Reaction system for preparing polymer polyol and method for preparing polymer polyol

A method for preparing polymer polyol, wherein a reaction system for preparing polymer polyol comprises a reactor (4), a reaction cavity of the reactor (4) is divided by a partition plate (43) into a first reaction chamber (41) and a second reaction chamber (42), the volume of the first reaction chamber (41) is greater than the volume of the second reaction chamber (42), and the top of the partition plate (43) is provided with an overflow port (44) to communicate the first reaction chamber (41) and the second reaction chamber (42) with each other;

• and the method comprises the following steps:
• 1) In a first reaction stage:
• adding a first reaction material to the second reaction chamber (42) and heating the first reaction material;
• when the temperature of the first reaction material reaches a first temperature, continuously adding part of a second reaction material to the second reaction chamber (42), and maintaining the reaction temperature at the first temperature for a time period;
• 2) In a second reaction stage:
• maintaining the reaction temperature at a temperature near the first temperature by stopping adding the second reaction material to the second reaction chamber (42) when the reaction temperature of the reaction system in the first reaction stage rises by 0.5° C. or more, continuously adding the remaining second reaction material to the first reaction chamber (41), reacting the second reaction material with the first reaction material and/or the second reaction material and/or a reaction product thereof that overflows from the second reaction chamber (42) to the first reaction chamber (41) through the overflow port (44);
• and
• 3) In an aging stage:
• after the feeding of the second reaction material is completed, delivering all material remaining in the second reaction chamber (42) after the second reaction stage to the first reaction chamber (41) to mix with the material in the first reaction chamber (41) and age.