2. Raw material stirring: stir the prepared raw materials evenly to improve the uniform fertilizer efficiency content of the whole fertilizer particles.
3. Granulation of raw materials: send the evenly stirred raw materials to a granulator for granulation (drum granulator or extrusion granulator can be used).
4. Drying of particles: the particles made by the granulator are sent to a dryer to dry the moisture contained in the particles, so as to increase the strength of the particles and facilitate storage.
5. Particle cooling: The temperature of dried fertilizer particles is too high and it is easy to agglomerate. It is easy to bag, store and transport after cooling.
6. Particle classification: the cooled particles are classified, the unqualified particles are crushed and granulated, and the qualified products are screened out.
7. Finished film: coating qualified products to increase the brightness and roundness of particles.
8. Packaging of finished products: Bag the coated particles, that is, the finished products, and store them in a ventilated place. (1) tubular reactor technology
This set of NPK production equipment is the advanced patented technology of "tubular reactor" of Norwegian Hydro Company introduced by Songshan Heavy Industry, including hardware and process software package. Compared with the traditional neutralization reaction tank+ammoniation granulation process, this patented technology has great advantages in product quality. Characterized in that:
● Advanced granulating technology.
According to the nutrient requirements of compound fertilizer products, all kinds of liquids and Guyuan materials measured by microcomputer are synthesized into compound fertilizer by chemical reaction in granulator and tubular reactor, and completely spherical particles are obtained by continuous wrapping in ammoniation granulator. All kinds of nutrient ratios can meet the standard, which is stable and guaranteed.
● The nutritional components of the product granules are equally balanced.
Due to chemical synthesis and granulation, the nutrient content of granular fertilizer is the same as that of the label, which can provide nitrogen, phosphorus, potassium and other nutrients for crops at the same time according to a certain proportion to ensure the balanced growth of crops.
● The physical properties of the product are good, and the particle size distribution of the product is uniform, and 90% are particles with a particle size of 2-4 mm; The particles have high strength and good fluidity, and are not easy to break during transportation, storage and stacking. The third design institute of the Ministry of Chemical Industry also absorbed the advanced technology of French AZF company and Spanish INCRO company in the engineering design, and further optimized the design performance of the device.
(2) Granulation technology of molten urine
The device adopts molten urine granulation technology, which can meet the requirements of producing various high-nitrogen nutrient compound fertilizers on the one hand; On the other hand, the granulation quality can be further improved, so that the nitrogen content of fertilizer particles is more balanced, the surface is smooth and the gloss is high.
(3) DCS control technology
● According to the production characteristics of this plant, phosphoric acid and NPK control rooms are set up and distributed control system (DCS) is adopted. Through the dynamic picture of the whole process, centralized monitoring is carried out for grinding, phosphoric acid, sulfuric acid/phosphoric acid tank farm, NPK and other devices. The CRT in the control room can display various process parameters and the running state of the pump; The automatic control of important process parameters and the start and stop of main pump can be carried out in the control room; Using the powerful function of DCS, you can print production reports of various specifications regularly or in time; Can timely display parameter overrun, production accident or system failure; Ability to store and display historical trends and provide rich operational guidance information; Easy to operate and maintain.
Main functions of DCS operation station:
Process parameter display and over-limit alarm
The control loop is easy to operate, such as adjusting the set value.
Real-time recording and trend recording of important parameters
Operation and display of running equipment
Switch operation and position display of valve
Self-diagnosis of system fault
Process flow screen display
Screen display of control loop
Print the report regularly.
DCS control technology this production device adopts DCS microcomputer control technology in the whole process of raw material batching, production process adjustment and control, which significantly reduces the phenomenon of large deviation of nutrition ratio and unstable production operation caused by inaccurate manual or mechanical batching and human operation errors. The stable production of the device is ensured, and the nutritional ratio of the product is accurate and qualified.
(4) coating and wrapping technology
The coating system of the device adopts the latest scientific research achievement of National Fertilizer Catalyst Engineering Research Center-active coating agent, and selects high-quality coating powder. After coating, the product can effectively prevent moisture absorption and particle adhesion and agglomeration, and has good fluidity, which is convenient for fertilization operation, further improves the appearance quality and meets the quality requirements of users for internal quality and external beauty.
The above two technologies-ammonium phosphate slurry and molten urine double spray granulation technology, are unique among the domestic similar devices known at present. The 200,000-ton/year compound fertilizer plant of Fujian Sinochem Zhisheng Fertilizer Co., Ltd. was put into operation in April of 200 1 year. After more than a year of production practice, the production level has been gradually improved, and the internal quality of the products has made great progress, but the products are caked after leaving the factory. The device stores about 5000 tons of finished products, which is equivalent to about 7 days' storage. With the output gradually reaching the production standard, the contradiction of product inventory is increasingly prominent; In order to fundamentally solve the problem of product caking and small inventory capacity, after repeated discussions and studies, it is planned to build a finished product bulk warehouse and supporting facilities. At present, in the domestic market, our company is the second domestic investment company with a total investment of 2,090,700 yuan. The construction of bulk warehouse has the following characteristics:
● Increase storage capacity.
Compared with the original bagged warehouse, the storage capacity of bulk warehouse increased from 2,000 tons to 4,030 tons, an increase of 1.0 times; A simple bagged finished product warehouse of 864㎡ was added, and the reserve was increased by about 900 tons. Storage days increased from 3 days to 8 days.
● Balanced nutrition
Due to the measurement deviation of raw materials, human factors in operation, etc. The instantaneous fluctuation of nutritional components of products often occurs, but it is relatively average over a period of time. Therefore, after entering the bulk warehouse, it can play the role of buffering fluctuation and distributing nutrition evenly, and ensure that the nutrition of the factory products is balanced and up to standard.
● Reduce product caking.
Because the physical and chemical reaction and salt bridge occur constantly in the storage process of compound fertilizer, it is easy to agglomerate in the packaging bag and escape when it enters the bulk bin, and the salt bridge is easy to be destroyed during homogenization and mixing, so the caking phenomenon of the product after homogenization in the bulk bin can be greatly reduced.
● Reduce transshipment times and transshipment costs.
Because the finished products in bulk warehouse are changed from bagged to bulk, they can leave the factory in time after packaging, reducing or avoiding secondary transshipment and reducing transshipment cost.
● Reduce packaging displacement and improve packaging efficiency.
Because the packaging capacity of the packaging machine is small, the output is large. After adopting bulk warehouse, the capacity of packaging machine can be fully exerted and centralized packaging can be carried out. The packing shift can be changed from three shifts to two shifts, which can improve the packing efficiency and reduce the packing cost.
● After using bulk warehouse for balanced variety production, products with different specifications can be packaged according to different needs of users, which can reduce the impact of frequent variety replacement on production.
● Improve the appearance quality of packaged products.
Bulk warehouse can ensure the timely delivery after packaging to a great extent, and avoid the obsolete feeling after bagged storage, which is beneficial to the appearance and image of products.
Equipment modification
● Dissolution: The problem of product dissolution was completely solved through careful selection and reasonable proportion of fillers and moderate addition of solvents to insoluble varieties.
● Hardening:
Answer: In 2003, when the plant was overhauled, the company consulted domestic experts on phosphate and compound fertilizer, and carried out modification according to the secondary drying process of the plant products in the same period in China, so that the water content was reduced to below 65,438 0.2%, effectively controlling the salt dissolution of the products caused by free water, forming crystal bridges and easily forming secondary crystals;
B: In cooperation with the Catalyst Research Center of Fuzhou University, the newly developed new active wrapping agent (surfactant) was tested and verified in the products produced by the device to prevent surface crystallization. After the test, the compaction rate is below 10%, that is, the material is in a flowing state, and the effect is remarkable.
C: refitting the wrapping equipment: after the product is wrapped, the surface wrapping film will be easily damaged during packaging, and this unfavorable factor can be eliminated by wrapping before packaging; The wrapping material is more stable and the fuel injection quantity is constant, which can play a better wrapping effect;
D: Adding wrapping powder: inert materials such as liquid wax stone powder and talcum powder are selected to form an isolation film on the surface to reduce the mutual contact of materials. Through the above measures, the current hardening phenomenon has been obviously improved.
Low chromatic aberration:
A: Choose raw and auxiliary materials and stabilize supply sources and channels, mainly MAP, K 2 SO 4 and fillers.
B: Strengthen the incoming inspection of raw materials that affect the color difference by purchasing chromaticity testing instruments, formulate supply indicators, put forward requirements for supply indicators, and strictly control the incoming inspection of raw materials;
C: By reasonably blending raw and auxiliary materials with different colorities, the chromaticity of the products manufactured by the factory tends to be consistent.