Hazards linked to the operation of powder charging in vessels containing flammable vapour atmospheres are well known. As well, several industrial solutions exist to avoid these hazards and perform such operations in a safe way, meaning that electrostatic ignition sources are reliably avoided.

However, in some industrial situations, the proposed solutions are difficult to implement due to the characteristics of the vessels, for instance not tight enough to implement a reliable inerting strategy; the layout of the location, for instance not enough room to install additional equipment; or services available at site level, for instance lack of vacuum or nitrogen supply in some plants.

For these reasons, a detailed assessment has been performed focusing in the following points as those linked to the generation of effective electrostatic ignition sources:

1. Nature of the liquid generating the flammable vapours.

2. Characteristics and use of bags containing powders being charged.

3. Powder falling into the vessel.

4. Powder clouds in the vessel.

5. Powder layers generated on top of the liquid.

The assessment included a theoretical approach confirmed by experimental tests in site and lab.

The paper will describe the detailed assessment performed in each of the identified points, present the experimental results and describe the final proposed solutions to ensure safety during powder charging to vessels containing flammable vapour atmospheres. Current situation requires adding powders from bags through manholes, which is considered as a non-acceptable practice from a risk assessment point of view.

众所周知，与在含有易燃蒸气环境的容器中装粉有关的危险。此外，存在多种工业解决方案来避免这些危险并以安全的方式执行此类操作，这意味着可靠地避免了静电点火源。

然而，在某些工业情况下，由于船舶的特性，建议的解决方案难以实施，例如不够紧密，无法实施可靠的惰化策略；位置的布局，例如没有足够的空间来安装额外的设备；或现场可用的服务，例如某些工厂缺乏真空或氮气供应。

由于这些原因，已经进行了详细评估，重点关注与有效静电点火源的产生相关的以下几点：

1. 产生易燃蒸气的液体性质。

2.装装粉末的袋子的特点和用途。

3. 粉末落入容器中。

4. 容器中的粉末云。

5. 液体顶部产生的粉末层。

评估包括通过现场和实验室的实验测试证实的理论方法。

本文将描述在每个确定的点进行的详细评估，展示实验结果并描述最终提出的解决方案，以确保在将粉末装入含有易燃蒸气气氛的容器中时的安全性。目前的情况需要通过人孔从袋子中添加粉末，从风险评估的角度来看，这被认为是不可接受的做法。