizes from 6-in through 24-in shell diameter. They are usually selected for a pressure drop of 1 / 4 to 2 psi (clean). Like the MT filters, they are guaranteed to remove 100 percent of all particles larger than 3 microns diameter and 99 1 / 2 percent of all particles 1 / 2 to 3 microns. Construction Each filter cartridge is made up of closely packed glass fibers covered with a knitted cotton sock. The cartridge is stiffened by a perforated metal liner. It is held in place by a longitudinal rod and wingnut. The shell is ASME Code stamped, as in the series MT. The O-ring closure allows quick access to the interior. Optional features A davit can be installed to facilitate removing the closure head. A mounting base (cylindrical in the VGF, angle iron in the HGF) can be added. F-10 Filters *Source: Peerless, USA. Adapted with permission. FIG . F-14 In-line gas filter. (Source: Peerless.) F-11 Flare Stacks (see also Stacks) A flare stack is a stack that conducts vented gases that are then lit at its top exit by a burner and ignition system (which has its own fuel supply line). The stack has to be a minimum distance (worked out as a function of substances being flared and their heat-release rates) from the rest of the plant for the purpose of preventing fires, ignition, and secondary damage to other equipment such as storage tanks. Floating Covers In the petrochemical and chemical industries, evaporation losses from stored liquid product can be sizable and costly. When these products are stored in tanks, they can be covered with a movable floating cover that will eliminate evaporation. Tank manufacturers can supply suitable covers for the application in question (see Tanks). Fluidized Bed In a large-scale reaction process, a catalyst is often used to assist the reaction. To maximize catalyst surface area, the catalyst may be pulverized and then held in suspension (fluid suspension or fluidized bed). See Reactors. Forest Products These products form part of the agricultural sector in that they require that good agricultural practices, such as selective log felling and timely seedling planting, be followed so that the raw material resource can be sustained. The forest products industry is also in a position to inadvertently or otherwise affect many other industries and quality-of-life factors. For instance, it has been determined that the damage done to much of the Canadian west coast salmon stock was a result of high levels of lumber mill sawdust that clogged salmon spawning grounds. Deforestation that occurs if logging is not done selectively has severe consequences, including loss of wildlife habitat (see Ecosystem) with consequential loss of revenue for personnel who work in these areas and soil erosion. It is widely accepted that had severe deforestation occurred in the rain forest around the Panama Canal, the canal would have been irretrievably clogged with eroded soil soon after. The forest products industry, therefore, is an industry that could be thoroughly interwoven into the community in which it is located. As an illustration, the following extracts adapted from the 1997 AssiDomän company report regarding its corporate environmental objectives are included here. Further understanding of this material is evident by reading the sections on Environmental Economics and Pulp and Paper; and the total material summaries, the material on the contemporary forest and timber industry, and the packaging materials production data in this section. Contemporary Forest and Timber Industry Practices* In many countries of the world, the forest products industries carry on as before, with developers hastily cutting, clearing, and burning down forest to make their F-12 Flare Stacks *Source: AssiDomän, Sweden. Adapted with permission. products. This form of production is not sustainable. In the United States and Canada, consumption of forest materials in industry is still high compared to the western European countries that aim at maximizing the output from forest products, thereby minimizing their use and maintaining other practices that help ensure their raw material supply will be sustainable. Case study 1: Forestry management at AssiDomän This case describes typical, sophisticated, state-of-the-art western European management of the raw materials required for forest products. See also Tables F- 2 and F-4 through F-6 and Figs. F-15 through F-17. Note that measures involving emissions reduction take on considerably more significance in a country with NO x and SO x taxes (like Sweden). Forestry work ᭿ All forest management regions work in accordance with the Environmental Management System (EMS) standard ISO 14001. This means that they have established a local environmental policy as well as goals and programs for their environmental work. EMS registration was not possible for forestry until 1997, so work is currently focused on ISO 14001. ᭿ The forest management regions in Kalix, Älvsbyn, Lycksele, Örebro, and Värnamo were approved for certification in accordance with ISO 14001. See Fig. F-16. ᭿ The two timber units started work with the introduction of EMS. ᭿ More than half of AssiDomän’s productive forest land area, 1.7 million hectares, was approved during 1997 in accordance with the Forest Stewardship Council’s (FSC) Swedish standard for certification of forestry. ᭿ Ecological landscape plans will be drafted for the entire forest holdings by 2002. Forest Products F-13 FIG. F-15 AssiDomän operations regions in Sweden. (Source: AssiDomän.) ᭿ New directions for precommercial thinning were put into use during the year. Regeneration planning prior to final felling was finished in time for the 1998 field season. ᭿ This source imported 11 percent of the pulp and paper industry’s wood needs in the form of roundwood and chips during 1997. The imported wood comes mainly from the Baltic states and otherwise from Finland, Russia, Germany, and Brazil. F-14 Forest Products TABLE F-2 Activities on Corporate Environmental Objectives Corporate Environmental Objectives 1997 Outcome Further Work To certify the Group’s forest More than half of the forest holdings The remaining forest holdings are expected holdings in accordance with were certified during the year. to obtain certification during the first half FSC’s standard during 1997. of 1998. That all units will have begun Approx. 90% of the units have begun Some 15 units are expected to be certified in the work on introducing EMS this work. Some 15 units were 1998 and the remainder in 1999 and 2000. by year-end 1997. approved for certification according to ISO 14001 and/or EMAS registration. To implement cost-effective Life-cycle assessments are an important The environmental objective remains. The environmental measures based part of the environmental work and Group’s environmental work will be on life-cycle assessments. have been used in product pursued in a holistic perspective. development and in choice of transport mode. To achieve ecocycle compatibility An “ash restoration group” has been Field studies and development projects in the Group’s operations. Ash formed to promote the recycling continue. restoration in large-scale tests. of ashes and residual products to the forest. A field study has been started. To reduce the use of fossil fuels, The environmental objective was not The environmental objective remains. As a mainly at the Group’s pulp achieved at most mills in 1997. At result of modernizations and other strategic and paper mills. some mills use has increased as a investments in energy and recovery result of production increases and systems in the mills, the use of fossil fuels higher prices for biofuels than oil is expected to decline progressively up to (due to national energy tax policy) the turn of the century. A black liquor and rebuilding work in the plants. gasification plant is being designed at The biofuel boiler at AssiDomän Frövi AssiDomän Kraftliner. This will yield was rebuilt, permitting increased higher energy efficiency and increase biofuel use. Energy-saving measures electricity production from biofuel. have been implemented at AssiDomän Skärblacka so that oil use will be reduced by 9000 m 3 per year. To collaborate with carriers in Collaboration with carriers in transport The environmental objective remains. Work is projects aimed at greater of both timber and finished products. being pursued in prioritized areas. environmental compatibility Reduced specific transport volume has and shorter transport distances. been achieved by scheduled route transport. Environmental questionnaires are used to evaluate carriers. Environmental calculations comprise part of the basis for choice of transport mode. To promote the development of Several new packaging solutions with Working toward the environmental objective lighter weight and more common environmental profiles were is integrated in the daily work of resource-efficient packaging developed during the year. Reduced developing new products. materials and packaging. packaging weight is an important factor in this work. To participate in and carry to AssiDomän has been represented in the AssiDomän will actively participate in completion the joint sectoral management of the project, which continued activities within the sector’s environmental research project will be concluded in 1998. environmental research. within SSVL. SOURCE: AssiDomän. Forest Products F-15 TABLE F-3 Production Data on Barrier Coating 1997 1996 Per Tonne Per Tonne Total End Product Total End Product Paper raw material, tonnes/kg 131,700 881 110,400 870 Plastic, tonnes/kg 26,800 179 25,500 200 Fossil fuels, TJ/GJ 108 0.7 120 0.9 Purchased electricity, 44 0.30 32 0.25 GWh/MWh SO 2 , tonnes/kg 1 1 0.007 1 0.006 NO x , tonnes/kg 1 19 0.13 9 0.07 Production of plastic-coated 149,500 127,000 paper, tonnes By-products to recycling, tonnes 5,450 8,850 1. Estimated values. TABLE F-4 Total Material Summary of AssiDomän Operations: Forest Management Regions (8 Units) 1997 1996 Raw material use Harvested own forest, excl. standing timber, 1000 sm 3 ub 6,190 5,930 of which harvested with own machinery, 1000 sm 3 ub 3,600 3,760 of which harvested by contractors, 1000 sm 3 ub 2,590 2,170 Purchased forest, 1000 sm 3 ub 1,160 980 of which harvested with own machinery, 1000 sm 3 ub 120 50 of which harvested by contractors, 1000 sm 3 ub 1,040 930 Total wood raw material, 1000 sm 3 ub 7,350 6,910 Oils, m 3 730 625 of which vegetable, m 3 240 ND Fertilizer, tonnes N 360 350 Energy use Total fossil fuels, own machinery, TJ 245 445 3 Emissions to air 1 SO 2 , tonnes 0.2 0.7 NO x , tonnes 320 615 CO 2 fossil, tonnes 18,100 33,200 Waste Hazardous waste, m 3 2 156 145 Recovered spent oil, % 32 23 Land Total land area, 1000 ha 4,49 4 4,430 Productive forestland, 1000 ha 3,280 3,320 Cultivated forestland, 1000 ha 3,030 5 3,090 Finally felled area, ha 26,800 28,700 Products Wood to AssiDomän, 1000 m 3 fub 5,020 3,690 Wood, sold externally, 1000 m 3 fub 2,330 3,220 Total wood delivered, 1000 m 3 fub 7,350 6,910 ND = No data available. 1. From own machines. 2. Collected oil. 3. Over available estimated values. 4. Incl. 123,000 ha not inventoried previously. 5. Certain areas have been redefined in conjunction with ecological landscape planning. Total Total Continued environmental work. All forest management regions and timber units were certified according to ISO 14001 during the first half of 1998. At the same time, AssiDomän’s entire holdings of productive forest land were FSC-certified. With the introduction of EMS, each unit set up environmental objectives. Examples of areas covered by the objectives are: reduced usage of fossil fuels, improved waste management and resource management, and programs for the preservation of biodiversity in the forest landscape. The FSC certification affects AssiDomän’s forestry practices in a number of ways. Some of the more important changes are the requirements on an increased hardwood fraction and controlled burning on forest land, and the fact that more deadwood should be left. Besides consideration for the environment, the FSC’s criteria also include economic and social consideration. One example of the latter is that consideration be given to reindeer herding. Ecological balance sheet. For the purpose of evaluating how well the forest-related objectives have been achieved, internal follow-up has been done since 1993 in the F-16 Forest Products TABLE F-5 Total Material Summary of AssiDomän Operations: Sawmills and Wood Processing (11 Units 1 ) 1997 1996 Raw material use Wood, 1000 sm 3 ub/sm 3 ub 2,380 2.2 2,090 2.1 Oils, m 3 /dm 3 2 233 0.21 200 0.20 Externally supplied energy Fossil fuels, TJ/GJ 90 0.082 73 10.073 Purchased thermal energy, TJ/GJ 3 194 0.18 234 0.23 Purchased electricity, GWh/MWh 96 0.088 92 0.092 Emissions to air 4 SO 2 , tonnes/kg 33 0.030 37 0.037 NO x , tonnes/kg 179 0.16 142 0.14 Particles, tonnes/kg 78 0.071 95 0.095 CO 2 fossil, tonnes/kg 6,810 6.2 4,850 4.9 CO 2 biogenic, tonnes/kg 97,500 89 82,600 83 Residual products and waste Hazardous waste, m 3 /dm 3 5 45 0.04 60 0.06 Landfilled material, m 3 /dm 3 16,000 15 24,000 24 Products Sawn timber, 1000 m 3 1,100 1,000 By-products for external delivery Sawdust, bark, chips, 1000 m 3 /m 3 1,210 1.1 1,020 1.0 Pulp chips, 1000 m 3 /m 3 6 2,050 1.9 1,820 1.8 Heat, GJ/MJ 7,100 6.4 1,200 1.2 1. Of which one unit was sold as per 31 March 1997 and one as per 31 December 1997. 2. Lubricating and hydraulic oils. 3. Based on biofuels. 4. Only from own energy generation. 5. Collected oil and chemical residues. 6. Raw material for the pulp industry. Total Per m 3 Sawn Timber Total Per m 3 Sawn Timber Forest Products F-17 TABLE F-6 Total Material Summary of AssiDomän Operations: Transport Activities 1997 1996 3 Transport volume 1 Road, mill. tonne-km 2,860 1,770 Sea, mill. tonne-km 5,230 4,800 Rail, mill. tonne-km 1,670 1,240 Total, mill. tonne-km 9,760 7,810 Energy use Fossil fuels, TJ/MJ 3,420 0.35 2,330 0.30 Electricity, GWh/kWh 68 0.007 57 0.007 Emissions to air SO 2 , tonnes/g 1,670 0.17 1,710 0.22 NO x , tonnes/g 3,630 0.37 3,610 0.47 CH, tonnes/g 2 225 0.023 185 0.024 CO 2 fossil, tonnes/g 254,000 26 181,000 23 1. Return trips only included for system traffic at sea. 2. Hydrocarbons. Common key figure for transport emissions. 3. Excl. Central and Eastern Europe. Total Per tonne- km Per tonne- km Total form of an ecological balance sheet. The balance sheet is a good aid in the further training of forestry workers. See also Figs. F-18 through F-22. The grades for final felling show that the former trend of improvements from year to year has been improved. This is true for site-adapted forestry as well as for nature and water conservation. The number of evaluated categories, as well as the requirements for getting the highest grade for the individual site, have gradually increased as knowledge has grown and the criteria for FSC certification have taken firmer shape. An example of a new category for the year 1997 was evaluation of whether the nature conservation measures were concentrated and targeted correctly within the felled site. Only 44 percent of the final felling area received the highest grade in this respect. This is an important, but difficult, category that will require further training. On more than 16 percent of the evaluated sites, so many trees have been left on the productive land that an appreciable portion of these trees are not judged to contribute to better functional nature conservation. Here the production target was disregarded, resulting in a lower yield. The 1997 balance sheet showed that on 88 percent of the final-felled area, the best possible combination of felling method, tree species, and regeneration method were chosen. The thinnings in the 1997 balance sheet showed no great changes in grades compared with 1996. Water conservation improved slightly, however. The removal of hardwood trees in the thinnings decreased since the introduction of the new thinning instruction in 1996. However removals were still too high to meet the long- range target of a 10 percent hardwood fraction of standing timber. Precommercial thinning was included in the ecological balance sheet starting in 1998: It is important for tying together the follow-up of stand management during the entire rotation period. [...]... Value, MJ/kg (Btu/lb) 42. 7 43.0 43 .2 44 .2 45 .2 19.9 26 .8 41 .2 39.6 (18,400) (18 ,50 0) (18,600) (19,000) (19,400) (8 ,55 5) (11, 52 2 ) (17,700) (17,000) Comments* (1), (2) (2) (2) , (2) , (2) , (2) , (7), (7), (2) ( 12) , (13), (14) ( 12) , (13), (14) ( 12) ( 12) (13) ( 15) * Comments nomenclature: (1) standard fuel; (2) clean burning; (3) needs vaporization; (4) low transportation and storage cost; (5) medium transportation... furnace gas Coke oven gas Hydrogen 35. 5 (900) 35. 5 (900) 104.8 (2, 700) 91 .2 (2, 300) 118 .5 (3,000) Varies 3.6 (90) 11.8 (300) 10.8 (27 0) Comments* (1), (2) , (2) , (2) , (2) , (7) (7), (7), (9), (2) , (4) (3), (6) (3), (5) (5) (5) (8), (17) (11), (14), (16) (10), (16) * Refer to comments nomenclature below Table F-9 TABLE F-9 Liquid Fuels for Gas Turbines Fuel Distillate No 2 Kerosene (K-1) Jet A Naphtha Condensate... conversion of combustible process waste to marketable Forest Products F -23 TABLE F-7 Production Data on Sacks 1997 Total Paper raw material, tonnes/kg Fossil fuels, TJ/GJ Purchased electricity, GWh/MWh SO2, tonnes/kg* NOx, tonnes/kg* Landfilled waste, tonnes/kg Sack production, tonnes By-products to recycling, tonnes 156 ,000 177 38 9 18 3,190 7 45 5,660 Per 1,000 Sacks 20 9 0 .24 0. 05 0.0 12 0. 024 4.3 * Estimated... larger, 99 percent for particles of 6 to 8 microns, 90 percent for particles of 4 to 6 microns, and 85 percent for particles of 2 to 4 microns See Fig F- 32 Vertical absolute separators Definition: Vertical single or two-stage separator for removal of solids and very fine mists with liquid removal efficiency of 100 percent for particles 3 microns and larger, and 99.98 percent for particles less than 3 microns... actuators: Medium Natural gas Diesel oil Water Nominal Widths Up to 20 0 mm (8 in) Up to 100 mm (4 in) Up to 100 mm (4 in) Nominal Pressure Stages Up to 63 bar (914 psig) Up to 160 bar (23 20 psig) Up to 160 bar (23 20 psig) Performance parameters: ᭿ Maximum flow rate of gas valves: 450 m3/h (19 82 GPM) ᭿ Maximum flow rate of oil/water valves: 160 m3/h (7 05 GPM) ᭿ Design of the valves to: ANSI or DIN specifications... Current: 25 to 60 ma max Position switch Voltage: 28 VDC Current: 2. 5 amp Connector: Terminal block INSTALLATION DATA: Flanges: Per ANSI B16 .5, 1 .5 inch pipe, Class 600 both ends WEIGHT: 80 lb max PERFORMANCE: Flow: 0 to 4.0 lb/sec, in direction shown effective area linearly propertional to valve stroke Accuracy ±1% from 1.0 to 4.0 lb/sec Pressure: Operating: 100 to 600 psig Proof: 1,440 psig DP: 15 psid... with permission Fuel Gas Conditioning System(s) FIG F -24 Key environmental data for AssiDomän Frövi (Source: AssiDomän.) F - 25 F -26 Fuel Gas Conditioning System(s) FIG F - 25 Position of vertical dry scrubber upstream of gas turbine (Source: Peerless.) FIG F -26 Pressure regulating station (PRS) upstream of vertical dry scrubber (Source: Peerless.) FIG F -27 Vertical gas scrubber upstream of pressure regulating... for particles of 10 microns and larger See Fig F-31 Filter separators Definition: Vertical or horizontal two-stage separators for removal of solids and liquids with liquid removal efficiency of 100 percent for particles of 8 microns and larger and 99 .5 percent for particles of 0 .5 to 8 microns Solids removal efficiency: 100 percent for particles that are 3 microns and larger and 99 .5 percent for particles... From the source the gas is piped to a coastal location where it is processed to remove impurities and inerts After extracting heavy ends, the processed gas is finally refrigerated to make LNG and stored at atmospheric pressure and at a temperature of approximately -160°C ( - 25 6°F) After the LNG is loaded into a tanker (generally 1 25 ,000/1 35, 000 m3) and transported, it is offloaded into storage tank(s) at... Suitable liquid fuels include: ᭿ Distillate No 2 (diesel fuel) ᭿ Kerosene (K-1) ᭿ Jet A ᭿ Naphtha ᭿ Condensate fuels ᭿ Methanol (CH3OH) ᭿ Ethanol (C2H5OH) ᭿ Crude oil ᭿ Heavy fuel oil * Source: Adapted from extracts from Narula, “Alternative Fuels for Gas Turbine Plants—An Engineering, Procurement, and Construction Contractor’s Perspective,” ASME paper 98-GT- 122 F-38 Fuels, Alternative; Fuels, Gas Turbine . 0.007 57 0.007 Emissions to air SO 2 , tonnes/g 1,670 0.17 1,710 0 .22 NO x , tonnes/g 3,630 0.37 3,610 0.47 CH, tonnes/g 2 2 25 0. 023 1 85 0. 024 CO 2 fossil, tonnes/g 25 4,000 26 181,000 23 1. Return. machinery, TJ 24 5 4 45 3 Emissions to air 1 SO 2 , tonnes 0 .2 0.7 NO x , tonnes 320 6 15 CO 2 fossil, tonnes 18,100 33 ,20 0 Waste Hazardous waste, m 3 2 156 1 45 Recovered spent oil, % 32 23 Land Total. air 4 SO 2 , tonnes/kg 33 0.030 37 0.037 NO x , tonnes/kg 179 0.16 1 42 0.14 Particles, tonnes/kg 78 0.071 95 0.0 95 CO 2 fossil, tonnes/kg 6,810 6 .2 4, 850 4.9 CO 2 biogenic, tonnes/kg 97 ,50 0 89 82, 600