CA1248906A - Process for transporting particulate material - Google Patents
Process for transporting particulate materialInfo
- Publication number
- CA1248906A CA1248906A CA000445552A CA445552A CA1248906A CA 1248906 A CA1248906 A CA 1248906A CA 000445552 A CA000445552 A CA 000445552A CA 445552 A CA445552 A CA 445552A CA 1248906 A CA1248906 A CA 1248906A
- Authority
- CA
- Canada
- Prior art keywords
- vessel
- gas
- process according
- pressure
- gas pressure
- 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
Abstract
A B S T R A C T
PROCESS FOR TRANSPORTING
PARTICULATE MATERIAL
Particulate material is transported from a low pressure zone to an elevated pressure zone by - passing the material from the low pressure zone to the top of the first one of a number of vertical oblong vessels;
- passing the material in each vessel by gravity as a moving bed from the top of the vessel to the bottom thereof;
- passing the material from the bottom of each vessel but the last one to the top of the subsequent vessel by means of a carrier gas which is separated from the material at the top of each vessel and recycled to the bottom of an earlier vessel than the immediately preceding vessel in the series;
- discharging the powder from the bottom of the last vessel to the elevated pressure zone.
The gas pressure is built up stagewise; at the bottom of each vessel a gas pressure higher than the one prevailing at the top is applied, while the gas pressure at the top of each vessel is kept substantially equal to the one prevailing at the bottom of the preceding vessel.
PROCESS FOR TRANSPORTING
PARTICULATE MATERIAL
Particulate material is transported from a low pressure zone to an elevated pressure zone by - passing the material from the low pressure zone to the top of the first one of a number of vertical oblong vessels;
- passing the material in each vessel by gravity as a moving bed from the top of the vessel to the bottom thereof;
- passing the material from the bottom of each vessel but the last one to the top of the subsequent vessel by means of a carrier gas which is separated from the material at the top of each vessel and recycled to the bottom of an earlier vessel than the immediately preceding vessel in the series;
- discharging the powder from the bottom of the last vessel to the elevated pressure zone.
The gas pressure is built up stagewise; at the bottom of each vessel a gas pressure higher than the one prevailing at the top is applied, while the gas pressure at the top of each vessel is kept substantially equal to the one prevailing at the bottom of the preceding vessel.
Description
12489()6 PRQCESS FOR TRANS æ RTIN~
PARTIC~ MZ~L
The invention relates to a process for transporting parti-culate material from a low pressure zone to an elevated pressure zone, characterized in that 1) the material is passed frcm the low pressure zone to the top of the first one of a series of at least two vertical oblong vessels;
PARTIC~ MZ~L
The invention relates to a process for transporting parti-culate material from a low pressure zone to an elevated pressure zone, characterized in that 1) the material is passed frcm the low pressure zone to the top of the first one of a series of at least two vertical oblong vessels;
2~ the material is passed as a moving bed from the top of each vessel to the bottom thereof by gravity;
3) the material is transported from the bottom of each vessel to the top of the subsequent vessel pneumatically by means of a carrier gas;
4) the gas pressure at the top of the first vessel is kept relatively low, while the gas pressure at the top of each successive vessel is kept substantially equal to the gas pressure prevailing at the bottom of the preceding vessel;
5) at the bottom of each vessel a gas pres Æ e is applied higher than the gas pressure at the top of that vessel, such that practically no gas escapes frcm the top;
6) the elevated gas pressure is applied at the bottom of the last vessel;
7~ the material at the bottom of the last vessel is discharged to the elevated pressure zone;
8) the carrier gas is separated from the material at the top of each vessel;
9~ the carrier gas separated from the top of a vessel is re-cycled to the bottom of an earlier vessel than the imme-diately preceding vessel in the series.
: .
lf~'~89~
The transport of particlllate material from a relatively lcw pressure zone to a relatively high pressure zon~ is usually done by means of a lock hopper system. By oFening a first valve the material is transferred from a storage vessel to a lock hopper.
me valve is closed and the lock hopper is brought to an ele-vated gas pressure. A second valve, connecting the lock hopper to a vessel at elevated pressure, is then ope~ed and the ma-terial is fed into this latter vessel and from there to the elevated pressure zone. The second valve is then closed and the gas pressure in the lock hopper is reduced. Opening the first valve marks the beginning of a new cycle.
This process is discontinuous. Moreover, the valves connec-ting the vessels beccme badly worn by the abrasive effect of the material in combination with the frèquent open m g and closing.
This necessitates regul æ replacement of these valves.
The process according to the invention has the advantage that it is continuous and no valves æ e used which would be subjected to abrasion by the material. In the process according to the in~ention the gas pressure is built up stagewise in a number of vessels arranged in series. The gas pressure applied at the bottom of each vessel is such that the pressure differ-ence between the bottcm and the top is too small to cause fluidization. This ensures that no gas, or almost no gas, escapes frcm the top of the vessel, which means that no gas, or almost no gas, needs to be supplied to the bottcm of the vessels in order to maintain the higher gas pressure. The stagewise pressure build-up according to the invention enables relatively large pressure differences to be overcome with relatively low vessels.
The material is transported to the top of each of the vessels pneumatically by means of a carrier gas, preferably of an inert nature such as N2 or CO2. If particulate coal has to be pressurized in order to intrcduce it into a gasification reactor clean synthesis gas may be used as a carrier gas. This ~2~8~306 carrier gas flows continuously fran an outlet for the parti-culate material at the bottom of each vessel to the top of the following vessel, which could entail a high gas consumption. m e carrier qas is separated at the top of the vessel frcm the material. mis can be done by any suitable means, preferably by means of a cyclone and/or a filter~ If the separated carrier gas is vented directly into the atmosphere the volume of spent carrier gas is very great, hence the compression costs are high.
Therefore separated carrier gas should be recycled as far possible. If carrier gas, separated at the top of a vessel A is recycled to the bott~n of the vessel 8, directly preceding vessel A, the carrier gas has to be compressed again because the pressure at the bottan of vessel B is somewhat higher than that at the top of the subsequent vessel A. In order to save compres-sion costs the carrier gas, separated at the top of a vessel A
is not recycled to the bottan of a vessel B, but to the bottcm of a vessel C, which preceeds vessel B. me pressure at the bctt~n of vessel C is lower than that at the top of vessel A.
Therefore, according to the present invention, the carrier gas separated fr~n the top of a vessel is recycled to the bottom of an earlier vessel than the immediately preceding vessel in the series.
Preferably carrier gas fran the top(s) of one or more vessels is recycled to the bottan of the penultimate preceding vessel or the respective penultimate preceding vessels in the series.
As regards the transport of the material to each of the sub-sequent vessels, consideration should be given to a regular dis charge fonn the bottan of the preceding vessel. Discharge can be regulated by means of a star valve or by a screw conve~or.
m e discharge from the last vessel is done mechanically or pneumatically. Which is preferable depends on the purpose for which the material is keing transported to the high pressure zone. Coal powder is preferably carried to a high-pressure gasi-fier by means of an inert carrier gas. In this case it s lZ489(~6 preferable to transport the coal pcwder pneumatically from the last vessel to the gasifier. There are therefore cases in which it is preferable to discharge the material pneumatically from the bottcm of the last vessel.
During the transport of the material frcm the top to the bottom the material particles in each of the vessels can adhere to one another and cause bridging so that the transport becomes irregular or even stops altogether. miS is particularly likely to happen with fine cohesive substances. For this reason the material in each vessel is preferably subjected to vibration. To this end, one or more vibrators can be installed in each vessel, preferably in the side wall. The vibrators can operate con-tinuously or intermittently. Bridging can also prevented by keeping the material in ~Dtion in other ways, for example by means of a stirring installation or gas injection.
Due to the fact that the gas pressure at the bottom of each vessel is higher than that at the top of the vessel, the gas tends to flow from the bottom to the top. This is opposed by the downward flowing material particles. It is preferable to carry out tne process according to the invention such that the gas pressure at the bottom of each vessel is ma mtained without gas escaping from the top and without gas being entrained with the material particles. If gas is entrained with the material, it ends up at the bottcm of the last vessel and is carried away with the material to the high-pressure zone. This may scmetimes be un-desirable. me material is therefore preferably passed to the bottom of each vessel at such a velocity that the velocity with with the material passes a certain horizontal cross-section of the vessel is equal to the upward velocity of the gas relative to 3o the material at that cross-section. The gas velocity is influen-ced by the pressure difference over the material bed and the height of the bed. Care is preferably taken, therefore, by maintaining the correct rate of material supply to ensure that the ~ed height of the material does not fall.
124~39~6 If the material at the bottom of the last vessel is dis-charged by a carrier gas, a similar gas can be used in the pres-surized gas system. Incidentally, only a small quantity of gas will be consumed if the installation works normally, since ac-cording to the invention practically no gas escapes from thetop of each vessel.
Although the process according to the invention can be used for transporting material from a zone at any lcw pressure, the low pressure will generally be atmospheric. Material with a wide particle size distribution can be used in the present process.
The mean particle size is not critical either. Preferably, the material has a mean particle size of 0.005 to 1.0 mm and a par-ticle size distribution of 0.001 to 3.0 mm.
An important field of application of the present invention is high pressure gasification of a solid fuel such as coal, brcwn coal, peat, wood, etc. Preferably, the prccess is applied when the material is a solid fuel and the fuel is transported at a pressure of 3.5 to 50 bar from the last vessel to a gasification reactor where it is advantageously gasified at a pressure of 3 to 40 bar with the aid of an oxygen-containing gas and/or steam to synthesis gas containing mainly carbon noxide and hydrogen. The fuel can be transported to the reactor pneumatically, e.g. by an inert gas such as nitrogen, carbon dioxide or purified synthesis gas acting as carrier gas. A gas of this sort can also be used in the pressurized gas system, if present.
If the process according to the invention is used with the gasification of a fuel, air must be prevented fram being carried along with the fuel fram the last vessel to the gasification reactor. This can be done by bringing the fuel frcm a bunker with 3 an inert gas atmophere. Alternatively, the gas pressure at the bottom of the first vessel can be made so high by an mert gas that no air flows dcwnwards and so all the air around the fuel is displaced by inert gas.
In the process for transporting fuel to a high-pressure gasification reactor use is preferably made of 2 to 9 vessels.
At the bottom of each vessel a gas pressure is advantageously applied which is 2 to 6 bar higher than the gas pressure at the top of that vessel. The height of the vessels is preferably between 30 and 100 m.
The invention will now be explained in greater detail with reference to the schematic figure, to which the invention, by no means is limited.
Ancillary apparatus, such as valves, compressors and pumps, is in general not shown in the figure.
Pressurized gas supplied through a line 1 transpor~s a particulate material which is supplied via a rokary gas-lock feeder 2 continuously from a storage vessel 3 via a riser 4 to the top of a vessel 5. The material is first separated from the gas m a cyclone separator 6 and flows then as a moving bed to the bottom of the vessel S, from which it is transported by a gas supplied through a line 7 to a vessel 8 via a riser 9. The gas, separated from the material in the cyclone separator 6, is vented via a line 10, a filter 11 and a line 12. The material which has been pneumatically supplied to the top of the vessel 8 is separ-ated from the conveying gas in a cyclone separator 13. The separated gas is recycled via the line 1 to the connection of the riser 4 with the rotary gas-lock feeder 2. The separated material flows as a moving bed to the bottcm of the vessel 8, from which it is transported by a conveying gas supplied through a line 14 to the top of a vessel 15 via a riser 16.
At the top of the vessel 15 the material is separated from the conveying gas in a cyclone separator 17. The separated con-3o veying gas is recycled from the cyclone separator 17 via the line 7 to the outlet at the bottom of the vessel 5. The separated material flows as a moving bed to the bottom of the vessel l5, from which it is transported by a fresh high pressure conveying gas, supplied through a line 18, to the top of an ultimate 12~8~V6 vessel 19 via a riser 20. The conveying gas is separated from the material in a cyclone separator 21 at the top of the vessel 19, and recycled via the line 14 to the outlet at the bottom of the vessel 8. The separated material flows down as a moving bed from the top to the bottom of the vessel 19 and at the bottom it is discharged pneumatically via a pipe 22. m e carrier gas for the pneumatic transport cQmes via a line 23.
me pressure build-up is achieved and regulated with the aid of compressed gas system. The carrier gas, coming via the line 23, is at the desired elevated pressure. Via the line 20 and possibly a reducing valve a pressure is applied to the top of vessel 19 such that the pressure difference between the top and bottom of vessel l9 is smaller than the pseudo-hydrostatic pressure of the solid material in the vessel l9. By an appro-priate choice of the dcwnward velocity of the material it can be ensured that almost no gas flcws from the bottom to the top.
Since the top of the vessel 19 is connected gas-tightly by the pipe 14 to the bottom of vessel 8, the pressure prevailing there is slightly lcwer than the pressure at the top of vessel 19.
The pressure at the bottom of the vessel 5 is slightly lower than the pressure at the tcp of the vessel 15 on account of the gas-tight connection by the pipe 7. Similarly, the pressure at the bottom of vessel 3 is al~ost the same as that at the top of the vessel 8.
m e pressure build-up is regulated with the aid of this pressurized gas system. If the pressure at the top of one of the vessels becomes too high, the pressure is vented to the set value via the line connecting the vessel with the penultimate preceding one. If this happens in vessel 5, the excess gas is discharged to a gas reprocessing plant (not shown in the figure). If the pressure at the top of a vessel becomes too low, gas at a higher pressure is supplied via the line connecting the vessel in question to the top of the vessel following the next one until the pressure in the vessel has reached the correct value.
~2~8906 EX~ME~E
In an installation, basically as described in the (des-cription of the) figure, 10,000 kg/h of coal powder in a series of 4 vessels was brought to a pressure of 21 bar. The vessels were 85 m high and had a diameter of 0.56 m. Coal powder was added continuously via the pneumatic risers at a sufficient rate to maintain the height of the coal powder beds at 78.4 m. The velocity at which the coal powder was carried dcwnwards amounted to 1.81 m/s. The pressure at the bottams of vessels 5, 8, 15 and 19 was 6, 11, 16 and 21 bar respectively. The gas velocity in the risers was 0.1 m3/sec (calculated at normal temperature and pressure).
Via the line 12 0.1 m3/sec (N.T.P.) was vented to the a~l~s-phere.
: .
lf~'~89~
The transport of particlllate material from a relatively lcw pressure zone to a relatively high pressure zon~ is usually done by means of a lock hopper system. By oFening a first valve the material is transferred from a storage vessel to a lock hopper.
me valve is closed and the lock hopper is brought to an ele-vated gas pressure. A second valve, connecting the lock hopper to a vessel at elevated pressure, is then ope~ed and the ma-terial is fed into this latter vessel and from there to the elevated pressure zone. The second valve is then closed and the gas pressure in the lock hopper is reduced. Opening the first valve marks the beginning of a new cycle.
This process is discontinuous. Moreover, the valves connec-ting the vessels beccme badly worn by the abrasive effect of the material in combination with the frèquent open m g and closing.
This necessitates regul æ replacement of these valves.
The process according to the invention has the advantage that it is continuous and no valves æ e used which would be subjected to abrasion by the material. In the process according to the in~ention the gas pressure is built up stagewise in a number of vessels arranged in series. The gas pressure applied at the bottom of each vessel is such that the pressure differ-ence between the bottcm and the top is too small to cause fluidization. This ensures that no gas, or almost no gas, escapes frcm the top of the vessel, which means that no gas, or almost no gas, needs to be supplied to the bottcm of the vessels in order to maintain the higher gas pressure. The stagewise pressure build-up according to the invention enables relatively large pressure differences to be overcome with relatively low vessels.
The material is transported to the top of each of the vessels pneumatically by means of a carrier gas, preferably of an inert nature such as N2 or CO2. If particulate coal has to be pressurized in order to intrcduce it into a gasification reactor clean synthesis gas may be used as a carrier gas. This ~2~8~306 carrier gas flows continuously fran an outlet for the parti-culate material at the bottom of each vessel to the top of the following vessel, which could entail a high gas consumption. m e carrier qas is separated at the top of the vessel frcm the material. mis can be done by any suitable means, preferably by means of a cyclone and/or a filter~ If the separated carrier gas is vented directly into the atmosphere the volume of spent carrier gas is very great, hence the compression costs are high.
Therefore separated carrier gas should be recycled as far possible. If carrier gas, separated at the top of a vessel A is recycled to the bott~n of the vessel 8, directly preceding vessel A, the carrier gas has to be compressed again because the pressure at the bottan of vessel B is somewhat higher than that at the top of the subsequent vessel A. In order to save compres-sion costs the carrier gas, separated at the top of a vessel A
is not recycled to the bottan of a vessel B, but to the bottcm of a vessel C, which preceeds vessel B. me pressure at the bctt~n of vessel C is lower than that at the top of vessel A.
Therefore, according to the present invention, the carrier gas separated fr~n the top of a vessel is recycled to the bottom of an earlier vessel than the immediately preceding vessel in the series.
Preferably carrier gas fran the top(s) of one or more vessels is recycled to the bottan of the penultimate preceding vessel or the respective penultimate preceding vessels in the series.
As regards the transport of the material to each of the sub-sequent vessels, consideration should be given to a regular dis charge fonn the bottan of the preceding vessel. Discharge can be regulated by means of a star valve or by a screw conve~or.
m e discharge from the last vessel is done mechanically or pneumatically. Which is preferable depends on the purpose for which the material is keing transported to the high pressure zone. Coal powder is preferably carried to a high-pressure gasi-fier by means of an inert carrier gas. In this case it s lZ489(~6 preferable to transport the coal pcwder pneumatically from the last vessel to the gasifier. There are therefore cases in which it is preferable to discharge the material pneumatically from the bottcm of the last vessel.
During the transport of the material frcm the top to the bottom the material particles in each of the vessels can adhere to one another and cause bridging so that the transport becomes irregular or even stops altogether. miS is particularly likely to happen with fine cohesive substances. For this reason the material in each vessel is preferably subjected to vibration. To this end, one or more vibrators can be installed in each vessel, preferably in the side wall. The vibrators can operate con-tinuously or intermittently. Bridging can also prevented by keeping the material in ~Dtion in other ways, for example by means of a stirring installation or gas injection.
Due to the fact that the gas pressure at the bottom of each vessel is higher than that at the top of the vessel, the gas tends to flow from the bottom to the top. This is opposed by the downward flowing material particles. It is preferable to carry out tne process according to the invention such that the gas pressure at the bottom of each vessel is ma mtained without gas escaping from the top and without gas being entrained with the material particles. If gas is entrained with the material, it ends up at the bottcm of the last vessel and is carried away with the material to the high-pressure zone. This may scmetimes be un-desirable. me material is therefore preferably passed to the bottom of each vessel at such a velocity that the velocity with with the material passes a certain horizontal cross-section of the vessel is equal to the upward velocity of the gas relative to 3o the material at that cross-section. The gas velocity is influen-ced by the pressure difference over the material bed and the height of the bed. Care is preferably taken, therefore, by maintaining the correct rate of material supply to ensure that the ~ed height of the material does not fall.
124~39~6 If the material at the bottom of the last vessel is dis-charged by a carrier gas, a similar gas can be used in the pres-surized gas system. Incidentally, only a small quantity of gas will be consumed if the installation works normally, since ac-cording to the invention practically no gas escapes from thetop of each vessel.
Although the process according to the invention can be used for transporting material from a zone at any lcw pressure, the low pressure will generally be atmospheric. Material with a wide particle size distribution can be used in the present process.
The mean particle size is not critical either. Preferably, the material has a mean particle size of 0.005 to 1.0 mm and a par-ticle size distribution of 0.001 to 3.0 mm.
An important field of application of the present invention is high pressure gasification of a solid fuel such as coal, brcwn coal, peat, wood, etc. Preferably, the prccess is applied when the material is a solid fuel and the fuel is transported at a pressure of 3.5 to 50 bar from the last vessel to a gasification reactor where it is advantageously gasified at a pressure of 3 to 40 bar with the aid of an oxygen-containing gas and/or steam to synthesis gas containing mainly carbon noxide and hydrogen. The fuel can be transported to the reactor pneumatically, e.g. by an inert gas such as nitrogen, carbon dioxide or purified synthesis gas acting as carrier gas. A gas of this sort can also be used in the pressurized gas system, if present.
If the process according to the invention is used with the gasification of a fuel, air must be prevented fram being carried along with the fuel fram the last vessel to the gasification reactor. This can be done by bringing the fuel frcm a bunker with 3 an inert gas atmophere. Alternatively, the gas pressure at the bottom of the first vessel can be made so high by an mert gas that no air flows dcwnwards and so all the air around the fuel is displaced by inert gas.
In the process for transporting fuel to a high-pressure gasification reactor use is preferably made of 2 to 9 vessels.
At the bottom of each vessel a gas pressure is advantageously applied which is 2 to 6 bar higher than the gas pressure at the top of that vessel. The height of the vessels is preferably between 30 and 100 m.
The invention will now be explained in greater detail with reference to the schematic figure, to which the invention, by no means is limited.
Ancillary apparatus, such as valves, compressors and pumps, is in general not shown in the figure.
Pressurized gas supplied through a line 1 transpor~s a particulate material which is supplied via a rokary gas-lock feeder 2 continuously from a storage vessel 3 via a riser 4 to the top of a vessel 5. The material is first separated from the gas m a cyclone separator 6 and flows then as a moving bed to the bottom of the vessel S, from which it is transported by a gas supplied through a line 7 to a vessel 8 via a riser 9. The gas, separated from the material in the cyclone separator 6, is vented via a line 10, a filter 11 and a line 12. The material which has been pneumatically supplied to the top of the vessel 8 is separ-ated from the conveying gas in a cyclone separator 13. The separated gas is recycled via the line 1 to the connection of the riser 4 with the rotary gas-lock feeder 2. The separated material flows as a moving bed to the bottcm of the vessel 8, from which it is transported by a conveying gas supplied through a line 14 to the top of a vessel 15 via a riser 16.
At the top of the vessel 15 the material is separated from the conveying gas in a cyclone separator 17. The separated con-3o veying gas is recycled from the cyclone separator 17 via the line 7 to the outlet at the bottom of the vessel 5. The separated material flows as a moving bed to the bottom of the vessel l5, from which it is transported by a fresh high pressure conveying gas, supplied through a line 18, to the top of an ultimate 12~8~V6 vessel 19 via a riser 20. The conveying gas is separated from the material in a cyclone separator 21 at the top of the vessel 19, and recycled via the line 14 to the outlet at the bottom of the vessel 8. The separated material flows down as a moving bed from the top to the bottom of the vessel 19 and at the bottom it is discharged pneumatically via a pipe 22. m e carrier gas for the pneumatic transport cQmes via a line 23.
me pressure build-up is achieved and regulated with the aid of compressed gas system. The carrier gas, coming via the line 23, is at the desired elevated pressure. Via the line 20 and possibly a reducing valve a pressure is applied to the top of vessel 19 such that the pressure difference between the top and bottom of vessel l9 is smaller than the pseudo-hydrostatic pressure of the solid material in the vessel l9. By an appro-priate choice of the dcwnward velocity of the material it can be ensured that almost no gas flcws from the bottom to the top.
Since the top of the vessel 19 is connected gas-tightly by the pipe 14 to the bottom of vessel 8, the pressure prevailing there is slightly lcwer than the pressure at the top of vessel 19.
The pressure at the bottom of the vessel 5 is slightly lower than the pressure at the tcp of the vessel 15 on account of the gas-tight connection by the pipe 7. Similarly, the pressure at the bottom of vessel 3 is al~ost the same as that at the top of the vessel 8.
m e pressure build-up is regulated with the aid of this pressurized gas system. If the pressure at the top of one of the vessels becomes too high, the pressure is vented to the set value via the line connecting the vessel with the penultimate preceding one. If this happens in vessel 5, the excess gas is discharged to a gas reprocessing plant (not shown in the figure). If the pressure at the top of a vessel becomes too low, gas at a higher pressure is supplied via the line connecting the vessel in question to the top of the vessel following the next one until the pressure in the vessel has reached the correct value.
~2~8906 EX~ME~E
In an installation, basically as described in the (des-cription of the) figure, 10,000 kg/h of coal powder in a series of 4 vessels was brought to a pressure of 21 bar. The vessels were 85 m high and had a diameter of 0.56 m. Coal powder was added continuously via the pneumatic risers at a sufficient rate to maintain the height of the coal powder beds at 78.4 m. The velocity at which the coal powder was carried dcwnwards amounted to 1.81 m/s. The pressure at the bottams of vessels 5, 8, 15 and 19 was 6, 11, 16 and 21 bar respectively. The gas velocity in the risers was 0.1 m3/sec (calculated at normal temperature and pressure).
Via the line 12 0.1 m3/sec (N.T.P.) was vented to the a~l~s-phere.
Claims (13)
1. Process for transporting particulate material from a low pressure zone to an elevated pressure zone, characterized in that:
1) the material is passed from the low pressure zone to the top of the first one of a series of at least two vertical oblong vessels;
2) the material is passed as a moving bed from the top of each vessel to the bottom thereof by gravity;
3) the material is transported from the bottom of each vessel to the top of the subsequent vessel pneumatically by means of a carrier gas;
4) the gas pressure at the top of the first vessel is kept relatively low, while the gas pressure at the top of each successive vessel is kept substantially equal to the gas pressure prevailing at the bottom of the preceding vessel;
5) at the bottom of each vessel a gas pressure is applied higher than the gas pressure at the top of that vessel, such that practically no gas escapes from the top;
6) the elevated gas pressure is applied at the bottom of the last vessel;
7) the material at the bottom of the last vessel is discharged to the elevated pressure zone.
8) the carrier gas is separated from the material at the top of each vessel;
9) the carrier gas separated from the top of a vessel is recycled to the bottom of an earlier vessel than the im-mediately preceding vessel in the series.
1) the material is passed from the low pressure zone to the top of the first one of a series of at least two vertical oblong vessels;
2) the material is passed as a moving bed from the top of each vessel to the bottom thereof by gravity;
3) the material is transported from the bottom of each vessel to the top of the subsequent vessel pneumatically by means of a carrier gas;
4) the gas pressure at the top of the first vessel is kept relatively low, while the gas pressure at the top of each successive vessel is kept substantially equal to the gas pressure prevailing at the bottom of the preceding vessel;
5) at the bottom of each vessel a gas pressure is applied higher than the gas pressure at the top of that vessel, such that practically no gas escapes from the top;
6) the elevated gas pressure is applied at the bottom of the last vessel;
7) the material at the bottom of the last vessel is discharged to the elevated pressure zone.
8) the carrier gas is separated from the material at the top of each vessel;
9) the carrier gas separated from the top of a vessel is recycled to the bottom of an earlier vessel than the im-mediately preceding vessel in the series.
2. Process according to claim 1, characterized in that the carrier gas separated from the top of at least one vessel is recycled to the bottom of the penultimate preceding vessel(s) in the series.
3. Process according to claim 1 , characterized in that the carrier gas is separated from the material at the top of each vessel by means of a filter and/or a cyclone.
4. Process according to claim 1, 2 or 3, characterized in that the material is discharged pneumatically from the bottom of the last vessel.
5. Process according to claim 1, 2 or 3, characterized in that the material in each vessel is subjected to vibration.
6. Process according to claim 1, 2 or 3, characterized in that the material is passed to the bottom of each vessel at such a velocity that the velocity with which the material passes a certain horizontal cross-section of the vessel is equal to the upward velocity of the gas relative to the material at that cross-section.
7. Process according to claim 1, 2 or 3, characterized in that the gas pressure in each vessel is regulated with the aid of a common pressurized gas system.
8. Process according to claim 1, 2 or 3, characterized in that the gas pressure at the top of the first vessel is atmospheric.
9. Process according to claim 1, 2 or 3, characterized in that the material has a mean particle size of 0.005 to 1.0 mm.
10. Process according to claim 1, characterized in that the material is a solid fuel.
11. Process according to claim 10, characterized in that the fuel is transported at a pressure of 3.5 to 50 bar from the last vessel to a gasification reactor.
12. Process according to claim 10, characterized in that use is made of 2 to 9 vessels.
13. Process according to claim 10, 11 or 12, characterized in that at the bottom of each vessel a gas pressure is applied which is 2 to 6 bar higher than the gas pressure at the top of that vessel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3328233 | 1983-08-04 | ||
| DEP3328233.1 | 1983-08-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1248906A true CA1248906A (en) | 1989-01-17 |
Family
ID=6205819
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000445552A Expired CA1248906A (en) | 1983-08-04 | 1984-01-18 | Process for transporting particulate material |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1248906A (en) |
-
1984
- 1984-01-18 CA CA000445552A patent/CA1248906A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2496854C2 (en) | System for continuous fuel feed to reactor for coal gasification | |
| EP0101098B1 (en) | A process for conveying a particulate solid fuel | |
| EP1934311B2 (en) | Method for producing a hydrocarbon product | |
| US5017196A (en) | Method for enhancing energy recovery from a high temperature, high pressure synthesis gas stream | |
| CN100526436C (en) | Safety sealing and air flow conveying method for fine coal gasification process | |
| JPH03128990A (en) | Method and deive for pneumatically conveying particulate or dust-like fuel from storage bunker under atmospheric pressure into gasifier under raised pressure | |
| US5143521A (en) | Method for producing gas using energy recovering coal feeding steps | |
| JP2633678B2 (en) | Method for transporting fine or dusty fuel into a gasification reactor under elevated pressure | |
| US4516989A (en) | Process for removing fly ash particles from a gas at elevated pressure | |
| CA1248906A (en) | Process for transporting particulate material | |
| CA1248905A (en) | Process for transporting particulate material | |
| EP0118929B1 (en) | Process for transporting particulate material | |
| CA2255811A1 (en) | Process for the treatment of particulate matter by fluidisation, and vessel with apparatus to carry out the treatment | |
| US5232466A (en) | Apparatus for producing gas using energy recovering pressurizing system | |
| US5516356A (en) | Process and apparatus for feeding a second stream of pulverulent materials into a pneumatic conveying line carrying a first controllable flow of pulverulent materials | |
| CN1032368C (en) | Apparatus and method for feeding granular/pulverulent fuels to gasificating reactor | |
| US4094651A (en) | Process for pseudohydrostatic feeding of solids into a reactor | |
| CN217997081U (en) | High-pressure dense-phase conveying simulation system applied to pulverized coal gasification in test stage | |
| US20220387954A1 (en) | Method for operating a descending moving bed reactor with flowable granular material | |
| WO1986002912A1 (en) | A particulate solid feeding device | |
| US2774635A (en) | Solids pump applied to coal gasification | |
| JPH0532977A (en) | Method for detecting abnormal feeding of coal into coal gasification device | |
| CA2058132A1 (en) | Process and apparatus for effecting regenerative sulfur binding | |
| JPH0960801A (en) | Fluidized bed combustion equipment | |
| KR20180094061A (en) | Gasification Process and Supply System |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |