Automatic temperature control system for urea melting spraying granulation production

Abstract

The invention discloses an automatic temperature control system for urea melting spraying granulation production, which comprises a melting tank and an electric control unit, a temperature sensor is arranged in the melting tank, the electric control unit comprises a controller for adjusting the heating temperature of the melting tank, and the electric control unit further comprises a temperature acquisition signal amplifying circuit, a feedback stability adjusting circuit and a filtering noise reduction circuit, the feedback stability regulation circuit is adopted to perform sampling feedback regulation on an output signal of the following amplification assembly, so that temperature drift imbalance in the signal amplification processing process is effectively avoided, error voltage is eliminated, and the self-adaptive regulation capability of the system is improved; the infrared temperature measurement sensor is adopted to collect the heating temperature in the melting tank, temperature collection signals are sent to the electric control unit to be conditioned, the defects that in the prior art, the time lag of a temperature sensor is high, and temperature control feedback is not timely are effectively overcome, temperature collection signal processing is accurate and effective, the precision of a temperature control system is high, and the system is suitable for popularization and application. And the production quality of urea melting spraying granulation is effectively improved.

Description

technical field [0001] The invention relates to the technical field of compound fertilizer production equipment, in particular to an automatic temperature control system for the production of urea melt-spraying and granulation. Background technique [0002] At present, domestic compound fertilizer production mainly includes three processes: extrusion method, agglomeration method and slurry method. At present, the extrusion method has a small output; the slurry method is mainly used in a small number of large enterprises due to factors such as production scale and investment scale; and the agglomeration method has the characteristics of simple process, low investment and convenient operation. Most of the manufacturers use it, but the disadvantage is that there are many empirical factors in production, and the product has relatively large limitations on raw materials, especially the production of compound fertilizers with high nitrogen content and high urea, which is very diff...

AI Technical Summary

Problems solved by technology

The output of the extrusion process is small at present; the slurry process is mainly used in a few large enterprises due to factors such as production scale and investment scale; Most manufacturers adopt it, but its disadvantage is that there are many empirical factors in production, and the product has relatively large limitations on raw materials, especially the production of compound fertilizers with high nitrogen content and urea is very difficult.

The production process principle of urea melt spray granulation is between the agglomerate method and the slurry method, and has both advantages, which can significantly increase the output, and the product particles are round and smooth, high in strength, and not easy to agglomerate, such as Chinese patent CN 102731171 B discloses a solid urea melting and spraying granulation system, which rapidly melts the solid urea entering the melter by steam to form urine without dissolving in water and avoiding the loss of effective nutrients; and during the solid urea melting process There are strict process indicators, for example, the temperature of the urine in the melting tank must meet the set temperature range of the system to ensure the smooth surface of the sprayed particles and prevent agglomeration. However, the existing temperature control system of the melter usually uses a thermocouple as a temperature sensor. Temperature acquisition not only has the defects of high time lag and untimely temperature control feedback, but also tends to generate temperature drift and imbalance in the process of signal amplification processing, and the generated common mode noise will be output by gain later, becoming an error voltage, causing temperature detection There is a deviation between the value and the actual temperature of the urine in the melting tank, which seriously affects the accuracy of the temperature control system, and then affects the production quality of melt spray granulation

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