RH -VD
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RH-LF和LF-VD工艺生产管线钢洁净度的比较一、电弧炉炼钢的时代特点1、变为初炼炉进入20 世纪80年代后,随着炉外精炼技术、工艺、装备的快速发展,原冶炼工艺中在电弧炉内完成的合金钢、特殊钢的脱氧、合金化、除气、去夹杂的电炉“重头戏”移到炉外精炼炉去进行了。
电弧炉及转炉皆变为只须向炉外精炼炉提供含碳、硫、磷、温度、合金化合格或基本合格的钢水就算完成任务的炼钢初炼炉。
改变和结束了原电弧炉的熔时长(三个多小时)、老三期操作(熔化期、氧化期、还原期)以及产量低、渣量大、炉容小、成本高的状况。
2、炉容大型化随着电炉—炉外精炼—连铸—直接轧材工艺的发展,这种短流程(相对于焦化、烧结—高炉—转炉—炉外精炼炉—连铸—)轧材工艺而言的轧机产量要求电炉与之相匹配,例如长材年产50-80 万t、板材100-200 万t 、热轧卷年产200万t以上,因此单一匹配电炉的炉容量和生产率,生产速率必须与轧机相衔接.目前, 较多采用公称炉容量80-120万t 左右的电弧炉,从趋势看炉容量仍在提高。
变压器向超高功率发展(1000KV A/t)。
3 、电炉转炉化氧气顶吹转炉依靠铁水为原料,吹氧冶炼故冶炼周期短(20min左右),产量高,即获得了比电炉高的多的生产率和生产速率( 科技工作者在20 世纪50年代在电弧炉上吹氧(炉门和炉顶)兑入约30%~50%的铁水(EOF 炉),把转炉的工艺优势移植过来,电炉的冶炼周期大大缩短,目前均在45min 左右( 故电炉顶吹氧、热装铁水、电炉双炉壳很快得到推广。
4、电弧炉钢产量大幅增长在上述三项电炉自身工艺变化的同时,随着社会发电技术,能力的增长(核电站、水力发电等)及社会废钢量的增加,直接还原铁DRI、HBI、Fe3C 技术工艺的发展,都为电弧炉快速发展提供了条件. 因此,世界各国电弧炉钢产量由1950 年占世界总产钢量的6.5%增至1990 年的27.5% , 2003 年的36%.5、提质、降耗、防污染使电弧炉获得新的活力电弧炉使用废钢为原料与使用高炉铁水的转炉相比,总能耗是高炉-转炉工艺的1/2~1/3。
RhD阴性和其它稀有血型患者用血管理制度Rh(D)阴性和其它稀有血型患者用血管理制度1.一般情况:择期手术或平诊Rh(D)阴性患者需要输血时,要求提前3天申请并向血站预约,尽可能输注Rh(D)阴性血。
2.紧急情况:患者为Rh(D)阴性,没有检测到抗-D,如需紧急输血抢救生命,又无同型血时,应本着抢救生命第一的原则,先输Rh(D)阳性血抢救。
同时应向患者家属说明征得同意并在输血同意书上签字确认。
3.自身输血:Rh(D)阴性患者如符合自身输血条件,根据需要采集自身血备用。
XXX(D)阴性育龄妇女及女童输血时,尽可能使用Rh(D)阴性血液。
5.血小板输注:尽管血小板表面无D抗原,但血小板制品中有一定量的红细胞(可使患者致敏),故Rh(D)阴性育龄期的女性患者(包括女童)应输注Rh(D)阴性血小板。
Rh(D)阴性男性患者及不再生育的中老年妇女,只要体内无抗-D可输Rh(D)阳性血小板。
6.血浆及冷沉淀:Rh(D)阴性患者需要输注血浆及冷沉淀时,Rh(D)血型可忽略。
XXX(D)阴性冰冻红细胞:由于冰冻红细胞在使用前需要洗涤脱甘油,而且洗涤的速度很慢,故要提前预约。
XXX(D)阴性血液成分的费用是Rh(D)阳性成分的3-5倍,预约时应向经治医师和受血者或家属说明,预约血液须及时输用。
临床需要对患者说明的书面情况一、如无抗-D的Rh阴性患者输注RhD阳性血液时,必须书面向患者说明后果和并发症:1、不会出现溶血性输血反应;2、由于该类Rh阴性红细胞缺乏,不输Rh阳性红细胞危及生命,此时抢救生命是第一位的,输注Rh阳性红细胞是抢救生命的必要条件;3、输Rh阳性红细胞后可能会给以后用血带来困难(由于产生抗-D抗体而不能再输Rh阳性红细胞);对于女性患者,可能会给妊娠带来不良后果,如妊娠的流产、早产或新生儿溶血等;4、患者因本身原发病不治而非输血治疗所能挽回时,不能借口归罪输血治疗不当。
患者或家属知情后签字认可。
Viro R eal ® Kit RHDVManualFor use with the∙ ABI PRISM ®7500 (Fast)∙ Mx3005P ® ∙LightCycler ® 480DVEV03111, DVEV03113100For veterinary use onlyDVEV03151, DVEV03153 50inge n etix GmbH Arsenalstraße 11 1030 Vienna, Austria T +43(0)1 36 198 0 198 F +43(0)1 36 198 0 199 ********************Index1. Product description ................................................................................................................................... 3 2. Pathogen information ................................................................................................................................ 3 3. Principle of real-time PCR ........................................................................................................................ 3 4. General Precautions ................................................................................................................................. 4 5. Contents of the Kit .................................................................................................................................... 5 5.1. ViroReal ® Kit RHDV order no. DVEV03111 or DVEV03151 .............................................................. 5 5.2. ViroReal ® Kit RHDV order no. DVEV03113 or DVEV03153 .............................................................. 5 6. Additionally required materials and devices .............................................................................................. 5 7. Preparation of real-time PCR .................................................................................................................... 6 7.1. Internal RNA positive control (RNA IPC) ........................................................................................... 6 7.2. Positive Control ................................................................................................................................. 6 7.3. Pipetting scheme .............................................................................................................................. 6 7.4. Programming of the temperature profile ............................................................................................ 7 8. Interpretation of PCR-data ........................................................................................................................ 7 8.1. Signal in FAM channel ...................................................................................................................... 7 8.2. No signal in FAM channel but signal of the RNA IPC ........................................................................ 7 8.3. No signal in FAM channel and no signal with the RNA IPC ............................................................... 7 9. Troubleshooting ........................................................................................................................................ 8 9.1. No RHDV specific signal with positive control ................................................................................... 8 9.2. No signal with RNA IPC and no RHDV specific signal with sample ................................................... 8 9.3. RHDV specific signal with negative control ....................................................................................... 8 9.4. RHDV specific signal with negative control of RNA-extraction (optional) ........................................... 8 10. Specifications and performance evaluation ............................................................................................. 9 10.1. Analytical sensitivity and linearity .................................................................................................... 9 10.2. Analytical specificity ........................................................................................................................ 9 10.3. Kit performance .. (10)Explanation of symbolsBatch codeUse byCatalogue numberManufactured byContains sufficient for <n> testsStore atCorrosion, GHS05Exclamation mark, GHS071. Product descriptionViro R eal® Kit RHDV is a real-time PCR kit for the detection of rabbit hemorrhagic disease virus (RHDV) RNA using one-step reverse transcription real-time PCR. It detects both subtypes RHDV1 and RHDV2. This test was developed for the ABI PRISM®7500 (Fast) instrument (Thermo Fisher Scientific), LightCycler®480 (Roche) and for Mx3005P® (Agilent),but is also suitable for other real-time PCR instruments. This test allows the rapid and sensitive detection of RHDV RNA purified from tissues (e.g. spleen, liver), feces, urine and blood (e.g. with the QIAamp Viral RNA Mini Kit, Qiagen).Viro R eal® Kit RHDV detects the capsid protein gene vp60 of RHDV. A probe-specific amplification-curve at 530 nm (FAM channel) indicates the amplification of RHDV specific RNA.An internal RNA positive control system for detection in VIC/HEX channel (order no. DVEV03111 or DVEV03151) or in Cy5 channel (order no. DVEV03113 or DVEV03153) allows control of RNA extraction and excludes false-negative interpretation of results due to inhibition of reverse transcription real-time PCR (see 8. Interpretation of PCR-data).When using PCR-platforms not validated by inge n etix, an evaluation of the multiplex-PCR is recommended. Please be aware that some PCR-platforms have to be calibrated with the corresponding dye before performing multiplex-PCR.Bacto R eal®, Myco R eal, Paro R eal and Viro R eal® Kits are optimized to run under the same thermal cycling conditions. RNA and DNA material can be analysed in one run.2. Pathogen informationRabbit haemorrhagic disease virus (RHDV), also called rabbit calicivirus (RCV) or european brown hare virus is a nonenveloped, positive-sense, single-stranded RNA calicivirus of the genus Lagovirus that causes rabbit haemorrhagic disease (RHD). This disease was first reported in China in 1984 and is a highly contagious and fatal disease for European rabbit (Oryctolagus cuniculus). There exist three distinct groups: the classic RHDV with the genogroups G1–G5 isolated from 1984 onwards, the antigenic variant RHDVa/G6 identified in 1996, and RHDV2 identified in 2010.References:Abrantes J., van der Loo W., Le Pendu J. & Esteves P.J. (2011). Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review. Vet. Res., 43, 12.3. Principle of real-time PCRWhen detecting pathogens by reverse transcription real-time PCR, a specific RNA sequence of the pathogen genome is transcribed into cDNA and amplified. The generated PCR-product is detected by an oligonucleotide-probe labelled with a fluorescent dye. This technology allows for a sequence-specific detection of PCR amplificates.4. General Precautions∙Always include a negative control per PCR-run (Nuclease-free water instead of sample).∙Optional: for valid interpretation of results, a negative control should be included during RNA-extraction (for example extraction of water instead of sample material), in order to exclude false-positive results due to contamination with RHDV RNA during extraction.∙Be careful when handling the positive control.∙Store and extract positive material (specimens, controls and amplicons) separately from all other reagents and add it to the reaction mix in a spatially separated workspace.∙Periodically decontaminate benches and devices.∙Use sterile pipette tips with filters.∙Thaw all components thoroughly at room temperature before starting an assay. When thawed, mix the components and centrifuge briefly.∙Always keep the RNA Reaction Mix on ice.∙Use the RNA immediately after extraction and store at -20°C to -80°C as soon as possible.∙Caution:the Positive Control and the RNA IPC Target are stored in RNA stabilizer that contains Guanidinium thiocyanate/Triton X-100 (see MSDS, ).5. Contents of the Kit5.1. Viro R eal® Kit RHDV order no. DVEV03111 or DVEV031515.2. Viro R eal® Kit RHDV order no. DVEV03113 or DVEV03153The components of Viro R eal® Kit RHDV are stable until the expiry date stated on the label. Repeated thawing and freezing should be avoided. Please protect kit components from light.6. Additionally required materials and devices∙Reagents and devices for RNA-extraction∙Nuclease-free water for dilution of RNA IPC Target and positive control∙Disposable powder-free gloves∙Pipettes (adjustable)∙Sterile pipette tips with filters∙Vortex mixer∙Desktop centrifuge with rotor for 2 ml reaction tubes∙Real-time PCR instrument which is able to detect and differentiate fluorescence in FAM and VIC/HEX or Cy5 channel∙Appropriate 96 well reaction plates or reaction tubes with corresponding (optical) closing material7. Preparation of real-time PCRPlease make sure that at least one negative control (water, blue cap), as well as one positive control (red cap) and one extraction negative control (optional, recommended) are included per PCR run.Inge n etix highly recommends performing PCR analyses in duplicates, which increases the probability of detection of the pathogen and facilitates interpretation of results.∙Prepare master mix on ice.∙Thaw RNA Reaction Mix on ice, and invert 2 to 3 times to ensure homogenous solution. Do not let it warm to room temperature.∙Use RNA immediately after extraction and store at -20 to -80°C as soon as possible.7.1. Internal RNA positive control (RNA IPC)An internal RNA positive control system containing the RNA IPC assay and the RNA IPC Target excludes false-negative interpretation of results due to inhibition of reverse transcription real-time PCR.→ Dilute RNA IPC Target freshly 1:500 with nuclease-free water and add to the master mix (use 1 µl/reaction).→ Alternatively, for control of RNA extraction and PCR inhibition the RNA IPC Target can be added during extraction. Spike 1 µl of undiluted RNA IPC Target into the sample material after the lysis buffer was added. Caution: Do not add the RNA IPC Target directly to the sample material.7.2. Positive ControlThe RHDV Positive Control is an in vitro synthesized RNA in RNA-stabilizer. It has to be stored at -20°C. Before use it has to be freshly diluted 1:500 with nuclease-free water, which corresponds to approx. 30,000 target copies/µl.→ As positive control use 1 µl of the freshly 1:500 diluted RHDV Positive Control + 9 µl nuclease-free water.Caution: The use of more than 1 µl positive control (diluted 1:500) inhibits the RT-PCR reaction.O2has to be changed accordingly.#If RNA IPC Target not already added during extraction.7.4. Programming of the temperature profilePlease find further information on programming the real-time PCR instrument in the respective operator’s manual. Please be aware that some PCR-platforms have to be calibrated with the corresponding dye before performing multiplex-PCR.Select dyes: FAM-TAMRA for detection of RHDVCy5-NONE (RNA IPC-3 Assay Mix) or VIC/HEX-TAMRA (RNA IPC-1 Assay Mix) for detection of RNA IPCSelect reference dye (passive reference): ROX Sample Volume: 20 µlTemperature Profile:Note: These instrument parameters can be used for all Viro R eal ®, Bacto R eal ® and Paro R eal kits (inge n etix) on all PCR instruments.8. Interpretation of PCR-dataFor analysis of PCR data please proceed as follows:For analysis of PCR results gained with Viro R eal ® Kit RHDV please select fluorescence display options FAM channel for the RHDV target and VIC/HEX channel (order no. DVEV03111, DVEV03151) or Cy5 channel (order no. DVEV03113, DVEV03153) for the internal RNA positive control target (RNA IPC). Samples with a positive Cp or Ct-value are considered positive. Please also check amplification-curves manually.8.1. Signal in FAM channel→ RNA of RHDV was amplified. The sample has to be interpreted as positive. RHDV RNA can lead to a reduced or absent fluorescence signal of the RNA IPC.8.2. No signal in FAM channel but signal of the RNA IPC→ No RHDV RNA is detectable in the sample. The sample has to be interpreted as negative. The positive signal of the RNA IPC assay excludes a putative PCR inhibition.8.3. No signal in FAM channel and no signal with the RNA IPC→ No interpretation statement can be made.Information about possible sources of error and their solution can be found in 9. Troubleshooting.For ABI PRISM ® 7500:Ramp speed: Without “fast cycling” parameterFor LightCycler ® 480 instrument:Detection format: 2 Color Hydrolysis Probe (dyes see above)9. Troubleshooting9.1. No RHDV specific signal with positive control∙Incorrect programming of the temperature profile of the real-time PCR instrument.→ Compare the temperature profile with the protocol (see 7. Preparation of real-time PCR).∙Incorrect configuration of the PCR reaction.→ Check your work steps (see 7. Preparation of real-time PCR) and repeat the PCR, if necessary.∙RNA might be degraded.→ Prepare a fresh 1:500 dilution of the positive control and repeat the PCR.9.2. No signal with RNA IPC and no RHDV specific signal with sample∙The PCR reaction was inhibited. No interpretation can be made.→Make sure that you use a recommended method for RNA isolation and stick closely to the manufacturer’s instructions.→ If no operating mistakes during extractions can be retraced, it is recommended to repeat the PCR with lower amounts of RNA-eluate (1/5 or 1/10 of sample volume + the adequate amount of H2O).∙Incorrect PCR conditions.→ Check the PCR conditions and repeat the PCR, if necessary.9.3. RHDV specific signal with negative control∙ A contamination occurred during preparation of the PCR.→ Repeat PCR with new reagents in replicates.→ Strictly pipette the positive controls at last.→ Make sure that work space and instruments are decontaminated at regular intervals.9.4. RHDV specific signal with negative control of RNA-extraction (optional)∙ A contamination occurred during extraction.→ Repeat the extraction and PCR using new reagents.→ Make sure that work space and instruments are decontaminated at regular intervals.10. Specifications and performance evaluationViro R eal® Kit RHDV was evaluated with the ABI PRISM® 7500 (Fast) instrument. For further validation data please contact inge n etix GmbH.10.1. Analytical sensitivity and linearityViro R eal® Kit RHDV was tested with a 10-fold dilution series of a synthetic RNA representing a fragment of RHDV RNA. At least 100 target copies/reaction could be detected.The assay shows linearity over the range of 100 to 1,000,000 target copies/reaction with a slope of -3.3 and a R2 of > 0.9 as shown in Figure 1.Figure 1 Ten-fold dilution series of a RHDV RNA standard plotted against CT10.2. Analytical specificityThe specificity is ensured by the selection of highly specific primers and probes. The primers and probes were checked for possible homologies to currently published sequences by sequence comparison analyses. This also validated the detection of so far known RHDV strains. This kit detects both subtypes RHDV1 and RHDV2.10.3. Kit performancePerformance of Viro R eal® Kit RHDV with an Applied Biosystems® 7500 Fast Real-time PCR System is shownABI Prism® 7500: FAM channel, 530 nmABI Prism® 7500: FAM channel, 530 nmABI Prism® 7500: Cy5 channel, 667 nmABI Prism® 7500: VIC/HEX channel, 554 nmFigure 2 Performance of Viro R eal® Kit RHDV。
广州某三甲医院Rh(D)阴性血的管理及临床应用1. 引言1.1 广州某三甲医院Rh(D)阴性血的重要性广州某三甲医院Rh(D)阴性血的重要性在临床实践中扮演着重要的角色。
Rh(D)阴性血是一种特殊的血型,在人群中所占比例较少,然而其在某些临床情况下却显得尤为重要。
由于Rh(D)阴性血在胎儿发展过程中可能引发Rh(D)阳性抗原的产生,导致母婴之间发生Rh(D)血型不相容而产生溶血反应,严重影响胎儿健康甚至危及生命。
提前进行Rh(D)阴性血的筛查和管理至关重要,可以有效减少溶血反应的发生,保障母婴的健康。
在临床应用中,广州某三甲医院积极推动Rh(D)阴性血的捐赠与储备工作,确保在紧急情况下及时供血,保障患者的治疗需求。
医院也加强对Rh(D)阴性血的使用管理,提高安全性,减少潜在的风险。
广州某三甲医院Rh(D)阴性血的管理及临床应用具有重要意义,不仅可以保障患者的健康,也展现了医院在血液管理领域的专业性和责任心。
2. 正文2.1 Rh(D)阴性血的筛查与管理Rh(D)阴性血的筛查与管理在医院血液管理中起着至关重要的作用。
对于广州某三甲医院来说,正确筛查和管理Rh(D)阴性血是确保医疗安全和患者治疗效果的关键步骤。
对于患者的Rh(D)血型应当在首次就诊时进行检测。
通过正确的实验室技术,可准确鉴定患者的Rh(D)血型,包括Rh阴性和Rh阳性。
医院应建立完善的信息管理系统,将患者的Rh(D)血型信息准确记录并传递至各临床科室。
在医院内部,应设立专门的Rh(D)阴性血库存,确保在需要时能及时获取到适合的血液制品。
医院需制定相关的标本采集、储存和运输流程,确保Rh(D)阴性血制品的安全性和有效性。
在医院的医疗团队中,应加强对Rh(D)阴性血的管理培训,包括正确使用和存储Rh(D)阴性血制品的操作技能和相关知识。
只有通过全员培训,才能有效减少医疗事故的风险,确保患者得到最佳的治疗效果。
广州某三甲医院必须高度重视Rh(D)阴性血的筛查与管理工作,建立科学规范的管理体系,确保在临床应用中的安全性和有效性,从而提升医院的医疗服务水平和患者的治疗体验。
分析生产高质量管线钢通常,有两种基本的工艺来生产这种钢材:(1)传统的“转炉—钢包炉—VD”工艺,某些钢厂应用该流程生产各自的产品;(2)“电弧炉/转炉—钢包炉—RH”工艺,某些钢厂已经使用了这种新的流程。
两种工艺有各自的优缺点。
根据用户的具体要求,选择不同的优化方案。
根据最终产品的所需特性和冶金要求,制定了一系列标准。
利用新的“电弧炉/转炉—钢包炉—RH”工艺生产高质量管线钢时,经过顶渣脱硫后,可以得到与VD炉脱硫效果相当的最终硫含量。
但是,其结果是增加了钢水中氮含量,因此,在RH后续的脱气过程中需要进一步脱氮,以满足钢材性能要求。
因此,应用不同的工艺流程可以得到相同的效果,但是需要根据具体情况来正确评估优化方案。
4 利用RH和VD生产特殊钢RH工艺主要用于高产条件下实现快速脱碳和较短的循环时间。
在RH炉内的真空环境下,CO大量生成,炉内的钢水飞溅强烈,这将导致钢水在炉内结壳,降低产量。
保持炉内的耐火材料较高的温度可以有效减少钢水结壳。
许多年前SMS Mavac已经成功证实,通过弯曲的热排管可以从气体冷却过程中吸热。
然后,炉顶的喷枪加热装置可进一步加热RH炉。
人们希望钢水在RH炉内的循环次数越少越好,因此,钢水喷射用的真空泵吸入量必须越来越大。
虽然RH炉具有上文所述的特点,然而在实际生产中的脱碳初期,真空条件下钢水的飞溅降低了脱碳速率。
为了优化该工艺,RH炉内的真空度必须加以控制。
通常来讲,泄露装置的引入可以用于控制炉内的真空度。
如果操作正确,脱碳初期的钢水飞溅可以随时控制在可接受范围内。
但是,必须充分考虑错误的漏气分析和漏气测量带来的负面影响。
自SMS Mevac引入吸入量可调节的钢水喷射装置后,很好地解决了该问题。
值得注意的是,影响RH炉内的钢水飞溅因素主要有以下几点:(1)钢水中碳元素和氧元素在钢水中的溶解度;(2)RH炉内真空度下降速率;(3)气体循环量;(4)排气管道的物理形状。
当前,现代RH装置配备了可调真空泵。
一、前言1、RH的历史与发展RH精炼全称为:RH真空循环脱气精炼法。
于1959年由德国人发明,其中RH为当时德国采用RH精炼技术的两个厂家的第一个字母。
真空技术在炼钢上开始应用起始于1952年,当时人们在生产含硅量在2%左右的硅钢时在浇注过程中经常出现冒渣现象,经过各种试验,终于发现钢水中的氢和氮是产生冒渣无法浇注或轧制后产生废品的主要原因,随之各种真空精炼技术开始出现,如真空铸锭法、钢包滴流脱气法、钢包脱气法等,从而开创了工业规模的钢水真空处理方法,特别是蒸汽喷射泵的出现,更是加速了真空炼钢技术的发展。
随着真空炼钢技术的开发与发展,最终RH和VD因为处理时间短、成本低、可以大量处理钢水等优点而成为真空炼钢技术的主流,70年代开始随着全连铸车间的出现,RH因为采用钢水在真空槽环流的技术从而达到处理时间短、效率高、能够与转炉连铸匹配的优点而被转炉工序大量采用。
RH从开始出现到现在40多年来,有多项关键性技术的出现,从而加速了RH精炼技术的发展。
2、RH系统概述RH系统设备是一种用于生产优质钢的钢水二次精炼工艺装备。
整个钢水冶金反应是在砌有耐火衬的真空槽内进行的。
真空槽的下部是两个带耐火衬的浸渍管,上部装有热弯管。
被抽气体由热弯管经气体冷却器至真空泵系统排到厂房外。
钢水处理前,先将浸渍管浸入待处理的钢包钢水中。
当真空槽抽真空时,钢水表面的大气压力迫使钢水从浸渍管流入真空槽内。
与真空槽连通的两个浸渍管,一个为上升管,一个为下降管。
由于上升管不断向钢液吹入氩气,相对没有吹氩的下降管产生了一个较高的静压差,使钢水从上升管进入并通过真空槽下部流向下降管,如此不断循环反复。
在真空状态下,流经真空槽钢水中的氩气、氢气、一氧化碳等气体在钢液循环过程中被抽走。
同时,进入真空槽内的钢水还进行一系列的冶金反应,比如碳氧反应等;如此循环脱气精炼使钢液得到净化。
经RH处理的钢水优点明显:合金基本不与炉渣反应,合金直接加入钢水之中,收得率高;钢水能快速均匀混合;合金成分可控制在狭窄的范围之内;气体含量低,夹杂物少,钢水纯净度高;还可以用顶枪进行化学升温的温度调整,为连铸机提供流动性好、纯净度高、符合浇铸温度的钢水,以利于连铸生产的多炉连浇。
1、RH、VD炉都是用于钢水真空脱气的装置,但是他们的使用原理不同,RH是真空循环脱气,而VD仅仅是脱气;当然有些厂在使用VD炉时,配有钢包底吹氩,但是氩气的流量、压力很难控制,在抽真空的过程虽然内部很激烈,但是始终不能达到每滴钢水都真空;但是RH就克服了这一点,它可以使钢水通过上吸管进入真空室,然后在通过下吸管回到钢包中,这一过程使钢水得到很好的脱气。
2、由于RH、VD的脱气原理不同所以造成它们的脱气效果也不同,RH正常情况下可以使轴承钢的氧含量达到9ppm,而VD炉最好情况都在15ppm。
3、但是RH的使用对钢水、钢包有很多严格的要求,;例如钢水量、渣厚、包况等等,而VD炉对这些的要求就松了许多。
而且RH对温度的控制相对VD炉要困难点,因为它受外界的影响比较大。
4、RH的造价要比VD炉的造价要高的多,因为RH需要优质的Mg-Cr质的砖,而且这种砖使用的寿命比较短,上下吸嘴更是更换频繁,对生产带来很大的不便,而且维护时相当辛苦,的费用很高;而VD炉的造价就相对低多啦,使用一些高铝砖就可以啦,而且维护简单,但是如果经常性的溢渣,那样清渣是相当困难的。