CN113369263B - Method for removing calcium sulfate scale - Google Patents
Method for removing calcium sulfate scale Download PDFInfo
- Publication number
- CN113369263B CN113369263B CN202110581746.6A CN202110581746A CN113369263B CN 113369263 B CN113369263 B CN 113369263B CN 202110581746 A CN202110581746 A CN 202110581746A CN 113369263 B CN113369263 B CN 113369263B
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- CN
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- Prior art keywords
- calcium sulfate
- container
- scale
- water
- scaling
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto
- B08B9/08—Cleaning containers, e.g. tanks
- B08B9/093—Cleaning containers, e.g. tanks by the force of jets or sprays
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D1/00—Evaporating
- B01D1/30—Accessories for evaporators ; Constructional details thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
- B08B3/04—Cleaning involving contact with liquid
- B08B3/10—Cleaning involving contact with liquid with additional treatment of the liquid or of the object being cleaned, e.g. by heat, by electricity or by vibration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B7/00—Cleaning by methods not provided for in a single other subclass or a single group in this subclass
- B08B7/0064—Cleaning by methods not provided for in a single other subclass or a single group in this subclass by temperature changes
- B08B7/0071—Cleaning by methods not provided for in a single other subclass or a single group in this subclass by temperature changes by heating
- B08B7/0085—Cleaning by methods not provided for in a single other subclass or a single group in this subclass by temperature changes by heating by pyrolysis
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Abstract
The invention relates to the technical field of calcium sulfate descaling, in particular to a method for removing calcium sulfate scale, which comprises the steps of washing a container with an inner wall containing anhydrous calcium sulfate scale by clear water, and keeping the interior of the container full of clear water; introducing steam into a heating jacket on the outer wall of the container to enable the temperature of water in the container to rise to 20-45 ℃, and converting the anhydrous calcium sulfate scaling substances into calcium sulfate dihydrate scaling substances; stopping introducing steam, draining accumulated water in the container, introducing steam into the heating jacket again to integrally heat the interior of the container to 100-150 ℃, and converting the calcium sulfate dihydrate scaling substances into calcium sulfate hemihydrate scaling substances; and stopping introducing the steam again, introducing clear water into the container, hydrating the calcium sulfate hemihydrate scale into calcium sulfate dihydrate scale, wherein the calcium sulfate dihydrate scale expands in volume until the calcium sulfate dihydrate scale is crushed and rushes out along with the outlet water. The invention can improve the descaling efficiency of calcium sulfate and ensure the reliability of equipment operation after descaling, thereby improving the product yield.
Description
Technical Field
The invention relates to the technical field of calcium sulfate scale removal, in particular to a method for removing calcium sulfate scale.
Background
In the titanium dioxide production concentration process, a film evaporator is used for carrying out concentration treatment on titanium liquid, the film evaporator runs for about 1 month, obvious calcium sulfate scaling phenomenon can occur on internal tubes, the concentration efficiency is seriously influenced, the titanium liquid concentration process is in a high-sulfuric acid system, so precipitated scaling substances are mainly anhydrous calcium sulfate, the acid and alkali soaking treatment effect is not ideal due to the compact structure of the scaling substances of the anhydrous calcium sulfate, the film evaporator is firstly dismantled, a high-pressure water gun is used for strongly washing the tubes in the film evaporator, the kinetic energy provided by high-pressure water is used for achieving the effect of removing the calcium sulfate scaling, but the treatment method can cause serious abrasion on the tubes in the film evaporator, and the treatment time is long (about two weeks), so that the titanium dioxide yield is influenced.
Therefore, there is a need to develop a new method for removing calcium sulfate scale, so as to improve the calcium sulfate scale removal efficiency, ensure the reliability of equipment operation after scale removal, and improve the product yield.
Disclosure of Invention
The invention aims to overcome the defects and provides a method for removing calcium sulfate scale, which comprises the following steps:
1) washing the container with the anhydrous calcium sulfate scaling compound in the inner wall with clear water to remove the residual original medium in the inner wall of the container and keep the interior of the container full of clear water;
2) introducing steam into a heating jacket on the outer wall of the container, raising the temperature of water in the container to 20-45 ℃, and preserving the heat for 1-2 days to convert anhydrous calcium sulfate scaling substances on the inner wall of the container into calcium sulfate dihydrate scaling substances;
3) stopping introducing steam, draining accumulated water in the container, introducing steam into the heating jacket again to integrally heat the interior of the container to 100-150 ℃, and preserving heat for 1-3 hours to convert the calcium sulfate dihydrate scaling compound converted in the step 2) into a calcium sulfate hemihydrate scaling compound;
4) stopping introducing steam again, introducing clear water into the container, hydrating the converted calcium sulfate hemihydrate scale in the step 3) into calcium sulfate dihydrate scale, wherein the calcium sulfate dihydrate scale can expand in volume until the calcium sulfate dihydrate scale is crushed and flushed out along with the effluent, and stopping introducing the clear water after the effluent does not contain solid matters.
Preferably, the clean water is softened water, desalted water or condensed water.
Preferably, the steps 1) to 4) may be performed by an on-line processing method.
Preferably, the temperature of the water in the container in the step 2) is raised to 35 ℃, and the temperature is kept for 1 day.
Preferably, the temperature of the whole container in the step 3) is raised to 120 ℃, and the temperature is kept for 2 h.
Preferably, the method can combine the steps 1) to 4) or independently use the corresponding steps according to the components of anhydrous calcium sulfate, calcium sulfate hemihydrate or calcium sulfate dihydrate contained in the scaling compound in the container, so as to realize the removal of the anhydrous calcium sulfate scaling compound, the calcium sulfate hemihydrate scaling compound or the calcium sulfate dihydrate scaling compound.
The invention has the following action principle:
for the removal of the scaling substances of the anhydrous calcium sulfate, firstly, the anhydrous calcium sulfate absorbs water at the temperature of 20-45 ℃ and is converted into calcium sulfate dihydrate, then, the calcium sulfate dihydrate is dehydrated and converted into calcium sulfate hemihydrate at the temperature of 100-150 ℃ in a heating mode, the characteristic of self crushing is realized by volume expansion in the process of hydrating the calcium sulfate hemihydrate into the calcium sulfate dihydrate, and the purpose of removing the scaling of the calcium sulfate is achieved by water flushing.
Compared with the prior art, the invention has the beneficial effects that:
the method is realized by applying the physical and chemical changes of the calcium sulfate during the conversion of different forms, equipment does not need to be dismantled, and the problem of calcium sulfate scaling in the container can be eliminated on line, so that the labor intensity of workers is greatly reduced, the running reliability of the equipment after scale removal is ensured, and the product yield is improved. Especially when the descaling agent is applied to descaling of a film evaporator in a titanium white production and concentration process, the descaling time can be obviously saved, and the titanium white yield is improved.
Detailed Description
The present invention will be further described with reference to specific examples, which are illustrative of the invention and are not to be construed as limiting the invention.
Examples
In the titanium white production concentration process, the treatment capacity of the film evaporator is reduced to 14m 3 Stopping feeding, switching pipelines, flushing residual titanium liquid with demineralized water, closing a water outlet pipe after the effluent is clear, introducing steam into a heating jacket outside a tube of the thin film evaporator to enable the water temperature in the tube to rise to 35 ℃, preserving the heat for 1 day, discharging accumulated water in the tube, introducing steam into the heating jacket outside the tube again to enable the tube to be integratedHeating the liquid to 120 ℃, keeping the temperature for 2h, stopping introducing steam, introducing a large amount of desalted water into the tube array to flush the tube array, and recovering the titanium liquid treatment capacity of the film evaporator to 19m after the online descaling process treatment until the effluent does not contain solid substances 3 /h。
The invention has the following action principle: for the removal of the scaling substances of the anhydrous calcium sulfate, firstly, the anhydrous calcium sulfate absorbs water at the temperature of 20-45 ℃ and is converted into calcium sulfate dihydrate, then, the calcium sulfate dihydrate is dehydrated and converted into calcium sulfate hemihydrate at the temperature of 100-150 ℃ in a heating mode, the characteristic of self crushing is realized by volume expansion in the process of hydrating the calcium sulfate hemihydrate into the calcium sulfate dihydrate, and the purpose of removing the scaling of the calcium sulfate is achieved by water flushing.
The technical solution of the present invention is not limited to the limitations of the above specific embodiments, and all technical modifications made according to the technical solution of the present invention fall within the protection scope of the present invention.
Claims (6)
1. A method of removing calcium sulfate scale comprising the steps of:
1) washing the container with the anhydrous calcium sulfate scaling compound in the inner wall with clear water to remove the residual original medium in the inner wall of the container and keep the interior of the container full of clear water;
2) introducing steam into a heating jacket on the outer wall of the container, raising the temperature of water in the container to 20-45 ℃, and preserving the heat for 1-2 days to convert anhydrous calcium sulfate scaling substances on the inner wall of the container into calcium sulfate dihydrate scaling substances;
3) stopping introducing steam, draining accumulated water in the container, introducing steam into the heating jacket again to integrally heat the interior of the container to 100-150 ℃, and preserving heat for 1-3 hours to convert the calcium sulfate dihydrate scaling compound converted in the step 2) into a calcium sulfate hemihydrate scaling compound;
4) stopping introducing steam again, introducing clear water into the container, hydrating the converted calcium sulfate hemihydrate scale in the step 3) into calcium sulfate dihydrate scale, wherein the calcium sulfate dihydrate scale can expand in volume until the calcium sulfate dihydrate scale is crushed and flushed out along with the effluent, and stopping introducing the clear water after the effluent does not contain solid matters.
2. The method of removing calcium sulfate scale according to claim 1, wherein: the clear water is softened water, demineralized water or condensed water.
3. A method of removing calcium sulfate scale according to claim 1 wherein: the steps 1) to 4) are carried out in an online processing mode.
4. A method of removing calcium sulfate scale according to claim 1 wherein: and (3) heating the water in the container to 35 ℃ in the step 2), and preserving the heat for 1 day.
5. The method of removing calcium sulfate scale according to claim 1, wherein: in the step 3), the temperature of the whole interior of the container is raised to 120 ℃, and the temperature is kept for 2 h.
6. A method for removing calcium sulphate scale according to any one of claims 1 to 5 wherein: and (3) combining the steps 1) to 4) or independently using the corresponding steps according to the components of anhydrous calcium sulfate, calcium sulfate hemihydrate or calcium sulfate dihydrate contained in the scaling substances in the container, so as to remove the anhydrous calcium sulfate scaling substances, the calcium sulfate hemihydrate scaling substances or the calcium sulfate dihydrate scaling substances.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110581746.6A CN113369263B (en) | 2021-05-24 | 2021-05-24 | Method for removing calcium sulfate scale |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110581746.6A CN113369263B (en) | 2021-05-24 | 2021-05-24 | Method for removing calcium sulfate scale |
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| Publication Number | Publication Date |
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| CN113369263A CN113369263A (en) | 2021-09-10 |
| CN113369263B true CN113369263B (en) | 2022-08-09 |
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| CN202110581746.6A Active CN113369263B (en) | 2021-05-24 | 2021-05-24 | Method for removing calcium sulfate scale |
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Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114191833A (en) * | 2021-12-19 | 2022-03-18 | 山东清沂山石化科技有限公司 | Online steam tower salt washing system for amine liquid regeneration tower |
Citations (7)
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|---|---|---|---|---|
| US4247371A (en) * | 1966-03-15 | 1981-01-27 | Roller Paul S | Precipitating scale-forming compounds from water, and forming fresh water |
| US4756769A (en) * | 1984-01-27 | 1988-07-12 | Innus Industrial Nuclear Services S.A. | Method for cleaning with high pressure an evaporator and device used thereby |
| US9427784B2 (en) * | 2011-05-18 | 2016-08-30 | Basf Se | Device and method for draining and rinsing containers filled with fluid |
| CN205676239U (en) * | 2016-04-19 | 2016-11-09 | 林俊生 | A kind of supercharging apparatus for eliminating sludge and supercharging descaling equipment |
| CN107560493A (en) * | 2017-10-23 | 2018-01-09 | 济南大学 | A kind of vacuum salt production vapo(u)rization system cleaning and descaling method |
| WO2018022195A1 (en) * | 2016-07-28 | 2018-02-01 | Exxonmobil Chemical Patents Inc. | High pressure separator cleaning method and apparatus |
| CN212746911U (en) * | 2020-08-18 | 2021-03-19 | 重庆民祺节能科技有限公司 | Air energy water heater with descaling device |
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| US6936112B2 (en) * | 2002-11-26 | 2005-08-30 | Refined Technologies, Inc. | Heat exchanger cleaning process |
| CN103542766A (en) * | 2012-07-12 | 2014-01-29 | 崔骥 | Coating on heat exchange sheet of heat exchange device and method for removing dirt |
| CN104928752B (en) * | 2015-07-06 | 2016-06-01 | 宁远县隆翔新型材料科技有限公司 | A kind of normal temperature prepares Dihydrate gypsum whiskers and normal pressure turns the method for anhydrous whisker |
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2021
- 2021-05-24 CN CN202110581746.6A patent/CN113369263B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4247371A (en) * | 1966-03-15 | 1981-01-27 | Roller Paul S | Precipitating scale-forming compounds from water, and forming fresh water |
| US4756769A (en) * | 1984-01-27 | 1988-07-12 | Innus Industrial Nuclear Services S.A. | Method for cleaning with high pressure an evaporator and device used thereby |
| US9427784B2 (en) * | 2011-05-18 | 2016-08-30 | Basf Se | Device and method for draining and rinsing containers filled with fluid |
| CN205676239U (en) * | 2016-04-19 | 2016-11-09 | 林俊生 | A kind of supercharging apparatus for eliminating sludge and supercharging descaling equipment |
| WO2018022195A1 (en) * | 2016-07-28 | 2018-02-01 | Exxonmobil Chemical Patents Inc. | High pressure separator cleaning method and apparatus |
| CN107560493A (en) * | 2017-10-23 | 2018-01-09 | 济南大学 | A kind of vacuum salt production vapo(u)rization system cleaning and descaling method |
| CN212746911U (en) * | 2020-08-18 | 2021-03-19 | 重庆民祺节能科技有限公司 | Air energy water heater with descaling device |
Non-Patent Citations (1)
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| 利用锅炉连续排污水清洗结垢管道的实践;王志刚等;《硫酸工业》;20200728(第07期);第33－34页 * |
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| CN113369263A (en) | 2021-09-10 |
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