A urea ammonium nitrate solution continuous filtration system and method of use thereof

Abstract

The present application relates to the field of chemical apparatus, provide a kind of urea ammonium nitrate solution continuous filtration system and its use method, first agitator tank is provided with urea feed pipe, ammonium nitrate solution feed pipe and process water feed pipe;Urea feed pipe is provided with screen, process water feed pipe is sequentially provided with disc filter system, ultrafiltration system and RO reverse osmosis system;The connecting pipe between first agitator tank and second agitator tank is provided with Y filter, second agitator tank discharge pipe is provided with first bag filter, the outlet pipe of first bag filter is provided with sampling valve, sintered filter element filter and second bag filter are connected in parallel after sampling valve.The beneficial effects of the present application are that: finished product has good filtering effect, impurities such as oily substances, and dust particles invisible to the naked eye in finished product are fully filtered, chroma value is significantly reduced compared with before use, transparency is significantly improved, and finished product quality of urea ammonium nitrate solution is significantly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical devices, in particular to a urea ammonium nitrate solution continuous filtration system and a use method thereof. BACKGROUND

[0002] Liquid nitrogen fertilizer urea ammonium nitrate solution contains nitrate nitrogen, ammonium nitrogen and amide nitrogen, which can be directly applied after dilution with water, or used as raw material to produce ternary liquid fertilizer. Generally, the process principle adopted by each manufacturer in the production of urea ammonium nitrate solution is that urea particles and 92% ammonium nitrate solution are metered according to the formula requirements, and a certain proportion of process water is added into a static mixer for mixing and stirring reaction. The mixed urea ammonium nitrate solution is cooled and then sent to a storage tank for storage, while being loaded or packaged according to requirements, and the packaged product is sold or stored.

[0003] Urea ammonium nitrate is originally a colorless liquid, but during its production process, impurities such as oily substances and dust particles invisible to the naked eye may be mixed therein, which may cause the liquid to appear turbid, the liquid to change color, the color to be out of standard, or the oily substances on the surface of the liquid to float, etc. Therefore, filters must be added to each link of urea ammonium nitrate solution production to filter the raw materials and finished liquid. Since the traditional filtration system is relatively simple and the filter is not reasonably arranged, the liquid product may not meet the standards. Patent No. ZL201710421487.4 provides a method for simultaneously removing turbidity and filling urea ammonium nitrate solution, which filters and removes turbidity from urea ammonium nitrate solution before filling. The method adopted is to use two-stage polyester filter bags for filtration. This filtration method is relatively extensive and cannot guarantee that the impurity content of the solution remains at a low level.

[0004] Therefore, according to the actual situation of urea ammonium nitrate solution in production, a filtration system for continuous production of urea ammonium nitrate solution is designed. SUMMARY

[0005] In view of the deficiencies of the prior art, the problem of excessive impurities in urea ammonium nitrate solution under the traditional filtration process is solved.

[0006] The present application provides a urea ammonium nitrate solution continuous filtration system, comprising a first stirring tank and a second stirring tank, wherein the first stirring tank is provided with a urea feeding pipe, an ammonium nitrate solution feeding pipe and a process water feeding pipe;

[0007] A screen is arranged on the urea feeding pipe, and a disc filter system, an ultrafiltration system and an RO reverse osmosis system are arranged in sequence on the process water feeding pipe;

[0008] The connecting pipeline between the first stirring tank and the second stirring tank is provided with a Y-type filter, the second stirring tank is provided with a discharge pipeline, the discharge pipeline is provided with a first bag filter, the outlet pipeline of the first bag filter is provided with a sampling valve, and a sintered filter element filter and a second bag filter are connected in parallel after the sampling valve.

[0009] Further, the screen mesh has a screen hole diameter of 3.5 mm, and is provided with a vibrating mechanism.

[0010] Further, a water production tank for detecting process water is arranged between the RO reverse osmosis system and the first stirring tank, and a water pump is arranged on the water outlet pipeline of the water production tank.

[0011] As a preferred solution, the Y-type filter adopts a 60-mesh filter element, and a water pump is arranged on the water outlet pipeline of the Y-type filter.

[0012] As a preferred solution, the first bag filter adopts a 600-mesh filter element, a water pump is arranged on the water outlet pipeline of the first bag filter, the second bag filter adopts a 1000-mesh filter element, and the filter element precision of the sintered filter element filter is 5 μm.

[0013] As a preferred solution, a tee pipe is arranged on the water outlet pipeline of the sampling valve, the water outlet pipeline of the sampling valve is arranged in the water inlet of the tee pipe, a reflux pipeline for refluxing to the second stirring tank is arranged in the first water outlet of the tee pipe, the water inlets of the sintered filter element filter and the second bag filter are arranged in the second water outlet of the tee pipe, a sequence valve is arranged on the water inlets of the sintered filter element filter and the second bag filter, and a reflux valve is arranged on the reflux pipeline.

[0014] A use method of a urea-ammonium nitrate solution continuous filtration system, using the above urea-ammonium nitrate solution continuous filtration system, the use steps comprising:

[0015] S1: using a screen mesh to filter impurities with a diameter greater than 3.5 mm in urea raw materials;

[0016] S2: the ammonium nitrate solution adopts 92% concentration raw materials, and a colorimetric detector is used to sample and analyze the ammonium nitrate solution before feeding, and the colorimetric index of the ammonium nitrate solution needs to be less than 40 degrees;

[0017] S3: The process water enters a disc filter system through a booster pump to filter water particles with a diameter of more than 50 microns; enters an ultrafiltration system to filter water particles with a diameter of 0.001-0.1 microns; enters an RO reverse osmosis system to filter water particles with a diameter of 0.0001-0.001 microns; after three-stage filtration, the process water enters a product water tank, and the process water in the product water tank is sampled and detected; the color index of the process water needs to be less than 40 degrees, the ammonia nitrogen content needs to be less than 6 mg / l, the PH value needs to be 6-9, and the electric conductivity needs to be less than 50 us / cm;

[0018] S4: The urea raw material, the ammonium nitrate solution and the process water enter a first stirring tank for stirring and mixing;

[0019] S5: The stirred urea ammonium nitrate solution enters a Y-type filter to filter out bag strips and sundries with a size of more than 60 mesh and less than 3.5 mm, and then enters a second stirring tank through a centrifugal pump;

[0020] S6: The urea ammonium nitrate solution is stirred again in the second stirring tank to gradually cool the mixed urea ammonium nitrate solution;

[0021] S7: The urea ammonium nitrate solution enters a first bag filter to filter out oily floating matter on the surface of the urea ammonium nitrate solution, and the color of the urea ammonium nitrate solution is detected by a colorimeter through a sampling valve; if the color is greater than 40 degrees, a sequence valve is closed and a reflux valve is opened, so that the urea ammonium nitrate solution is refluxed into the second stirring tank to repeat the steps S6 and S7; if the color is less than 40 degrees, the reflux valve is closed and the sequence valve is opened, and the next step is entered;

[0022] S8: If the transportation mode of the required finished urea ammonium nitrate liquid is tank car transportation or liquid bag transportation, and the single demand is greater than or equal to 20 tons, the urea ammonium nitrate liquid enters a second bag filter for filtration; if the impurity content of the required finished urea ammonium nitrate liquid is less than 5 microns, the urea ammonium nitrate liquid enters a sintered filter element filter for filtration; after filtration, the finished product tank is filled for collection and preservation.

[0023] Further, after the equipment is closed, the impurities on the screen are cleaned using the vibrating mechanism.

[0024] Further, when the outlet pressure of the centrifugal pump between the Y-type filter and the second stirring tank is less than 0.8 Mpa, the centrifugal pump is cleaned.

[0025] Further, when the pressure difference between the front end and the rear end of the sintered filter element filter is greater than 0.2 Mpa, the filter element of the sintered filter element filter is cleaned.

[0026] The present application has the following beneficial effects:

[0027] 1、The application has good filtering effect on finished products by setting targeted filtering of each link, fully filtering impurities such as oily floating matter in finished products (main ion content is Bal 73.07%, Si 16.76%, AL 2.19%, Fe 6.94% by spectrum test), and dust particles invisible to the naked eye, the color value is obviously reduced compared with before use, the transparency is significantly improved, and the finished product quality of urea ammonium nitrate solution is significantly improved.

[0028] 2、The filtering system of the application is convenient to observe, and the filtering system of each link is convenient to replace, which significantly reduces the maintenance cost of the machine. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to make the content of the application more easily understood, the application will be further described in detail below according to specific embodiments and in combination with the drawings, in which

[0030] Figure 1 The system arrangement schematic diagram of the application.

[0031] Reference numerals in the drawings are:

[0032] 1, screen; 2, disc filter system; 3, ultrafiltration system; 4, RO reverse osmosis system; 5, Y filter; 6, first bag filter; 7, sintered filter element filter; 8, second bag filter; 9, first stirring tank; 10, second stirring tank; 11, water production tank; 12, sampling valve; 13, sequence valve; 14, backflow valve. DETAILED DESCRIPTION

[0033] In order to illustrate the characteristics of the application, the application will be further described below in combination with the drawings and examples.

[0034] Example:

[0035] Please refer to Figure 1 The application embodiment provides a urea ammonium nitrate solution continuous filtering system, which comprises a first stirring tank 9 and a second stirring tank 10, the first stirring tank 9 is provided with a urea feeding pipe, an ammonium nitrate solution feeding pipe and a process water feeding pipe, a screen 1 with a screen hole diameter of 3.5 mm is arranged on the urea feeding pipe, which is used for filtering large impurities in urea raw materials, and a vibrating mechanism is further arranged on the screen 1 for cleaning the screen, disc filter systems 2, ultrafiltration systems 3 and RO reverse osmosis systems 4 are sequentially arranged on the process water feeding pipe, and 2-400 μm particles contained in the process water are filtered out through the three-stage filter, including metal ions which can react with ammonium nitrate in water. A water production tank 11 for detecting process water is arranged between the RO reverse osmosis system 4 and the first stirring tank 9, and a water pump is arranged on the water outlet pipe of the water production tank 11.

[0036] The connecting pipeline between the first stirring tank 9 and the second stirring tank 10 is provided with a 60-mesh Y-type filter 5, and the water outlet pipeline of the Y-type filter 5 is provided with a water suction pump. The Y-type filter 5 has simple structure, convenient disassembly and reassembly, low cost, and the filter screen can be reused after cleaning. Too small filter screen will cause more blockage of the filter screen, so the Y-type filter screen is selected to be 60 mesh. The filter screen can be cleaned regularly or according to the value of the centrifugal pump outlet pressure gauge.

[0037] The second stirring tank 10 is provided with a discharge pipeline, and the discharge pipeline is provided with a 600-mesh first bag filter 6. The outlet pipeline of the first bag filter 6 is provided with a sampling valve 12 and a water suction pump, which facilitates colorimetric detection of the colority of the finished liquid. The water outlet pipeline of the sampling valve 12 is provided with a tee pipe, the water outlet pipeline of the sampling valve 12 is arranged in the water inlet of the tee pipe, the first water outlet of the tee pipe is provided with a reflux pipeline for refluxing to the second stirring tank 10, and the second water outlet is provided with the water inlet pipeline of the sintered filter element filter 7 and the second bag filter 8. The water inlet pipeline of the sintered filter element filter 7 and the second bag filter 8 is provided with a sequence valve 13, and the reflux pipeline is provided with a reflux valve 14. By arranging the reflux pipeline, the solution that does not meet the detection standard can be returned to the second stirring tank for circulation filtration.

[0038] The sintered filter element filter 7 with a filter core precision of 5 microns and the 1000-mesh second bag filter 8 are arranged in parallel after the sampling valve 12. The sintered filter element filter 7 has high precision, high strength, can be reused, has large flux, and is easy to clean. The arrangement of the sintered filter element filter 7 can ensure high quality of the finished product but low yield, which is suitable for the processing requirements of less and precision. The arrangement of the second bag filter 8 can meet the requirement of large demand of finished products.

[0039] A use method of a urea ammonium nitrate solution continuous filtration system, using the above urea ammonium nitrate solution continuous filtration system, the use steps comprising:

[0040] S1: using a screen 1 to filter impurities (>3.5mm) in urea raw materials;

[0041] S2: the ammonium nitrate solution uses 92% concentration raw materials, and a colorimetric detector is used to sample and analyze the ammonium nitrate solution before feeding. The colority index of the ammonium nitrate solution needs to be less than 40 degrees. Colority exceeding 40 directly leads to unqualified finished products in subsequent production.

[0042] S3: The process water is filtered by a booster pump into a disc filter system 2 to filter water particles above 50 μm, into an ultrafiltration system 3 to filter water particles between 0.001 and 0.1 μm, and into an RO reverse osmosis system 4 to filter water particles between 0.0001 and 0.001 μm. After the three-stage filtration, the process water enters a product water tank 11, and the process water in the product water tank 11 is sampled and detected. The color index of the process water needs to be less than 40 degrees, the ammonia nitrogen content needs to be less than 6 mg / l, the PH value needs to be between 6 and 9, and the electric conductivity needs to be less than 50 us / cm.

[0043] S4: The urea raw material, the ammonium nitrate solution, and the process water enter a first stirring tank 9 for stirring and mixing.

[0044] S5: The stirred urea ammonium nitrate solution enters a Y-type filter 5 to filter off oily floating matter, and then enters a second stirring tank 10 through a centrifugal pump.

[0045] S6: The urea ammonium nitrate solution is stirred again in the second stirring tank 10 to gradually cool the mixed urea ammonium nitrate solution.

[0046] S7: The urea ammonium nitrate solution enters a first bag filter 6 to filter off oily floating matter on the surface of the urea ammonium nitrate solution. The urea ammonium nitrate solution is detected by a colorimeter through a sampling valve 12. If the color index is greater than 40 degrees, a sequence valve 13 is closed and a reflux valve 14 is opened, so that the urea ammonium nitrate solution is refluxed into the second stirring tank 10 to repeat the steps S6 and S7. If the color index is less than 40 degrees, the reflux valve 14 is closed and the sequence valve 13 is opened, and the next step is entered.

[0047] S8: If the required finished urea ammonium nitrate liquid is transported by tank or liquid bag, and the single demand is ≥20T, the urea ammonium nitrate liquid enters a second bag filter 8 for filtration. If the impurity content of the required finished urea ammonium nitrate liquid is less than 5 μm, the urea ammonium nitrate liquid enters a sintered filter element filter 7 for filtration. After filtration, the finished product is collected and stored in a finished product tank.

[0048] In order to ensure the durability of the equipment, the vibrating mechanism is used to clean the impurities on the screen 1 after the equipment is closed.

[0049] When the outlet pressure of the centrifugal pump between the Y-type filter 5 and the second stirring tank 10 is lower than 0.8 Mpa, the centrifugal pump is cleaned.

[0050] When the pressure difference between the front and rear ends of the sintered filter element filter 7 is greater than 0.2 Mpa, the filter element of the sintered filter element filter 7 is cleaned.

[0051] The above examples and drawings are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. The present application is described in detail with reference to the preferred embodiments. It should be understood by those skilled in the art that the changes, modifications, additions or substitutions made by those skilled in the art within the spirit and principle of the present application do not depart from the purpose of the present application and should also fall within the protection scope of the present application. Other related technical structures not described in detail in the present application are the existing technologies in the art.

Claims

1. A continuous filtration method of a urea ammonium nitrate solution, characterized by, The method comprises the following steps: S1: using a screen to filter out impurities with a diameter greater than 3.5 mm in the urea raw material; S2: the ammonium nitrate solution uses 92% concentrated raw materials, and a colorimetric detector is used to sample and analyze the ammonium nitrate solution before feeding, and the colorimetric index of the ammonium nitrate solution needs to be less than 40 degrees; S3: the process water is filtered through a booster pump into a disc filter system to filter out particles in the water with a diameter greater than 50 μm, into an ultrafiltration system to filter out particles in the water with a diameter of 0.001-0.1 μm, and into an RO reverse osmosis system to filter out particles in the water with a diameter of 0.0001-0.001 μm; after three-stage filtration, the process water enters a product water tank, and the process water in the product water tank is sampled and detected, and the colorimetric index of the process water needs to be less than 40 degrees, the ammonia nitrogen content is less than 6 mg / l, the PH value is 6-9, and the electric conductivity is less than 50 us / cm; S4: the urea raw material, the ammonium nitrate solution and the process water enter the first stirring tank for stirring and mixing; S5: the stirred urea ammonium nitrate solution enters a Y-type filter to filter out bag strips and impurities with a diameter greater than 60 mesh and less than 3.5 mm, and then enters the second stirring tank through a centrifugal pump; S6: the urea ammonium nitrate solution is stirred again in the second stirring tank to gradually cool the mixed urea ammonium nitrate solution; S7: the urea ammonium nitrate solution enters the first bag filter to filter out oily floating matter on the surface of the urea ammonium nitrate solution, and the urea ammonium nitrate solution is detected by a colorimetric detector through a sampling valve; if the colorimetric value is greater than 40 degrees, the sequence valve is closed and the reflux valve is opened, so that the urea ammonium nitrate solution is refluxed into the second stirring tank to repeat steps S6 and S7; if the colorimetric value is less than 40 degrees, the reflux valve is closed and the sequence valve is opened, and the next step is entered; S8: if the required finished urea ammonium nitrate liquid is transported by a tank car or a liquid bag and the single demand is greater than or equal to 20 tons, the urea ammonium nitrate liquid enters the second bag filter for filtration; if the impurity content of the required finished urea ammonium nitrate liquid is less than 5 um, the urea ammonium nitrate liquid enters the sintered filter element filter for filtration; after filtration, the finished product tank is filled for collection and preservation.

2. The process for continuous filtration of urea ammonium nitrate solution according to claim 1, characterized by the fact that: After the equipment is closed, the screen is cleaned by using a vibrating mechanism to clean the impurities on the screen.

3. The continuous filtration process for urea ammonium nitrate solution according to claim 1, characterized by: When the outlet pressure of the centrifugal pump between the Y-type filter and the second stirring tank is less than 0.8 Mpa, the centrifugal pump is cleaned.

4. The continuous filtration process for urea ammonium nitrate solution according to claim 1, characterized in that: When the pressure difference between the front and rear ends of the sintered filter element filter is greater than 0.2 Mpa, the filter element of the sintered filter element filter is cleaned.

5. A filtering system for continuously filtering the urea ammonium nitrate solution according to any one of claims 1 to 4, comprising a first stirring tank and a second stirring tank, and the first stirring tank is provided with a urea feeding pipe, an ammonium nitrate solution feeding pipe and a process water feeding pipe; characterized in that: a screen is arranged on the urea feeding pipe, and disc filter system, ultrafiltration system and RO reverse osmosis system are arranged in sequence on the process water feeding pipe; A Y-type filter is arranged on the connecting pipeline between the first stirring tank and the second stirring tank, the second stirring tank is provided with a discharging pipeline, the discharging pipeline is provided with a first bag filter, an outlet pipeline of the first bag filter is provided with a sampling valve, and a sintered filter element filter and a second bag filter are arranged in parallel after the sampling valve.

6. The filtration system of claim 5, wherein: The screen mesh has a screen hole diameter of 3.5 mm, and is provided with a vibrating mechanism.

7. The filtration system of claim 5, wherein: A water production tank for detecting process water is arranged between the RO reverse osmosis system and the first stirring tank, and a water pump is arranged on an outlet pipeline of the water production tank.

8. The filtration system of claim 5, wherein: The Y-type filter adopts a 60-mesh filter element, and a water pump is arranged on an outlet pipeline of the Y-type filter.

9. The filtration system of claim 5, wherein: The first bag filter adopts a 600-mesh filter element, a water pump is arranged on an outlet pipeline of the first bag filter, the second bag filter adopts a 1000-mesh filter element, and the filter element precision of the sintered filter element filter is 5 microns.

10. The filtration system of claim 5, wherein: A three-way pipe is arranged on the sampling valve outlet pipeline, the sampling valve outlet pipeline is arranged in the water inlet of the three-way pipe, a backflow pipeline for backflow to the second stirring tank is arranged in the first water outlet of the three-way pipe, the water inlets of the sintered filter element filter and the second bag filter are arranged in the second water outlet of the three-way pipe, a sequence valve is arranged on the water inlets of the sintered filter element filter and the second bag filter, and a backflow valve is arranged on the backflow pipeline.

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