CA1115055A - Wet pelletizing of brown coal and drying - Google Patents
Wet pelletizing of brown coal and dryingInfo
- Publication number
- CA1115055A CA1115055A CA326,492A CA326492A CA1115055A CA 1115055 A CA1115055 A CA 1115055A CA 326492 A CA326492 A CA 326492A CA 1115055 A CA1115055 A CA 1115055A
- Authority
- CA
- Canada
- Prior art keywords
- brown coal
- pellets
- drying
- particles
- coal
- 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
Landscapes
- Solid Fuels And Fuel-Associated Substances (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method of drying brown coal in which the brown coal is pelletized before the drying into pellets of 2 to 5 mm dia. by a wet pelletizing process making use of the water contained by the coal itself as the binder. The brown coal in the form of dried pellets has a larger bulk density than the brown coal in the form of fine powders which are obtained when the brown coal after the exploitation is directly dried, and, therefore, contributes to the reduction of the transportation cost.
In addition, the dried brown coal in the form of pellets can be handled and transported in quite an easy manner, as compared with the case of powdered brown coal.
Further, thanks to the improved ventilation affored by the gaps between the pellets, the possibility or chance of undesirable spontaneous combustion is greatly reduced.
A method of drying brown coal in which the brown coal is pelletized before the drying into pellets of 2 to 5 mm dia. by a wet pelletizing process making use of the water contained by the coal itself as the binder. The brown coal in the form of dried pellets has a larger bulk density than the brown coal in the form of fine powders which are obtained when the brown coal after the exploitation is directly dried, and, therefore, contributes to the reduction of the transportation cost.
In addition, the dried brown coal in the form of pellets can be handled and transported in quite an easy manner, as compared with the case of powdered brown coal.
Further, thanks to the improved ventilation affored by the gaps between the pellets, the possibility or chance of undesirable spontaneous combustion is greatly reduced.
Description
i~ 3~
l BACXGROUND OF THE INVENTION
The present invention relates to a method of drying brown coal and, more particularly, to a method of drying brown coal which can obviate various problems in handling and transpor~ation of dried brown coal.
Nowadays, most of energy consumed in the civilized society owes to petroleum. In the 1960's, an additional petroleum deposite of 5 billion KQ as a mean has been confirmed every year. This petroleum deposite addi-tionally confirmed is said to amount to 35 years'supply of petroleum, when calculated on the basis of present rate of yield per-year. However, from now on, the new exploitation of the petroleum will be concent-rated to areas where the natural conditoins are ~ 15 extremely severe. These severe conditions will render ;~ the discovery of new petroleum deposit in both aspect of exploitation technique and fund.
. . : ;.
Even if an ad~itional discovery of petroleum deposite of 5 billion KQ per year is possible in the ~uture, the amount~of pétroleum reserves will be reduced to 20 years' supply 13 years after now and to 5 years' -~
.
supply 28 years after now. It is clear that the world , will face a limit of exploitation of petroleum technically and financially, within several decades. Thus, it will become extremely difficult to obtain petroleum of amount , . . ~ .-. . : -:, . . . . : .: ,, : - -- . : .: . : . :- - . . :
. . : , . , ;: :.
- :~-: - ... .:. : . .. . : ., :. :
- : : : .. . ~ . ~. ,. :
. . . . . .
L5ir~;;~ ~
1 meeting the energy demand, particularly for those countries having little oil resources under their grounds.
Under these circumstances, there is an increas~
ing demand for new energy technique as measures for avoiding future energy crisis.
One of these measures is to exploit and use brown coal as a new energy source. The utilization of the brown coal has not been developed yet in spite of its low price and abundance. It is estimated that there is a deposite of wood coal and brown coal of 2 trlllion tons over the world. In fact, a deposite of 2700 billion tons of wood coal and brown coal, which amounts to 1350 billion tins in coal base, has been confirmed~ 39%, 34% and 18% of which belong to U.S.Sr, European countries and Australia.
The brown coal burried under the territory of, for example, Australia contains 66.7 to 50% of water, O.7 to 4.9% of ash content, 16.8 to 24.8% of volatile matter and 15.8% to 23.5% of fixed carbon.
One of the most serious defects of the brown coal is the large water content. The transportation cost will be raised unless the water content is suitably removed. It is therefore essential to dry and dehydrate the brown coal when the brown coal is used for industrial purposes.
In most cases, the natural brown coal exists in the form of extremely fine particles of a particle size of about 40 ~ or smaller, bonded to one another. Therefore, r,
l BACXGROUND OF THE INVENTION
The present invention relates to a method of drying brown coal and, more particularly, to a method of drying brown coal which can obviate various problems in handling and transpor~ation of dried brown coal.
Nowadays, most of energy consumed in the civilized society owes to petroleum. In the 1960's, an additional petroleum deposite of 5 billion KQ as a mean has been confirmed every year. This petroleum deposite addi-tionally confirmed is said to amount to 35 years'supply of petroleum, when calculated on the basis of present rate of yield per-year. However, from now on, the new exploitation of the petroleum will be concent-rated to areas where the natural conditoins are ~ 15 extremely severe. These severe conditions will render ;~ the discovery of new petroleum deposit in both aspect of exploitation technique and fund.
. . : ;.
Even if an ad~itional discovery of petroleum deposite of 5 billion KQ per year is possible in the ~uture, the amount~of pétroleum reserves will be reduced to 20 years' supply 13 years after now and to 5 years' -~
.
supply 28 years after now. It is clear that the world , will face a limit of exploitation of petroleum technically and financially, within several decades. Thus, it will become extremely difficult to obtain petroleum of amount , . . ~ .-. . : -:, . . . . : .: ,, : - -- . : .: . : . :- - . . :
. . : , . , ;: :.
- :~-: - ... .:. : . .. . : ., :. :
- : : : .. . ~ . ~. ,. :
. . . . . .
L5ir~;;~ ~
1 meeting the energy demand, particularly for those countries having little oil resources under their grounds.
Under these circumstances, there is an increas~
ing demand for new energy technique as measures for avoiding future energy crisis.
One of these measures is to exploit and use brown coal as a new energy source. The utilization of the brown coal has not been developed yet in spite of its low price and abundance. It is estimated that there is a deposite of wood coal and brown coal of 2 trlllion tons over the world. In fact, a deposite of 2700 billion tons of wood coal and brown coal, which amounts to 1350 billion tins in coal base, has been confirmed~ 39%, 34% and 18% of which belong to U.S.Sr, European countries and Australia.
The brown coal burried under the territory of, for example, Australia contains 66.7 to 50% of water, O.7 to 4.9% of ash content, 16.8 to 24.8% of volatile matter and 15.8% to 23.5% of fixed carbon.
One of the most serious defects of the brown coal is the large water content. The transportation cost will be raised unless the water content is suitably removed. It is therefore essential to dry and dehydrate the brown coal when the brown coal is used for industrial purposes.
In most cases, the natural brown coal exists in the form of extremely fine particles of a particle size of about 40 ~ or smaller, bonded to one another. Therefore, r,
- 2 ~
..
.
~' " , ~ ' when the natural brown coal is dried and dehydrated, these fine particles are freed from onc another to take the form of powders, incurring various problems such as environmental pollution by the scattering of fine particles, difficulty in handling and so forth. In addition, the bulk density of the brown coal in the dried state is as low as about 0.3, which considerably raises the cost of transportation. Further, there is a danger of spontaneous combustion of the powders of brown coal during transportation and storage.
SUMMARY OF THE INVENTION
It is therefore a major object of the invention to provide a method of drying brown coal, which can obviate various problems as stated above.
To this end, according to the present invention, there is provided a method of wet pelletizing of brown coal and drying, comprising the steps of:
forming a body of coarsely crushed particles of brown coal;
admixing an organic liquid with said body of coarsely crushed particles ;~
of brown coal and stirring the mixture to pulverize the coarse particles into minuscule particles while allowing the minuscule particles to be dispersed as a dispersion phase in the organic liquid serving as a dispersion medium; -forming pellets from said minuscle particles by utilizing the naturally occurring water moisture content of brown coal as a binder; and air cooling the pellets.
The wet pelletizing process is a process to obtain pellets directly from the suspension, through stirring and mixing any constituent of the dispersed phase of the suspension by a suitable method to effect a separation of the dispersed phase and dispersion medium of the suspension from each other or a preferential pelletizing of the dispersed phase.
It is advantageous that, since the brown coal B
-, . . ...... .. .... . .. . . . .... . . . ~ . . ~.
.. ,......... . . ...... . .. . . . . . ~ .. .
1 has a hydrophilic nature, it is possible to use water as the bridge forming substance, i.e. the binder. In addi-tion, because the brown coal itself immediately after the exploitation is rich in water, the pelletizing can be achieved without using any specific additive other than water, contributing greatly to the reduction of the cost.
An organic liquid is used as the dispersion medium, in case where the water is used as the binder.
More specifically, mineral oils such as heavy oil, kerosene and the like can suitably be used as the dis-persion medium.
The above and other objects, as well as advan-tageous features of the invention will become more clear from the following description of the preferred embodiment taken in conjuncticn with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
~he attached sole Figure is a flow sheet of a method~of the invention for drying brown coal.
-DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the preferred embodiment of the invention, the brown coal (dry), a dispersion medium and a binder are mlxed at a ratio of 1 : 4 : 2 and are vigorously stirred in a stirring chamber for several minutes. As a result, the brown coal is pelletized into pellets of about 5 to~2 mm dia., through the action of the water as the binder. These pellets can .... . .
1 easily be separated from the dispersion medium by means of a screen.
The pellets of 5 to 2 mm dia. thus obtained are then dried by a drying apparatus. Since the pellets have considerable weights, they are never scattered as powders or dusts, after the drying. In addition, these dried pellets can be handled and transported at a low cost by a con~eyor belt or the like, without employing any specific transportation apparatus.
The pellets of brown coal after the drying :~
exhibit a suf~icienlty high hardness and, therefore, almost no crushing of the pellets take place during the handling thereof. Also, the bulk denslty of the brown coal in the forrn of dried pe1lets is about 1.4 to 1,7 times as large that of the brown coal in the form of powders obtained when the exploited brown coal is directly dried, and reduces the transportation cost ;
correspondingly. In addition, the gaps in the brown coal-in the form of accumulatlon of pellets of 5 to 2 mm dia. provide good ventilation passages and suppreys the natural temperature rise, so that the possibility or chance of the spontaneous combustion is greatly reduced.
The accompanying drawings show an example of the flow sheet of process for drying the brown coal in accordance with the method of the invention.
The material coal is crushed by a crusher 1 and is then fed into a preparation chamber 2 together with .
., . - . ~.. , . .. ~...... ~
' ',. '' ~' ~,. ."'.'.'', "" ', ' ','. '1' ~ , :, .
1 a mineral oil as a dispersion medium. The material and the mineral oil are then mixed, s~irred and crushed in the preparation chamber 2. The admixture liquid of the brown coal and the mineral oil is then fed into a wet type pelletizing machine 5~ via a feed pump sump 3, feed pump 4 and an inlet port 6. The admixture liquid fed into the pelletizing machine is then vigorously stirred and moved toward an overflow 7, during whiGh the admixture is changed into pellets of brown coal of about 5 to 2 mm dia. The mixture of the pellets and the mineral oil is then spilt from the overflow 7 of the pelletizing machine, and are then separated from each other by means of a screen 8. The pellets of the brown coal arrested by the screen 8 are then delivered to a centrifugal oil separator 9 adapted to completely remove the oil from the pellets.
After the removal of the oil, the pellets are dried by a drying apparatus 10, and are conveyed by a conveyor 11 to a place where the pellets are to be storéd. Meanwhile, the mineral oil separated~in the screen 8 and the centri-fugal oil separator 9 is collected and fed back to the preparation chamber 2, through oil recirculation pump sump 12 and an oil recirculation pump 12, for a repeated use as the dispersion medium.
Although the invention has been described .
through its preferred form, it is to be noted that the described embodiment is not exclusive, and various changes and modifications may be imparted thereto without departing from the scope of the invention which is delimited solely by the appended claims.
, . . , ~ :
, - .
: :: - :
:. .
: - - ,
..
.
~' " , ~ ' when the natural brown coal is dried and dehydrated, these fine particles are freed from onc another to take the form of powders, incurring various problems such as environmental pollution by the scattering of fine particles, difficulty in handling and so forth. In addition, the bulk density of the brown coal in the dried state is as low as about 0.3, which considerably raises the cost of transportation. Further, there is a danger of spontaneous combustion of the powders of brown coal during transportation and storage.
SUMMARY OF THE INVENTION
It is therefore a major object of the invention to provide a method of drying brown coal, which can obviate various problems as stated above.
To this end, according to the present invention, there is provided a method of wet pelletizing of brown coal and drying, comprising the steps of:
forming a body of coarsely crushed particles of brown coal;
admixing an organic liquid with said body of coarsely crushed particles ;~
of brown coal and stirring the mixture to pulverize the coarse particles into minuscule particles while allowing the minuscule particles to be dispersed as a dispersion phase in the organic liquid serving as a dispersion medium; -forming pellets from said minuscle particles by utilizing the naturally occurring water moisture content of brown coal as a binder; and air cooling the pellets.
The wet pelletizing process is a process to obtain pellets directly from the suspension, through stirring and mixing any constituent of the dispersed phase of the suspension by a suitable method to effect a separation of the dispersed phase and dispersion medium of the suspension from each other or a preferential pelletizing of the dispersed phase.
It is advantageous that, since the brown coal B
-, . . ...... .. .... . .. . . . .... . . . ~ . . ~.
.. ,......... . . ...... . .. . . . . . ~ .. .
1 has a hydrophilic nature, it is possible to use water as the bridge forming substance, i.e. the binder. In addi-tion, because the brown coal itself immediately after the exploitation is rich in water, the pelletizing can be achieved without using any specific additive other than water, contributing greatly to the reduction of the cost.
An organic liquid is used as the dispersion medium, in case where the water is used as the binder.
More specifically, mineral oils such as heavy oil, kerosene and the like can suitably be used as the dis-persion medium.
The above and other objects, as well as advan-tageous features of the invention will become more clear from the following description of the preferred embodiment taken in conjuncticn with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
~he attached sole Figure is a flow sheet of a method~of the invention for drying brown coal.
-DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the preferred embodiment of the invention, the brown coal (dry), a dispersion medium and a binder are mlxed at a ratio of 1 : 4 : 2 and are vigorously stirred in a stirring chamber for several minutes. As a result, the brown coal is pelletized into pellets of about 5 to~2 mm dia., through the action of the water as the binder. These pellets can .... . .
1 easily be separated from the dispersion medium by means of a screen.
The pellets of 5 to 2 mm dia. thus obtained are then dried by a drying apparatus. Since the pellets have considerable weights, they are never scattered as powders or dusts, after the drying. In addition, these dried pellets can be handled and transported at a low cost by a con~eyor belt or the like, without employing any specific transportation apparatus.
The pellets of brown coal after the drying :~
exhibit a suf~icienlty high hardness and, therefore, almost no crushing of the pellets take place during the handling thereof. Also, the bulk denslty of the brown coal in the forrn of dried pe1lets is about 1.4 to 1,7 times as large that of the brown coal in the form of powders obtained when the exploited brown coal is directly dried, and reduces the transportation cost ;
correspondingly. In addition, the gaps in the brown coal-in the form of accumulatlon of pellets of 5 to 2 mm dia. provide good ventilation passages and suppreys the natural temperature rise, so that the possibility or chance of the spontaneous combustion is greatly reduced.
The accompanying drawings show an example of the flow sheet of process for drying the brown coal in accordance with the method of the invention.
The material coal is crushed by a crusher 1 and is then fed into a preparation chamber 2 together with .
., . - . ~.. , . .. ~...... ~
' ',. '' ~' ~,. ."'.'.'', "" ', ' ','. '1' ~ , :, .
1 a mineral oil as a dispersion medium. The material and the mineral oil are then mixed, s~irred and crushed in the preparation chamber 2. The admixture liquid of the brown coal and the mineral oil is then fed into a wet type pelletizing machine 5~ via a feed pump sump 3, feed pump 4 and an inlet port 6. The admixture liquid fed into the pelletizing machine is then vigorously stirred and moved toward an overflow 7, during whiGh the admixture is changed into pellets of brown coal of about 5 to 2 mm dia. The mixture of the pellets and the mineral oil is then spilt from the overflow 7 of the pelletizing machine, and are then separated from each other by means of a screen 8. The pellets of the brown coal arrested by the screen 8 are then delivered to a centrifugal oil separator 9 adapted to completely remove the oil from the pellets.
After the removal of the oil, the pellets are dried by a drying apparatus 10, and are conveyed by a conveyor 11 to a place where the pellets are to be storéd. Meanwhile, the mineral oil separated~in the screen 8 and the centri-fugal oil separator 9 is collected and fed back to the preparation chamber 2, through oil recirculation pump sump 12 and an oil recirculation pump 12, for a repeated use as the dispersion medium.
Although the invention has been described .
through its preferred form, it is to be noted that the described embodiment is not exclusive, and various changes and modifications may be imparted thereto without departing from the scope of the invention which is delimited solely by the appended claims.
, . . , ~ :
, - .
: :: - :
:. .
: - - ,
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of wet pelletizing of brown coal and drying, comprising the steps of:
forming a body of coarsely crushed particles of brown coal;
admixing an organic liquid with said body of coarsely crushed particles of brown coal and stirring the mixture to pulverize the coarse particles into minuscule particles while allowing the minuscule particles to be dispersed as a dispersion phase in the organic liquid serving as a dispersion medium;
forming pellets from said minuscle particles by utilizing the naturally occurring water moisture content of brown coal as a binder; and air cooling the pellets.
forming a body of coarsely crushed particles of brown coal;
admixing an organic liquid with said body of coarsely crushed particles of brown coal and stirring the mixture to pulverize the coarse particles into minuscule particles while allowing the minuscule particles to be dispersed as a dispersion phase in the organic liquid serving as a dispersion medium;
forming pellets from said minuscle particles by utilizing the naturally occurring water moisture content of brown coal as a binder; and air cooling the pellets.
2. A method as set forth in claim 1, wherein said organic liquid is mineral oil.
3. A method as claimed in claim 1, wherein said brown coal is hydrophilic brown coal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA326,492A CA1115055A (en) | 1979-04-27 | 1979-04-27 | Wet pelletizing of brown coal and drying |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA326,492A CA1115055A (en) | 1979-04-27 | 1979-04-27 | Wet pelletizing of brown coal and drying |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1115055A true CA1115055A (en) | 1981-12-29 |
Family
ID=4114078
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA326,492A Expired CA1115055A (en) | 1979-04-27 | 1979-04-27 | Wet pelletizing of brown coal and drying |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1115055A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102585954A (en) * | 2012-03-09 | 2012-07-18 | 何永峰 | Industrial automation production equipment and production method used for lignite fine-drying and quality-improving moulding |
| CN102977969A (en) * | 2012-11-27 | 2013-03-20 | 陈赐来 | Upgrading method of brown coals |
-
1979
- 1979-04-27 CA CA326,492A patent/CA1115055A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102585954A (en) * | 2012-03-09 | 2012-07-18 | 何永峰 | Industrial automation production equipment and production method used for lignite fine-drying and quality-improving moulding |
| CN102585954B (en) * | 2012-03-09 | 2013-08-28 | 何永峰 | Industrial automation production equipment and production method used for lignite fine-drying and quality-improving moulding |
| CN102977969A (en) * | 2012-11-27 | 2013-03-20 | 陈赐来 | Upgrading method of brown coals |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |