专注通风管道加工·排烟罩

通风管道变形的原因主要有以下四点：

The main reasons for the deformation of ventilation ducts are as follows:

1、镁水泥在自然养护条件下其体积是一个连续膨胀过程，其线膨胀率为0.1-0.2%，体积膨胀率约为1%。

1. Magnesium cement undergoes a continuous expansion process under natural curing conditions, with a linear expansion rate of 0.1-0.2% and a volume expansion rate of approximately 1%.

2、菱镁矿在服烧过程中不可避免地产生局部过烧，使一部分MgO呈死烧状态，过烧的MgO水化过程很慢，当已形成强度的水泥石中的MgO再遇水进行水化时，生成Mg(OH)2，体积膨胀120%。

2. During the sintering process of magnesite, local overburning is inevitable, causing a portion of MgO to be in a dead burning state. The hydration process of overburned MgO is slow. When MgO in the cement stone that has formed strength is hydrated again with water, it generates Mg (OH) 2, with a volume expansion of 120%.

3、轻烧氧化镁中游离CaO水化时体积膨胀90%，而卤片中存在着 SO42-，当Ca(OH)2转化成石膏时，固体体积将增加2倍以上，导致制品变形，这也是限制轻烧氧化镁中游离CaO含量、卤片中SO42-含量的原因。

3. During the hydration of free CaO in lightly burned magnesium oxide, the volume expands by 90%, while there is SO42- present in the brine sheet. When Ca (OH) 2 is converted into gypsum, the solid volume will increase by more than twice, causing deformation of the product. This is also the reason for limiting the content of free CaO in lightly burned magnesium oxide and SO42- in the brine sheet.

4、MgO-Mg-C12-H2O系统水化过程是一个强烈的放热反应过程，而生产的管道体积又大，若环境温度较高，则反应升温过程，板材本体温度过高，反应不充分，造成较大的结晶应力和热膨胀应力，使制品体积膨胀。

4. The hydration process of MgO-Mg-C12-H2O system is a strong exothermic reaction process, and the volume of the produced pipeline is large. If the ambient temperature is high, the reaction temperature will rise, and the temperature of the board body will be too high, resulting in insufficient reaction and causing significant crystallization stress and thermal expansion stress, causing the volume of the product to expand.

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