CN1212427C - 浓硫酸输送管道的恒压阳极保护方法 - Google Patents
浓硫酸输送管道的恒压阳极保护方法 Download PDFInfo
- Publication number
- CN1212427C CN1212427C CN 02154414 CN02154414A CN1212427C CN 1212427 C CN1212427 C CN 1212427C CN 02154414 CN02154414 CN 02154414 CN 02154414 A CN02154414 A CN 02154414A CN 1212427 C CN1212427 C CN 1212427C
- Authority
- CN
- China
- Prior art keywords
- vitriol oil
- pipeline
- cathode
- protection
- pipe
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Prevention Of Electric Corrosion (AREA)
Abstract
一种浓硫酸输送管道的恒压阳极保护方法，将浓硫酸输送管道(1)作为阳极，与管道保护控制仪(3)的正极相连；辅助阴极(2)起导通电流的作用，与管道保护控制仪(3)的负极相连，阴极(2)制成棒状形式，沿管道径向插入浓硫酸管道中；管道保护控制仪(3)选择能够输出稳定直流电流、电压可调的整流器、稳压电源或恒槽压仪。该方法参比电极不参与控制，克服了参比电极不稳定对保护效果的影响；克服了参比电极故障导致的系统失控，即使在管道内未充满酸的情况下阳极保护系统也能正常工作；阴极材料处于阴极保护状态，延长了使用寿命，降低了更换费用；阳极保护电源简便、可靠、稳定、操作简单且成本大大降低；浓硫酸输送管道处于恒压阳极保护状态时，年腐蚀率在0.05mm以下，可达到理想的保护效果。
Description
技术领域 本发明属于电化学防腐蚀阳极保护技术领域，特别是一种浓硫酸输送管道的防腐蚀恒压阳极保护方法。
背景技术 目前，绝大多数硫酸生产厂家采用铸铁管道、不锈钢管道输送浓硫酸，这些管道在低温浓硫酸中耐蚀性较强，但在高温浓硫酸中(70～120℃，93～98％H2SO4)耐蚀性较差，不锈钢管道年腐蚀率在1mm以上，铸铁管道腐蚀更严重，管道的使用寿命很短，经常造成停产，无法满足制酸生产的正常运行，并且生产的硫酸质量达不到标准。也有关于不锈钢浓硫酸输送管道采用恒电位法阳极保护的应用，但此种使用恒电位仪控制管道电位的方法，不仅阳极保护系统组成复杂，而且恒电位仪的成本高。尤其当工艺出现故障，如管道内部未充满酸、参比电极悬空，将导致阳极保护系统失控。
发明内容 为了克服恒电位法保护的以上缺点，本发明提供一种简便、安全、可靠、成本低的输送浓硫酸管道的恒压阳极保护方法。
本发明提供的浓硫酸管道恒压阳极保护方法的依据是：测定不锈钢在浓硫酸中的阳极极化曲线可知，不锈钢在浓硫酸中有很宽的钝化区。如：304L不锈钢在25℃、98％H2SO4中，钝化电位区间为-400～+1,000mV(本文电位值均相对于Hg-Hg2SO4参比电极)，维钝电流密度为0.03A/m2；在80℃、98％H2SO4中，钝化电位区间为-200～+700mV，维钝电流密度为0.13A/m2。可以看出，钝化电位区范围近1,000mV，为实施恒压法阳极保护提供了足够空间。若304L不锈钢管道控制在此钝化电位区间，年腐蚀率可控制在0.05mm以下，从而达到理想的保护效果。
表1 304L和316L不锈钢在浓H2SO4中的电化学参数
| 材质 | 浓度(％) | 温度(℃) | 致钝电流密度(A/m2) | 维钝电流密度(A/m2) | 钝化区间(mV) | 腐蚀率(mm/a) | |
| 自然 | 保护 | ||||||
| 304L | 93 | 25 | 0.45 | 0.030 | - | - | - |
| 50 | 5.66 | 0.046 | - | - | - | ||
| 80 | 9.72 | 0.124 | - | 2.00 | ＜0.10 | ||
| 98 | 25 | 2.30 | 0.033 | -400～+1000 | - | - | |
| 50 | 2.51 | 0.049 | -200～+900 | - | - | ||
| 80 | 4.92 | 0.133 | -200～+700 | 0.60 | ＜0.05 | ||
| 316L | 93 | 25 | 1.00 | 0.032 | - | - | - |
| 50 | 1.30 | 0.041 | - | - | - | ||
| 80 | 5.45 | 0.160 | - | 1.20 | ＜0.10 | ||
| 98 | 25 | 自钝化 | 0.014 | -200～+1000 | - | - | |
| 50 | 0.16 | 0.019 | -200～+800 | - | - | ||
| 80 | 0.23 | 0.064 | -200～+600 | 0.30 | ＜0.02 | ||
| 100 | 0.20 | 0.365 | - | - | - | ||
| 120 | 6.80 | 1.14 | - | - | - | ||
鉴于以上方法依据，为实现上述目的，本发明采取的技术方案为：浓硫酸输送管道的恒压阳极保护方法，是将浓硫酸输送管道作为阳极，与管道保护控制仪的正极相连；辅助阴极起导通电流的作用，与管道保护控制仪的负极相连，阴极制成棒状形式，沿管道径向插入浓硫酸管道中，阴极面积和阴极间距随着管道直径、长度和形状的变化而变化；管道保护控制仪可选择能够输出稳定直流电流、电压可调的整流器、稳压电源、恒槽压仪等。
恒压法阳极保护系统以电解槽阴阳极之间的电压E槽压作为控制指标，经过理论分析与现场试验，根据不锈钢管道在不同浓度的浓硫酸中的保护电位，列出如表2所示的控制指标。
表2 304L/316L不锈钢浓硫酸输送管道的恒压法阳极保护控制指标
| 材质 | 浓度 | 保护电位范围(mV) | 控制指标E槽压(mV) |
| 304L316L | 93％ | -200～600 | 200～1100 |
| 98％ | -300～700 | 100～1200 |
理想的阴极材料应电位稳定、耐腐蚀、成本低，并且具有一定的强度，如18-8型不锈钢、25-20型不锈钢、哈氏合金、Inconel合金等。阴极材料在93～98％H2SO4中应表现出如图2所示的阴极极化特性，也就是说，阳极保护系统正常工作时，阴极电位处于φ2值，相对应的阴极电流密度为i2。若浓硫酸生产中工艺条件变化，如浓硫酸温度、浓度变化，则管道的维钝电流密度变化，导致阴极电流密度变为i1或i3，相对应的阴极电位为φ1和φ3。i2与i1和i3相比变化较大，但φ2与φ1和φ3较接近。即当阴极电流密度变化的幅度较大时，阴极电位的变化很小。
对于电化学系统因为有：i阴＝(S阳×i阳)÷S阴
式中：i阴—辅助阴极的电流密度，A/m2
S阳—管道(阳极)的保护面积，m2
S阴—阴极面积，m2；
i阳—管道(阳极)处在钝态时的维钝电流密度，A/m2；
在方法实施中，管道面积S阳确定，维钝电流密度i阳确定，即S阳×i阳确定，因此，阴极面积的大小直接影响i阴的大小，一般情况下S阳∶S阴为300～700∶1。
阴极间距与管道的管径和浓硫酸的浓度有关，其有关数据列于表3中。在保证阴极面积恒定和强度许可的情况下，增加阴极的长度有利于电流的分散，使管道的阳极保护电位更趋一致，以达到理想的保护状态。
表3 阴极布置间距
| 管径(mm) | ≤300 | 300～500 | ≥500 | |
| 间距(m) | 93％H2SO4 | 2～3 | 2～4 | 3～5 |
| 98％H2SO4 | 2～4 | 2～4 | 3～5 | |
本发明提供的浓硫酸输送管道的恒压阳极保护方法，充分挖掘、利用了该体系阳极保护的潜力，无论在阴极选择，还是在电源方面与恒电位阳极保护方法相比具有以下突出的优点：
(1)该方法参比电极不参与控制，克服了参比电极不稳定对保护效果的影响。
(2)克服了参比电极故障导致的系统失控，即使在管道内未充满酸的情况下阳极保护系统也能正常工作。
(3)阴极材料在阳极保护系统正常工作时处于阴极保护状态。试验证明，在阳极保护系统正常工作时，阴极的保护度在75～90％，阴极材料得到很好的保护，延长了使用寿命，降低了阴极的更换费用。
(4)阳极保护电源简便、可靠、稳定、操作简单且成本大大降低。
(5)浓硫酸输送管道处于恒压阳极保护状态时，年腐蚀率可控制在0.05mm以下，可达到理想的保护效果。
附图说明 图1为浓硫酸输送管道的恒压法阳极保护的系统布置图；
图2为阴极材料的阴极极化曲线图。
具体实施方式
实施例一：
对一条30米长、φ＝200mm的输送浓硫酸管道进行阳极保护，浓硫酸浓度为98％，温度为85～90℃。阳极保护系统接线如图1布置，将浓硫酸输送管道1作为阳极，与管道保护控制仪3的正极相连；棒状形式阴极2与管道保护控制仪3的负极相连，沿管道径向插入浓硫酸管道中，阴极间距为2m，共布置阴极16支，沿管道1轴向一字排列，以并联方式接管道保护控制仪3，S阳∶S阴＝500∶1。阳极保护系统开始工作时，调节阳极保护控制仪，使其输出1.7V的电压，在5～10分钟后，测得管道(阳极)电位为200～250mV，此时，降低阳极保护控制仪的输出电压，使其输出0.8V的稳定电压，管道(阳极)电位逐渐下降，最终稳定在150～250mV区间内，处于良好的保护状态。阴极电位最终稳定在-400～-500mV区间内，处于阴极保护状态。
实施例二：
对某制酸厂家的三条输酸管道进行阳极保护。输酸管道管径φ＝400mm，每条管线长度L≈35m，浓硫酸浓度为93％和98％，浓硫酸温度为70～90℃。阳极保护系统接线如图1布置，将浓硫酸输送管道1作为阳极，与管道保护控制仪3的正极相连；棒状形式阴极2与管道保护控制仪3的负极相连，沿管道径向插入浓硫酸管道中，输送93％和98％浓硫酸的管道由不同的控制仪控制。阴极间距为2.5m，共布置阴极45支，沿管道1轴向一字排列，以并联方式接管道保护控制仪3，S阳∶S阴＝550∶1。阳极保护系统开始工作时，调节阳极保护控制仪，使其输出1.7V的电压，在5～10分钟后，测得管道(阳极)电位为200～250mV，此时，降低阳极保护控制仪的输出电压，输送93％浓硫酸的管道控制仪输出700mV的电压，管道(阳极)电位逐渐下降，最终稳定在50～150mV区间内，处于良好的保护状态。输送98％浓硫酸的管道控制仪输出800mV的电压，管道(阳极)电位逐渐下降，最终稳定在150～250mV区间内，处于良好的保护状态。所有阴极电位最终为-400～-500mV区间内，处于阴极保护状态。
上述方法实施例中，阳极保护电位与管道直径、材料、浓硫酸的浓度、温度等有关，阴极的材料、设置的阴极个数与间距，也与浓硫酸的浓度、温度、管道直径及长度有关，具体数据可以在本发明技术方案及具体实施例的引导下，通过对具体的工艺条件做具体的试验得到，没有一个可以包容上述变量的函数式。
Claims (6)
1、一种浓硫酸输送管道的恒压阳极保护方法，其特征在于将浓硫酸输送管道(1)作为阳极，与管道保护控制仪(3)的正极相连；辅助阴极(2)起导通电流的作用，与管道保护控制仪(3)的负极相连，阴极(2)制成棒状形式，沿管道径向插入浓硫酸管道中；管道保护控制仪选择能够输出稳定直流电流、电压可调的整流器、稳压电源或恒槽压仪。
2、根据权利要求1所述的浓硫酸输送管道的恒压阳极保护方法，其特征在于上述阳极保护系统以电解槽阴阳极之间的电压E槽压作为控制指标，对于304L、316L不锈钢浓硫酸输送管道，浓硫酸浓度为93％，保护电位范围为-200～600mV，控制指标E槽压为200～1100mV；对于304L、316L不锈钢浓硫酸输送管道，浓硫酸浓度为98％，保护电位范围为-300～700mV，控制指标E槽压为100～1200mV。
3、根据权利要求1所述的浓硫酸输送管道的恒压阳极保护方法，其特征在于上述阴极的材料符合电位稳定、耐腐蚀、成本低，并且具有一定的强度的特点，在93～98％H2SO4中表现出的阴极极化特性为：阴极电流密度变化的幅度较大时，阴极电位的变化却很小。
4、根据权利要求1或3所述的浓硫酸输送管道的恒压阳极保护方法，其特征在于上述阴极的材料选择18-8型不锈钢、25-20型不锈钢、哈氏合金或Inconel合金。
5、根据权利要求1或3所述的浓硫酸输送管道的恒压阳极保护方法，其特征在于上述阴极的间距与管道管径和浓硫酸浓度有关，间距为2～5米，沿管道轴向一字排列，以并联方式接管道保护控制仪(3)。
6、根据权利要求1或3所述的浓硫酸输送管道的恒压阳极保护方法，其特征在于上述阳极的保护面积S阳与阴极面积S阴的比例为300～700∶1。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02154414 CN1212427C (zh) | 2002-12-10 | 2002-12-10 | 浓硫酸输送管道的恒压阳极保护方法 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 02154414 CN1212427C (zh) | 2002-12-10 | 2002-12-10 | 浓硫酸输送管道的恒压阳极保护方法 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1506497A CN1506497A (zh) | 2004-06-23 |
| CN1212427C true CN1212427C (zh) | 2005-07-27 |
Family
ID=34235488
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02154414 Expired - Fee Related CN1212427C (zh) | 2002-12-10 | 2002-12-10 | 浓硫酸输送管道的恒压阳极保护方法 |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1212427C (zh) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7672567B2 (en) | 2002-06-24 | 2010-03-02 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple reproduction path video data for at least a segment of a title recorded thereon and recording and reproducing methods and apparatuses |
| US7693394B2 (en) | 2003-02-26 | 2010-04-06 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of data streams recorded thereon and recording and reproducing methods and apparatuses |
| US7769272B2 (en) | 2002-11-20 | 2010-08-03 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of at least video data recorded thereon and recording and reproducing methods and apparatuses |
| US7809775B2 (en) | 2003-02-27 | 2010-10-05 | Lg Electronics, Inc. | Recording medium having data structure for managing playback control recorded thereon and recording and reproducing methods and apparatuses |
| US7809243B2 (en) | 2002-06-24 | 2010-10-05 | Lg Electronics, Inc. | Recording medium having data structure including navigation control information for managing reproduction of video data recorded thereon and recording and reproducing methods and apparatuses |
| US7813237B2 (en) | 2002-10-14 | 2010-10-12 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple audio streams recorded thereon and recording and reproducing methods and apparatuses |
| US7835622B2 (en) | 2002-06-21 | 2010-11-16 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of video data recorded thereon and recording and reproducing methods and apparatuses |
| US7835623B2 (en) | 2002-06-21 | 2010-11-16 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of video data recorded thereon |
| US7840121B2 (en) | 2002-10-15 | 2010-11-23 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple graphics streams recorded thereon and recording and reproducing methods and apparatuses |
| US7848619B2 (en) | 2003-04-04 | 2010-12-07 | Lg Electronics Inc. | Recording medium having data structure for managing to resume reproduction of video data recorded thereon and recording and reproducing methods and apparatuses |
| US7912338B2 (en) | 2003-02-28 | 2011-03-22 | Lg Electronics Inc. | Recording medium having data structure for managing random/shuffle reproduction of video data recorded thereon and recording and reproducing methods and apparatuses |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102011126B (zh) * | 2009-12-11 | 2012-07-04 | 天华化工机械及自动化研究设计院 | 阳极保护浓硫酸槽 |
| CN106990742B (zh) * | 2017-06-02 | 2023-07-21 | 天津隆顺技术服务有限公司 | 反电位法防腐保护联动控制装置和系统 |
| CN109668455A (zh) * | 2017-10-13 | 2019-04-23 | 天华化工机械及自动化研究设计院有限公司 | 含钼合金在浓硫酸设备中的用途 |
| CN108441709A (zh) * | 2018-05-09 | 2018-08-24 | 天华化工机械及自动化研究设计院有限公司 | 含铬镍合金立式浓硫酸冷却器在低温位余热回收装置及其组成的发电系统中的用途 |
| CN110241426A (zh) * | 2019-06-14 | 2019-09-17 | 南京高源环保工程有限公司 | 一种阳极保护氨水管道的方法及装置 |
-
2002
- 2002-12-10 CN CN 02154414 patent/CN1212427C/zh not_active Expired - Fee Related
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7835622B2 (en) | 2002-06-21 | 2010-11-16 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of video data recorded thereon and recording and reproducing methods and apparatuses |
| US7835623B2 (en) | 2002-06-21 | 2010-11-16 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of video data recorded thereon |
| US7949231B2 (en) | 2002-06-24 | 2011-05-24 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple reproduction path video data recorded thereon and recording and reproducing methods and apparatuses |
| US7783159B2 (en) | 2002-06-24 | 2010-08-24 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple reproduction path video data for at least a segment of a title recorded thereon and recording and reproducing methods and apparatuses |
| US7672567B2 (en) | 2002-06-24 | 2010-03-02 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple reproduction path video data for at least a segment of a title recorded thereon and recording and reproducing methods and apparatuses |
| US7809243B2 (en) | 2002-06-24 | 2010-10-05 | Lg Electronics, Inc. | Recording medium having data structure including navigation control information for managing reproduction of video data recorded thereon and recording and reproducing methods and apparatuses |
| US7813237B2 (en) | 2002-10-14 | 2010-10-12 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple audio streams recorded thereon and recording and reproducing methods and apparatuses |
| US7961570B2 (en) | 2002-10-14 | 2011-06-14 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple audio streams recorded thereon and recording and reproducing methods and apparatuses |
| US7840121B2 (en) | 2002-10-15 | 2010-11-23 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of multiple graphics streams recorded thereon and recording and reproducing methods and apparatuses |
| US7769272B2 (en) | 2002-11-20 | 2010-08-03 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of at least video data recorded thereon and recording and reproducing methods and apparatuses |
| US8831406B2 (en) | 2002-11-20 | 2014-09-09 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of at least video data recorded thereon and recording and reproducing methods and apparatuses |
| US8886021B2 (en) | 2002-11-20 | 2014-11-11 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of at least video data recorded thereon and recording and reproducing methods and apparatuses |
| US7693394B2 (en) | 2003-02-26 | 2010-04-06 | Lg Electronics Inc. | Recording medium having data structure for managing reproduction of data streams recorded thereon and recording and reproducing methods and apparatuses |
| US7809775B2 (en) | 2003-02-27 | 2010-10-05 | Lg Electronics, Inc. | Recording medium having data structure for managing playback control recorded thereon and recording and reproducing methods and apparatuses |
| US7912338B2 (en) | 2003-02-28 | 2011-03-22 | Lg Electronics Inc. | Recording medium having data structure for managing random/shuffle reproduction of video data recorded thereon and recording and reproducing methods and apparatuses |
| US7848619B2 (en) | 2003-04-04 | 2010-12-07 | Lg Electronics Inc. | Recording medium having data structure for managing to resume reproduction of video data recorded thereon and recording and reproducing methods and apparatuses |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1506497A (zh) | 2004-06-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1212427C (zh) | 浓硫酸输送管道的恒压阳极保护方法 | |
| Morel et al. | Microbial desalination cells packed with ion-exchange resin to enhance water desalination rate | |
| CN103579147B (zh) | 一种换流阀用等电位电极 | |
| DE102009035440A1 (de) | Verfahren und Vorrichtung zur Erzeugung von Wasserstoff und Sauerstoff | |
| CN102277580A (zh) | 导管架平台外加电流阴极保护方法 | |
| Blanc et al. | Electrode potential monitoring and electrolytic control in anaerobic digestion | |
| Rusdianasari et al. | Hydrogen gas production using water electrolyzer as hydrogen power | |
| JP6972038B2 (ja) | アンモニア合成法及びシステム | |
| US6968028B1 (en) | Nuclear power station having a gas-injection device for a coolant | |
| Jatoi et al. | Comparative study of different biomass on bio-electricity generation using microbial fuel cell | |
| US3560365A (en) | Corrosion protection of pipelines | |
| Compton | Factors Involved in Corrosion of Lead Cable Sheath | |
| CN211036112U (zh) | 利用太阳能发电实现海水设备防腐蚀的装置 | |
| CN210632632U (zh) | 一种土壤重金属治理用阳极结构及土壤重金属处理装置 | |
| Rusdianasari et al. | Effect of Sodium Chloride Solution Concentration on Hydrogen Gas Production in Water Electrolyzer Prototype | |
| CN118127511A (zh) | 一种浓硫酸分布器防腐蚀装置及方法 | |
| CN107236960A (zh) | 一种用于除油器的强制电流阴极保护装置 | |
| Nicholls et al. | An investigation into impressed current cathodic protection systems in Australian wharves. | |
| CN113789546B (zh) | 一种隔膜完整性测试系统及使用方法 | |
| Cao et al. | Stray Current Corrosion of Aluminum Electrolysis System | |
| Kotowicz et al. | Equipment exploitation in power to gas installation | |
| Nelabhotla et al. | Optimisation of Electrochemical Treatment of Artificial Wastewater using Cyclic Voltammetry | |
| CN1101785C (zh) | 加气装置 | |
| Putra et al. | A CHLORINE PRODUCTION IN A CHLORINE PLANT SYSTEM USING AC AND DC CURRENT AT THE PANGKALAN SUSU | |
| Azman et al. | Effect of pH at Anode and Cathode Chamber on the Performance of Biological Cathodic Protection |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: TIANHUA INSTITUTE OF CHEMICAL MACHINERY + AUTOMATI Free format text: FORMER NAME: TIANHUA CHEMICAL MACHINERY + AUTOMATION RESEARCH INST. |
|
| CP01 | Change in the name or title of a patent holder |
Address after: 730060 Gansu city of Lanzhou province Xigu District Heshui Road No. 3 Patentee after: Tianhua Institute of Chemical Machinery & Automation Co., Ltd. Address before: 730060 Gansu city of Lanzhou province Xigu District Heshui Road No. 3 Patentee before: Tianhua Chemical Machinery & Automation Research Inst. |
|
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20050727 Termination date: 20161210 |