Cleaning of Vessels and Other Equipment

Occasional cleaning of equipment of a process plant is unavoidable in order to remove fouling products (scale) and dirt. This serves to maintain the functioning of the plant and the product quality. Cleaning mostly requires work in narrow spaces especially if vessels are concerned. Specihc hazards for the personnel may then derive from residual harmful substances still present. Therefore systems are preferred which automatically carry out the necessary cleaning procedures such as  

They make access of personnel to narrow confined spaces unnecessary. Additionally, there are a number of procedures which reduce the necessity for manual cleaning by plant personnel and thus their exposure  

However, it should always be borne in mind that high pressure and ultra high pressure jets are capable of easily cutting solid materials. Hence, they lead to severe and often lethal injuries when persons are hit. The high pressure jet liquids are often contaminated and can enter deeply into body tissue thus causing inflammations in addition to injuries. The equipment should therefore only be used by informed and experienced personnel. If possible, mechanically guided jet cleaning devices should be applied. 

In any case the necessary protective measures have to be adopted and maintained during work. This includes as well the use of personal protective equipment. 

In order to repair a valve of a biogas plant a worker goes down into a pit. However, hydrogen sulphide had escaped inadvertently from the plant. Since it is a heavy gas (density relative to that of air 1.2), it had accumulated in the pit. Two minutes later a rescuer arrives who is equipped with a self-contained breathing apparatus (independent from the surrounding air). 

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