What is high tower granulation method?
High-tower granulation is a technology for manufacturing granular materials, mainly used in the fertilizer and chemical industries. The specific process of high-tower granulation is to heat and melt the raw materials (such as solid urea or ammonium nitrate) or use the evaporated and concentrated melt, and then add phosphate fertilizers, potash fertilizers, fillers, and additives to the melt to make a mixture. Pulp. High tower granulation feature high capacity and uniform product.
History development of high tower prilling method in the 60's
Norwegian tower spray granulation process The high tower granulation spray process was developed by NorsK Hydro in the late 1960s. It is also the earliest melt granulation technology proposed in the world, and is a typical method of directly using molten urine (or It is a compound fertilizer production process connected to the urea production line) with melt monoammonium phosphate and powdered potassium chloride as the matrix. The molten urine with w[(NH2)2CO] as 99% and the monoammonium phosphate melt prepared through the tubular reactor are pumped to the mixer at the top of the prilling tower respectively, and then mixed with the preheated chlorinated The potassium fine powder is mixed together, and then sprayed into the tower with a fan-shaped coverage through a rotating porous nozzle with a scraper at the bottom. During the process of falling by its own weight, it is cooled and solidified by the rising airflow, and the compound fertilizer is collected at the bottom of the tower.
History development of high tower granulation in the 90's
The Dutch state-owned mining company’s nitro compound fertilizer process uses ammonia and nitric acid to pressurize and neutralize to produce ammonium nitrate. The w(NH4NO3) 72% ammonium nitrate solution is concentrated in a vacuum evaporator to 92% to 94%, and then mixed with w( P2O5) 50% wet phosphoric acid is mixed, the mixture is neutralized with ammonia to n(N)/n(P)≈1, and then concentrated in a vacuum evaporator to form a 175°C melt with a water content of about 0.5%. It is pumped to the melt intermediate tank at the top of the granulation tower, mixed with preheated powdered potassium chloride in a special mixer, and the mixture is directly added to the rotating nozzle for granulation. This process requires the fineness of potassium chloride to be less than 0.5mm, the preheating temperature to be 140-160°C, and the mixing time to be very short.
Modern high tower granualtion method
The high-tower granulation process developed by Zhejiang Tongli Heavy Machinery Manufacturing Co., Ltd. and Shanghai Research Institute of Chemical Industry combines molten urine with a temperature of 135 to 145°C and other raw materials with particles smaller than 0.5 mm heated to 100 to 125°C. The mixing temperature is 115 to 135 ℃, and keep the mixing time less than 4 minutes. The eutectic point of the composite salt is used to form an NPK eutectic with good fluidity, which is then sprayed into the prilling tower through a nozzle and cooled in the air to solidify into particles.
How to set up a high tower granulation npk compound fertilizer plant?
Zhejiang Tongli Heavy Machinery Manufacturing Co., Ltd., founded in 1958, is the earliest high-tower compound fertilizer production line manufacturer in China. It has advanced R&D capabilities and manufacturing capabilities. It is now known as the largest compound fertilizer equipment export base in China and even the world.
Tongli adopts the internationally advanced melt urea carrier tower granulation technology. The key innovation point of the project is to use molten urea, phosphorus, potassium and other raw materials, fully mixed, sprayed down from the top of the tower, and naturally cooled for granulation. , the production process does not introduce moisture and discharge three wastes. The design of the twin-tower shape is a major breakthrough on the original basis. It saves civil construction investment and makes the process more connected. The product has a smooth appearance and a pinhole shape. It has anti-counterfeiting functions. It contains The amount of nitrogen is the highest in the world’s compound fertilizer manufacturing field; adding a biological enzyme preparation during the production process can effectively inhibit the decomposition and loss of various nutrients in the fertilizer in the soil, and the prospects are very bright.
