Production Preparation

Before feeding, carefully inspect the relevant equipment, pipelines, pumps, valves, safety devices, etc. for any abnormalities; Electricity and gas supply

Whether it is normal; Check whether the raw and auxiliary materials are complete and qualified; Confirm that there is no pollution during the raw material delivery process.

Process Flow

1. Dissolution operation section

Start the water inlet control system, complete the system parameter settings, and inject the set amount of pure water into the urea dissolution tank. After adding pure water, turn on the pulse stirring device and add the specified amount of solid urea into the dissolution tank through the feeding device. After the feeding is completed, continue pulse stirring for 1 hour.

Process control indicators:

Inlet water temperature: Process control temperature 30 ℃± 10 ℃.

Water inflow quantity: automatically controlled through flow meter settings.

Mixing timing and time: At the beginning of feeding, turn on the pulse device. After the feeding is completed, continue to pulse for 1 hour.

Feeding quantity: Feed according to the formula requirements.

2.  Primary filtration

By sequentially controlling the discharge through the on-site control system, the dissolution tank material is filtered into the intermediate tank through a set of (1, 2, 3, and 4) filtration groups. During the filtration process, the filtration flow rate is 15-80m3/h, and the filtration pressure does not exceed 0.4MPa. At the same time, the pressure value during the filtration process should be recorded.

Process control indicators:

Filtration flow rate: 40-80m3/h, during the filtration process, the filtration flow rate can be adjusted through the valve to be within the standard range. There is a chain relationship between the flow rate and filtration pressure. If the filtration pressure exceeds 0.4MPa, the flow rate can be adjusted to ensure that the filtration pressure is qualified. However, if the filtration pressure cannot be reduced within the standard range through pressure adjustment, the filtration needs to be stopped and the filter element needs to be replaced in a timely manner after replacing the filtration group.

Filter pressure: ≤ 0.4MPa

3. Secondary filtration

By sequentially controlling the discharge through the DCS system, the intermediate tank material is filtered into the finished product tank through a set of (5, 6, 7, 8) filtration groups. During the filtration process, the filtration flow rate is 40-80m3/h, and the filtration pressure does not exceed 0.4MPa. At the same time, the pressure value during the filtration process should be recorded.

Process control indicators:

Filtration flow rate: 40-80m3/h, during the filtration process, the filtration flow rate can be adjusted through the valve to be within the standard range. There is a chain relationship between the flow rate and filtration pressure. If the filtration pressure exceeds 0.4MPa, the flow rate can be adjusted to ensure that the filtration pressure is qualified. However, if the filtration pressure cannot be reduced within the standard range through pressure adjustment, the filtration needs to be stopped and the filter element needs to be replaced in a timely manner after replacing the filtration group

Filter pressure: ≤ 0.4MPa

Overall , the production of urea is a strict process that uses a multi-stage filtration process to ensure the stability of quality .