CN102019208B - Continuous steeping method for grain carrier and equipment thereof - Google Patents

Abstract

A continuous impregnation method and equipment for particle carriers. The continuous impregnation method includes: the impregnation liquid is atomized into droplets through a nozzle and sprayed into the atomizer, the carrier particles are introduced into the atomizer, and after the impregnation liquid droplets and the carrier particles are mixed in the atomizer, the mixture enters the atomizer. Full contact is carried out in an immersion mixer, the average particle diameter of the carrier particles is 40-90 microns, the average particle diameter of the impregnating liquid droplets is 0.5 to 1.0 times the average particle diameter of the carrier particles, and the volume of the impregnating liquid The ratio of the flow rate to the mass flow rate of the carrier is 0.30-0.60 liters/kg. The continuous impregnation equipment includes an atomizer and an impregnation mixer connected to its outlet. The method provided by the invention can realize the continuous impregnation process of the microparticle carrier, and can realize the uniform distribution of the active component inside the carrier, thereby ensuring the strength of the finished product of the adsorbent.

Description

A continuous impregnation method and equipment for particulate carrier

technical field

The invention relates to a method and equipment for impregnating particulate carriers, more specifically, a continuous impregnation method and continuous impregnation equipment for particulate carriers.

Background technique

In modern petrochemical and chemical production processes, many catalysts or adsorbents are prepared by impregnation, that is, the carrier is prepared first, and then the active components are impregnated on the carrier. In the general industrial process, there are two methods of supersaturated impregnation and saturated impregnation. For example, the adsorbent used in adsorption desulfurization technology is an adsorbent loaded with active components on particulate carriers. However, there is no continuous impregnation method and related equipment for particulate carriers in the prior art.

Adsorption desulfurization is one of the important technologies for clean fuel production. Its technological advantages are low hydrogen consumption, less hydrogenation reaction of unsaturated hydrocarbons, and less loss of octane number of products. This technology uses the principle of adsorption reaction technology to store the sulfur in gasoline on the adsorbent, and remove the sulfur stored in the adsorbent through regeneration. Since the adsorption desulfurization technology uses a fluidized bed reactor, there are high requirements for the adsorbent. In addition to having good desulfurization activity, the adsorbent must also have a certain particle size distribution and anti-wear strength to meet the needs of fluidization. From the perspective of process requirements, the adsorbent used in adsorption desulfurization technology is different from any type of industrial catalyst at present. From the current industrial use of adsorbents, the strength of the adsorbent is not good, and it is easy to break in actual operation. Larger, so the strength of the adsorbent is a crucial physical property.

The preparation of adsorbent mainly includes two steps of carrier preparation and active component impregnation, and impregnation is a more important step. Supersaturated impregnation includes hanging basket and mesh belt impregnation, and roller impregnation, but these methods are not suitable for the impregnation process of adsorbent particles in the adsorption desulfurization process, because the prepared adsorbent has poor abrasion strength and the active components are unevenly distributed on the carrier. Saturated impregnation is generally achieved by a drum machine, but during the tumbling process of the drum machine, the wear resistance of the particle carrier is lost, and the drum machine can only be operated intermittently and cannot be continuously produced. For the adsorbent in the adsorption desulfurization process, since the carrier contains more than 60% ZnO amphoteric compounds, and the impregnation solution is an acidic solution, supersaturated impregnation or uneven impregnation will also damage the support structure.

CN1422177A discloses desulfurization, an adsorbent for desulfurization, and a preparation method of the desulfurization adsorbent. The impregnation process involved in the examples of the specification is to use a Sono-Tec sprayer to spray the active ingredient onto the adsorbent while rotating the adsorbent particles in a baffled mastic mixer type drum, and then The nickel-impregnated adsorbent is calcined. But this impregnation method cannot be produced continuously.

CN 201200962Y discloses a continuous spraying and drying device for preparing layered composites. The device includes a slurry spraying device, an air spraying device and a drum, wherein the slurry spraying device and the air spraying device work in a pulsed manner, thereby realizing continuous drying. Spray dry. However, the equipment uses a roller, and the wear resistance of the particle carrier is relatively large.

Contents of the invention

The purpose of the present invention is to provide a continuous impregnation method and equipment for particle carriers on the basis of the prior art. What needs to be solved is the problem that the strength of the adsorbent prepared by the particle carrier is poor in the prior art, and the impregnation process cannot be continuously produced.

The content provided by the present invention relates to a continuous impregnation method for particle carriers and continuous impregnation equipment dedicated to the method.

A method of continuous impregnation of particulate carriers comprising:

(1) The immersion liquid is atomized into droplets through the nozzle and sprayed into the atomizer,

(2) The carrier particles are introduced into the atomizer,

(3) After the impregnating liquid droplets and the carrier particles are mixed in the atomizer, they enter the impregnation mixer for full contact,

The average particle diameter of the carrier particles is 40-90 microns, the average particle diameter of the impregnating liquid droplets is 0.5-1.0 times the average particle diameter of the carrier particles, and the ratio of the volume flow rate of the impregnating liquid to the mass flow rate of the carrier is 0.30- 0.60 L/kg.

The residence time of the carrier particles in the atomizer and dip mixer is 5-120 seconds.

The method provided by the invention can realize the continuous impregnation process of the particle carrier with an average particle diameter of 40-90 microns. First, the impregnating liquid is atomized into droplets through the nozzle to produce droplets with a relatively concentrated particle size distribution. The average particle diameter of the impregnating liquid droplets is 0.5 to 1.0 times the average particle diameter of the carrier particles. The volume flow rate of the impregnating liquid and the mass flow rate of the carrier The ratio is 0.30-0.60 liters/kg. The droplets of impregnating liquid and the carrier particles are initially mixed and contacted in the atomizer, and then enter into the impregnating mixer for full contact. Since the average diameter of the atomized droplets is slightly smaller than the carrier particles, and the particle size distribution of the droplets is concentrated, the particle droplets can be quickly and uniformly adsorbed on the carrier, and it is not easy to cause local supersaturated impregnation of the carrier particles (for example, the carrier particles are soaked in the impregnated liquid), which can ensure the structure and strength of the adsorbent. In addition, due to the high capillary pressure of the micropores of the carrier, the impregnation process can be completed in a short period of time, and the active component can be quickly dispersed in the carrier, so that the active component can be distributed evenly in the carrier, especially inside, so that The impregnated carrier has good activity. The method provided by the invention not only solves the problem of uniform distribution of active components during the impregnation process, but also ensures the particle size distribution and strength of the impregnated carrier, so that the finished adsorbent after preparation has good wear resistance during the reaction process.

The shape of the atomizer is consistent with the shape of the Venturi tube. According to the flow direction of the immersion liquid, the atomizer is composed of a nozzle, a receiving chamber, a mixing chamber and a diffusion chamber in sequence. , setting an opening.

In a preferred version, the continuous impregnation method comprises:

(1) The immersion liquid is atomized into droplets through the nozzle and sprayed into the receiving chamber of the atomizer, and a negative pressure is formed in the receiving chamber,

(2) When the receiving chamber becomes a negative pressure zone, the carrier particles are introduced into the receiving chamber of the atomizer from the opening on the outside of the atomizer corresponding to the receiving chamber,

(3) The impregnating liquid droplets and the carrier particles enter the mixing chamber and the diffusion chamber of the atomizer in turn, and the mixed material comes out of the diffusion chamber of the atomizer and enters the impregnation mixer for full contact.

The jetting fluid speed of the nozzle is 1-20 m/s.

Preferably said nozzle is a gas assisted atomizing nozzle. Wherein, the working medium of the gas-assisted atomizing nozzle is air or an inert gas, and the gauge pressure of the working medium pressure is 0.1-2.0 MPaG; the gauge pressure of the immersion liquid in the gas-assisted atomizing nozzle is 0.1-1.0 MPaG, wherein The volume ratio of atomizing gas to immersion liquid is 0.30-1.00. The inert gas refers to a gas that has no chemical effect on the immersion liquid and/or the carrier, and is selected from one or more of N ₂ , CO, and CO ₂ .

The carrier particles are fed into the atomizer from a feeder and/or a feeder; wherein the feeder is a screw pump; and the feeder is pressurized with nitrogen or air at a pressure of 0.1-0.5 MPaG.

The dipping mixer is a hollow pipe, and a screw is arranged in the pipe. A loose tuyere is provided at the bottom of the pipeline of the dipping mixer.

The mixture coming out of the atomizer can be further mixed with the impregnating liquid in the hollow pipe through the screw pusher. Driven by the screw, the mixture continues to rotate and move forward. A loose state advances.

In another preferred embodiment, the mixture in step (3) is flash-dried. The impregnated carrier particles coming out of the impregnating mixer are quickly flash-dried, and the impregnating liquid is quickly volatilized to avoid the migration of active components and the destruction of the structure of the carrier microspheres. The bottom of the preferred flash dryer is equipped with high-speed rotating paddles, which can not only break up bulk materials, but also strengthen the disturbance of airflow and wet materials, and improve the drying strength.

The dried material can be sent into the cyclone separator to obtain the qualified semi-finished material, and then further roasted to make the finished product.

A continuous impregnation device specially used in the above continuous impregnation method, comprising an atomizer and an impregnation mixer connected to its outlet.

The shape of the atomizer is consistent with the shape of the Venturi tube. According to the flow direction of the immersion liquid, the atomizer is sequentially composed of a nozzle, a receiving chamber, a mixing chamber and a diffusion chamber. On the outside of the atomizer corresponding to the receiving chamber, Set up an opening.

The dipping mixer is a hollow pipeline, and a screw pump is arranged in the pipeline.

A flash dryer is also included, and the outlet of the dip mixer is connected with the flash dryer.

The bottom of the flash dryer is provided with high-speed rotating paddles.

The advantages of the present invention are:

(1) The method provided by the present invention can realize the continuous impregnation of the particle carrier, and the active component is loaded on the carrier in a very short time in the atomizer, and then it is transported by the agitation of the screw in the impregnation mixer to further complete Saturated impregnation improves the impregnation efficiency of materials. At the same time, because the influence of inhalation, deposition, adsorption and diffusion is considered in the whole impregnation process, the preparation method can run continuously, which greatly improves the preparation efficiency.

(2) The method provided by the present invention not only solves the problem of uniform distribution of active components in the impregnation process, but also ensures the particle size distribution and strength of the impregnated carrier, so that the finished adsorbent after preparation has good wear performance in the reaction process .

(3) The device provided by the present invention has a simple structure, and the connection between each device is also very simple. The cost of equipment is low, and it is easy to scale up industrially.

Description of drawings

Fig. 1 is a schematic flow chart of the continuous impregnation method for particulate carriers provided by the present invention.

Fig. 2 is a schematic diagram of the atomizer device provided by the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited thereto.

Fig. 1 is a schematic flow chart of the continuous impregnation method for particulate carriers provided by the present invention. The specific process is described as follows: the immersion liquid from the pipeline 126 enters the nozzle, is atomized into liquid droplets by the air gas from the pipeline 127, and then sprayed into the atomizer 2 at high speed. The carrier from the pipeline 124 is sucked into the atomizer 2 after passing through the feeder 1. After the liquid droplets and the carrier particles are fully contacted in the atomizer 2, they enter the immersion mixer 3 and are further deepened in the immersion mixer 3. The impregnation process is then sent to the flash dryer 4 after being agitated by the screw and controlling a short residence time. The air from the pipeline 128 enters the heating furnace 7 through the fan 9, and the heated air enters the flash dryer 4 through the pipeline 129 to dry the mixed material. The dried and impregnated carrier is sent to the cyclone separator 5 through the pipeline 130, the impregnated carrier particles with a qualified particle size are sent to the semi-finished product silo through the pipeline 133, the pulverized material enters the bag filter 6 through the pipeline 131, and the flash-dried tail gas passes through the pipeline 132 and the blower 8 go to the absorption system, and the impregnated carrier powder is discharged from the device through the pipeline 134.

Fig. 2 is a schematic diagram of the atomizer device provided by the present invention. The shape of the atomizer is consistent with the shape of the Venturi tube. The immersion liquid and atomizing air fluid enter the atomizer through the nozzle 11, and then enter the impregnation mixer through the receiving chamber 12, the mixing chamber 13 and the diffusion chamber 14 in sequence. On the outside of the atomizer corresponding to the receiving chamber 12, an opening 15 is provided, through which the carrier material is sucked into the atomizer to realize the mixing of the carrier and the impregnating liquid in the atomizer.

The present invention will be further described below in conjunction with embodiment, but does not limit the present invention thereby. The carrier used in the examples is an adsorbent carrier containing 60% by weight of ZnO, and its average particle size is 65 microns. The impregnation solution used is nickel nitrate solution. The immersion liquid is sprayed into the atomizer through the nozzle at high speed, and the average particle size of the immersion liquid droplets is 45 microns. The carrier is sucked into the atomizer, and the droplet particles and the carrier particles are fully contacted in the atomizer, and then enter the impregnation mixer, and the impregnation process is further deepened in the impregnation mixer, and then sent to flash drying by screw agitation. The residence time of the carrier particles in the atomizer and immersion mixer was 75 seconds. The dynamic atomization pressure of the nickel nitrate impregnating liquid is 0.6MPaG, the impregnating liquid delivery rate is 270 liters/hour, the carrier delivery rate is 486 kg/hour, and the semi-finished product is 687 kg/hour.

The characterization results are shown in Table 1. The results show that the wear resistance value DI of the impregnated adsorbent system is significantly improved compared with the traditional process. The average particle size of the semi-finished product prepared by this patent is 73 microns, and the particle size distribution is uniform. The Ni content of the active component meets the requirements of the process. Indicator requirements.

Table 1 Physicochemical properties of adsorbent

Claims (14)

1. the continuous impregnating method of a particulate carrier comprises:

(1) maceration extract becomes drop by nozzle atomization and spurts in the atomizer,

(2) carrier particles is introduced in the atomizer,

(3) the maceration extract drop is with after carrier particles is mixed in atomizer, and its mixture enters in the dipping blender and fully contacts,

The average grain diameter of described carrier particles is 40～90 microns, and the average grain diameter of described maceration extract drop is 0.5～1.0 times of carrier particles average grain diameter, and maceration extract volume flow is 0.30～0.60 liter/kilogram with the carrier mass flow rate ratio.

2. in accordance with the method for claim 1, the shape that it is characterized in that described atomizer is consistent with venturi-shaped, direction according to the maceration extract Fluid Flow in A, atomizer is comprised of nozzle, receiving chamber, mixing chamber and diffuser casing successively, the atomizer outside at corresponding receiving chamber position arranges an opening.

3. in accordance with the method for claim 2, it is characterized in that described continuous impregnating method comprises:

(1) maceration extract becomes drop by nozzle atomization and spurts in the receiving chamber of atomizer, forms negative pressure in the receiving chamber,

(2) after becoming negative pressuren zone in the receiving chamber, with the opening part of carrier particles from the atomizer outside at corresponding receiving chamber position, introduce in the receiving chamber of atomizer,

(3) the maceration extract drop enters mixing chamber and the diffuser casing of atomizer successively with carrier particles, mixed material from diffuser casing out after, enter in the dipping blender and fully contact.

4. according to claim 1 or 3 described methods, it is characterized in that the time of staying 5～120 second of described carrier particles in atomizer and dipping blender.

5. according to claim 1 or 3 described methods, the injection fluid velocity that it is characterized in that described nozzle is 1～20 meter per second.

6. according to claim 1 or 3 described methods, it is characterized in that described nozzle is gas assisted atomization nozzle.

7. in accordance with the method for claim 6, the working media that it is characterized in that described gas assisted atomization nozzle is air or inert gas, and working medium pressure is 0.1～2.0MPaG; The maceration extract operating pressure is 0.1～1.0MPaG in the described gas assisted atomization nozzle, and wherein atomization gas is 0.30～1.00 with maceration extract volume ratio.

8. according to claim 1 or 3 described methods, it is characterized in that the mixture of step (3) is carried out expansion drying.

9. according to claim 1 or 3 described methods, it is characterized in that described dipping blender is a hollow pipe, arranges screw rod in the pipeline.

10. the duct bottom that in accordance with the method for claim 9, it is characterized in that described dipping blender arranges loosening air port.

11. according to claim 1 or 3 described methods, it is characterized in that described carrier particles is to add in the atomizer from batcher and/or feed bin; Wherein batcher is screw pump; Wherein be nitrogen or air pressurising in the feed bin, pressure is 0.1～0.5MPaG.

12. a continuous impregnating equipment that is exclusively used in the described continuous impregnating method of claim 1 is characterized in that, comprises atomizer and the dipping blender that is connected with its outlet; The shape of described atomizer is consistent with venturi-shaped, direction according to the maceration extract Fluid Flow in A, atomizer is comprised of nozzle, receiving chamber, mixing chamber and diffuser casing successively, the atomizer outside at corresponding receiving chamber position, an opening is set, described dipping blender is a hollow pipe, and screw rod is set in the pipeline.

13., it is characterized in that also comprise a flash distillation dryer, the outlet of described dipping blender is connected with flash distillation dryer according to the described equipment of claim 12.

14. according to the described equipment of claim 13, it is characterized in that the bottom of described flash distillation dryer arranges the High Rotation Speed oar.

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