Dry separation device and method for all-clay catalyst white powder

Abstract

The invention discloses a dry separation device for all-clay catalyst white powder. The dry separation device comprises a rotary flash dryer, a first-stage cyclone separator, a second-stage cyclone separator and a bag-type dust collector which are connected in sequence. The invention also discloses a dry separation method of the full-clay catalyst white powder, which comprises the following steps: heating, scattering and fluidizing a full-clay catalyst filter cake, and separating out fine-particle white powder in the full-clay catalyst filter cake after the full-clay catalyst filter cake passes through a two-stage cyclone dust collector, thereby achieving the use standard of the full-clay catalyst. According to the method, no wastewater is discharged and treated, the investment and energy consumption of equipment are greatly reduced, and the production cost of the all-clay catalyst is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of oil refining catalyst production, and specifically relates to a dry separation device for white powder of a full-kaolin catalyst. The invention also relates to a method for separating the catalyst using the device. Background Art

[0002] The all-kaolin catalyst has a high activity index, strong resistance to heavy metals, good hydrothermal stability, and a pore distribution that meets the requirements of residue oil cracking. Therefore, it is widely used in the catalytic cracking industry. With the continuous advancement of my country's oil refining technology, its market demand is increasing, and various catalyst manufacturers are constantly expanding their production capacity. The all-kaolin catalyst used in the refining industry generally requires a particle size of not less than 40μm. In the production process of all-kaolin, about 30% of fine powder less than 40μm is produced. This part of fine powder is called "white powder" and needs to be separated before it can be used as a refining production catalyst.

[0003] At present, the main method for separating catalyst white powder is: the whole clay catalyst after reaction synthesis first enters the crystallization kettle for crystallization, and then enters the plate and frame filter for liquid-solid separation. The formed filter cake then enters the pulping tank for pulping. The whole clay catalyst slurry after pulping enters the hydrocyclone separator to separate the white powder therein. The separated large-particle size whole clay catalyst material enters the rotary flash dryer for drying. The separated white powder and wastewater enter the subsequent wastewater treatment system. This separation method has the following main disadvantages:

[0004] (1) The use of a hydrocyclone separator for white powder separation requires a large amount of water to be used for pulping the filter cake of the full-clay catalyst. On the one hand, the consumption of fresh water is increased, which causes a certain waste of water resources. On the other hand, the pulping tank consumes a large amount of electricity, and the feed of the hydrocyclone separator requires a feed pump, which also increases the power consumption of the system. Therefore, the production cost of the full-clay catalyst increases;

[0005] (2) The use of a cyclone separator to separate the white powder produces a large amount of wastewater. Since the white powder is suspended in the liquid, the subsequent wastewater treatment becomes more difficult. In addition, as the production capacity of the all-white clay catalyst continues to increase, the subsequent wastewater treatment system needs to be modified and treated, which not only increases the investment in equipment, but also consumes a large amount of energy in the wastewater treatment process, resulting in a significant increase in the production cost of the all-white clay catalyst.

[0006] Based on this, it is an urgent need in this field to adopt a reasonable, simple and efficient white powder separation method. Summary of the invention

[0007] The purpose of the present invention is to provide a dry separation method for white powder of a full-clay catalyst, which separation method does not require the use of water, reduces water consumption, does not require wastewater treatment, and reduces the production cost of the full-clay catalyst.

[0008] Another object of the present invention is to provide a separation device used in the above dry separation method.

[0009] The technical solution adopted by the present invention is a dry separation device for all-kaolin catalyst white powder, which includes a flash dryer, a primary cyclone separator, a secondary cyclone separator and a bag dust collector connected in sequence.

[0010] The present invention is also characterized in that:

[0011] The lower part of the flash dryer is connected with an electric heater, the other end of the electric heater is connected with a blower, and the blower is communicated with the outside air.

[0012] The feed inlet of the whirl dryer is connected with a whirl dryer screw conveyor, and a disperser is arranged at the bottom of the whirl dryer.

[0013] A primary rotary discharge valve and a secondary rotary discharge valve are respectively arranged at the bottom of the primary cyclone separator and the bottom of the secondary cyclone separator.

[0014] A bag rotary discharge valve is arranged at the bottom of the bag dust collector, and an induced draft fan is connected to the top of the bag dust collector.

[0015] Another technical solution adopted by the present invention is a dry separation method of all-kaolin catalyst white powder, in which the all-kaolin catalyst filter cake is heated, broken up and fluidized in a rotary flash dryer, and the dispersed catalyst particles are sequentially passed through a primary cyclone dust collector and a secondary cyclone dust collector to separate the catalyst particles, and fine granular white powder is obtained at the top of the secondary cyclone dust collector. Finally, the fine granular white powder is passed through a bag dust collector for gas-solid separation to obtain all-kaolin catalyst white powder.

[0016] Another technical solution of the present invention is also characterized in that:

[0017] The dry separation method of the whole clay catalyst white powder is specifically implemented according to the following steps:

[0018] Step 1: Start the blower and the electric heater to allow the hot air to enter the bottom of the flash dryer tangentially;

[0019] Step 2: The whole clay catalyst filter cake is conveyed to the flash dryer by the flash dryer screw conveyor. Under the action of hot air and the disperser, the filter cake is heated, dispersed, and fluidized, and then rises to the top of the flash dryer;

[0020] Step 3, the whole clay catalyst dried and dispersed in step 2 is discharged from the top of the rotary flash dryer into the primary cyclone dust collector, where it is preliminarily separated, most of the large particles are separated, and the separated large particles are discharged from the bottom of the primary cyclone dust collector;

[0021] Step 4: The finer particle catalyst separated in step 3 enters the secondary cyclone dust collector from the top of the primary cyclone dust collector and is further separated therein. The large particle material of the separated full-clay catalyst is discharged from the bottom of the secondary cyclone dust collector, and the fine particle white powder rises to the top of the secondary cyclone dust collector with the air flow;

[0022] Step 5. The white powder of the whole clay catalyst separated in step 4 enters the bag filter, where gas-solid separation is performed. The white powder produced by the separation is discharged from the bottom of the bag filter, and the purified dry exhaust gas is discharged to the subsequent treatment system through the induced draft fan.

[0023] The temperature of the hot air in step 1 is 150°C to 180°C.

[0024] The hot air flow rate in the spin flash dryer in step 2 is 800kg / h to 1200kg / h.

[0025] The critical particle size of dust removal for the first-stage cyclone dust collector is 80 microns, and the critical particle size of dust removal for the second-stage cyclone dust collector is 40 microns.

[0026] The beneficial effects of the present invention are:

[0027] (1) The method of the present invention can separate white powder and large catalyst particles of different particle sizes by using dry separation technology, without consuming additional fresh water or generating wastewater, thus saving a large amount of water resources; the method of the present invention does not require wastewater discharge and treatment, greatly reducing equipment investment and energy consumption, and reducing the production cost of the full clay catalyst;

[0028] (2) The method of the present invention adopts a flash drying + two-stage cyclone separation system to replace the original pulping tank + hydrocyclone separation + flash drying + wastewater treatment system, shortening the process flow of the full-clay catalyst production process, and adopting a two-stage cyclone dust collector in series to achieve the separation effect of the existing hydrocyclone separator, which is simpler to operate, and greatly reduces equipment investment, land occupation, and energy consumption;

[0029] (3) The method of the present invention does not discharge any wastewater. The dry tail gas after dust removal and purification is directly discharged into the existing washing and dust removal system, which greatly reduces the discharge of wastewater and is of great significance for environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic structural diagram of the dry separation device of the present invention.

[0031] In the figure, 1. blower, 2. electric heater, 3. flash dryer, 4. flash dryer screw conveyor, 5. primary cyclone separator, 6. secondary cyclone separator, 7. bag dust collector, 8. induced draft fan, 9. primary rotary discharge valve, 10. secondary rotary discharge valve, 11. bag rotary discharge valve. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The present invention provides a dry separation device for white powder of a whole clay catalyst, such as Figure 1 As shown, it includes a flash dryer 3, a primary cyclone separator 5, a secondary cyclone separator 6 and a bag dust collector 7 connected in sequence. The lower part of the flash dryer 3 is connected to an electric heater 2, and the other end of the electric heater 2 is connected to a blower 1. The blower 1 is connected to the outside air. The outside air enters the electric heater 2 under the action of the blower 1, and after being heated to a certain temperature, it enters tangentially from the lower part of the flash dryer 3. The feed port of the flash dryer 3 is connected to a flash drying screw conveyor 4, and the whole white clay material to be separated enters the flash dryer 3 from the flash drying screw conveyor 4. A disperser is provided at the bottom of the flash dryer 3. A primary rotary discharge valve 9 and a secondary rotary discharge valve 10 are respectively provided at the bottom of the primary cyclone separator 5 and the secondary cyclone separator 6; a bag rotary discharge valve 11 is provided at the bottom of the bag dust collector 7; and an induced draft fan 8 is connected to the top of the bag dust collector 7, and the induced draft fan 8 discharges the purified dry exhaust gas in the bag dust collector 7 to a subsequent treatment system.

[0034] The present invention provides a dry separation method for white powder of a full-clay catalyst, which is specifically implemented according to the following steps:

[0035] Step 1, start the blower 1 and the electric heater 2, ensure that the temperature of the hot air passing through the electric heater 2 and reaching the bottom of the flash dryer 3 reaches 150° C. to 180° C., and the hot air enters tangentially from the bottom of the flash dryer 3;

[0036] The heat source in the drying process can be hot air or hot flue gas. If hot air is used as the heat source, the heater can be an electric heater or a steam-heated fin tube heat exchanger. If factory flue gas is used as the heat source, the hot flue gas can directly enter the flash dryer 3 without the blower 1 and the electric heater 2.

[0037] Step 2, the 30°C to 40°C full-clay catalyst filter cake from the upstream plate and frame filter, whose moisture content is about 40%, enters the rotary flash drying screw conveyor 4, and then is conveyed to the rotary flash dryer 3, falls to the bottom of the rotary flash dryer 3, and the disperser at the bottom rotates at a high speed to disperse the full-clay catalyst filter cake; under the action of the blower 1 and the electric heater 2, the hot air or hot flue gas at 150°C to 180°C enters tangentially from the bottom of the rotary flash dryer 3, the full-clay catalyst material is fluidized, and spirally rises to the top of the rotary flash dryer with the hot air or hot flue gas. In this process, the moisture in the full-clay catalyst is continuously evaporated, and a full-clay catalyst with a moisture content of about 4% is obtained at the outlet of the rotary flash dryer 3;

[0038] Step 3, the whole clay catalyst, the dry tail gas and the water evaporated during the evaporation process after being dried and dispersed in step 2 are discharged from the top of the flash dryer 3 to the primary cyclone dust collector 5. In the primary cyclone dust collector 5, the whole clay catalyst is preliminarily separated, and most of the large particles are separated. The separated large particles are discharged to the subsequent system through the primary rotary discharge valve 9;

[0039] Step 4, the dry tail gas and part of the whole clay catalyst particles separated by the primary cyclone dust collector 5 then enter the secondary cyclone dust collector 6, in which the large particles of the whole clay catalyst are further separated, and the separated large particles of the whole clay catalyst are discharged to the subsequent system through the secondary rotary discharge valve 10, and the fine particles of white powder rise to the top of the secondary cyclone dust collector 6 with the airflow;

[0040] Step 5, the dry exhaust gas and the white powder of the whole white clay catalyst separated by the secondary cyclone dust collector 6 enter the bag dust collector 7, where gas-solid separation is carried out, and the white powder produced by the separation is discharged by the bag rotary discharge valve 11, and the purified dry exhaust gas is discharged to the subsequent treatment system through the induced draft fan 8.

[0041] Example 1

[0042] In this embodiment, an electric heater is used to heat the air to 150-160°C and pass it into the flash dryer 3. The temperature of the full-kaolin catalyst filter cake is 30°C and the moisture content is 41-43%. The filter cake is conveyed to the flash dryer 3 through the flash drying screw conveyor 4. The wet material is directly contacted with the hot air for heat exchange. The hot air flow rate is 800-1000 kg / h. The dried material is taken out of the flash dryer 3 under the action of the dry tail gas. The temperature of the dry tail gas is 120-130°C and then enters the primary cyclone separator 5, where the initial gas-solid separation is performed. The primary cyclone separator 5 is designed according to the critical diameter of 80 microns, and most of the particles above 80 microns are separated. Then the dry tail gas enters the secondary cyclone separator 6, which is designed according to the critical diameter of 40 microns. The particles above 40 microns are further separated. The separated dry tail gas and part of the dust enter the bag filter 7 to remove the white powder therein. After two-stage separation, solid particles larger than 40 microns account for 87.8%, solid particles smaller than 40 microns account for 12.2%, the yield of solid particles larger than 40 microns of the desired product is 93.6%, and the pressure drop of each cyclone separation is 300-500 Pa. It has been verified that after the full clay catalyst is separated by a hydrocyclone separator, solid particles larger than 40 microns account for 85-90%, and similar separation effects can be achieved after dry separation by the present invention.

[0043] Example 2

[0044] This embodiment uses an electric heater. The temperature of the hot air passing through the electric heater 2 and reaching the bottom of the flash dryer 3 reaches 160°C to 180°C, and the hot air flow rate is 1000 to 1200 kg / h. The rest is the same as in Example 1. The yield of solid particles larger than 40 microns finally separated is 94.5%.

[0045] Example 3

[0046] In this embodiment, hot flue gas is directly introduced into the flash dryer 3, the hot flue gas temperature is 170°C to 180°C, the hot air flow rate is 1000 to 1200 kg / h, and the rest is the same as in Example 1. The yield of solid particles larger than 40 microns obtained by separation is 92.4%.

Claims

1. A dry separation device for white powder of a whole clay catalyst, characterized in that: The invention comprises a flash drier (3), a primary cyclone separator (5), a secondary cyclone separator (6) and a bag dust collector (7) which are connected in sequence.

2. The dry separation device for the whole clay catalyst white powder according to claim 1, characterized in that: The lower part of the flash dryer (3) is connected to an electric heater (2), the other end of the electric heater (2) is connected to a blower (1), and the blower (1) is in communication with the outside air.

3. The dry separation device of the whole clay catalyst white powder according to claim 2 is characterized in that: The feed inlet of the whirl dryer (3) is connected to a whirl dryer screw conveyor (4), and a disperser is provided at the bottom of the whirl dryer (3).

4. The dry separation device for the whole clay catalyst white powder according to claim 3 is characterized in that: A primary rotary discharge valve (9) and a secondary rotary discharge valve (10) are respectively provided at the bottom of the primary cyclone separator (5) and the secondary cyclone separator (6).

5. The dry separation device of the whole clay catalyst white powder according to claim 4, characterized in that: A bag rotary discharge valve (11) is provided at the bottom of the bag dust collector (7), and an induced draft fan (8) is connected to the top of the bag dust collector (7).

6. A dry separation method for white powder of a whole clay catalyst, characterized in that: Using the dry separation device as described in claim 5, the whole clay catalyst filter cake is heated, broken up and fluidized in a cyclone dryer (3), and the dispersed catalyst particles are sequentially passed through a primary cyclone dust collector (5) and a secondary cyclone dust collector (6) to separate the catalyst particles, and fine granular white powder is obtained at the top of the secondary cyclone dust collector (6). Finally, the fine granular white powder is passed into a bag dust collector (7) for gas-solid separation, thereby obtaining whole clay catalyst white powder.

7. The dry separation method of the whole clay catalyst white powder according to claim 6, characterized in that: Follow the steps below to implement it: Step 1, start the blower (1) and the electric heater (2) to allow hot air to enter the bottom of the flash dryer (3) tangentially; Step 2: The whole clay catalyst filter cake is conveyed to the flash dryer (3) by the flash dryer screw conveyor (4); under the action of hot air and the disperser, the filter cake is heated, dispersed, and fluidized, and then rises to the top of the flash dryer (3); Step 3, the whole clay catalyst dried and dispersed in step 2 is discharged from the top of the flash dryer (3) into the primary cyclone dust collector (5), where it is preliminarily separated, and most of the large particles are separated. The separated large particles are discharged from the bottom of the primary cyclone dust collector (5); Step 4: The finer particle catalyst separated in step 3 enters the secondary cyclone dust collector (6) from the top of the primary cyclone dust collector (5) and is further separated therein. The large particle material of the separated full-clay catalyst is discharged from the bottom of the secondary cyclone dust collector (6), and the fine particle white powder rises to the top of the secondary cyclone dust collector (6) along with the air flow; Step 5, the white powder of the whole clay catalyst separated in step 4 enters the bag filter (7), where gas-solid separation is performed, and the white powder produced by the separation is discharged from the bottom of the bag filter (7), and the purified dry exhaust gas is discharged to the subsequent treatment system through the induced draft fan (8).

8. The dry separation method of the whole clay catalyst white powder according to claim 7, characterized in that: The temperature of the hot air in step 1 is 150°C to 180°C.

9. The dry separation method of the whole clay catalyst white powder according to claim 7, characterized in that: The hot air flow rate in the flash dryer (3) in step 2 is 800kg / h to 1200kg / h.

10. The dry separation method of the whole clay catalyst white powder according to claim 7, characterized in that: The critical particle size of dust removal of the first-stage cyclone dust collector (5) is 80 microns, and the critical particle size of dust removal of the second-stage cyclone dust collector (6) is 40 microns.

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