白米水冷却降温提高抛光后整精米率

Improving head rice rate with water cooling process

为解决白米抛光前风冷降温工艺过程中产生裂纹米的问题,提出抛光前白米水冷却降温工艺。采用自制的白米水冷却试验台,研究水冷却降温过程中冷却水水温、冷却时间与冷却后米温的关系,探究白米水冷却降温过程的综合传热系数,以期为白米水冷却降温设备的设计和应用提供参考依据,并以抛光后大米的整精米率为考核指标,将水冷却与风冷却降温工艺进行了对比试验。用Excel软件和SAS软件处理试验数据,结果表明水冷却降温过程中冷却水温度、冷却时间对冷却后米温影响显著,白米水冷却降温的综合传热系数大小为181.13kJ/(m2·℃·h),白米在适宜碾米的含水率(15%～16%)条件下,经水冷却降温后抛光的整精米率可较风冷却降温提高4～9%。研究结果可为白米的水冷却降温工艺提供参考依据。

In order to reduce the formation and growth of cracks within milled rice kernel caused by air cooling before the further polishing process, a new technical process was explored. The influences of temperature of cooling water and cooling time on the final temperature of rice, and the effects of water cooling method on the head rice rate of polished rice were investigated on a self-design test-bed for the water-cooling rice. And the complex heat transfer coefficient of rice with water cooling method was determined. The head rice rate of rice after the polishing process was abtained with water and air cooling method respectively. Excel and SAS software were used to analyze the experimental data. The results showed that, the temperature of cooling water and cooling time had significant effects on the final temperature of rice; the complex heat transfer coefficient of rice of 181.13 kJ/（m2？℃？h） was determined; the head rice rate with water cooling was 4 to 9 percentage higher than that with air cooling method when the moisture content of the brown rice was 15%-16%. The results can provide a theoretical basis for water cooling method of rice and design of water cooling equipment.