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关于脱硫系统中的GGH问题? 烟气脱硫中,增设GGH,请问国内使用业绩较好的有那几家? GGH配供的 测量仪表 ,一般包括哪些(压力、温度、流量、液位等)?查看更多 4个回答 . 5人已关注
硫回收液硫管上的视镜问题? 硫回收液硫管线上需要安装视镜么?安装视镜后能看到内部流动么?会不会 硫磺 把视镜糊住了,但是液硫仍然正常流动?视镜选择的是夹套保温视镜(不知道有没有这种视镜)么?还是给视镜伴热?查看更多 16个回答 . 5人已关注
如何计算气控管道的减压孔板直径? 气相管道,管径:DN40 板前压力:15MPa 板后压力:0.7MPa 气体体积240L,持续通过孔的时间为10分钟,此减压孔板孔径的大小如何计算?可以教给我计算方法吗?查看更多 9个回答 . 5人已关注
带夹套不锈钢反应釜或搪玻璃反应釜夹套体积如何计算? 没有标准可查吧,夹套内容积减去夹套包含部分内容器的外容积,查看更多 4个回答 . 3人已关注
公司油泥处理做冷焦使用,对于环保局来说,如何解释答复 ...? 我厂污油经处理后,在焦化切完四通后,打至 焦炭 塔泡焦冷焦,根据焦炭灰分来计算打污油量。既节约处理污油成本,又将污油掺至焦炭,但是出现个环保问题,对于环保局来说,如何让他们能对这样的无害化处理认可那?查看更多 0个回答 . 3人已关注
2015年化肥进口配额先来先领? 本文由 盖德化工论坛转载自互联网 10月15日,商务部公布《2015年化肥进口关税配额总量、分配原则》,指出企业申领化肥进口关税配额实行先来先领,直至化肥进口关税配额总量申领完毕。   根据公布的数据,2015年化肥进口关税配额总量为1365万吨。其中, 尿素 330万吨; 磷酸二铵 690万吨;复合肥345万吨。2015年化肥国营贸易配额数量分别为尿素297万吨,磷酸二铵352万吨,复合肥176万吨。国营贸易企业中国中化集团公司、中国农业生产资料集团公司在国营贸易总量内申请配额。   2015年化肥非国营贸易配额数量分别为尿素33万吨,磷酸二铵338万吨,复合肥169万吨。经备案的非国营贸易企业在非国营贸易总量内申请配额。   其他企业根据实际进口需要选择申请国营贸易配额或非国营贸易配额,由国营贸易企业或非国营贸易企业代理进口。 查看更多 0个回答 . 3人已关注
蒸汽灭菌柜的压力容器许可? 蒸汽灭菌柜是我们公司德国工厂在2013年购买的,但是由于各种原因,该灭菌柜一直未曾开箱安装使用,最近由于我们在国内的一个工厂需要增加灭菌柜,遂通过其代理商将该灭菌柜转运到国内,在等待法检过程中从进出口部门同事处得知,商检人员说不需要进行法检,我们可以直接开箱安装,投入使用前再到现场查验即可。我的疑问是虽然这个灭菌柜的欧洲制造商持有SELO的制造许可证,但是该灭菌柜的供货是针对当时的购买方德国工厂生产的,满足PED和欧洲标准要求,不一定符合中国SELO的要求。我有点糊涂了,下面该如何是好。 查看更多 2个回答 . 4人已关注
螺杆机内的冷冻机油多久换油? 螺杆机 内的 冷冻机油 多久换油最好,是一次换部分还是全部换哪种方式好 # hcbbs 查看更多 3个回答 . 3人已关注
关于法兰螺栓长度的计算? 请大家指教下,对于法兰连接所需要的紧固螺栓长度的计算方法。 两片法兰的厚度+ 密封件 的厚度+螺母厚度+平垫厚度+弹垫厚度+余量(5mm) 这样算行吗 感觉算出的数值差距有点大 , , - 查看更多 1个回答 . 2人已关注
铜洗问题:如何回收铜泵柱塞的漏液? 各位盖德,大家有什么好办法回收铜 泵柱塞 的漏液(有铜液和油)查看更多 7个回答 . 1人已关注
活性炭的吸附能力的两种表示方法?   静活性-----即通常所指的 吸附剂 达到平衡的吸附量。   动活性----是指流体 混合物 通过 活性炭 床层,其中吸附质被吸附,经一些时间的运作,活性炭床层流出的流体中开始出现含有一定的吸附质,说明活性炭床层失去吸附能力,此时活性炭上已吸附的吸附质的量,就称为活性炭的活性。是设计大量的、经常的、重要的吸附系统所需的数据。   用液相等温线法测定活性炭吸附能力的标准实用方法,可用于测定原始的和再活化的和粉状活性炭的吸什能力。   吸附分液相吸附和气相吸附两类,液相吸附能力常以吸附等温线进行评价,气相吸附能力以溶剂蒸气吸附量评价。   吸附等温线表示一定温度下吸附系统中被吸附物质的分压或浓度与吸附量之间的关系,即当保持温度不变,可测得平衡吸附量和分压或浓度间的变化关系。以剩余浓度为横轴,以活性炭单质量的吸附量为纵轴可绘出关系曲线。   当保持分压或浓度不变,可测得平衡吸附量和温度间的变化关系,绘出关系曲线,即吸附等压线。由于在工业装置中少量成分吸附大致在等温状态下进行,所以吸附等温线最为重要和常用。   溶剂蒸气吸附量表示气相吸附性能,可用颗粒活性炭的四氯化碳吸附率的测定为例,在规定的试验条件下,即规定的炭层高度、气流比速、吸附温度、测定管截面积、四氯化碳蒸气浓度的条件下,持含有一定四氯化碳蒸气浓度的混合空气流不断地通过活性炭,当达到吸附饱和时,活性炭试样所吸附的四氯化碳的质量与试样质量之百分比作为四氯化碳的吸附率。   活性炭应用中对于吸附能力,最好用实际拟用的活性炭、操作的条件、具体的处理物进行评价测试。   活性炭的吸附量,即单位 活性炭 所吸附的吸附质的量,工业上也有称为活性炭的活性。 查看更多 2个回答 . 3人已关注
甲醇全球市场预测? Over the last two decades, a major shift in regional methanol capacity and production has occurred. Countries with large reserves of natural gas and often limited domestic consumption have built world-scale methanol facilities to monetize their low-cost natural gas. The largest producing region/country in 2007 was China (more than 10 million tons); in 2012, it will continue to have the largest capacity and be the largest producer. Another significant factor is that the size of the new mega-methanol plants (1.0–2.0 million metric tons per year) is much larger than existing plants. Thus, they will have reduced fixed costs, as well as greatly reduced natural gas costs due to strategically located feedstock giving a significant cost advantage. This will drive down the cost of methanol, and cause major shifts in trade patterns. Locations for these large new methanol plants are (or will be) Iran, Saudi Arabia, Oman, and Trinidad and Tobago. These natural gas–advantaged countries export much of their product to developed regions such as North America, Western Europe and Japan. Consequently, producers in the more economically developed regions have shut down inefficient methanol capacity as cheaper imports have become more readily available. For example, Japan, once a major producer, now has no operating capacity. North American capacity accounted for 50% of world capacity as recently as the mid-1980s, but in 2007, accounted for less than 2%. This trend will continue, and in some regions, the effective capacity will be different from the nameplate capacity, as a result of expected idling of capacity. Worldwide, formaldehyde production is the largest consumer of methanol. This demand is driven by the construction industry since formaldehyde is used primarily to produce adhesives for the manufacture of various construction board products. Historically, the major end product has been plywood, but in developed countries, demand is also driven by the expanding use of engineering board products such as OSB (oriented strandboard). These wood composite products require more formaldehyde-based resin per square foot of board than plywood. Demand for formaldehyde is highly dependent on general economic conditions, and, as an example, a slowdown in construction can considerably reduce formaldehyde demand. The second-largest market for methanol worldwide is methyl tertiary-butyl ether (MTBE). In the United States, consumption increased substantially when the Clean Air Act Amendments (CAAA) of 1990 mandated that oxygenated compounds be added to gasoline as one aspect of a program to alleviate air pollution. In recent years, MTBE has come under environmental attack, primarily because it has been found in groundwater that has come into contact with leaking underground gasoline tanks. California—formerly the leading consumer of MTBE—banned the use of MTBE at the end of 2003 and several states followed suit. Methanol consumption for MTBE has been on the decline in the United States since 1999 and it is likely that MTBE’s consumption will decline further at a steady level, supported only by export-driven demand. Acetic acid is the third-largest methanol derivative. A major portion of acetic acid is consumed for the production of vinyl acetate monomer (VAM). Demand for acetic acid tracks the demand for VAM, which (globally) is projected to grow at a moderate average annual rate from 2007 to 2012. 1. MARKET PERSPECTIVES 1.1 Capacity forecast Worldwide capacity of methanol is 41 million tons in 2005, 48 million tons in 2006, 83 million tons in 2007, more than 100 million tons in 2008. The main capacity is in Middle East, Rissia, and China, almost 60 million tons of methanol. And the capacity keeps increasing rapidly. There are some big investments in Middle East as below. The future investment in methanol project (Unit: x104 ton) Area Invenstor Capacity Completion expected Iran NIOC 260 2010 Yemen Soco Yemen 165 ― Qatar PetroWorld 396 ~ 495 2008 Saudi Ar-razi 165 ― In China, methanol went through a rapid increase. The average increase rate of production capacity is 24.8%, and the average increase rate of consumption is 18.9%. In 2007, there are 177 suppliers in China, and the total capacity is 16.4 million tons. But, the production was 10.8 million tons, and the consumption is 11 million tons. The average operating rate is only 65.7%. The current number of applied methanol project is 34 (exclude the produce will be used for DME and olefin), and the capacity reaches to 26--31 million. But, for the consumption, it is difficult to be forecasted . Forecasted methanol worldwide capacity in 2008 (Unit: x104 ton) Area Comapny Capacity Area Comapny Capacity Middle East 3518 Canada Methanex Woodxard 57 Saudi Arabia Ar-razi 1# 85 Methanex Beauiont 50 Ar-razi 2# 85 Hoechst-CelaneseCanada 80 Ar-razi 3# 66 MethanexKITIMAT 50 Ar-razi 4# 66 Europe 1410 Ibn Sina 90 Russia Metafrax Gubakha 100 Al-Jubail IMC 100 Tomsk Methanol 82 SIMC 105 Matafrax 84 Saudi Arabia Bosabike Co. 170 NCK 78 TAS-nee 180 Togliatti 45 Mitsubishi Gas 150 Azot Shchyokino 36 Iran Zagros Assaluyeh 1# 165 Gazprom 32 Zagros Assaluyeh 1# 165 Novocherkasskii 32 NPC 140 Tobolsk 60 Zagros Assaluyeh 2# 165 AzotFactorySchenkino 35 Zagros 4# 165 Ukraine Swverodonetsk Azot 65 Kharg Island 66 Estonia Gazprom Qatar Qafac 1# 82.5 Germany BASF Aktiengesellschaft 45 Qatar Petro. 360 Mider-Helm Leuna 66 Qatar Fuel Additives 220 DEA Mineraloel AG 44 Ras Laftan 100 Schwarze Pumpe 14 Yemen Yemen Petrochem. 165 Viba Gelsenkirchen 30 Bahrain GPIC 42.5 Lausitzer Analytik Gmbh 10 Oman OOC 165 Mitteldeutsche Erdoel 54 OMHC 100 Ruhr Oel Gmbh 24 GT/OOC 99 BP 24 OOC 91 UK Air Poulenc PLC 52.5 Egypt Echem 130 ICI 50 Latin America 1626.5 Netherlands Methanol Co. 84 Trinidad and Tobago CaribbeanMethanol Co. 55 Methanor 1# 48 Titan Methanol 85 Methanor 2# 48 Methanex-BP 175 Methanor Delfzyl 1# 47.5 TPC/Petrocon/con 97.5 Norway National petrol. Co. 120 Atlas 170 Asia-Pacific (exclude China) 1154 Methanol Pointlisas 180 Australia GIL 100 Methanol Holding 190 Victoria 50 Chile Methanex 1# 75 Methanex 130 Methanex 2# 92.5 GIL Resources 100 Methanex 3# 97.5 Indonesia Katim 66 Methanex 4# 84 Pertamine 33 Methanex 30 New Zealand Methanex 3# 70 Venezuela Supermetanol-1# 85 Methanex 4# 70 Metor 85 Methanex 1# 55 Supermetanol-2# 85 Methanex 2# 50 Argentina Pepsol YPE 40 Malaysia Petronas 66 North America 1021.5 Petronas 170 USA Celanese (Texas) 60 India Pertamina 33 Celanese BISHOP 50 Deepar 10 Borden 99 Vietnam Petrovietnam 66 Terra 85 Brunei MGC 85 BMC 60 Africa 676 MilleaniumPetrochemicals 66 Africa Nobel AMPCO 85 EnxonCheyenne 37.5 Equatorial Guinea Atlantic Methanol 110 BP/sterling 45 Libya Sirte 66 Tennessee Eastman 85 Nigeria Viva 250 Lyondell 75 Silicon 165 Carbonic 62 Airproductsandchemicals 18 Motivaenterprises LLC 30 Terra-woodxard, Okdue 12 SUM 9406 1.2 Production and consumption forecast In 2008-20010, there will be many methanol factories newly built, and the increased amount will be more than 20 million tons. In this period, the methanol production and consumption will be greatly increased if the usage standard used in cars as fuel is officially formally confirmed. Unfortunately, until now, this usage hasn’t been broadly spreaded. In USA, the increase rate was slow; the main cause is low wood demand because the depressed estate. In 2008, the demand from methyl tert-butyl ether ( MTBE) will be terminated in American and Europe, so there will be limited increase in the following years. But, methanol still needs to be imported although it is not as big as that in Asia-pacific. The main use of methanol is to produce formaldehyde in Europe. The use demand in biodiesel will be the highlight and get rapid increase in Europe. It will reach 1 million in Europe. The import and export forecast is as below. The import and export forecast in 2010 (Unit: thousand tons) Area 2010 USA 359 0 Canada -151 0 Central and South America -628 0 Western Europe 477 0 Eastern Europe -132 0 Middle East -697 0 Africa -54 0 Japan 394 0 Oceania -77 0 1.3 Price forecast From December 2007, the high methanol price caused a bad effect to the downstream. Except that, so many new methanol factories put into production. In turn, this year, the methanol prices keep decreasing, but the trade amount is more than last year. With the completion of more and more new factory, the price hike will be limited. 2. ECONOMIC ASPECTS The methanol economy is a suggested future economy in which methanol replaces fossil fuels as a mean of energy storage, fuel and raw material for synthetic hydrocarbons and their products. It offers an alternative to the proposed hydrogen economy or ethanol economy . In 2005 Nobel prize winner George A. Olah advocated the methanol economy in an essay and in 2006 he and two co-authors published a book around this theme. In these publications, they summarize the state of our fossil fuel and alternative energy sources, their availability and limitations before suggesting a new approach in the so called methanol economy. Methanol is a fuel for heat engines and fuel cells. Due to its high octane rating it can be used directly as a fuel in cars (including hybrid and plug-in vehicles) using existing internal combustion engines (ICE). Methanol can also be used as a fuel in fuel cells, either directly in Direct Methanol Fuel Cells (DMFC) or indirectly after conversion into hydrogen by reforming. Methanol is a liquid under normal conditions, allowing it to be stored, transported and dispensed easily, much like gasoline and diesel fuel is currently. It can also be readily transformed by dehydration into dimethyl ether , a diesel fuel substitute with a cetane number of 55. Methanol is already used today on a large scale (about 37 million tonnes per year) [3] as a raw material to produce numerous chemical products and materials. In addition, it can be readily converted in the methanol to olefin (MTO) process into ethylene and propylene, which can be used to produce synthetic hydrocarbons and their products, currently obtained from oil and natural gas. Methanol can be efficiently produced from a wide variety of sources including still abundant fossil fuels ( natural gas , coal , oil shale , tar sands , etc.), but also agricultural products and municipal waste, wood and varied biomass . More importantly, it can also be made from chemical recycling of carbon dioxide . Initially the major source will be the CO2 rich flue gases of fossil fuel burning power plants or exhaust of cement and other factories. In the longer range however, considering diminishing fossil fuel resources and the effect of their utilization on earth's atmosphere , even the low concentration of atmospheric CO2 itself could be captured and recycled via methanol, thus supplementing nature’s own photosynthetic cycle. Efficient new absorbents to capture atmospheric CO2 are being developed, mimicking plant life’s ability. Chemical recycling of CO2 to new fuels and materials could thus become feasible, making them renewable on the human timescale. 1 M3 of Methanol at ambient pressure and temperature contains 1.660 Nm3 of hydrogen(H2)compared to liquid hydrogen 1 M3 of liquid hydrogen (LH2) at -253°C contains 788 Nm3 of hydrogen (H2). Uses of methanol in a methanol economy Fuel uses In an economy based on methanol, methanol could be used as a fuel · In ICEs: Methanol has a high octane rating (RON of 107 and MON of 92), which makes it a suitable gasoline substitute. It has a higher flame speed than gasoline, leading to higher efficiency as well as a higher latent heat of vaporization (3.7 times higher than gasoline), meaning that the heat generated by the engine can be removed more effectively, making it possible to use air cooled engines. Besides this methanol burns cleaner than gasoline and is safer in the case of a fire. However, methanol has only half the volumetric energy content of gasoline (8,600 BTU/lb). · In compression ignition engines ( diesel engine ) Methanol itself is not a good substitute for diesel fuels. Methanol can, however, be converted by dehydration to dimethyl ether , which is a good diesel fuel with a cetane number of 55-60 as compared to 45-55 for regular diesel fuel. Compared to diesel fuel, DME has much lower emissions of particulate matter, NOx and CO and does not emit any SOx. Methanol can also be used, and is in fact already used, to produce biodiesel via transesterification of vegetable oil. · In advanced methanol powered vehicles The use of methanol and dimethyl ether can be combined with hybrid and plug-in vehicle technologies allowing higher gas mileage and lower emissions. These fuels can also be used in fuel cells either via onboard reforming to hydrogen or directly in Direct Methanol Fuel Cells (DMFC). · For electricity production: Methanol and DME can be used in existing gas turbines to generate electricity. Fuel cells (PAFC, MCFC, SOFC) can also be used for electricity generation · As a domestic fuel Methanol and DME can be used in commercial buildings and homes to generate heat and/or electricity. DME can be used in a commercial gas stove without modifications. In developing countries methanol could also be used as a cooking fuel, burning much cleaner than wood, thus mitigating indoor air quality problems. Raw material for chemicals and materials Methanol is already used today on a large scale as raw material to produce a variety of chemicals and products. Through the methanol to gasoline (MTG) process, it can be transformed into gasoline. Using the methanol to olefin (MTO) process, methanol can also be converted to ethylene and propylene, the two largest chemicals produced by the petrochemical industry. These are important building blocks for the production of essential polymers (LDPE, HDPE, PP) and other chemical intermediates are currently produced mainly from petroleum feedstock. Their production from methanol could therefore reduce our dependency on petroleum. It would also make it possible to still produce these chemicals when fossil fuels reserves will be depleted. Advantages over other energy storage media Advantages over hydrogen Methanol economy advantages compared to a hydrogen economy: · efficient energy storage (by volume) and also by weight as compared with compressed hydrogen , when hydrogen pressure-confinement vessel is taken into account. The volumetric energy density of methanol is considerably higher than liquid hydrogen, in part because of the low density of liquid hydrogen of 71 grams/liter. Hence there is actually more hydrogen in a liter of methanol (99 grams/liter) than in a liter of liquid hydrogen, and methanol needs no cryogenic container maintained at a temperature of -253°C. · required hydrogen infrastructure would be prohibitively expensive. Methanol can use existing gasoline infrastructure with only limited modifications. · can be blended with gasoline (for example in M85, a mixture containing 85% methanol and 15% gasoline). · user friendly. Hydrogen is volatile and requires high pressure or cryogenic system confinement. Methanol economy advantages compared to ethanol · can be made from any organic material using the proven Fischer Tropsch method going through syngas. No need to use food crops and compete with food production. Amount of methanol that can be generated from biomass much greater than ethanol. · can compete with and complement ethanol in a diversified energy marketplace. Methanol obtained from fossil fuels has a lower price than ethanol. · can be blended in gasoline like ethanol. This year already China blended more than 1 billion gallons of methanol into fuel and will introduce methanol fuel standard by mid-2008. M85,a mixture of 85% methanol and 15% gasoline can be used much like E85 sold in some gas stations today. Methanol economy disadvantages · high energy costs associated with generating hydrogen (when needed to synthesize methanol) · depending on the feedstock the generation in itself can be not clean · presently generated from syngas still dependent on fossil fuels (although in theory any energy source can be used). · energy density (by weight or volume) one half of that of gasoline and 24% less than ethanol · corrosive to some metals including aluminum , zinc and manganese . Parts of the engine fuel-intake systems is made from aluminum. Similar to ethanol, compatible material for fuel tanks, gasket and engine intake have to be used. · hydrophilic : attracts water: in mixture with gasoline this could lead to phase separation and difficulty to start the engine or make it run smoothly · methanol, as an alcohol, increases the permeability of some plastics to fuel vapors (e.g. high-density polyethylene). This property of methanol has the possibility of increasing emissions of volatile organic compounds (VOCs) from fuel, which contributes to increased tropospheric ozone and possibly human exposure. · low volatility in cold weather: pure methanol-fueled engines can be difficult to start, and they run inefficiently until warmed up. This is why a mixture containing 85% methanol and 15% gasoline called M85 is generally used in ICEs. The gasoline allows the engine to start even at lower temperatures. · Methanol is generally considered toxic.Methanol is in fact toxic and eventually lethal when ingested in larger amounts (30 to 100 mL). But so are most motor fuels, including gasoline (120 to 300 mL) and diesel fuel. Gasoline also contains many compounds known to be carcinogenic (e.g. benzene). Methanol is not a carcinogen, nor does it contain any carcinogens. However, methanol may be metabolized in the body to formaldehyde, which is both toxic and carcinogenic. · methanol is a liquid: this creates a greater fire risk compared to hydrogen in open spaces. Methanol leaks do not dissipate. Compared to gasoline, however, methanol is much safer. It is more difficult to ignite and releases less heat when it burns. The EPA has estimated that switching fuels from gasoline to methanol would reduce the incidence of fuel related fires by 90%. · methanol accidentally released from leaking underground fuel storage tanks may undergo relatively rapid groundwater transport and contaminate well water, although this risk has not been thoroughly studied. The history of the fuel additive methyl t-butyl ether ( MTBE ) as a groundwater contaminant has highlighted the importance of assessing the potential impacts of fuel and fuel additives on multiple environmental media. An accidental release of methanol in the environment would, however, cause much less damage than a comparable gasoline or crude oil spill. Unlike these fuels, methanol, being totally soluble in water, would be rapidly diluted to a concentration low enough for microorganism to start biodegradation . Methanol is in fact used for denitrification in water treatment plant as a nutrient for bacterias. 查看更多 2个回答 . 2人已关注
催化分馏塔工艺计算? 谁有催化 分馏塔 工艺计算的资料啊查看更多 1个回答 . 1人已关注
求甲醇资料? 求煤制 甲醇 ,合成及精馏操作方面的最新资料、书籍?要实用、全面、有针对性。查看更多 7个回答 . 1人已关注
2014年6月24日山东可燃气体回收设施项目2万立方米橡胶膜 ...? 2014年6月24日山东可燃气体回收设施项目2万立方米橡胶膜气柜柜顶第一次提升,下午开始安装第一带柜壁板。查看更多 4个回答 . 5人已关注
93#汽油的调和? 各位老师们,恳求指导-----利用纯 90#汽油 和mtbe的调和 93#汽油 ,在车辆装车时先装入mtbe后装入90#,到家后在通过管道(有 静态混合器 )和卸油泵打入储罐,这种调和可行么? 查看更多 3个回答 . 1人已关注
恩德炉的技术特点与优势? 恩德炉的废水,废渣比较难处理, 目前有什么比较好的处理方案吗?查看更多 12个回答 . 5人已关注
氯化氢合成炉燃烧段经常泄漏? 氯化氢合成炉 燃烧段经常泄漏 , 我厂是二合一 合成炉 ,共5台合成炉 使用近三年时, 将燃烧段全部更换后, 筒体经常漏, 新更改的筒体 比原来筒体大点,就将接口接头扩大, 将底部氯气、氢气 阻火器 更换为鹅暖石类阻火器; 请教大侠是什么原因影响的燃烧段内漏? 个人认为是筒体壁厚变薄 查看更多 1个回答 . 3人已关注
16MnR的上转变温度和下转变温度? 如果我们以16MnR16mm厚的钢板进行工艺评定,那么如果热处理和不热处理的话,那么它能够覆盖的板厚范围是多少呢?还有如果进行焊前预热,那么对板厚的覆盖范围有没有影响呢?查看更多 13个回答 . 5人已关注
关于污泥沉降比? 各位盖德: 关于SV5,向大家请教:在做SV5试验的过程中,都需要观察那些项目?查看更多 6个回答 . 1人已关注
简介
职业:浙江新汇化工仓储有限公司 - 给排水工程师
学校:烟台大学 - 自动化
地区:吉林省
个人简介:等我闺蜜结婚那天,我会给她买辆拖拉机,并且很大方的告诉她,拿去。查看更多
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