JPS598172B2 - Powder transfer method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for transferring powder or granular material, and in particular, to a method and apparatus for transferring powder or granular material, particularly for transferring powder or granular material from a container under pressure to another container under low pressure while maintaining the pressure. The present invention relates to a method and an apparatus for transporting.

BACKGROUND ART In various industrial processes that handle powder and granular materials, means are always used to transport the powder and granular materials from one fixed location to another fixed location at a predetermined transfer speed.

In these transfers, if the pressures on the transfer side and the transferred side are equal, only the amount of powder or granular material transferred needs to be considered, but if the pressures on the two sides are different, the gas pressure on the side with higher pressure should be considered. It is necessary to seal the two to eliminate the flow of gas between the two and to move only the desired powder or granular material.

For example, in the petroleum industry, attempts have been made to develop a process that uses a fluidized bed reaction tower to decompose heavy oil such as vacuum residue by contacting it with high-temperature catalyst particles, making it lighter and removing metals. In the process, by-product coke precipitates on the catalyst particles and reduces the catalyst activity, so the catalyst particles are transferred together with the precipitated coke to a fluidized bed regeneration tower, the coke is burned and removed by air, and the catalyst is regenerated.
It is transferred again to the fluidized bed reaction tower and brought into contact with heavy oil.

In this process, the fluidized bed reaction tower is operated under pressure in consideration of the pressure required for processes such as the subsequent distillation tower.

On the other hand, attempts have been made to operate the fluidized bed regeneration tower at a lower pressure than the fluidized bed reaction tower in order to reduce the power required for the air compressor.

In addition, the gas body of the fluidized bed reaction tower in the high pressure section contains a high concentration of hydrocarbons such as oil vapor generated by decomposition of heavy oil, while air is supplied to the regeneration tower in the low pressure section. Therefore, for safety reasons such as explosions and to prevent loss of hydrocarbons, the flow of gas in the reaction tower to the regeneration tower is sealed, and furthermore, to ensure stable operation, the gas pressure of the reaction tower is maintained constant. Catalyst particles must be continuously transferred from the reaction tower to the regeneration tower. In general, the method of sealing the gas pressure and transferring the powder from the high pressure section to the low pressure section requires a transfer between the high pressure section and the low pressure section. There is a method using a lock hopper or a blow tank, in which an intermediate tank with a fixed capacity is provided, and the pressure in this tank is alternately switched between the pressure in a high pressure part and the pressure in a low pressure part, and the pressure is balanced and transferred.

However, these methods require discontinuous transportation of powder and granules;
Furthermore, since the gas body corresponding to the volume filled in the intermediate tank moves to the low pressure section, strictly speaking, the gas body is not sealed.

There is also a rotary feeder screw feeder in which the gap between the sliding parts of the transfer machine is made as small as possible, or small gaps are arranged in series to utilize the labyrinth effect to minimize gas leakage in the high-pressure part.

However, in general, it is only possible to obtain a seal of about 1,000 to 10,000 mm of mercury, and to seal larger than this, it is necessary to use several of these devices, and in addition, there is a problem with cohesiveness,
In the case of highly adhesive powder or granular material whose pulverization is to be avoided, it is often impossible to use a transfer method with a direct sliding surface.

Furthermore, when transferring high-temperature granular materials such as in the above-mentioned heavy oil decomposition process, this device having a rotating part that requires bearings is not preferred from the viewpoint of maintenance.

An object of the present invention is to provide a method and apparatus for continuously transferring powder and granular material in a pressurized container to a low-pressure container while maintaining the pressure in the pressurized container. from the first container to the second container, which has a lower pressure than the pressure in this container.
A moving layer composed of the transported powder and granular material with a length corresponding to the pressure difference between the first and second containers is formed in the pipe line for transferring the powder and granular material to the container, and the average moving speed of the powder and granular material is increased. By flowing a sealing gas having a higher speed based on the empty tube in the direction of movement of the powder or granule, the pressure in the first container is maintained and the powder or granule is transferred into the second container. An apparatus characterized in that one end is substantially connected to a first container in a high pressure state, the other end is connected to a second container in a low pressure state, and for transferring powder or granular material from the first container to the second container. , a sealing gas supply means for flowing a sealing gas having a speed based on an empty tube higher than an average moving speed of the powdery material in the moving direction of the powdery material; a filling section in which the powdery material is filled with the sealing gas; The 20th feature includes a fluidizing section that fluidizes the powder and granular material filled in the low pressure side of the section, and a feeding section that feeds the powder and granular material fluidized by the fluidizing section to the low pressure side. , the filling section, the fluidizing section and the feeding section are substantially connected to a first container in a high pressure state, and a first piping is provided with a sealing gas supply means;
A second pipe provided so that the moving direction of the powder or granular material in the pipe is reversed, a gas inlet opening to the side of the second pipe, and a second pipe provided at the end of the second pipe. It consists of a gas inlet opening in the same direction as the moving direction of the powder and granular material in the piping No. 2.

That is, the present invention applies the pressure difference generated between the inlet and outlet of the packed bed of powder and granules when gas is passed through the packed powder to the packed bed in the transferred state, that is, the moving bed of the powder and granules. By passing a seal gas through the moving bed at a flow rate based on an empty tube that is higher than the average moving speed of the particles to be transferred, the pressure on the high pressure side is sealed and the powder and granules are continuously transferred.

When gas is passed through the moving bed of powder and granular material in the same direction as the particles at a speed based on an empty tube that is higher than the average particle moving speed, the pressure loss at the entrance and exit of the moving bed is determined by the physical properties of the powder and the properties of the sealing gas. The following relationship exists between the moving layer length and the moving layer length, etc.

Here, ΔP: Pressure loss Ug: Sealing gas velocity based on empty tube (m/s) U,: Moving speed of powder (m/s) 7g: Viscosity of sealing gas (Iy-s/m) D, : Average particle diameter of powder (71t) φ8 : Formation coefficient of powder (-) ε : Porosity of powder moving layer (1) L : Length of moving layer (771) Pressure loss in this equation ΔP becomes the pressure difference (kg/m) that can be sealed by the moving layer.

Therefore, as is clear from this equation, when the physical properties of the powder and granule are the same, the difference Ug-U between the moving speed of the powder and the empty tube reference speed of the seal gas and the length L of the moving layer are By varying it, any pressure differential can be sealed.

In addition, in order to realize the relative velocity Ug-U between the particle velocity and the sealing gas velocity in this equation, that is, to maintain a powder moving velocity lower than the sealing gas velocity, it is necessary to move the powder against the flow of the sealing gas. A means to control the body movement speed to a desired value is required, but as mentioned above, rotary feeders, screw feeders, etc. are suitable for handling powders with strong cohesiveness and stickiness, and powders that need to be avoided from being crushed. cannot be used.

The present invention was developed to solve this problem, and it is possible to provide a reversal region of the powder streamline at the end of the moving bed, thereby suppressing and making the moving speed of the powder variable. be.

Examples will be described below with reference to the drawings.

FIG. 1 shows an application to a heavy oil decomposition process in which heavy oil such as vacuum residue oil is brought into contact with high-temperature catalyst particles and decomposed using a fluidized bed reaction tower to lighten it and remove metals.

This device is composed of a reaction tower 1, a regeneration tower 2, a stripper 3, a moving bed transfer pipe 4 for catalyst particles, an inversion vessel 5, a lift pipe 6, and a regenerated catalyst circulation pipe 7. The precipitated catalyst particles are passed through a stripper 3, a moving bed transfer pipe 4, an inversion container 5, and a lift pipe 6 to a regeneration tower 2.
The precipitated catalyst particles of the transferred coke are burned and removed by air in the regeneration tower 2, and sent to the reaction tower 1 as a regenerated catalyst through the regenerated catalyst circulation conduit 7.

The reaction tower 1 has a fluidized bed 11 formed of catalyst particles, a feed nozzle 13 for heavy oil raw material 12 is opened in the middle part of the fluidized bed 11, and the upper surface of the fluidized bed 11 is connected to the fluidized bed 11 by conduits 14 and 15. Connected to stripper 3, reaction column 1
A circulating conduit 7 for regenerated catalyst and an inlet pipe 17 for fluidizing steam 16 for catalyst particles are connected to the lower part of the reactor 1, and an exhaust gas conduit 19 is installed at the top of the reaction tower 1 via a cyclone 18.

The stripper 3 is provided with a plurality of buckles 31 inside thereof, and the bottom thereof is connected to a moving bed transfer pipe 4 for catalyst particles and a reversing container 5 for catalyst particles following this.

Furthermore, the stripper 3 has an introduction pipe 33 for introducing stripping steam 32 at the bottom thereof, which opens at a position above the connecting portion of the moving bed transfer pipe 4.

The reversing vessel 5 is connected to the regeneration tower 2 via a pumping pipe 6, and a conduit 52 for a pumping gas 51 of catalyst particles is connected to the bottom.

The catalyst particle lifting pipe 6 is inserted up to the inner bottom of the reversing container 5, and a moving layer portion 53 and an inverting portion 54 of the catalyst particles are inserted into the reversing container 5.
and includes a pumping gas conduit 52 at the lower end of the pumping pipe to form an annular particle flow path 55.

A conduit 57 for aeration gas 56 is connected to this annular particle flow path 55 and opens into this flow path.

A regeneration tower 2 connected to an inversion container 5 via a lift pipe 6
A fluidized bed 22 is formed of catalyst particles by a dispersion plate 21, and an inlet pipe 24 for regenerating air 23 is installed at the bottom of the fluidized bed 22, and an exhaust gas conduit 26 is installed at the top via a cyclone 25.

In such a configuration, the reaction tower 1 and the stripper 3 are operated in a pressurized state to compensate for pressure loss in the subsequent process, and the regeneration tower 2 is operated in a low pressure state for the purpose of reducing the power of the air compressor. .

That is, the heavy oil raw material 12 such as vacuum residual oil is transferred to the inlet pipe 17.
It is fluidized by fluidizing steam 16 supplied from the feed nozzle 13 into the fluidized bed 11 in the reaction tower 1, which is maintained at a temperature of about 500°C.

Heavy oil supplied to the fluidized bed 11 is decomposed within the fluidized bed 11, and gaseous decomposition products such as light oil are passed through a conduit 19 to a subsequent process after removing floating catalyst particles in a cyclone 18. Sent.

On the other hand, by-product coke is deposited from the heavy oil on the surface of the catalyst particles forming the fluidized bed 11, and the catalyst activity is reduced.

The catalyst particles whose catalyst performance has been degraded in this way are transferred to the regeneration tower 2, where the precipitated coke is burned and removed.

For this transfer, the coke-deposited catalyst particles enter the stripper 3 from the reaction column 1 through the conduit 14, where they pass through the stripping steam 3 supplied from the inlet pipe 33.
The volatile matter in the coke is stripped in the fluidized state according to 2.

The stripped volatiles are returned to the reaction column 1 through conduit 15 along with steam.

The precipitated catalyst particles of the stripped coke enter the catalyst particle moving bed transfer pipe 4 from the bottom of the stripper 3;
Subsequently, the particles enter an inversion container 5.

In the moving bed transfer pipe 4 and the reversing container 5, the catalyst particles form a moving bed and descend, and in the reversing section 54 of the reversing container 50, the catalyst particles are reversed and enter the pumping pipe 6 through the annular particle flow path 55. .

Since the streamlines of the catalyst particles are reversed in the reversing section 54, the moving speed of the particles is suppressed, and therefore the particle layer in the moving bed transfer pipe 4 and the reversing container 50 is in a densely packed state, and the stripping introduced from the introduction pipe 33 is A part of the steam 32 passes as a seal gas through the moving bed transfer pipe 4 and the gap in the moving particle bed of the reversing vessel 5 at a flow rate higher than the movement speed of the particles, causing a pressure drop, and applying pressure to the stripper 3 and the reaction column 1. hold under pressure.

On the other hand, the flow of the catalyst particles suppressed by the reversing section 54 is fluidized by the supply of aeration gas 56 from the conduit 57 to the annular particle flow path 55 and is fluidized, and is then supplied from the pumping gas conduit 52. The pumping gas 51 is sent to the regeneration tower 2 through the pumping pipe 6.

The state of the particles in the lift tube 6 is a dilute bed state or a fluidized bed state, which can be selected depending on the process.

The coke-adhered catalyst particles 22 sent to the regeneration tower 2 are
Regeneration air 2 supplied through the introduction pipe 24 and the distribution plate 21
3, the precipitated coke is burned off, removed and heated at about 850° C. and recycled through the regenerated catalyst circulation conduit 7 to the lower part of the reaction column 1, where it is reused as catalyst and heat carrier.

The gas generated in the regeneration tower 2 passes through a cyclone 25 and an exhaust gas conduit 26 and is led to the next process such as a heat exchanger.

Three specific examples of this embodiment will be explained below.

(1) The moving bed transfer pipe 4 has an inner diameter of 52.9 mm and an outer diameter of 60 mm.
Constructed of 5m7IL tube material, the inversion container 5 has an inner diameter of 67.9
mm, tubing with an outer diameter of 76.3 mm and an inner diameter]. 2.7m
m, lifting pipe 6 with an outer diameter of 17.3 mm and an inner diameter of 9.2 mm.
, a pumping gas conduit 52 with an outer diameter of 13.8 mm and an inner diameter 2
This transfer is composed of an expanding tube that continues to the lower end of the lifting tube with a diameter of 7.6 mm and an outer diameter of 34 van, and the distance L between the inverting container 50 and the inverting section 54 is 2 m from the upper end of the stripping steam introduction tube 33 in the stripper 3. The device was installed in the heavy oil cracking equipment shown in Figure 1.

After filling the entire system with a predetermined amount of catalyst particles having an average particle size of 210 μm, 10 Nm3/h of air is supplied as the pumping gas from the pumping gas conduit 52, and air is supplied as the aeration gas 56 from the conduit 57. to reactor 1 by supplying
While circulating the catalyst particles between the regeneration tower 2, the pressure of the reaction tower 1 and the stripper 3 is set to 1. When the pressure was increased to 5 kg/iG, the regeneration tower pressure became 3000 mm water column, and the pressures of reaction tower 1 and stripper 3 were sealed.

At this time, the circulation rate of catalyst particles detected by the differential pressure in the lift pipe 6 was 340 kg/h, and the leakage of stripping steam as seal gas into the lift pipe 6 was estimated to be 340 kg/h. It was 630g/h.

Only traces of hydrocarbon components were contained in the leaked steam, and a portion of the stripping steam leaked into the seal gas.

At this time, the reaction tower temperature is 500°C and the regeneration tower temperature is 850°C. The seal was held at

(2) Using the same equipment and catalyst particle size as in (1) above,
While maintaining the pressure of the regeneration tower 2 at 3000 mm water column, the pressure of the reaction tower 1 is maintained at 2.0 mm. When the pressure rose to 5 kg/iG, it was possible to seal the reaction tower pressure, and the catalyst circulation amount was 360 kg/iG.
kg/h, the estimated amount of steam leaking from IJ Tupper 3 was 1300 g/h.

Note that the temperature conditions of the reaction tower and regeneration tower at this time are the same as in the case (1).

(3) Using an apparatus having the same shape as in (1) above, the length L of the moving bed in Fig. 1 is set to 4000 r/lm, and catalyst particles with an average particle size of 490 μ are packed between the reaction column 1 and the regeneration column 20. While circulating the particles, the reaction tower pressure was increased to 1. It was increased to 5 kg/crltG.

At this time, the regeneration tower pressure was 3500 mm water column, the amount of catalyst circulation was 290 kg7/h, and the estimated amount of leaked steam was 1100 g/h.

FIG. 2 shows another embodiment of the present invention, in which the same parts as in FIG. 1 are denoted by the same reference numerals. Separate from layer pipe,
This device has only the function of reversing the powder and granules, and can reduce the complexity of the device.

In this way, the powder or granular material transfer device described in the examples can continuously transfer the powder or granular material in the container to the low-pressure container while maintaining the pressure in the pressurized container. Furthermore, it is possible to prevent agglomeration or pulverization of powder particles during transportation.

As described above, the method and apparatus for transferring powder and granular materials of the present invention are as follows:
This makes it possible to continuously transfer powder and granules in a container to a container under low pressure while maintaining the pressure in the pressurized container, which has a great industrial effect. .

[Brief explanation of drawings]

FIG. 1 is a sectional view of one embodiment of a powder transfer device of the present invention, and FIG. 2 is a sectional view of a main part of another embodiment. Explanation of symbols: 1... Reaction tower, 2... Regeneration tower, 3... Stripper, 4... Moving bed transfer tube, 5...・・Inversion container, 6・・・・・
Lifting pipe, 7...Regenerated catalyst circulation pipe, 52...
... Pumping gas conduit, 53 ... Moving layer section,
54... Reversing section, 55... Annular particle flow path, 57... Aeration gas conduit.

Claims (1)

[Scope of Claims] 1. The first and second containers are connected to a conduit for transferring powder and granular material from a first container under pressure to a second container under pressure lower than the pressure inside the container. A moving layer is formed by the transferred powder and granular material having a length corresponding to the pressure difference, and a sealing gas having a velocity based on an empty tube that is higher than the average moving speed of the powder and granular material is applied in the moving direction of the powder and granular material. A method for transferring powder or granular material, characterized in that the powder or granular material is transferred to the second container while maintaining the pressure in the first container by flowing the powder into the second container. 2. The method of transferring powder or granular material according to claim 1, wherein the formation of the moving layer is performed by reversing the powder or granular material on the low-pressure side of the channel. 3. In an apparatus for transferring powder and granular material from the first container to the second container, with one end substantially connected to a first container in a high pressure state and the other end connected to a second container in a low pressure state, a sealing gas supply means for flowing a sealing gas having a speed based on an empty tube higher than an average moving speed of the granular material in the moving direction of the granular material; a filling section in which the granular material is filled with the sealing gas;
On the low pressure side of the filling section, a fluidizing section that fluidizes the filled powder and granules, and a feeding section that feeds the powder and granules fluidized in the fluidizing section to the low pressure side. A powder or granular material transfer device comprising: 4. A first pipe in which the filling part, the fluidizing part, and the feeding part are substantially connected to the first container in the high-pressure state, and the seal gas supply means is provided, and the powder particles in the pipe are provided. A second pipe provided so that the body movement direction is reversed, a gas inlet opening to the side of the second pipe, and a gas inlet provided at the end of the pipe to control the movement of powder and granular material in the second pipe. 4. The powder and granular material transfer device according to claim 3, comprising a gas inlet opening in the same direction. 5. The powder or granular material transfer device according to claim 4, wherein the first pipe is provided on the outer periphery of the second pipe. 6. The granular material transfer device according to claim 4, wherein the first pipe opens at the bottom of the second pipe.