Apparatus and method for pyrolyzing coal with wide particle size distribution

Abstract

A carbonization apparatus for coal with wide particle size distribution, a carbonization apparatus unit, and a carbonization method using the apparatus. The apparatus includes a char discharge outlet, a combustion heating chamber, a coal feeding inlet, a pyrolysis gas exhausting pipe, and two partition plates between which a pyrolysis gas channel is formed. Orifices are provided on the partition plates to form a gas flow path from the fuel bed to the pyrolysis gas channel. The pyrolysis gas channel in the carbonization apparatus permits the gaseous products generated from coal pyrolysis to flow out in a timely manner.

Claims

1. A carbonization apparatus for coal with wide particle size distribution, comprising: a char discharge outlet (1), a combustion heating chamber (3), a coal feeding inlet (5), and a pyrolysis gas exhausting pipe (4), characterized in that two partition plates between which a pyrolysis gas channel (2) is formed are further provided in the carbonization apparatus, and orifices are provided on the partition plates to form a gas flow path from a fuel bed to the pyrolysis gas channel (2).

2. The carbonization apparatus according to claim 1, characterized in that each of the partition plates is a plate (9) having sieved orifices, or a plate (10) having a window blind structure formed by arranging many solid plates in parallel with intervals.

3. The carbonization apparatus according to claim 1, characterized in that the pyrolysis gas channel (2) has its upper part closed and is connected with the pyrolysis gas exhausting pipe (4), and there is a certain distance between the top end of the channel and a top roof of the carbonization apparatus to enable even fuel feeding.

4. The carbonization apparatus according to claim 1, characterized in that the lower end of the pyrolysis gas channel (2) is open to the char discharge outlet (1) mounted on the bottom of the carbonization apparatus, which is used to discharge char in the pyrolysis gas channel (2).

5. The carbonization apparatus according to claim 1, characterized in that a plate-type internal (6) is further provided in the carbonization apparatus; the plate-type internal (6) being mounted perpendicular to the upper and lower surfaces of the carbonization apparatus, wherein one end of the plate-type internal (6) is connected to one heating wall (8) and the plate-type internal (6) extends from the heating wall (8) into the fuel bed.

6. A carbonization apparatus unit for coal with wide particle size distribution, which consists of numbers of the carbonization apparatus of claim 1 arranged in parallel, wherein the upper part of the pyrolysis gas channel (2) in each carbonization apparatus is connected to its respective pyrolysis gas exhausting pipe (4), the pyrolysis gas exhausting pipe (4) from each carbonization apparatus are connected to a main gas collection pipeline (7), and gaseous pyrolysis products exhaust from the main gas collection pipeline (7).

7. The carbonization apparatus unit according to claim 6, characterized in that each of the partition plates is a plate (9) having sieved orifices, or a plate (10) having a window blind structure formed by arranging many solid plates in parallel with intervals.

8. The carbonization apparatus unit according to claim 6, characterized in that a plate-type internal (6) is further provided in each carbonization apparatus; the plate-type internal (6) being mounted perpendicular to the upper and lower surfaces of the carbonization apparatus, wherein one end of the plate-type internal (6) is connected to one heating wall (8) and the plate-type internal (6) extends from the heating wall (8) into the fuel bed.

9. A carbonization method for coal with wide particle size distribution using the carbonization apparatus of claim 1, the carbonization method comprising the steps of: 1) loading the coal for pyrolysis into the carbonization apparatus via the coal feeding inlet (5), wherein the coal is packed in both sides of the pyrolysis gas channel (2); 2) heating the coal for pyrolysis in the carbonization apparatus by raising the temperature of a heating wall (8) with heat generated in the combustion heating chamber (3), and by utilizing heat carried by gaseous pyrolysis products when they flow to the pyrolysis gas channel (2); 3) collecting the gaseous pyrolysis products into the pyrolysis gas channel (2) through the orifices on the wall surface of the pyrolysis gas channel (2) and exhausting them from the carbonization apparatus through the pyrolysis gas exhausting pipe (4); and 4) discharging a solid product from the char discharge outlet (1).

10. The carbonization method for coal with wide particle size distribution according to claim 9, characterized in that a plate-type internal (6) is further provided in the carbonization apparatus, wherein the plate-type internal (6) extends into the fuel bed to enhance the heat and mass transfer by the plate-type internal (6).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a structural schematic diagram of the carbonization apparatus for coal with wide particle size distribution of the invention;

(2) FIG. 2 is a structural schematic diagram of the carbonization apparatus for coal with wide particle size distribution of the invention (the plate-type internal is included);

(3) FIG. 3 is a sectional plane overlooking the carbonization apparatus for coal with wide particle size distribution of the invention, wherein the partition plate of the pyrolysis gas channel is a kind of plate with sieved orifices;

(4) FIG. 4 is a sectional plane overlooking the carbonization apparatus for coal with wide particle size distribution of the invention, wherein the partition plate of the pyrolysis gas channel is a window blind structure formed by arranging many solid plates in parallel with intervals;

(5) FIG. 5 is a sectional plane overlooking the carbonization apparatus for coal with wide particle size distribution of the invention, wherein the partition plate of the pyrolysis gas channel is formed by arranging many tubular objects in parallel with intervals;

(6) FIG. 6 is a structural schematic diagram of the carbonization apparatus unit for coal with wide particle size distribution of the invention.

REFERENCE SIGNS LIST

(7) 1. char discharge outlet 2. pyrolysis gas channel 3. combustion heating chamber 4. pyrolysis gas exhausting pipe 5. coal feeding inlet 6. plate-type internal 7. main gas collection pipeline 8. heating wall 9. plate with sieved orifices 10. solid plate 11. tubular objects 12. coal bed

DESCRIPTION OF EMBODIMENTS

(8) The apparatus and the method for pyrolyzing or carbonizing coal with wide particle size distribution will be illustrated in the following with reference to the accompanying drawings and specific embodiments.

(9) As shown in FIGS. 1-6, the carbonization apparatus for coal with wide particle size distribution of the invention comprises: a char discharge outlet 1, a combustion heating chamber 3, a coal feeding inlet 5, and a pyrolysis gas exhausting pipe 4, wherein two partition plates between which a pyrolysis gas channel 2 is formed are further provided in the carbonization apparatus, and orifices are made on the partition plates to form a gas flow path from the combustion heating chamber side to the pyrolysis gas channel 2. The said partition plate is a kind of plate 9 with sieved orifices (FIG. 3), or a window blind structure formed by arranging many solid plates 10 in parallel with intervals between each two neighbor plates (FIG. 4), or by arranging many tubular objects 11 in parallel with intervals among the objects (FIG. 5). The said pyrolysis gas channel 2 has its upper part closed and is connected to the pyrolysis gas exhausting pipe 4, and there is a certain distance between the top end of the pyrolysis gas channel and the top roof of the carbonization apparatus such that raw material (fuel) for pyrolysis can be evenly distributed to the surrounding of the pyrolysis gas channel 2 in coal feeding. The lower end of the said pyrolysis gas channel 2 is opening to the char discharge outlet 1 mounted on the bottom of the carbonization apparatus so as to discharge the char inside pyrolysis gas channel 2 after the pyrolysis reactions.

(10) The plate-type internal 6 is further provided in the said carbonization apparatus (FIG. 2); the said plate-type internal 6 is mounted in the carbonization apparatus in a manner being perpendicular to the upper (i.e., cover) and lower (i.e., bottom) surfaces of the carbonization apparatus, wherein one end of the plate-type internal 6 is connected to one heating wall 8 and is uniformly mounted on the two heating walls 8; and the plate-type internal 6 extends itself from the heating wall 8 to the coal bed in the carbonization apparatus but is not in contact with the pyrolysis gas channel 2. There is a certain distance between the plate-type internal 6 and the bottom of the carbonization apparatus so as to discharge char after the pyrolysis reaction.

(11) The carbonization apparatus unit for coal with wide particle size distribution of the invention consists of numbers of carbonization apparatuses in parallel, as shown in FIG. 6, the carbonization apparatus comprises: a char discharge outlet 1, a combustion heating chamber 3, a coal feeding inlet 5, and a pyrolysis gas exhausting pipe 4, wherein two partition plates between which a pyrolysis gas channel 2 is formed are further provided in the said carbonization apparatus, and orifices are provided on the partition plates to form a gas flow path from the fuel bed to the pyrolysis gas channel 2. The upper part of the pyrolysis gas channel 2 in the said carbonization apparatus is connected to the pyrolysis gas exhausting pipe 4, all pyrolysis gas exhausting pipes 4 from the carbonization apparatus of the unit are connected to a main gas collection pipeline 7, and the gaseous pyrolysis products exhaust from the main gas collection pipeline 7. The said partition plate is a kind of plate 9 with sieved orifices, or a window blind structure formed by arranging many solid plates 10 in parallel with intervals between each two plates, or by arranging many tubular objects 11 in parallel with intervals among the objects. The plate-type internal 6 is further provided in the said carbonization apparatus, and the said plate-type internal 6 is mounted in the carbonization apparatus in a manner of being perpendicular to the upper (i.e., cover) and lower (i.e., bottom) surfaces of the carbonization apparatus, wherein one end of the plate-type internal 6 is connected to one heating wall 8 and is uniformly mounted on the two heating walls 8 of the carbonization apparatus; and the plate-type internal 6 extends itself from the heating wall 8 to the inner coal bed but is not in contact with the pyrolysis gas channel 2.

(12) The carbonization method based on the carbonization apparatus for coal with wide particle size distribution of the invention comprises the steps of:

(13) 1) loading the coal for pyrolysis into the carbonization apparatus via the coal feeding inlet 5, wherein the coal is packed in the both sides of the pyrolysis gas channel 2;

(14) 2) heating the coal for pyrolysis in the carbonization apparatus, on the one hand, via raising the temperature of the heating wall 8 under the heating by the combustion heating chamber 3, and on the other hand, by the heat carried by the gaseous pyrolysis products when they flow to the pyrolysis gas channel 2;

(15) 3) collecting the gaseous pyrolysis products into the pyrolysis gas channel 2 through the orifices on the wall surface of the pyrolysis gas channel 2 and in turn exhausting them from the carbonization apparatus through the pyrolysis gas exhausting pipe 4, and then processing them to separate the pyrolysis gas and pyrolysis oil; and discharging the solid product from the char discharge outlet 1 and in turn quenching it.

(16) Wherein, the plate-type internal 6 is further provided in the said carbonization apparatus, which extends into the pyrolysis coal bed and enhances the heat and mass transfer in the coal bed by the plate-type internal 6. An induction draft fan is preferably provided to the outlet of the said pyrolysis gas exhausting pipe 4 to form a relatively large pressure difference between the outlet and the pyrolysis gas channel 2 to speed up the exhaust of gaseous pyrolysis products.

(17) When the plate-type internal 6 is provided in the carbonization apparatus, the coal for pyrolysis is packed on both sides of the pyrolysis gas channel 2 after fed into the carbonization apparatus with the pyrolysis the gas channel 2 through the coal feeding inlet 5, thus allowing the plate-type internal 6 to extend itself into the coal bed 12. The carbonization apparatus, on the one hand, indirectly heats the coal for pyrolysis and increases its temperature by the combustion heating chamber 3, and on the other hand, it further enhances the heat and mass transfer through the plate-type internal 6. Meanwhile, the coal for pyrolysis is also directly heated to increase its temperature by the heat carried by the gaseous pyrolysis products during their flowing to the pyrolysis gas channel 2, whereby rapidly increasing the heating rate of the coal.

Example 1

(18) This example was the pyrolysis of Fugu coal with particle sizes below 5 mm in a fixed-bed indirectly heated. As shown in FIG. 1, the carbonization apparatus included a pyrolysis gas channel 2, a coal feeding inlet 5, a combustion heating chamber 3, a pyrolysis gas exhausting pipe 4, a char discharge outlet 1, and the walls of the pyrolysis gas channel 2 were in parallel to the combustion heating chamber 3. Heat was provided by burning fuel gas in the combustion heating chambers on both sides of the carbonization apparatus and further transferred into the coal bed from the combustion heating chamber 3. Coal was fed into the carbonization apparatus from the coal feeding inlet 5 and was heated up in the reactor to occur pyrolysis. The gaseous pyrolysis products were collected into the pyrolysis gas channel 2 and finally pooled into the pyrolysis gas exhausting pipe 4 to flow out. After the preset residence time at the preset pyrolysis reaction temperature, the operation was made to discharge char from the char discharge outlet 1. The char quenching, tar and coal gas processing could be performed according to the existing technologies.

(19) As compared to the carbonization apparatus without the pyrolysis gas collection channel, in 3 hours the coal temperature at the center of a 100-kg coal bed increased to 420 C. comparing to 280 C., indicating that the heat transfer rate is greatly increased by using the internals. Furthermore, the tar yield was doubled and the dust content in tar was blow 0.5 wt. %.

Example 2

(20) This example was the pyrolysis of Fugu coal with particle sizes below 5 mm in an indirectly heated fixed-bed mounted with the plate-type internal and also the gas collection channel. As shown in FIG. 2, the carbonization apparatus included a plate-type internal 6, a pyrolysis gas channel 2, a coal feeding inlet 5, a combustion heating chamber 3, a pyrolysis gas exhausting pipe 4, and a char discharge outlet 1. The plate-type internal 6 was mounted in the carbonization apparatus in a manner of being perpendicular to the heating walls of the pyrolysis reactor or apparatus and also to the bottom of the furnace. The pyrolysis gas channel 2 was in parallel with the combustion heating chamber 3 and was located between the two sets of the plate-type internal 6. Heat was provided by burning fuel gas in the combustion heating chambers on both sides of the carbonization apparatus and further transferred into the pyrolysis coal bed from the combustion heating chamber 3 and via the two sets of the plate-type internal 6. Coal was fed into the carbonization apparatus from the coal feeding inlet 5 and heated up in the reactor to occur pyrolysis. The gaseous pyrolysis products were collected into the pyrolysis gas channel 2 and finally pooled into the pyrolysis gas exhausting pipe 4 to flow out. After the preset residence time at the preset pyrolysis reaction temperature, the operation was made to discharge char from the char discharge outlet 1. The char quenching, tar and coal gas processing could be performed according to the existing technologies.

(21) As compared to the pyrolysis reactor without both plate-type internal and pyrolysis gas channel, in 3 hours the coal temperature at the center of a 100-kg coal bed increased to 553 C. comparing to 280 C., indicating that the heat transfer rate is nearly doubled by using the internals. Meanwhile, the tar yield was 1.3 times higher, and the dust content in tar was below 0.5 wt. %.

(22) It should be pointed out that modifications and improvements may be still performed on specific implementation methods of the carbonization apparatus, such as the size, shape and distribution of orifices on the pyrolysis gas channel wall, the configuration, size and installation pattern of the internals in the pyrolysis apparatus, and the integration method between pyrolysis reactor and other apparatus or units and the consequent operation, etc. All of these, however, will not depart from the scope and the basic spirit of the invention specified in the claims.