Combined nozzle granulation system

Abstract

The utility model provides a granulation system with combined nozzles. The granulation system comprises a granulation tower, nozzles, a feeding system and a discharging system, the spray head is a combined spray head and comprises a rotary spray head and a fixed spray disc; the rotary spray head is of a structure with two open ends, and the fixed spray disc is arranged at the bottom opening of the rotary spray head and sealed; the feeding system comprises a rotary spray head feeding system and a fixed spray disc feeding system, and the rotary spray head feeding system and the fixed spray disc feeding system respectively and independently supply materials to the rotary spray head and the fixed spray disc.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of bisphenol A prilling. BACKGROUND

[0002] The bisphenol A prilling system adopting the tower type spraying technology has two schemes of fixed spraying disc and rotating nozzle, and each of the two schemes has advantages and disadvantages. The fixed spraying disc has simple structure, small required tower diameter, but small yield of single spraying disc, and usually needs to arrange several or even dozens of prilling nozzles in the tower at the same time, so that the complex feeding system makes the operation and maintenance cumbersome. The rotating nozzle feeding system is simple, only needs one feeding pipe and does not need reflux, but the material is sprayed out by centrifugal force, the required tower diameter is large, and a hollow belt is formed in the prilling tower, so that the space utilization rate of the prilling tower is low. CONTENT OF THE UTILITY MODEL

[0003] The utility model solves the technical problem that a combined nozzle prilling system is provided, the rotating nozzle is combined with the fixed spraying disc, the load adjustment range of the prilling system is improved, and the space utilization rate of the prilling tower is also improved.

[0004] The technical solution of the utility model is as follows: a combined nozzle prilling system, which comprises a prilling tower, a nozzle, a feeding system and a discharging system; the nozzle is a combined nozzle and comprises a rotating nozzle and a fixed spraying disc; the rotating nozzle has an open structure at both ends, and the fixed spraying disc is arranged at the bottom opening of the rotating nozzle and is sealed; the feeding system comprises a rotating nozzle feeding system and a fixed spraying disc feeding system, and the rotating nozzle feeding system and the fixed spraying disc feeding system independently feed the rotating nozzle and the fixed spraying disc respectively.

[0005] Preferably, the rotating nozzle is a conical nozzle, and the spray hole adopts a horizontal straight hole.

[0006] Preferably, the opening diameter of the spray hole on the conical nozzle is 0.6-1 mm, and the hole center distance is 6-9 mm.

[0007] Preferably, the fixed spraying disc adopts a circular spherical arc surface structure, the opening direction is perpendicular to the spherical surface, the equidiameter concentric circles are arranged, the hole center distance is 6-9 mm, and the hole diameter is 0.5-1 mm.

[0008] Preferably, the spraying range of the fixed spraying disc is controlled within 2.4 m of the center of the tower diameter.

[0009] Preferably, a pressure regulating valve is arranged in the fixed spraying disc feeding system, and the pressure difference between the pressure in the prilling tower and the pressure of the incoming material is controlled to be 26-32 KPa by adjusting the pressure regulating valve.

[0010] Preferably, the discharging system comprises a reverse cone arranged at the bottom center of the prilling tower, a scraper, two falling grooves, a spiral conveyor and a Y-shaped feeding pipe.

[0011] The material slides along the reverse cone to the circumferential ring belt; the circumferential ring belt is provided with a material scraping machine, and the material scraping machine periodically sweeps the material into the material dropping groove; the lower parts of the two material dropping grooves are provided with screw conveyors, the conveyors are downwardly inclined, and Y-shaped material conveying pipes are arranged at the material outlets to combine the two material outlets into one and then send into the downstream screening or conveying equipment.

[0012] Preferably, the cone angle of the reverse cone is greater than 60 degrees.

[0013] Preferably, the annular area outside the reverse cone at the bottom of the prilling tower adopts a flat bottom, and the material dropping grooves are oppositely arranged at 180 degrees.

[0014] The beneficial effects of the utility model compared with the prior art are:

[0015] The utility model discloses a combined nozzle prilling system, the combined nozzle is composed of the rotating side wall and the center fixed bottom plate, and the side wall and the bottom plate are provided with spray holes and are respectively matched with feeding systems.

[0016] The utility model provides a kind of combined nozzle prilling system, combined nozzle is composed of rotating side wall and center fixed bottom plate, side wall and bottom plate open spray hole and are respectively matched with feeding system. Rotating side wall relies on centrifugal force and is thrown out to form tower bottom annular material dropping belt by bisphenol A molten liquid, fixed bottom plate spray hole relies on pressure and is sprayed by bisphenol A molten liquid, forms tower bottom center material dropping belt. Reverse cone is arranged in the center of prilling tower bottom, and the inclined plane falling into tower center slides along the reverse cone inclined plane to annular bottom plate, and bottom plate 180 degrees oppositely arranged material dropping groove, downwardly inclined screw conveyor is arranged below material dropping groove, and two screw conveyor outlets are sent into downstream screening conveying equipment by Y-shaped material conveying pipe.

[0017] The utility model discloses combined nozzle improves the prilling tower space utilization, and combined nozzle sets up two independent feeding systems, and is independently adjusted respectively, improves the load regulation range of prilling system;Reverse cone is arranged in the center of prilling tower bottom, and the angle of reverse cone is greater than 60 degrees, solves the material accumulation of tower bottom center part possibly caused by conventional material scraping machine discharging mode;Two central conveying screw conveyors and Y-shaped material conveying pipe solve the problem that material extrusion and breakage possibly generated in long-distance mechanical feeding process of long transmission shaft of spiral conveying machine of large load prilling tower. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is system schematic diagram;

[0019] In the figure: 1 is a fixed spray disc; 2 is a rotating spray head; 3 is a fixed spray disc feeding system; 4 is a rotating spray head feeding system; 5 is a prilling tower; 6 is a scraper center reverse cone; 7-1 is a prilling tower bottom discharge chute 1; 7-2 is a prilling tower bottom discharge chute 2; 8 is a scraper arm; 9-1 and 9-2 are screw conveyors; 10 is a Y-shaped feed pipe; 11 is a fixed spray disc pressure regulating valve; 12 is a rotating spray head flow regulating valve; 13 is a rotating spray head flow meter. DETAILED DESCRIPTION

[0020] The utility model will be further described below in combination with examples.

[0021] The combined spray head prilling system comprises a combined spray head, a rotating spray head feeding system, a fixed spray disc feeding system and a discharge system. The fixed spray disc and the rotating spray head adopt independent feeding systems, and the fixed spray disc and the rotating spray head can work independently or simultaneously.

[0022] A combined spray head is arranged at the top center of the prilling tower, and the combined spray head adopts a structure in which a rotating spray head and a fixed spray disc are combined. The rotating spray head is in a straight cylinder or a conical barrel structure, and the side wall of the spray head is in a straight cylinder inclined hole or a conical barrel straight hole. The linear velocity and centrifugal force at the spray hole of the spray head determine the initial velocity of the liquid droplets, and the angle of the spray hole determines the flight direction of the liquid droplets. When the spray head rotates, the molten liquid is sprayed out of the side wall spray hole, and the sprayed liquid droplets are cooled and solidified into solid particles during the descending process in the prilling tower and fall to the bottom of the tower. The bottom of the spray head is a fixed spray disc, and a sealing structure is arranged between the fixed spray disc and the rotating spray head. The fixed spray disc is in a flat plate or a circular arc structure, and the spray disc is provided with a hole. The angle of the spray hole determines the flight direction of the liquid droplets, and the pre-spray pressure determines the flight speed of the liquid droplets. The molten liquid is sprayed out of the spray hole under the action of pressure and is cooled and solidified into solid particles during the descending process and falls to the bottom of the tower. A sealing ring is arranged between the side wall of the rotating spray head and the bottom of the fixed spray head to ensure that there is no medium leakage. The rotating spray head is a normal pressure spray head, and the yield is adjusted by adjusting the rotating speed. The fixed spray disc is a pressure spray head, and the yield is adjusted by adjusting the pre-spray pressure.

[0023] The present application is obtained through theoretical research and experiment, and in the preferred embodiment, the rotating nozzle has a rotating speed of 150-240 rpm, a half-cone angle of 8-12°, and a horizontal straight hole. The hole spacing and the hole distance of each row are adjusted according to the half-cone angle and the yield. The rotating nozzle has different radii, different centrifugal pressure and linear velocity of the side wall, and different hole diameters (for a bisphenol A granulation system, the average particle diameter is 1.1 mm, and the hole diameter is 0.6-1 mm). The molten liquid is horizontally sprayed, and the particles fall along a parabolic trajectory. The hole center distance is 6-9 mm. The fixed nozzle plate has a circular spherical arc surface structure, the hole direction is perpendicular to the spherical surface, the hole diameters of the concentric circles are the same, and the hole center distance is 6-9 mm. The hole diameter is 0.5-1 mm. In order to ensure that the spraying line of the fixed nozzle plate does not intersect with the spraying line of the rotating nozzle, and to avoid the particles from colliding and sticking together before solidification, the spraying range of the fixed nozzle plate is controlled within 2.4 m from the center of the tower.

[0024] The rotating nozzle feeding system is composed of a centrifugal pump, a flow regulating valve, flow, pressure, and temperature measuring instruments, and a backflow pipeline. The molten liquid is sent into the rotating granulation nozzle at the top of the granulation tower by the centrifugal pump. The feeding pipe is provided with temperature, pressure, and flow measuring instruments and a flow regulating valve. The upper end cover of the rotating nozzle is connected with the atmosphere, and the molten liquid in the nozzle is kept at a constant pressure. When the flow changes, the molten liquid film thickness in the rotating nozzle also changes. The rotating speed of the nozzle can be adjusted to make the rotating liquid surface shape adapt to the flow.

[0025] The fixed nozzle plate feeding system is composed of a centrifugal pump, a feeding pipeline, a backflow pipeline, a shut-off valve, a pressure regulating valve, a metering flow meter, and corresponding temperature and pressure measuring instruments. The molten liquid is sent into the fixed nozzle plate at the top of the granulation tower by the centrifugal pump. The feeding pipe is provided with temperature, pressure, and flow measuring instruments and a pressure regulating valve. The pre-spraying pressure is controlled by the pressure regulating valve. The change of the pre-spraying pressure will cause the change of the yield. In order to ensure the stability of the particle size, the change range of the pre-spraying pressure is controlled within ±10%. When the feeding is stopped, the molten liquid is returned through the backflow pipeline.

[0026] The discharging system is composed of a center reverse cone of a scraper, a scraper arm (scraper), a 180-degree split discharging chute, and a Y-shaped conveying pipe. The bisphenol A particles after solidification and cooling fall at the bottom of the granulation tower. The center reverse cone area is a discharging belt of the fixed nozzle plate. The material slides along the reverse cone (the cone angle is greater than 60 degrees) to the circular annular belt. The scraper on the circular annular belt periodically sweeps the material to the 180-degree split discharging chute. The discharging chute can be rectangular. The bottom of the discharging chute is respectively provided with a spiral conveyor inclined to the center to convey the material to the Y-shaped conveying pipe. The conveying pipe is connected with a valve, a screening or conveying device. The discharging mode of the present application adopts a combination of self-weight and mechanical discharging. The center part of the tower bottom slides along the cone to the annular plane area under the action of self-weight, and is swept by the scraper arm to the discharging screw.

[0027] The biggest advantage of BPA granulation is easy to store and transport, molten BPA can be directly sent to the downstream resin or polycarbonate device, but the molten BPA is unstable and not easy to store, when the BPA production is unstable or the polycarbonate, resin device production changes, the BPA can be stored or sold after granulation. The low load operation of the granulation system, due to the low load, the side wall of the rotating granulation cylinder cannot be completely covered by the molten liquid, the traditional method is to replace the low load rotating nozzle, otherwise a large amount of dust and uneven particles will be produced. In this scheme, only the center fixed nozzle plate 1 is fed at low load, the molten BPA is transported to the fixed nozzle plate feeding system 3 by the centrifugal pump A, in order to control the pressure difference between the fixed nozzle plate extrusion pressure and the pressure in the granulation tower at 26-32KPa, the pump post pressure regulating valve 11 is set, and the control loop is formed with the pressure difference between the tower and the incoming material, so as to automatically stabilize the pressure difference to meet the production needs. When the granulation system increases the load or adjusts in a larger load, the center fixed nozzle plate cannot meet the requirements, the feeding system can be switched to the rotating nozzle feeding system 4, the molten BPA is sent to the centrifugal nozzle inlet pipeline through the centrifugal pump B, the rotating nozzle speed is adjusted according to the required output, and the single regulating loop formed by the flow regulating valve 12 and the flow meter 13 controls the material supply amount, so as to achieve the purpose of stabilizing and adjusting the production load. When the system further increases the operation load, the rotating nozzle adjustment cannot meet the load requirements, the system can be switched to the rotating nozzle and fixed nozzle plate feeding at the same time, so as to achieve greater production load requirements and adjustment range.

[0028] Taking two typical working conditions of a 120,000 tons / year bisphenol granulation device as an example, when the bisphenol A / polycarbonate or bisphenol A / epoxy resin is combined, most of the bisphenol A can be directly sent to the downstream polycarbonate or epoxy resin device without granulation, the granulation system operates at 10%-13% load, at this time, only the fixed nozzle plate device can be used for feeding; when the polycarbonate or epoxy resin device is shut down, all the bisphenol A can be granulated and stored, the granulation system can operate in the range of 70%-110%, 70%-100% range, only the rotating nozzle feeding; ~ 110% range, combined operation mode is adopted. The produced bisphenol particles are stored in the silo or sold. When the granulation system is shut down, the stored bisphenol A can also be used for the production of polycarbonate or epoxy resin.

[0029] The material falling area of the fixed nozzle plate is in the center of the granulation tower 5, the material falling into the center slides along the side of the center reverse cone 6 of the scraper to the circular ring falling belt, and is periodically swept into the falling chute 7-1 and 7-2 by the scraper 8 together with the material on the circular ring falling belt. The lower part of the two falling chutes is provided with a screw conveyor 9-1 and 9-2, the conveyor is downwardly inclined, and a Y-shaped conveying pipe 10 is arranged at the discharge port to combine the two routes into one route and then sent to the downstream screening or conveying equipment.

[0030] The utility model discloses although has disclosed as above with preferable embodiment, but it is not used to limit the utility model, any person skilled in the art without departing from the spirit and range of the utility model can utilize the method and technical content of above disclosure to make possible change and modification to the utility model technical scheme, therefore, all the content without departing from the utility model technical scheme, according to the technical essence of the utility model to the simple modification, equivalent change and modification of above embodiment, all belong to the protection range of the utility model technical scheme.

Claims

1. A combination spray head granulation system comprising a granulation column, a spray head, a feed system, a discharge system; characterized in that: The spray head is a combined spray head, comprising a rotating spray head and a fixed spray disc; the rotating spray head is of an open structure at both ends, and the fixed spray disc is arranged at the bottom opening of the rotating spray head and is sealed; the feeding system comprises a rotating spray head feeding system and a fixed spray disc feeding system, and the rotating spray head feeding system and the fixed spray disc feeding system are respectively used for independently feeding the rotating spray head and the fixed spray disc.

2. The combination jet granulator system of claim 1, wherein: The rotating spray head is a conical spray head, and the spray holes are horizontal straight holes.

3. The combination jet granulator system of claim 1, wherein: The opening diameter of the spray holes on the conical spray head is 0.6-1 mm, and the hole center distance is 6-9 mm.

4. The combination jet granulator system of claim 1, wherein: The fixed spray disc adopts a circular spherical arc surface structure, the opening direction is perpendicular to the spherical surface, the equidiameter concentric circles are arranged, the hole center distance is 6-9 mm, and the hole diameter is 0.5-1 mm.

5. The combination jet granulator system of claim 1 wherein: The spraying range of the fixed spray disc is controlled within 2.4 m of the center of the tower diameter.

6. The combination jet granulator system of claim 1 wherein: A pressure regulating valve is arranged in the fixed spray disc feeding system, and the pressure difference between the pressure in the prilling tower and the pressure of the incoming material is controlled to be 26-32 KPa by adjusting the pressure regulating valve.

7. The combination jet granulator system of claim 1 wherein: The discharge system comprises a reverse cone arranged at the bottom center of the prilling tower, a scraper, two falling grooves, a screw conveyor and a Y-shaped conveying pipe. The material slides along the reverse cone to the circumferential annular belt; the scraper is arranged on the circumferential annular belt, and the scraper periodically sweeps the falling material into the falling grooves; the screw conveyors are arranged at the lower portions of the two falling grooves, the conveyors are downwardly inclined, and the Y-shaped conveying pipe is arranged at the discharge port to combine the two routes of the discharged material into one route and then send the combined material into the downstream screening or conveying equipment.

8. The combination jet granulator system of claim 7, wherein: The cone angle of the reverse cone is greater than 60 degrees.

9. The combination jet granulator system of claim 7, wherein: The annular area outside the reverse cone at the bottom of the prilling tower adopts a flat tower bottom, and the falling grooves are oppositely arranged at 180 degrees.

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