CN201337869Y

CN201337869Y - Dust removal unit for urea cooling fluidized bed

Info

Publication number: CN201337869Y
Application number: CNU2008201713754U
Authority: CN
Inventors: 彭本成; 项文裕; 王�华
Original assignee: NINGBO YUANDONG INDUSTRY TECHNOLOGY Co Ltd
Current assignee: NINGBO YUANDONG INDUSTRY TECHNOLOGY Co Ltd
Priority date: 2008-12-19
Filing date: 2008-12-19
Publication date: 2009-11-04
Anticipated expiration: 2018-12-19

Abstract

The utility model discloses a dust removal unit for a urea cooling fluidized bed, which is characterized in that an air outlet (15) at the top of a fluidized bed (1) is connected with a separator I (5) through a pipeline; a gas-phase outlet at the top of the separator I (5) is connected with the inlet of a draught fan (6), the outlet of which is connected with a separator II (7). An air current outlet (73) at the top of the separator II (7) is connected with a dust washing recover (8) through a pipeline; the diluted urea fluid recovered by the dust washing recover (8) is pressurized by a circulating pump (9) through a pipeline; one branch of the diluted urea fluid is connected with a refluence inlet (84) of the dust washing recover (8); and the other branch is sent to the urea evaporation workshop section. Compared with the prior art, the dust removal unit has the advantages that the gases are separated through two stages of cyclone and the separation effect can be improved from 95% to above 98%. The gases at the outlet of the draught fan are connected with the dust washing recover and the dust recovery rate can exceed 99%. By adopting the combination of a round perforated plate and an inclined perforated plate with an inclination Alpha of 30-60 degrees, the dust removal unit enables the urea particles to change the motion direction frequently to be at better boiling state, thus reaching better cooling effect.

Description

Urea cooling bed dust arrester

Technical field

The utility model relates to a kind of urea cooling bed dust arrester.

Background technology

In urea production process, carry dense fusing urea through vacuum and deliver to the carbamide granulation top of tower by Melting pump pressurization and spray granulation.Urea granules when descending with the cold air counter current contacting heat exchange of rising, be cooled to after the uniform temperature to be sent to and pack the post packing and storing by belt feeder.Generally speaking, the urea particle temperature that goes out granulation tower is not more than 70 ℃, is cooled to during packing below 50 ℃.Too high as the urea particle temperature, in the temperature-fall period in packaging bag, part steam makes the urea granules surface dissolution in the particle surface condensation, thereby adhesion is lumpd mutually.

The height of urea particle tower exit temperature with the granulation tower diameter, highly, the cold air temperature is relevant with factors such as intensity, production loads.Granulation tower diameter and highly often according to design production scale decision is considered the construction investment problem sometimes, and granulation tower can not design very greatly.The a collection of little urea production of China enterprise particularly, the granulation tower diameter often has only 9 meters or 12 meters, highly be 60-70 rice, the transformation of constantly expanding production along with urea plant, the device that 40,000 tons or 60,000 tons are produced in former design per year often can reach ten thousand tons of 10-20, like this, granulation tower just can not satisfy the production needs, cause problems such as finished urea temperature too high (particularly reaching summer more than 80 ℃), dust content increase, the granularity qualification rate is on the low side, but also because of going into a bag temperature height, in storage and transportation, easily lump, cause product quality to descend.

In order to reduce urea granules temperature and dust content, Chinese utility model patent ZL03229978.8 has announced a kind of method of cooling off urea granules.This method be behind belt conveyer by setting up fluidizing fluid-bed and vibratory sieve, under air blast forced ventilation situation, urea granules is cooled off and dedusting.The weak point of this kind method is that the dust air that contains that fluid bed only passes through first separation, is discharged in the gas of atmosphere still to contain a certain amount of dust, and the design of fluidized bed gas distribution grid is reasonable inadequately, and therefore the improved place of needs is arranged.

Summary of the invention

Technical problem to be solved in the utility model is the urea cooling bed dust arrester that a kind of good dedusting effect, dust rate of recovery height is provided at above-mentioned prior art present situation and can saves production cost.

The utility model solves the problems of the technologies described above the technical scheme that is adopted: this urea cooling bed dust arrester, comprise fluid bed and the outer vibratory sieve of bed, the bottom of described fluid bed is equipped with the gas distribution grid in tape drum wind hole, this distribution grid is connected by the outer air blast of pipeline and fluid bed, top at fluid bed is provided with air outlet, the position that is positioned at the distribution grid top on the sidewall of fluid bed is respectively equipped with urea charging aperture and the urea discharging opening that is connected with described vibratory sieve, finished product packing portion is led in the flow of urea outlet of vibratory sieve, it is characterized in that: the top outlet inlet at fluid bed is connected by the import of pipeline with separator one, and the air stream outlet at separator one top is connected by the import of pipeline with the air inducing pump, and the air inducing delivery side of pump is connected by the import of pipeline with separator two, the powder outlet of the bottom powder outlet of described separator two and separator one bottom all leads to powder packaging portion by pipeline, and the air stream outlet at separator two tops is connected by the import of pipeline with dust washing and recycling device, the top of this dust washing and recycling device is provided with gas emptying outlet, and the outlet of dust washing and recycling device recovery thin urine is connected with inlet of circulating pump by pipeline, and outlet of circulating pump is connected by the import of returning of pipeline one tunnel with dust washing and recycling device, and the urea evaporation section is then delivered on another road.

As improvement: described distribution grid includes circular hole slab and is arranged alternately with counter direction jet trays and is in the same place, and the angle of inclination a on described counter direction jet trays and plane is 30～60 degree.

Improve, its bottom of described fluid bed is provided with the cleaning fluid discharge mouth that is used to clean distribution grid again.

Compared with prior art, be with the advantage of utility model: 1, in the prior art, the air that contains carbamide dust that is come out by the fluid bed top only passes through the one-level cyclonic separation, now be designed to: gas is through the secondary cyclonic separation, promptly change series connection into by original parallel connection, under the situation that does not increase equipment, separating effect can be brought up to more than 98% by original 95%; 2, in the prior art, the directly logical atmosphere of air-introduced machine outlet, still contain a certain amount of dust in the gas, now be designed to: the air-introduced machine exit gas connects dust washing and recycling device, carry out circulation cleaning with liquid to containing dusty gas, further reduce the dust content in the emission gases, the dust rate of recovery reaches more than 99%; 3, in the prior art, the gas distribution grid of fluid bed bottom air intlet all adopts counter direction jet trays, now be designed to: adopt circular hole slab to combine with counter direction jet trays, both alternately arrange, and the angle of inclination a of counter direction jet trays is 30-60 °, thereby make the urea particle constantly change the direction of motion, be in better fluidized state, reach better cooling effect; 4, in the prior art, when the granulating system fluctuation of service, the fluidized bed gas distribution grid may occur and stop up, need water to wash this moment, but the no floss hole in fluid bed bottom causes cleaning fluid to discharge, and influences the device operation.Now be designed to: in the fluid bed bottom one cleaning fluid discharge mouth is set, when water washed, flushing water can discharge smoothly.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment;

Fig. 2 is the structural representation of distribution grid among Fig. 1;

Fig. 3 is along the cutaway view Amplified image of A-A line among Fig. 2.

The specific embodiment

Embodiment describes in further detail the utility model below in conjunction with accompanying drawing.

As shown in Figure 1 to Figure 3, the urea cooling bed dust arrester of present embodiment, comprise fluid bed 1 and the outer vibratory sieve 13 of bed, the bottom of described fluid bed 1 is equipped with the gas distribution grid 3 in tape drum wind hole 31, this distribution grid 3 is connected with fluid bed 1 air blast 2 outward by pipeline, be provided with air outlet 15 at the top of fluid bed 1, the position that is positioned at distribution grid 3 tops on the sidewall of fluid bed 1 is respectively equipped with urea charging aperture 11 and the urea discharging opening 12 that is connected with described vibratory sieve 13, the flow of urea outlet of vibratory sieve 13 is through leading to the packing hopper of finished product packing portion 4, top outlet inlet 15 at fluid bed 1 is connected with the import 51 of separator 1 by pipeline, and the air stream outlet 53 at separator one 5 tops is connected with the import 61 of air inducing pump 6 by pipeline, and the outlet 62 of air inducing pump 6 is connected with the import 71 of separator 27 by pipeline, the powder outlet 52 of the bottom powder outlet 72 of described separator 27 and separator one 5 bottoms all leads to powder packaging portion by pipeline, the air stream outlet 73 at separator 27 tops is connected by the import 81 of pipeline with dust washing and recycling device 8, the top of this dust washing and recycling device 8 is provided with gas emptying outlet 83, and the outlet 82 that dust washing and recycling device 8 reclaims thin urine is connected with the import 91 of circulating pump 9 by pipeline, and the outlet 92 of circulating pump 9 is connected with the import 84 of returning of dust washing and recycling device 8 by pipeline one tunnel, and another road flows to recovery thin urine urea evaporization process section.Described distribution grid 3 includes circular hole slab 32 and counter direction jet trays 33, and both are arranged alternately and are in the same place, and described counter direction jet trays 33 is 30～60 degree with the angle of inclination a on plane.And be provided with the cleaning fluid discharge mouth 14 that is used to clean distribution grid 3 in the bottom of fluid bed 1.

Technological process of the present utility model is:

Granulation tower produces the urea particle and is delivered to fluid bed by belt feeder, and the air that is transported by air blast enters the fluid bed bottom, the urea particle is blown afloat to be the boiling shape after gas distribution grid distributes, and the contained dust of urea particle is taken out of fluid bed by air draught.Remove urea particle behind the dust and go out to enter vibratory sieve again behind the fluid bed and sieve, enter the package bucket after screening out the part granule, remove finished product packing then.After going out the containing dusty gas and be introduced into primary cyclone separating part dust of fluid bed, deliver to secondary cyclone by air-introduced machine and further separate, the gas that goes out secondary cyclone enters the dust washer again.

Gas enters dust washing and recycling device from the bottom, with the cleaning solution counter current contacting of getting off from the top, after dust in the gas is washed the liquid washing, by the emptying of coming out of dust washing and recycling device top, cleaning solution is drawn by dust washing and recycling device bottom, recycle by delivering to dust washing and recycling device top after the circulating pump pressurization, after cleaning solution reaches finite concentration, be sent to the evaporation section of carbamide production system.

Claims

1, a kind of urea cooling bed dust arrester, comprise fluid bed (1) and bed outer vibratory sieve (13), the bottom of described fluid bed (1) is equipped with the gas distribution grid (3) in tape drum wind hole (31), this distribution grid (3) is connected by the outer air blast (2) of pipeline and fluid bed (1), be provided with air outlet (15) at the top of fluid bed (1), the position that is positioned at distribution grid (3) top on the sidewall of fluid bed (1) is respectively equipped with urea charging aperture (11) and the urea discharging opening (12) that is connected with described vibratory sieve (13), finished product packing portion (4) is led in the flow of urea outlet of vibratory sieve (13), it is characterized in that: the top outlet inlet (15) in fluid bed (1) is connected with the import (51) of separator one (5) by pipeline, and the air stream outlet (53) at separator one (5) top is connected with the import (61) of air inducing pump (6) by pipeline, and the outlet (62) of air inducing pump (6) is connected with the import (71) of separator two (7) by pipeline, the bottom powder outlet (72) of described separator two (7) and the powder outlet (52) of separator one (5) bottom all lead to powder packaging portion by pipeline, and the air stream outlet (73) at separator two (7) tops is connected with the import (81) of dust washing and recycling device (8) by pipeline, the top of this dust washing and recycling device (8) is provided with gas emptying outlet (83), and the outlet (82) of dust washing and recycling device (8) recovery thin urine is connected with the import (91) of circulating pump (9) by pipeline, and the outlet (92) of circulating pump (9) is connected with the import (84) of returning of dust washing and recycling device (8) by pipeline one tunnel, and the urea evaporation section is then delivered on another road.

2, urea cooling bed dust arrester according to claim 1, it is characterized in that: described distribution grid (3) includes circular hole slab (32) and counter direction jet trays (33), and both are arranged alternately together, and described counter direction jet trays (33) is 30～60 degree with the angle of inclination a on plane.

3, urea cooling bed dust arrester according to claim 1 and 2 is characterized in that: its bottom of described fluid bed (1) is provided with the cleaning fluid discharge mouth (14) that is used to clean distribution grid (3).