Advanced treatment device for urea dust recovery liquid

Abstract

The utility model relates to an advanced treatment device for urea dust recovery liquid. Comprising a stock solution tank, the stock solution tank is connected with a multi-stage filtering unit through a high-pressure pump, a clear liquid outlet of the multi-stage filtering unit is connected with a urea production system, and a concentrated liquid outlet of the multi-stage filtering unit is connected with a sewage treatment system; the method has the characteristics that resources can be recycled, and the treatment load of a sewage treatment system can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to urea production technical field, concretely is a kind of urea dust recovery liquid depth treatment device. BACKGROUND

[0002] Urea production system produces dust in the process of producing urea, the source of dust mainly includes two categories: one is due to the decomposition of the sprayed melt at higher temperature and lower ammonia pressure to produce ammonia and isocyanic acid, but due to the cooling problem of cooling air, two kinds of medium are reformed urea, this kind of dust is extremely small, particle size is all below 10 μm;Two is the dust of physical properties, such as dust produced by prilling nozzle, dust produced by cooling air etc..The method for treating the dust at present mainly has two kinds: cloth bag dust removal and water washing type dust removal, the waste liquid produced by two methods is dust recovery liquid.In actual production process, dust recovery liquid is brown or black due to containing large-particle urea dust and impurities in air, which is not only directly difficult to utilize, and the produced urea particle has more impurities, and the quality is poor.Based on the above reasons, most enterprises choose to send dust recovery liquid into waste water station for treatment, and the nitrogen content in dust recovery liquid reaches 30%, which not only causes resource waste, but also increases the treatment load of waste water station. CONTENT OF THE UTILITY MODEL

[0003] The utility model aims at providing a kind of urea dust recovery liquid depth treatment device to overcome the defects in the prior art.

[0004] To achieve the above object, the utility model provides the following technical scheme:

[0005] A kind of urea dust recovery liquid depth treatment device, the depth treatment device includes original liquid tank, original liquid tank is connected with multistage filtration unit by high-pressure pump, the clear liquid outlet of multistage filtration unit is connected with urea production system, the thick liquid outlet of multistage filtration unit is connected with sewage treatment system.

[0006] The utility model has the advantages that: the utility model is according to the urea production system of existing basis to carry out the reform, by setting original liquid tank, dust recovery liquid from urea production system can be collected, when collecting certain amount, high-pressure pump is matched with multistage filtration unit, the centralized effective treatment of dust recovery liquid is realized, clear liquid after treatment is sent into urea production system to realize repeated cyclic utilization, thick liquid after treatment is sent into sewage treatment system to carry out subsequent treatment;In the above process, not only resource is recycled, but also the treatment load of sewage treatment system can be reduced.

[0007] Preferably, the multistage filtration unit includes a series of folding filters, bag filters and ultrafiltration filter units.

[0008] Preferably, the ultrafiltration filter part comprises a low-pressure pump, the front end of the low-pressure pump is connected with the outlet of the bag filter, and the tail end of the low-pressure pump is connected with a plurality of ultrafiltration filters arranged in series; the inlet of the first ultrafiltration filter is connected with the outlet of the low-pressure pump, and the outlet of the previous adjacent ultrafiltration filter is connected with the inlet of the next ultrafiltration filter.

[0009] Preferably, the clear liquid outlets of the plurality of ultrafiltration filters are respectively connected with a urea production system, and the concentrated liquid outlets of the plurality of ultrafiltration filters are respectively connected with a sewage treatment system.

[0010] Preferably, the clear liquid outlet is connected with a clear liquid tank through a clear liquid pump, and the outlet of the clear liquid tank is connected with the urea production system.

[0011] Preferably, the concentrated liquid outlet is connected with a concentrated liquid tank, and the outlet of the concentrated liquid tank is connected with the sewage treatment system.

[0012] Preferably, the ultrafiltration filter part further comprises a backwashing part for cleaning the ultrafiltration filter part, the backwashing part comprises a first three-way valve arranged between the outlet of the bag filter and the low-pressure pump, and a second three-way valve arranged at the clear liquid outlet, the third end of the first three-way valve is connected with the outlet of the treatment tank, the third end of the second three-way valve is connected with the inlet of the treatment tank, and the treatment tank is provided with a cleaning material inlet.

[0013] Preferably, a first valve is arranged between the outlet of the bag filter and the first three-way valve, a second valve is arranged between the third end of the first three-way valve and the outlet of the treatment tank, a third valve is arranged between the second three-way valve and the urea production system, a fourth valve is arranged between the third end of the second three-way valve and the inlet of the treatment tank, and a fifth valve is arranged on the cleaning material inlet.

[0014] Preferably, a first flow meter is arranged between the low-pressure pump and the ultrafiltration filter, a second flow meter is arranged between the fourth valve and the inlet of the treatment tank, and a third flow meter is arranged between the third valve and the urea production system.

[0015] Preferably, liquid level meters are arranged on the raw liquid tank and the clear liquid tank respectively.

[0016] The device for deep treatment of urea dust recovery liquid prepared according to the above scheme realizes deep treatment of the urea dust recovery liquid by adopting a three-stage filtration system, wherein the three-stage filtration system comprises a folding filter, a bag filter and an ultrafiltration filter unit, the folding filter is mainly used for visible precipitates and impurities in the dust recovery liquid, and the technical indexes of the folding filter are as follows: filtration capacity 0.05-10 t / h, use pressure 0.5-1.0 MPa, filter core material polytetrafluoroethylene membrane filter core, polyamide membrane filter core, polypropylene membrane filter core, cellulose acetate membrane filter core, and filtration precision greater than 50 μm; the bag filter is mainly used for suspended solids and microorganisms in the dust recovery liquid, and the technical indexes of the bag filter are as follows: filtration capacity 0.05-10 t / h, use pressure 0.5-1.0 MPa, filter core material stainless steel, polyester, polypropylene, nylon or polytetrafluoroethylene, and filtration precision greater than 5-50 μm; and the ultrafiltration filter is mainly used for colloids and macromolecular substances in the dust recovery liquid, and the technical indexes of the ultrafiltration filter are as follows: filtration capacity 0.05-10 t / h, use pressure 0.1-0.5 MPa, filter core material cellulose acetate, cellulose acetate ester, polyethylene, polysulfone, polyamide and aromatic polymer, and filtration precision less than 5 μm; further, the ultrafiltration filter unit is formed by connecting a plurality of ultrafiltration filters in series, and the amount of the clear liquid can be adjusted to achieve the characteristic of flexibly adjusting the treatment capacity of the recovery liquid; furthermore, the device is provided with a backwashing unit, the backwashing unit can be used for backwashing and cleaning the ultrafiltration filters in the ultrafiltration filter unit by using acid or alkali, and the device can realize re-filtering when the quality of the clear liquid after filtration is poor, so that the quality of the clear liquid is ensured and the subsequent production requirements are met. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 It is a structural schematic view of the device.

[0018] Fig. 2 It is a structural schematic view of the multi-stage filtration unit.

[0019] In the drawing: 1, original liquid tank; 2, high-pressure pump; 3, urea production system; 4, sewage treatment system; 5, folding filter; 6, bag filter; 7, low-pressure pump; 8, third flow meter; 9, ultrafiltration filter; 10, clear liquid pump; 11, clear liquid tank; 12, concentrated liquid tank; 13, liquid level meter; 14, first three-way valve; 15, second three-way valve; 16, treatment tank; 17, cleaning material inlet; 18, first valve; 19, second valve; 20, third valve; 21, fourth valve; 22, fifth valve; 23, first flow meter; 24, second flow meter. DETAILED DESCRIPTION

[0020] The technical scheme in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model.

[0021] Referring to Figs. 1-2 As shown in the figure, a urea dust recovery liquid deep treatment device is characterized in that the deep treatment device comprises a stock solution tank 1, the stock solution tank 1 is connected with a multi-stage filtration unit through a high-pressure pump 2, a clear liquid outlet of the multi-stage filtration unit is connected with a urea production system 3, and a thick liquid outlet of the multi-stage filtration unit is connected with a sewage treatment system 4.

[0022] Further, the multi-stage filtration unit comprises a folded filter 5, a bag filter 6 and an ultrafiltration filtration part arranged in series.

[0023] Further, the ultrafiltration filtration part comprises a low-pressure pump 7, a front end of the low-pressure pump 7 is connected with an outlet of the bag filter 6, and a tail end of the low-pressure pump 7 is connected with a plurality of ultrafiltration filters 9 arranged in series; an inlet of a first ultrafiltration filter 9 is connected with an outlet of the low-pressure pump 7, and an outlet of a previous ultrafiltration filter 9 is connected with an inlet of a next ultrafiltration filter 9.

[0024] Further, clear liquid outlets of the plurality of ultrafiltration filters 9 are respectively connected with the urea production system 3, and thick liquid outlets of the plurality of ultrafiltration filters 9 are respectively connected with the sewage treatment system 4.

[0025] Further, the clear liquid outlet is connected with a clear liquid tank 11 through a clear liquid pump 10, and an outlet of the clear liquid tank 11 is connected with the urea production system 3.

[0026] Further, the thick liquid outlet is connected with a thick liquid tank 12, and an outlet of the thick liquid tank 12 is connected with the sewage treatment system 4.

[0027] Further, a backwashing part for cleaning the ultrafiltration filtration part is further arranged in the ultrafiltration filtration part, the backwashing part comprises a first three-way joint 14 arranged between the outlet of the bag filter 6 and the low-pressure pump 7 and a second three-way joint 15 arranged at the clear liquid outlet, a third end of the first three-way joint 14 is connected with an outlet of a treatment tank 16, a third end of the second three-way joint 15 is connected with an inlet of the treatment tank 16, and a cleaning material inlet 17 is arranged on the treatment tank 16.

[0028] Further, a first valve 18 is arranged between the outlet of the bag filter 6 and the first three-way joint 14, a second valve 19 is arranged between the third end of the first three-way joint 14 and the outlet of the treatment tank 16, a third valve 20 is arranged between the second three-way joint 15 and the urea production system 3, a fourth valve 21 is arranged between the third end of the second three-way joint 15 and the inlet of the treatment tank 16, and a fifth valve 22 is arranged on the cleaning material inlet 17.

[0029] Further, a first flow meter 23 is arranged between the low pressure pump 7 and the ultrafiltration filter 9, a second flow meter 24 is arranged between the fourth valve 21 and the inlet of the treatment tank 16, and a third flow meter 8 is arranged between the third valve 20 and the urea production system 3.

[0030] Further, a liquid level meter 13 is arranged on the raw liquid tank 1 and the clear liquid tank 11 respectively.

[0031] The working principle of the utility model is that: the urea prilling tower in the urea production system 3 produces dust in the process of producing urea, the dust recovery liquid is produced by recycling the dust, the dust recovery liquid can be used by gravity flow into the stock tank 1, the dust recovery liquid can meet the continuous conveying requirements of the high-pressure pump 2 after being collected by the stock tank 1, preferably, when the liquid level of the stock tank 1 reaches 85%, the high-pressure pump 2 starts to run, when the liquid level is as low as 10%, the high-pressure pump 2 stops running; when the high-pressure pump 2 runs, the high-pressure pump is pressurized to 0.5-1.0Mpa and sent to the multi-stage filtering unit for filtering, the filtered liquid is divided into clear liquid and thick liquid, the clear liquid is sent into the clear liquid tank 11 and can be sent into the subsequent urea production system 3 to realize recycling when reaching 85%, the thick liquid is sent into the thick liquid tank 12 and can be sent into the subsequent sewage treatment system 4 for treatment when reaching 85%; when the dust recovery liquid enters the folding filter 5, it is responsible for treating the impurities such as large particles, dust and fibers in the recovery liquid, mainly filtering the particle substances with a diameter greater than 50μm; then it is sent into the bag filter 6 for further treatment, mainly used for treating the suspended solids and microorganisms in the recovery liquid, mainly filtering the particle substances with a diameter of 5-50μm; after the above treatment, the dust recovery liquid is pressurized to 0.1-0.5Mpa by the low-pressure pump 7 and then enters the multi-stage filtering unit for filtering treatment, the number of ultrafiltration filters 9 in the multi-stage filtering unit can be selected according to the treatment amount of the dust recovery liquid, which can use one ultrafiltration filter 9 or two ultrafiltration filters 9, etc., the ultrafiltration filter 9 is mainly used for treating impurities with a diameter greater than 0.01μm, realizing the deep separation function of impurities in the dust recovery liquid. The clear liquid after deep treatment is sent into the clear liquid tank 11 by the clear liquid pump 10, and the thick liquid after deep treatment is sent into the thick liquid tank 12; in addition, in order to accurately control the filtration ratio and the working state of the ultrafiltration filter 9, the filtration ratio can be adjusted according to the actual situation and the use of the clear liquid; for example: under the condition that the low-pressure pump 7 is running normally, the flow before the first flow meter 23, the second flow meter 24 and the third flow meter 8 is detected, and the flow of the pipeline is adjusted by adjusting the low-pressure pump 7 and the valve, wherein the pipeline where the third flow meter 8 is located is directly sent to the clear liquid tank 11, the pipeline where the second flow meter 24 is located can flow back to the treatment tank 16, and is filtered again by the low-pressure pump 7, and realizes deeper filtration. When the utility model runs for a period of time, acid or alkali needs to be used for flushing treatment; that is: the acid or alkali used for cleaning enters the treatment tank 16 through the cleaning material inlet 17 with the fifth valve 22, when the utility model is in the parking state, the cleaning agent in the treatment tank 16 is pressurized into multiple ultrafiltration filters 9 by the low-pressure pump 7 for cleaning, realizing online cleaning of the ultrafiltration membrane, greatly improving the cleaning efficiency and saving the cleaning time.

[0032] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A deep treatment device for urea dust recovery liquid, characterized in that, The advanced treatment device includes a raw liquid tank (1), which is connected to a multi-stage filtration unit via a high-pressure pump (2). The clear liquid outlet of the multi-stage filtration unit is connected to a urea production system (3), and the concentrated liquid outlet of the multi-stage filtration unit is connected to a wastewater treatment system (4). The multi-stage filtration unit includes a pleated filter (5), a bag filter (6), and an ultrafiltration unit arranged in series.

2. The urea dust recovery liquid deep treatment device according to claim 1, characterized in that: The ultrafiltration unit includes a low-pressure pump (7), the front end of which is connected to the outlet of the bag filter (6), and the end of which is connected to multiple ultrafiltration filters (9) arranged in series. The inlet of the first ultrafiltration filter (9) is connected to the outlet of the low-pressure pump (7), and the outlet of the adjacent preceding ultrafiltration filter (9) is connected to the inlet of the following ultrafiltration filter (9).

3. The urea dust recovery liquid deep treatment device according to claim 2, characterized in that: The clear liquid outlets of the multiple ultrafiltration filters (9) are respectively connected to the urea production system (3), and the concentrated liquid outlets of the multiple ultrafiltration filters (9) are respectively connected to the wastewater treatment system (4).

4. A deep treatment device for urea dust recovery liquid according to claim 1 or 3, characterized in that: The clear liquid outlet is connected to the clear liquid tank (11) via the clear liquid pump (10), and the outlet of the clear liquid tank (11) is connected to the urea production system (3).

5. A deep treatment device for urea dust recovery liquid according to claim 1 or 3, characterized in that: The concentrated liquid outlet is connected to the concentrated liquid tank (12), and the outlet of the concentrated liquid tank (12) is connected to the sewage treatment system (4).

6. The urea dust recovery liquid deep treatment device according to claim 3, characterized in that: The ultrafiltration unit is also provided with a backwashing unit for cleaning the ultrafiltration unit. The backwashing unit includes a first tee (14) located between the outlet of the bag filter (6) and the low-pressure pump (7), and a second tee (15) located at the clear liquid outlet. The third end of the first tee (14) is connected to the outlet of the treatment tank (16), and the third end of the second tee (15) is connected to the inlet of the treatment tank (16). The treatment tank (16) is provided with a cleaning material inlet (17).

7. The urea dust recovery liquid deep treatment device according to claim 6, characterized in that: A first valve (18) is provided between the outlet of the bag filter (6) and the first tee (14), a second valve (19) is provided between the third end of the first tee (14) and the outlet of the treatment tank (16), a third valve (20) is provided between the second tee (15) and the urea production system (3), a fourth valve (21) is provided between the third end of the second tee (15) and the inlet of the treatment tank (16), and a fifth valve (22) is provided on the cleaning material inlet (17).

8. The urea dust recovery liquid deep treatment device according to claim 7, characterized in that: A first flow meter (23) is provided between the low-pressure pump (7) and the ultrafiltration filter (9), a second flow meter (24) is provided between the fourth valve (21) and the inlet of the treatment tank (16), and a third flow meter (8) is provided between the third valve (20) and the urea production system (3).

9. The urea dust recovery liquid deep treatment device according to claim 4, characterized in that: Level gauges (13) are respectively installed on the raw liquid tank (1) and the clear liquid tank (11).

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