As the reverse reaction occurred in urea hydrolysis production which included ammonia

carbon dioxide and steam during the process of urea hydrolysis

the ammonium carbamate was generated so that the phenomenon of blockage occurred in the transmission system of gaseous products. In order to inhibit the generation of ammonium carbamate

systematical research were carried out and the anti-blocking measures were proposed. The results show that

with the whole of components of urea hydrolysis products existed as gas state

it was difficult to generate the ammonium carbamate. If the steam condensed into liquid in urea hydrolysis production

it was easy to generate the ammonium carbamate. At certain temperatures

the yield of the ammonium carbamate increased with the pressure.The pressure should be adjusted according to the temperature of gaseous products

so as to prevent steam from condensing and the measures of preventing temperature drop needed to be applied. The pressure control and loop pipe measures were adopted in two 600 MW units and two 300 MW units in Ezhou Power Generation Company. It was demonstrated that

adjusting the pressure of pipeline could effectively avoid the steam condensation

using annular pipeline to supply ammonia could not only prevent steam from condensation because of local temperature drop and flow dead zone

but also realize checking of the pressure pipieline without stopping the car in the condition of failure. The above measures effectively guaranteed the normal operation of the ammonia transport system

which had a reference for solving the problem of blockage in pipieline of urea hydrolysis gaseous products.