CN1560102A - Preparation process for polymeric formol of high formol content - Google Patents
Preparation process for polymeric formol of high formol content Download PDFInfo
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- CN1560102A CN1560102A CNA2003101109944A CN200310110994A CN1560102A CN 1560102 A CN1560102 A CN 1560102A CN A2003101109944 A CNA2003101109944 A CN A2003101109944A CN 200310110994 A CN200310110994 A CN 200310110994A CN 1560102 A CN1560102 A CN 1560102A
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Abstract
The invention is a method of preparing high-formaldehyde content polyformaldehyde by using thick formaldehyde water solution, and its main technical character: it replaces vibrated fluidized bed in existing technique with vibrated microwave drier, to dry granular polyformaldehyde with still relatively high humidity coming from spray-granulator. The drying course of the microwave drier gradually dries materials from inside to outside, different from traditional heating mode to gradually dry materials from outside to inside, thus beneficial to water evaporation inside the materials, therefore it has the advantages of fast drying, short heating time and uniform heating, molecular weight of product easy to control, good dissociation property of product, etc.
Description
The present invention relates to the Paraformaldehyde 96 technology of preparing, particularly relating to weight concentration is that 75～85% formalin is that the feedstock production formaldehyde content is the method for 94～97% Paraformaldehyde 96.
The Paraformaldehyde 96 for preparing high formaldehyde content reaches 94～97% Paraformaldehyde 96 as formaldehyde content, and normally reaching 75～85% the concentrated formaldehyde aqueous solution with the formaldehyde weight concentration is raw material, produces through mist projection granulating and drying process operating unit.Carrying out said process again after when low (some is 37～55% for the weight concentration of commercially available formalin), must concentrating processing as the concentration of the formalin of raw material earlier, making its concentration reach 75～85% processes.The prior art of preparation Paraformaldehyde 96 mainly contains two kinds, a kind of is that the concentrated formaldehyde aqueous solution that is about about 80% with weight concentration is raw material, carry out polyreaction earlier, reacted feed liquid is dried to solid by " rake type dryer ", makes the finished product Paraformaldehyde 96 through pulverizing then.Another kind method is to be that 75～90% the concentrated formaldehyde aqueous solution is raw material with weight concentration, earlier in granulating equipment by the nozzle mist projection granulating, make the bigger granular Paraformaldehyde 96 of psychromatic ratio, after vibratory liquefaction drying bed drying, make the finished product Paraformaldehyde 96 again.Dry materials process among these two kinds of preparation methods all belongs to conventional heating and drying method, and material all is that ecto-entad is dried gradually.The characteristics of this drying means are, behind the material superficial drying, its inner moisture content is difficult for evaporation, and exsiccant speed is slow, time is longer, and therefore, above-mentioned two kinds of Paraformaldehyde 96 preparation methods' common drawback is, the dry materials time is long, and energy expenditure is many, easily causes local superheating in drying process.Because when Paraformaldehyde 96 is heated the temperature that reaches certain in drying process, also can carry out polyreaction, thereby can cause molecular weight product wayward, dissociating property of product (water-soluble) is relatively poor, only first method is than second method, the molecular weight of product is more wayward, and dissociating property of product (water-soluble) is poorer, and Granularity Distribution is inhomogeneous.
Purpose of the present invention aims to provide a kind of method of Paraformaldehyde 96 of the new high formaldehyde content of preparation, the Paraformaldehyde 96 for preparing high formaldehyde content by method disclosed by the invention can overcome the deficiency of above-mentioned prior art, the molecular weight of product is controlled easily, the dissociating property of product (water-soluble) is good, and the size distribution of product is even.
In order to realize the foregoing invention purpose, the invention discloses the preparation method of the Paraformaldehyde 96 of following high formaldehyde content:
A, be 75～85% with the formaldehyde weight concentration, temperature is 90～150 ℃, pressure is that the formalin of 6～10atm is a raw material, and this aqueous solution become to drip the ejection of shape by the nozzle that is positioned at granulating equipment, and the temperature that drop feeds in by equipment in the process of landing is 30～60 ℃ of N
2Be condensed into the granulous Paraformaldehyde 96;
B, will send into the vibration microwave dryer from the also bigger granular Paraformaldehyde 96 of granulation operating unit humidity and carry out drying, feed the N have as the cooling and dehumidifying medium in the vibration microwave dryer
2, it is 94～97% finished product Paraformaldehyde 96 that granular Paraformaldehyde 96 is dried to formaldehyde content in the microwave dryer in vibration.
Paraformaldehyde 96 at above-mentioned disclosed high formaldehyde content prepares in the scheme, said vibration microwave dryer, determining of its dry power mainly is to consider that Paraformaldehyde 96 heated time in drying process is not too long, heating temperature is too not high, so that the molecular weight that can control the finished product Paraformaldehyde 96 is no more than the scope of requirement, ensure that the finished product Paraformaldehyde 96 has reasonable dissociating property (water-soluble).According to this guiding theory, the dry power of vibration microwave dryer should be at 3000～6000W/m
3Scope.The N that feeds in the microwave dryer
2, its effect one is that cooling is in the Paraformaldehyde 96 in the heat drying, the 2nd, take away the water vapor in the microwave dryer, and be beneficial to the drying of Paraformaldehyde 96.N in the microwave dryer
2The feeding amount, i.e. N
2Through flow velocity in microwave dryer, and N
2Temperature, also mainly be to consider to make the temperature of Paraformaldehyde 96 in microwave dryer too high not too long with the exsiccant time of being heated.For this reason, N
2Through flow velocity in the vibration microwave dryer should be can in time take away water vapor and the heat that the Paraformaldehyde 96 evaporation produces.N
2Temperature should between 20～30 ℃, be normal temperature.Select N in the present invention
2As the cooling and dehumidifying medium, mainly be because N
2Better chemical stability is arranged, obtain than being easier to, cost is lower.Can certainly be with other rare gas elementes as the cooling and dehumidifying medium, but, this will increase production cost.Therefore, preferred cooling and dehumidifying medium or N
2
In the microwave drying operating unit in such scheme, can adopt the two-stage vibration microwave dryer that the granular Paraformaldehyde 96 from the granulation operating unit is carried out drying, the drying that can more help Paraformaldehyde 96, can make the dry heated time of Paraformaldehyde 96 shorter, being heated will be more even also, promptly more help goal of the invention and realize.
When the microwave drying operating unit adopted the two-stage microwave drying process, the dry power of first step vibration microwave dryer can be 3000～4000W/m
3, it is 90～92% that the Paraformaldehyde 96 that is dried is dried to weight content; The dry power of second stage vibration microwave dryer can be 4000～6000W/m
3, it is 94～97% finished product Paraformaldehyde 96 that the Paraformaldehyde 96 that is dried is dried to weight content.
For above-mentioned two-stage microwave drying operating procedure, the cooling and dehumidifying medium that feeds in the two-stage vibration microwave dryer can all be fresh N
2, discharge respectively after the work.But preferably mode is, the cooling and dehumidifying medium that in second stage vibration microwave dryer, feeds, and a part is that another part is initiate fresh N from first step vibration microwave dryer expellant gas
2, discharge in the lump after the work.Certainly, the N that in first step vibration microwave dryer, feeds
2All should be fresh N
2For a kind of technology in back, help reclaiming the solid phase Paraformaldehyde 96 material of gas-entrained, simplify technical process.
In order to reclaim the entrained solid phase Paraformaldehyde 96 of gas, protect atmospheric environment, the present invention has also taked following technical measures.
Remove its entrained solid phase Paraformaldehyde 96 from the granulating equipment expellant gas by the cyclonic separator separation, the Paraformaldehyde 96 that is separated is sent into the vibration microwave dryer and is dried to the finished product Paraformaldehyde 96, the gas that comes out from cyclonic separator, can be admitted to washing isolation of purified equipment, remove the gaseous formaldehyde component in the gas, discharge atmosphere then.
Can remove entrained solid phase Paraformaldehyde 96 by the cyclonic separator separation of other configuration from vibration microwave dryer expellant gas, the Paraformaldehyde 96 that is separated can directly enter the finished product Paraformaldehyde 96.The gas that comes out from cyclonic separator can enter washing isolation of purified equipment in the lump with the cyclonic separator expellant gas that is used to handle granulation operating unit gas, removes the gaseous formaldehyde component in the gas, discharges atmosphere then.
The present invention has also taked some other technical measures.
Core concept of the present invention is to replace vibratory liquefaction drying bed drying of the prior art with vibration microwave drying.Because the process of microwave drying is that material is dried from inside to outside gradually, the ecto-entad that is different from traditional heating mode is dried gradually, the water evaporates that helps material inside, dry energy needed is few, exsiccant speed is fast, the dry materials heated time is short, also local superheating can not take place in drying process.Because the Paraformaldehyde 96 heated time that is dried is short, be heated evenly, easy control of temperature, so the molecular weight of product can be controlled, and the dissociating property of product is good, and the size distribution of product is even.The two-stage microwave drying process that the present invention further takes more helps the drying of Paraformaldehyde 96, and the time that the Paraformaldehyde 96 drying is heated will be shorter, and it is more even to be heated, and then more helps goal of the invention and realize.Material that the present invention further takes reclaims and purification process, can reclaim the formaldehyde in the gas on the one hand, improves the productive rate of technology, two can emission abatement gas, can not pollute atmosphere.
Accompanying drawing 1 is the process flow sheet of one embodiment of the invention.
Accompanying drawing 2 is process flow sheets of another embodiment of the present invention.
Accompanying drawing 3 is process flow sheets of another embodiment of the present invention.
Provide the embodiment of the invention below, the present invention is further illustrated by embodiment.
Embodiment 1
Technical process as shown in Figure 1.The N that feeds in the mist projection granulating tower 1
2Make its temperature maintenance about 40 ℃, through interchanger 4 heat exchange by N
2Transferpump 3 is sent into mist projection granulating tower 1, N
2Feed tower by the inlet pipe that is positioned at tower top.Be about 80% with weight concentration, temperature is about 100 ℃, and the formalin that pressure is about 8atm is a raw material, and formalin is made progress by the nozzle 2 that is positioned at the prilling tower bottom and becomes to drip the ejection of shape, the process that drop rises and falls, the N that is fed in the tower thereon
2The Paraformaldehyde 96 that evaporative condenser granulates.The injection diameter of nozzle is about about 1mm, and the bottom of prilling tower is a conic tube.Drop to the also very big granular Paraformaldehyde 96 of prilling tower bottom humidity and send into the first step of vibration microwave dryer.The dry power of first step vibration microwave dryer 5 is about 4000W/m
3About, feed the N that has as the cooling and dehumidifying medium in the moisture eliminator
2, its temperature is about 20 ℃, and through flow velocity is about about 0.6m/s.In this one-level microwave dryer, the Paraformaldehyde 96 that is dried is dried to weight content and is about 90～92%.Paraformaldehyde 96 has carried out behind the preliminarily dried in first step vibration microwave dryer, enters second stage vibration microwave dryer 6 subsequently again, proceeds drying.The dry power of second stage vibration microwave dryer is about 5000W/m
3About, the cooling and dehumidifying medium that feeds in it, a part is that another part is initiate N from first step vibration microwave dryer expellant gas
2, temperature is about about 20 ℃, and the through flow velocity of cooling and dehumidifying medium is 1.2m/s.Paraformaldehyde 96 is dried to weight content and is about 94～97% in second stage vibration microwave dryer, promptly make the finished product Paraformaldehyde 96.Expellant gas and all directly enter atmosphere in the prilling tower from second stage vibration microwave dryer expellant gas.Press present embodiment and produce Paraformaldehyde 96, the gas-entrained that is discharged in the atmosphere has a certain amount of solid phase Paraformaldehyde 96 material, and the gaseous formaldehyde component, atmospheric environment is had certain influence, but technical process is simple.
Embodiment 2
The technical process of present embodiment as shown in Figure 2.The granulation of present embodiment is identical with embodiment 1 with the microwave drying process flow process, and different is to have increased the solid phase Paraformaldehyde 96 technical process of reclaiming gas-entrained.Promptly the gas that comes out from prilling tower 1 enters the cyclonic separator 7 into its configuration, gas utilizes the speed of rotation of oneself that entrained solid phase Paraformaldehyde 96 is separated in cyclonic separator, the solid phase Paraformaldehyde 96 of separating enters the first step vibration microwave dryer of microwave drying operating unit, with the Paraformaldehyde 96 mixing of materials that directly enters from prilling tower, carry out drying processing.The gas of removing solid phase Paraformaldehyde 96 material directly discharges atmosphere.Enter other cyclonic separator 9 from second stage vibration microwave dryer expellant gas into its configuration, utilize own speed of rotation in cyclonic separator that entrained solid phase Paraformaldehyde 96 is separated, the Paraformaldehyde 96 of separating is the finished product Paraformaldehyde 96.The gas of removing entrained finished product Paraformaldehyde 96 directly enters atmosphere.Press present embodiment and produce Paraformaldehyde 96, the gas that is discharged in the atmosphere also contains the gaseous formaldehyde component, environment is had certain influence, but technology is simpler.
Embodiment 3
The technical process of present embodiment as shown in Figure 3, technical process such as the mist projection granulating of present embodiment, microwave drying, cyclonic separation are identical with embodiment 2.Present embodiment is on the basis of the technical process of embodiment 2, to send into water through different cyclonic separator expellant gas from prilling tower and second stage vibration microwave dryer is the washing isolation of purified tower 8 of washing composition, enters atmosphere again after removing the formaldehyde components in the gas.Formaldehyde content in the emission gases can not pollute atmosphere less than the emission standard that country allows.The technical process of washing isolation of purified is same as the prior art, is routine techniques.
Claims (9)
1. the preparation method of the Paraformaldehyde 96 of a high formaldehyde content is characterized in that:
A, be 75～85% with the formaldehyde weight concentration, temperature is 90～150 ℃, pressure is that the formalin of 6～10atm is a raw material, and this aqueous solution become to drip the shape ejection by the nozzle that is positioned at granulating equipment, and the temperature that drop feeds in by equipment in the process of landing is 30～60 ℃ N
2Be condensed into granular Paraformaldehyde 96;
B, will send into to feed from the granular Paraformaldehyde 96 of granulation operating unit and have as cooling and dehumidifying medium N
2The vibration microwave dryer carry out drying, be dried to the Paraformaldehyde 96 weight content and be 90～94% finished product Paraformaldehyde 96.
2. the preparation method of Paraformaldehyde 96 according to claim 1, the dry power that it is characterized in that vibrating microwave dryer is 3000～6000W/m
3, as cooling and dehumidifying medium N
2Temperature be 20～30 ℃.
3. the preparation method of Paraformaldehyde 96 according to claim 2 is characterized in that Paraformaldehyde 96 is dried to the finished product Paraformaldehyde 96 through the two-stage vibration microwave dryer.
4. the preparation method of Paraformaldehyde 96 according to claim 3 is characterized in that the dry power of first step vibration microwave dryer is 3000～4000W/m
3, it is 90～92% that Paraformaldehyde 96 is dried to weight content, the dry power of second stage vibration microwave dryer is 5000～6000W/m
2, it is 94～97% finished product Paraformaldehyde 96 that Paraformaldehyde 96 is dried to weight content.
5. the preparation method of Paraformaldehyde 96 according to claim 4 is characterized in that the cooling and dehumidifying medium-gas part in the second stage vibration microwave dryer is that another part is initiate fresh N from first step vibration microwave dryer expellant gas
2
6. according to the preparation method of claim 1 or 2 or 3 or 4 or 5 described Paraformaldehyde 96s, it is characterized in that removing its entrained solid phase Paraformaldehyde 96 from the granulating equipment expellant gas by cyclonic separator, the solid phase Paraformaldehyde 96 that is separated is sent into the vibration microwave dryer and is dried to the finished product Paraformaldehyde 96.
7. according to the preparation method of claim 1 or 2 or 3 or 4 or 5 described Paraformaldehyde 96s, it is characterized in that removing its entrained solid phase Paraformaldehyde 96 from vibration microwave dryer expellant gas by cyclonic separator, the solid phase Paraformaldehyde 96 of separating directly enters the finished product Paraformaldehyde 96.
8. the preparation method of Paraformaldehyde 96 according to claim 6 is characterized in that removing gaseous formaldehyde component discharging atmosphere by the cyclonic separator expellant gas through washing isolation of purified equipment.
9. the preparation method of Paraformaldehyde 96 according to claim 7 is characterized in that removing gaseous formaldehyde component discharging atmosphere from the cyclonic separator expellant gas through washing isolation of purified equipment.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200310110994 CN1252109C (en) | 2004-02-26 | 2004-02-26 | Preparation process for polymeric formol of high formol content |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200310110994 CN1252109C (en) | 2004-02-26 | 2004-02-26 | Preparation process for polymeric formol of high formol content |
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| CN1560102A true CN1560102A (en) | 2005-01-05 |
| CN1252109C CN1252109C (en) | 2006-04-19 |
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| CN 200310110994 Expired - Fee Related CN1252109C (en) | 2004-02-26 | 2004-02-26 | Preparation process for polymeric formol of high formol content |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100716542B1 (en) | 2005-09-23 | 2007-05-09 | 원진중공업 주식회사 | Manufacturing method for the highest purity of Paraformaldehyde |
| CN102443121A (en) * | 2011-10-31 | 2012-05-09 | 江苏恒茂机械制造有限公司 | Paraformaldehyde production process |
| CN104130359A (en) * | 2014-07-21 | 2014-11-05 | 江苏凯茂石化科技有限公司 | Paraformaldehyde production process unit |
| CN104130360A (en) * | 2014-07-21 | 2014-11-05 | 江苏凯茂石化科技有限公司 | Process for producing paraformaldehyde |
| CN104174326A (en) * | 2014-07-21 | 2014-12-03 | 江苏凯茂石化科技有限公司 | Spray granulating drying tower |
| CN104194006A (en) * | 2014-08-13 | 2014-12-10 | 山东滨州新天阳化工有限责任公司 | Spray granulation process in paraformaldehyde preparation |
| CN109265632A (en) * | 2018-09-12 | 2019-01-25 | 重庆大学 | A kind of preparation method of paraformaldehyde |
-
2004
- 2004-02-26 CN CN 200310110994 patent/CN1252109C/en not_active Expired - Fee Related
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100716542B1 (en) | 2005-09-23 | 2007-05-09 | 원진중공업 주식회사 | Manufacturing method for the highest purity of Paraformaldehyde |
| CN102443121A (en) * | 2011-10-31 | 2012-05-09 | 江苏恒茂机械制造有限公司 | Paraformaldehyde production process |
| CN104130359A (en) * | 2014-07-21 | 2014-11-05 | 江苏凯茂石化科技有限公司 | Paraformaldehyde production process unit |
| CN104130360A (en) * | 2014-07-21 | 2014-11-05 | 江苏凯茂石化科技有限公司 | Process for producing paraformaldehyde |
| CN104174326A (en) * | 2014-07-21 | 2014-12-03 | 江苏凯茂石化科技有限公司 | Spray granulating drying tower |
| WO2016011723A1 (en) * | 2014-07-21 | 2016-01-28 | 江苏凯茂石化科技有限公司 | Paraformaldehyde production method |
| WO2016011724A1 (en) * | 2014-07-21 | 2016-01-28 | 江苏凯茂石化科技有限公司 | Paraformaldehyde production apparatus |
| CN104130359B (en) * | 2014-07-21 | 2016-11-23 | 江苏凯茂石化科技有限公司 | A kind of production technology of paraformaldehyde device |
| CN104194006A (en) * | 2014-08-13 | 2014-12-10 | 山东滨州新天阳化工有限责任公司 | Spray granulation process in paraformaldehyde preparation |
| CN109265632A (en) * | 2018-09-12 | 2019-01-25 | 重庆大学 | A kind of preparation method of paraformaldehyde |
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|---|---|
| CN1252109C (en) | 2006-04-19 |
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