CA1200055A - Method for controlling the burning of liquor, which varies in its chemical consistency, in a recovery boiler - Google Patents
Method for controlling the burning of liquor, which varies in its chemical consistency, in a recovery boilerInfo
- Publication number
- CA1200055A CA1200055A CA000404146A CA404146A CA1200055A CA 1200055 A CA1200055 A CA 1200055A CA 000404146 A CA000404146 A CA 000404146A CA 404146 A CA404146 A CA 404146A CA 1200055 A CA1200055 A CA 1200055A
- Authority
- CA
- Canada
- Prior art keywords
- liquor
- viscosity
- feed
- recovery boiler
- burning
- 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
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
- D21C11/12—Combustion of pulp liquors
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
- F23G7/04—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste liquors, e.g. sulfite liquors
Landscapes
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Paper (AREA)
- Regulation And Control Of Combustion (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method to control the burning of liquor varying in its chemical consistency at the recovery boiler is disclosed. Considering the burning, for accomplishing the suitable size of the droplet in the recovery boiler, the viscosity of liquor will be controlled on the basis of density measurement, which, however, has proved to be an unreliable and slow way.
To overcome these disadvantages the feeding parameters are controlled directly on the basis of the measured viscosity of liquor.
A method to control the burning of liquor varying in its chemical consistency at the recovery boiler is disclosed. Considering the burning, for accomplishing the suitable size of the droplet in the recovery boiler, the viscosity of liquor will be controlled on the basis of density measurement, which, however, has proved to be an unreliable and slow way.
To overcome these disadvantages the feeding parameters are controlled directly on the basis of the measured viscosity of liquor.
Description
A method for controlling the burning of liquor, which varies in its chemical consistency, in a recovery boiler This invention relates to a method for controlling the feed of burning liquors, varying in their chemical and physical consistency, to the recovery boiler for accomp]ishing a suitable droplet size for burning in the recovery boiler, In additiong this invention relates to the use of 'che above-mentioned method for controlling the burning in such continuously operating recovery boiler~ wherein liquors from different wood qualities and/or sulphate - and sulphite cookings are burnt.
As known, spent liquor is produced in the cooking of ch'emical pulp, and it is particularly important from the viewpoint o economy in making chemical pulp that thermal content and chemicals of this spent liquor are recovered as throughly as possible for utilizing in the process of the chemical pulp manufacture. Before burning spent liquor so that thermal energy could be released and chemicals recovered water is evaporated from spent liquor so that burning liquor containing about 40% water is obtainedO ~urning liquor is bùrnt in the recovery boiler, when thermal energy to be released can be utilized in the process of the chemical pulp manufacture and chemicals can be recovered from the bottom of the recovery boiler, and after regenerating they can be utilized in making of cooking liquor.
When the price of energy continues to rise it has become still more important economically in the process of the chemical pulp ]nanufacture, to make the liq'uor burning in the recovery boiler function as undisturbed as possible and with good efficiency of energy.
Because of the primary task of the recovery boiler, the recovery and the regenerating of salts for cooking liquor, a reducing section of high temperature with a so-called stack in its bottom part, has to be accomplished for the bottom part of the recovery boiler. The regenerating degree in the boiler is Measured by means of the reduction of sulphur.
~, , ~
~ 5 ~ 2 The recovery of salts is measured by means o-f chemical losses.
The loss is developing, when gases, as e.g. SO2, are escaping with flue gases.
One task of the recovery boiler is also heat recovery from flue gases. Its efficiency can be measured by means of the quantity of the flue gas loss, the share of non-combustible gases and by means of the availability of the boiler i.e~ by means of laying days caused by the contamination of the fire surfaces.
Many different factors effect on the function of the recovery boiler.
There is still relatively much water ~about 40~) in the burning liquor to be fed into the recovery boiler. This water amount shall be evaporated in the recovery boiler and the evaporation shall essentially take place before the droplet, which falls toward the stack in the bottom of the recovery boiler, hits the surface of the stack. If it is not happening so, a great part of water shall be evaporated from the surface of the stack, which of course decreases the temperature of the stack, which in its turn increases sulphur dioxide emission. If the water has been evaporated before the stack, the droplets become so light that they are carried away with a rising gas flow in the recovery boiler, when they get pyrolyzed and burn in a gas phase, when the dust load of gas grows.
The purpose is to get the size of the liquor droplets such that the dry-solids content, when the droplet touches the surface of the stack is suitable and that the remaining small water amount quickly escapes from the surface of the stack accomplishing the porous stack.
Then the stack on the bottom of the furnace becomes hot, which makes low SO2 - releases and the good availability of the boiler possible.
From the point of view of the recovery boiler function, the suitable size of the droplet has been visually determined on the basis of the experience, among other things by checking on the basis of color the temperature of the stack on the bottom of the recovery kloiler. It has been established that the viscosity of liquor to be fed ~ 3~ 5~ 3 into the recovery boiler maillly determined the size of -the droplet which is formed in the gas space of the recovery boiler, when among other things the size and type of ~he nozzles feeding liquor into the recovery boiler and the feeding pressure essentially remain unchanged. Correspondingly, when the viscosity and the flow rate of the liquor remain unchanged, the si~e of the droplec is determined by the diameter of -the nozzle.
To maintain the size of the droplet in a before-mentioned way in a value established good e~perimentally the dry solids content of the burning liquor determined either by means of density or a refractometer has been used as a control variable. On the basis of the measurement results -those alterations have been determined, which were to be made in the temperature and the spray pressure of liquor to be fed into the recovery boiler, for accomplishing a droplet of the desired size for a gas space of the recovery boiler.
Mainly, the viscosity of liquor has then been regulated by heating it.
This kind of an adjustment has been described in the publication of Pulp and Paper 53, (1979) 9, pages 142 - 145.
The Baumé measurement is in general used in a density measurement.
The refractometer measurement for its part gives, when the cooking circumstances of the rawmaterial and cellulose remain unchanged, a quantityJ which can be utilized in the control of the recovery boiler.
The disturbance-free operation of ~he recovery boiler has been earlier achieved by keeping the manufacturing process and as its consequence the characteristics of the burning liquor as uniform as possible, due to which the burning process can have been driven by constant setting. Earlier only one wood quality determined by a mill was in general used in pulp mills and likewise only one specified pulp quality was in general produced, as a consequence o:~ which the chemical consistency of waste liquor remained in general unchanged.
s~
Instead, the dry~solids content of the burning 11quor varied according to the function of the evaporation plant, and the fluctuation limits have in general been 55-65~ of dry solids.
The function of the evaporation plant was regulated so that a certain constant dry solids consistency was achieved, accord-ing to which the burning process was regulated. The dry-solids consistency was regulated by an accuracy of about + 1,5 percent. If the fluctuations are great, they are reflecting to the use of the recovery boiler by causing changes in the reduction level, SO2 gas emissions and the contamination of the boiler. I~hen difficulties have appeared the user of the recovery boiler has asked to check, if the process values in the evaporation plant and cooking have remained within the set limits.
Continuously operating boilers have been developed for increas-ing the efficiency of the pulp mill. In those ones the cir-cumstances change quickly, when e.g. wood quality used as rawmaterial varies once a week or the yield of the cooking fluctuates. Fluctuations in the chemical consistency of liquor to be burnt are also caused by still more closed pro-cesses, i.e. by closed chemical circulations. These rawmaterial fluctuations require also new cooking values (residual alkali content) which aggravates the function of the evaporation plant. In these circumstances -the characteristics of liquor ..~ jt ,., S~
cannot be maintained as equal in quality as before.
When the cooking is continuous, the disturbance :is transferred directly to the recovery boiler if special corresponding steps are not taken in liquor stores.
In order to accomplish the better heat energy economy the dry-solids consistency of liquor is raised from earlier level of about 60% to a level of about 67%. In order -to guarantee the same circumstances in the furnace due to the spray the claim for the accuracy during the evaporation is greater by a 67% liquor than by a 60% liquor.
The dry-solids fluctuation of - 1,5% should be diminished to the value of - 0,4% for securing the same viscosity fluctuation.
In addition to the above-mentioned greater disturbances appear-ing in the recovery boilers the general requirement level set ~or devices has risen. The availability requirement under varying circumstances is great at the same time as the SO2 level in flue gasses and the reduction level in molten state remain at the controlled level.
In addition to the rise in requirements and to greater losses it has been established that the above-mentioned measurement methods do not any more give reliable knowledge on the size of the liquor droplet, which is formed in the gas space of .~
~ ~r~3~5~j the recovery boiler, while the chemical consistency of burn-ing liquor to be fed in-to the recovery boiler varies, for instance therefore tha-t wood quality or the cooking way has been altered during the cooking process of pulp. Furthermore it has been established that the density measurement o~ the burning liquor as a Baume~ measurement is unreliable when the dry-solids content rises above 6~%. A time delay of the dry-solids analysis is in addition so great (about 12 h) that it cannot be used for the control of the recovery boiler when quick alterations take place in the chemical consistency of burning liquor to be fed into the recovery boiler.
The purpose of the above invention is so to accomplish a method for maintaining the feeding parameters of burning liquor to be fed into the recovery boiler in desired values, which have been experimentally found as good or within the set limits so that burning liquor forms as suitable droplets as possible in the recovery boiler, from the viewpoint of burning. The way according to the above-mentioned invention is particularly applicable, when the chemical consistency and physical characteristics of liquor to be fed into the recovery boiler vary. The fluctuation can for instance be caused by the fact that burning liquor comes from a cooking process of pulp, wherein different wood quali-ties are used as rawmaterial or from a cooking process of a completely 5~
-6a-different type. The way according to -the invention is thus particularly appropriate for controlling such burning in the recovery boiler, wherein liquors from different wood qualities and/or sulphate and sulphite cookings are burnt.
According to the above invention the viscosity of burning liquor to be fed into the recovery boiler is rneasured at least immediately before the feeding and when using thismeasurement result as a control variable the feeding pressure of liquor to be fed into -the recovery boiler or the temperature or both are regulated so that the suitable droplet size is obtained.
When needed the viscosity can be measured at many places, for instance for a anticipating coarse control.
When that physical characteristic of burning liquor, which effects most upon the droplet formation, i9 used directly as a control variable, the fluctuation of the chemical consistency and physical charac-teristics of liquor do not disturb the uniformity of the burning process in the recovery boiler.
The invention is here under described in more detail referring to the drawings, in which Fig. 1 shows the change in the vis-cosity with the same dry-solids consistency when the dry-solids content changes, Fig. 2 shows the viscosity scattering of birch liquor (area A) and pine liquor (area B) with different dry-solids contents, and Fig. 3 shows embodirnent results achieved with a method according -~b-to the invention which results have been explained in the example below. In a preferred embodiment of -the invention burning liquor to be fed into the recovery boiler is cooled or heated for regulating its viscosity. Opposite to the earlier known me-thods, the dry-solids content or the refract-ing measurement of liquor is not, however, used as a control variable, but the cooling or the heating is performed directly on the basis of the viscosity measurement. The viscosity of burning liquor is on the basis of the measurement result kept between two limiting values, which have been empirically found out to be good. The cooling and the heating of burning liquor are controlled advantageously depending onthe speed with which its viscosity falls by the lowest value ~J~a~
of the limiting values or ~ises by the highest value, i.e.
on the basis of the so-called allgle cocfficient.
Alternatively, the viscosity of burning liquor can be controlled by mixing to it liquor, which has different kind of a viscosity.
In this way tlle me-thod according to the invention can be used for controlling the burning in such continuously operating recovery boiler, wherein liquors coming from different wood qualiiies and/or sulphate or sulphite cookings are burnt either simultaneously or at different timesO
If the viscosity fluctuations of liquor remain within the suitable area it is possible to use only the control of the ~emperature or the nozzle opening for regulating the droplet size.
It is also possible to regulate the droplet size by combining the mixture of liquors with different viscosities, the control of the nozzle opening and the heating and the cooling by the desired way so that all or only a part of different control ways are used together.
'I`he invention is illus~ra~ed beneath in more de~ail by an example.
Example Fig. 3 shows the fluctuations in the burning liquor quality as a function o time. ~n the picture A means a dry solids con-tenc~ B a viscosity after the mixing tank and C is a viscosity before the mixing tank. Area E illustrates a birch liquor sequence, which alternates with pine liquor.
The great changes in the viscosity shown in the picture~ which when coming as such into liquor nozzles would cause burning disturbances in the recovery boilcr, have been eliminated by regulating the viscosity of liquor going to burning by means of preheating and viscosimeter according to the set value, D.
As known, spent liquor is produced in the cooking of ch'emical pulp, and it is particularly important from the viewpoint o economy in making chemical pulp that thermal content and chemicals of this spent liquor are recovered as throughly as possible for utilizing in the process of the chemical pulp manufacture. Before burning spent liquor so that thermal energy could be released and chemicals recovered water is evaporated from spent liquor so that burning liquor containing about 40% water is obtainedO ~urning liquor is bùrnt in the recovery boiler, when thermal energy to be released can be utilized in the process of the chemical pulp manufacture and chemicals can be recovered from the bottom of the recovery boiler, and after regenerating they can be utilized in making of cooking liquor.
When the price of energy continues to rise it has become still more important economically in the process of the chemical pulp ]nanufacture, to make the liq'uor burning in the recovery boiler function as undisturbed as possible and with good efficiency of energy.
Because of the primary task of the recovery boiler, the recovery and the regenerating of salts for cooking liquor, a reducing section of high temperature with a so-called stack in its bottom part, has to be accomplished for the bottom part of the recovery boiler. The regenerating degree in the boiler is Measured by means of the reduction of sulphur.
~, , ~
~ 5 ~ 2 The recovery of salts is measured by means o-f chemical losses.
The loss is developing, when gases, as e.g. SO2, are escaping with flue gases.
One task of the recovery boiler is also heat recovery from flue gases. Its efficiency can be measured by means of the quantity of the flue gas loss, the share of non-combustible gases and by means of the availability of the boiler i.e~ by means of laying days caused by the contamination of the fire surfaces.
Many different factors effect on the function of the recovery boiler.
There is still relatively much water ~about 40~) in the burning liquor to be fed into the recovery boiler. This water amount shall be evaporated in the recovery boiler and the evaporation shall essentially take place before the droplet, which falls toward the stack in the bottom of the recovery boiler, hits the surface of the stack. If it is not happening so, a great part of water shall be evaporated from the surface of the stack, which of course decreases the temperature of the stack, which in its turn increases sulphur dioxide emission. If the water has been evaporated before the stack, the droplets become so light that they are carried away with a rising gas flow in the recovery boiler, when they get pyrolyzed and burn in a gas phase, when the dust load of gas grows.
The purpose is to get the size of the liquor droplets such that the dry-solids content, when the droplet touches the surface of the stack is suitable and that the remaining small water amount quickly escapes from the surface of the stack accomplishing the porous stack.
Then the stack on the bottom of the furnace becomes hot, which makes low SO2 - releases and the good availability of the boiler possible.
From the point of view of the recovery boiler function, the suitable size of the droplet has been visually determined on the basis of the experience, among other things by checking on the basis of color the temperature of the stack on the bottom of the recovery kloiler. It has been established that the viscosity of liquor to be fed ~ 3~ 5~ 3 into the recovery boiler maillly determined the size of -the droplet which is formed in the gas space of the recovery boiler, when among other things the size and type of ~he nozzles feeding liquor into the recovery boiler and the feeding pressure essentially remain unchanged. Correspondingly, when the viscosity and the flow rate of the liquor remain unchanged, the si~e of the droplec is determined by the diameter of -the nozzle.
To maintain the size of the droplet in a before-mentioned way in a value established good e~perimentally the dry solids content of the burning liquor determined either by means of density or a refractometer has been used as a control variable. On the basis of the measurement results -those alterations have been determined, which were to be made in the temperature and the spray pressure of liquor to be fed into the recovery boiler, for accomplishing a droplet of the desired size for a gas space of the recovery boiler.
Mainly, the viscosity of liquor has then been regulated by heating it.
This kind of an adjustment has been described in the publication of Pulp and Paper 53, (1979) 9, pages 142 - 145.
The Baumé measurement is in general used in a density measurement.
The refractometer measurement for its part gives, when the cooking circumstances of the rawmaterial and cellulose remain unchanged, a quantityJ which can be utilized in the control of the recovery boiler.
The disturbance-free operation of ~he recovery boiler has been earlier achieved by keeping the manufacturing process and as its consequence the characteristics of the burning liquor as uniform as possible, due to which the burning process can have been driven by constant setting. Earlier only one wood quality determined by a mill was in general used in pulp mills and likewise only one specified pulp quality was in general produced, as a consequence o:~ which the chemical consistency of waste liquor remained in general unchanged.
s~
Instead, the dry~solids content of the burning 11quor varied according to the function of the evaporation plant, and the fluctuation limits have in general been 55-65~ of dry solids.
The function of the evaporation plant was regulated so that a certain constant dry solids consistency was achieved, accord-ing to which the burning process was regulated. The dry-solids consistency was regulated by an accuracy of about + 1,5 percent. If the fluctuations are great, they are reflecting to the use of the recovery boiler by causing changes in the reduction level, SO2 gas emissions and the contamination of the boiler. I~hen difficulties have appeared the user of the recovery boiler has asked to check, if the process values in the evaporation plant and cooking have remained within the set limits.
Continuously operating boilers have been developed for increas-ing the efficiency of the pulp mill. In those ones the cir-cumstances change quickly, when e.g. wood quality used as rawmaterial varies once a week or the yield of the cooking fluctuates. Fluctuations in the chemical consistency of liquor to be burnt are also caused by still more closed pro-cesses, i.e. by closed chemical circulations. These rawmaterial fluctuations require also new cooking values (residual alkali content) which aggravates the function of the evaporation plant. In these circumstances -the characteristics of liquor ..~ jt ,., S~
cannot be maintained as equal in quality as before.
When the cooking is continuous, the disturbance :is transferred directly to the recovery boiler if special corresponding steps are not taken in liquor stores.
In order to accomplish the better heat energy economy the dry-solids consistency of liquor is raised from earlier level of about 60% to a level of about 67%. In order -to guarantee the same circumstances in the furnace due to the spray the claim for the accuracy during the evaporation is greater by a 67% liquor than by a 60% liquor.
The dry-solids fluctuation of - 1,5% should be diminished to the value of - 0,4% for securing the same viscosity fluctuation.
In addition to the above-mentioned greater disturbances appear-ing in the recovery boilers the general requirement level set ~or devices has risen. The availability requirement under varying circumstances is great at the same time as the SO2 level in flue gasses and the reduction level in molten state remain at the controlled level.
In addition to the rise in requirements and to greater losses it has been established that the above-mentioned measurement methods do not any more give reliable knowledge on the size of the liquor droplet, which is formed in the gas space of .~
~ ~r~3~5~j the recovery boiler, while the chemical consistency of burn-ing liquor to be fed in-to the recovery boiler varies, for instance therefore tha-t wood quality or the cooking way has been altered during the cooking process of pulp. Furthermore it has been established that the density measurement o~ the burning liquor as a Baume~ measurement is unreliable when the dry-solids content rises above 6~%. A time delay of the dry-solids analysis is in addition so great (about 12 h) that it cannot be used for the control of the recovery boiler when quick alterations take place in the chemical consistency of burning liquor to be fed into the recovery boiler.
The purpose of the above invention is so to accomplish a method for maintaining the feeding parameters of burning liquor to be fed into the recovery boiler in desired values, which have been experimentally found as good or within the set limits so that burning liquor forms as suitable droplets as possible in the recovery boiler, from the viewpoint of burning. The way according to the above-mentioned invention is particularly applicable, when the chemical consistency and physical characteristics of liquor to be fed into the recovery boiler vary. The fluctuation can for instance be caused by the fact that burning liquor comes from a cooking process of pulp, wherein different wood quali-ties are used as rawmaterial or from a cooking process of a completely 5~
-6a-different type. The way according to -the invention is thus particularly appropriate for controlling such burning in the recovery boiler, wherein liquors from different wood qualities and/or sulphate and sulphite cookings are burnt.
According to the above invention the viscosity of burning liquor to be fed into the recovery boiler is rneasured at least immediately before the feeding and when using thismeasurement result as a control variable the feeding pressure of liquor to be fed into -the recovery boiler or the temperature or both are regulated so that the suitable droplet size is obtained.
When needed the viscosity can be measured at many places, for instance for a anticipating coarse control.
When that physical characteristic of burning liquor, which effects most upon the droplet formation, i9 used directly as a control variable, the fluctuation of the chemical consistency and physical charac-teristics of liquor do not disturb the uniformity of the burning process in the recovery boiler.
The invention is here under described in more detail referring to the drawings, in which Fig. 1 shows the change in the vis-cosity with the same dry-solids consistency when the dry-solids content changes, Fig. 2 shows the viscosity scattering of birch liquor (area A) and pine liquor (area B) with different dry-solids contents, and Fig. 3 shows embodirnent results achieved with a method according -~b-to the invention which results have been explained in the example below. In a preferred embodiment of -the invention burning liquor to be fed into the recovery boiler is cooled or heated for regulating its viscosity. Opposite to the earlier known me-thods, the dry-solids content or the refract-ing measurement of liquor is not, however, used as a control variable, but the cooling or the heating is performed directly on the basis of the viscosity measurement. The viscosity of burning liquor is on the basis of the measurement result kept between two limiting values, which have been empirically found out to be good. The cooling and the heating of burning liquor are controlled advantageously depending onthe speed with which its viscosity falls by the lowest value ~J~a~
of the limiting values or ~ises by the highest value, i.e.
on the basis of the so-called allgle cocfficient.
Alternatively, the viscosity of burning liquor can be controlled by mixing to it liquor, which has different kind of a viscosity.
In this way tlle me-thod according to the invention can be used for controlling the burning in such continuously operating recovery boiler, wherein liquors coming from different wood qualiiies and/or sulphate or sulphite cookings are burnt either simultaneously or at different timesO
If the viscosity fluctuations of liquor remain within the suitable area it is possible to use only the control of the ~emperature or the nozzle opening for regulating the droplet size.
It is also possible to regulate the droplet size by combining the mixture of liquors with different viscosities, the control of the nozzle opening and the heating and the cooling by the desired way so that all or only a part of different control ways are used together.
'I`he invention is illus~ra~ed beneath in more de~ail by an example.
Example Fig. 3 shows the fluctuations in the burning liquor quality as a function o time. ~n the picture A means a dry solids con-tenc~ B a viscosity after the mixing tank and C is a viscosity before the mixing tank. Area E illustrates a birch liquor sequence, which alternates with pine liquor.
The great changes in the viscosity shown in the picture~ which when coming as such into liquor nozzles would cause burning disturbances in the recovery boilcr, have been eliminated by regulating the viscosity of liquor going to burning by means of preheating and viscosimeter according to the set value, D.
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for controlling the droplet size of burning liquor fed to a recovery boiler, said liquor feed varying in physical and chemical consistency and having a fluctuating dry-solids content, which method comprises measuring the viscosity of said liquor feed at least immediately prior to introduction of said feed into said recovery boiler, introducing said liquor feed into said recovery boiler for burning by means of a nozzle, and controlling the feeding parameters directly on the basis of the measured viscosity value of said liquor feed.
2. The method of claim 1 wherein said controlled feeding parameter com-prises controlling the opening of the nozzle utilized to feed said liquor to said recovery boiler.
3. The method of claim 1, wherein both the viscosity of said liquor feed and the opening of said nozzle utilized to feed said liquor into said recovery boiler are controlled directly on the basis of said measured viscosity value.
4. The method of claim 1, wherein the viscosity of said liquor feed is controlled in response to said measured viscosity value.
5. The method of claim 4, wherein the viscosity of said liquor feed is controlled by admixing said liquor with a liqour feed having a higher or lower viscosity than said feed liquor as required to achieve the desired viscosity.
6. The method of claim 4, wherein said controlled feeding parameter com-prises heating or cooling said liquor feed to achieve the desired viscosity.
7. The method of claim 4, wherein the viscosity of the liquor feed is controlled in response to said measured viscosity value by admixing liquors having different viscosities with said feed liquor and heating or cooling said feed liquor to obtain the desired viscosity.
8. The method of claim 4, wherein the viscosity of said liquor feed is maintained between two limit values.
9. The method of claim 6 or 7, wherein the viscosity of liquor feed is maintained between two limit values and the heating and cooling of liquor is controlled depending upon the response to viscosity changes within said limit values.
10. The method of claim 1, wherein said feed liquors are derived from different types of wood and/or sulphate cookings.
11. The method of claim 1, wherein the viscosity of the liquor feed is measured by means of a viscosimeter to obtain said measured value, and the viscosity of the feed is adjusted directly on the basis of said measured value to control the viscosity of the liquor fed into the recovery boiler at a predeter-mined value.
12. The process of claim 1, wherein the dry-solids content of the liquor feed fluctuates as a function of time and the viscosity of the liquor fed to the boiler is maintained at a constant value.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI811679 | 1981-06-01 | ||
| FI811679A FI64409C (en) | 1981-06-01 | 1981-06-01 | SAETT ATT STYRA FOERBRAENNINGEN AV EN TILL SIN KEMISKA KOMPOSITION VARIERANDE BRAENNLUT I SODAPANNAN |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1200055A true CA1200055A (en) | 1986-02-04 |
Family
ID=8514445
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000404146A Expired CA1200055A (en) | 1981-06-01 | 1982-05-31 | Method for controlling the burning of liquor, which varies in its chemical consistency, in a recovery boiler |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS57210217A (en) |
| BR (1) | BR8203222A (en) |
| CA (1) | CA1200055A (en) |
| FI (1) | FI64409C (en) |
| FR (1) | FR2506898B1 (en) |
| SE (1) | SE8203294L (en) |
| SU (1) | SU1461374A3 (en) |
| ZA (1) | ZA823318B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4768469A (en) * | 1985-07-31 | 1988-09-06 | Kabushiki Kaisha Toshiba | Operation control apparatus for recovery boilers |
| US4929307A (en) * | 1985-11-29 | 1990-05-29 | A. Ahlstrom Corporation | Method of decreasing black liquor viscosity |
| US5112441A (en) * | 1985-04-25 | 1992-05-12 | Oy Tampella Ab | Process for the recovery of heat and chemicals from spent liquor |
| US5636451A (en) * | 1992-08-11 | 1997-06-10 | Noell-Dbi-Energie Und Entsorgungstechnik Gmbh | Process for feeding sludge into a reactor for thermal disposal |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI70270C (en) * | 1985-03-18 | 1986-09-15 | Tampella Oy Ab | SAETT ATT REGLERA INMATNINGS- OCH FOERBRAENNINGSFOERHAOLLANDENA AV FOERBRAENNINGSLUTAR VARIERANDE TILL SIN KEMISKA OCH PHYSIKISISKA KOMPOSITION FOER FOERBRAENNING I EN SODAPANNA |
| JP2941831B2 (en) * | 1989-01-10 | 1999-08-30 | バブコツク日立株式会社 | Dust scattering prevention device for black liquor recovery boiler |
| DE9108106U1 (en) * | 1991-07-02 | 1992-10-29 | Siemens Ag, 8000 Muenchen, De |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2630819A (en) * | 1948-06-09 | 1953-03-10 | Austin S Norcross | Method and apparatus for controlling the viscosity of a processing liquid |
| DE1517164A1 (en) * | 1965-07-28 | 1969-09-04 | Bergwerksverband Gmbh | Process for incinerating sulphite liquor in combustion chambers |
| CH556000A (en) * | 1973-03-14 | 1974-11-15 | Heberlein & Co Ag | PROCESS FOR INCINERATING WASTE LIQUIDS CONTAINING WATER AND ADDITIONAL BURNERS AT INCINERATION PLANT TO PERFORM THE PROCESS. |
| US3977427A (en) * | 1975-09-18 | 1976-08-31 | John Zink Company | Control of the viscosity of fuel oil for burners |
| FR2366516A1 (en) * | 1976-10-04 | 1978-04-28 | Ferbeck Et Vincent Ets | LIQUID RESIDUE INCINERATION OVEN AND ROTARY INJECTOR SUITABLE FOR EQUIPMENT OF SUCH OVEN |
| US4249885A (en) * | 1978-07-20 | 1981-02-10 | Vapor Corporation | Heavy fuel oil nozzle |
| FR2445931A2 (en) * | 1978-07-21 | 1980-08-01 | Citroen Sa | Water and oil emulsion combustion plant - uses axial piston metering pump to regulate mix concentration fed via feed pumps to pipeline |
-
1981
- 1981-06-01 FI FI811679A patent/FI64409C/en not_active IP Right Cessation
-
1982
- 1982-05-13 ZA ZA823318A patent/ZA823318B/en unknown
- 1982-05-25 FR FR8209025A patent/FR2506898B1/en not_active Expired
- 1982-05-27 SE SE8203294A patent/SE8203294L/en unknown
- 1982-05-31 SU SU823445628A patent/SU1461374A3/en active
- 1982-05-31 CA CA000404146A patent/CA1200055A/en not_active Expired
- 1982-06-01 BR BR8203222A patent/BR8203222A/en unknown
- 1982-06-01 JP JP57093954A patent/JPS57210217A/en active Granted
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5112441A (en) * | 1985-04-25 | 1992-05-12 | Oy Tampella Ab | Process for the recovery of heat and chemicals from spent liquor |
| US4768469A (en) * | 1985-07-31 | 1988-09-06 | Kabushiki Kaisha Toshiba | Operation control apparatus for recovery boilers |
| US4929307A (en) * | 1985-11-29 | 1990-05-29 | A. Ahlstrom Corporation | Method of decreasing black liquor viscosity |
| US5636451A (en) * | 1992-08-11 | 1997-06-10 | Noell-Dbi-Energie Und Entsorgungstechnik Gmbh | Process for feeding sludge into a reactor for thermal disposal |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2506898B1 (en) | 1988-11-10 |
| FI811679A0 (en) | 1981-06-01 |
| ZA823318B (en) | 1983-03-30 |
| SE8203294L (en) | 1982-12-02 |
| FR2506898A1 (en) | 1982-12-03 |
| SU1461374A3 (en) | 1989-02-23 |
| BR8203222A (en) | 1983-05-17 |
| JPH0152657B2 (en) | 1989-11-09 |
| JPS57210217A (en) | 1982-12-23 |
| FI64409C (en) | 1983-11-10 |
| FI64409B (en) | 1983-07-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6408771B1 (en) | Methods of improving productivity of black liquor recovery boilers | |
| CA1200055A (en) | Method for controlling the burning of liquor, which varies in its chemical consistency, in a recovery boiler | |
| CA2122893C (en) | Chemical recovery from kraft black liquor | |
| US4768469A (en) | Operation control apparatus for recovery boilers | |
| US5419812A (en) | Method for regulating sulfur dioxide emissions from a recovery furnace | |
| US4891097A (en) | Method for regulating, the feeding-in or combustion conditions of concentrated spent liquors | |
| US5901527A (en) | Wedge splash plate for kraft recovery furnace black liquor burners | |
| US4683841A (en) | Control of a black liquor recovery boiler | |
| CA1247809A (en) | Spent pulping liquor recovery process | |
| EP0207908B1 (en) | Process for increasing the solids content of black liquour at its recovery in a sulfate pulping process | |
| KR920000600B1 (en) | Combustion of low b.t.u/high moisture content fuels | |
| JPS6052692A (en) | Production of kraft pulp | |
| SU1041811A1 (en) | Method of controlling black liquor combustion process | |
| US3008800A (en) | Method of operating furnace | |
| US5062921A (en) | Method for regulating the feed or combustion conditions of concentrated waste liquors in a soda recovery unit | |
| RU1813821C (en) | Black liquor combustion control method for sodium reclaming boiler operation | |
| US5518582A (en) | Method of affecting the sulphur content and/or sulphur compound composition of a melt in a recovery boiler | |
| Nikkanen | Liquor heat treatment and high-dry-solids firing | |
| SU1157034A1 (en) | Method of controlling liquid fluid feed to rotary furnace | |
| SU1242466A1 (en) | Method of automatic control for process of sodium bicarbonate calcination | |
| Shiang | Mathematical modeling and simulation of recovery furnace | |
| CLAY et al. | IPC TECHNICAL PAPER SERIES | |
| JPH0480156B2 (en) | ||
| JPS62123216A (en) | Optimum combustion control device for recovery boiler |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |