Tank cleaning

Purpose of the tank cleaning process? Duration of the complete cleaning cycle?

A common answer is "A completely clean tank in as little time as possible." It is not always that simple though, there are several factors to consider in order to achieve effective tank cleaning. By optimally dimensioning the tank cleaning process, it is possible to increase efficiency, reduce the amount of cleaning agents used, save time and reduce overall costs.

As a first step, the following questions need to be answered:

• Does the tank need to be 100% clean or is it suffient to rinse the tank between batches?
• Should the whole tank be cleaned or only part of the tank?
• Should product be recovered from the tank?
• Is the duration of the cleaning cycle important?

How the tank cleaning process is optimised and how to select the most suitable product depends on type of business, the process and any specific requirements, see examples below.

Example 1

Blue colour is produced in a process tank and the same blue colour is always made in the tank. There is a short time between batches, so the remaining colour does not have time to dry.

In this case, there is no need to clean the tank to 100%, as a small amount of residual colour will not affect the next batch. It may therefore be sufficient to simply rinse the tank between batches. For maximum process efficiency, the time between batches in this example may be more important than the washing result itself.

A tank cleaning nozzle with a short rinse cycle and minimum fluid consumption may be suitable for this specific process.

Example 2

The tank contains a high value pharmaceutical or chemical product. There is a risk that the product may ignite when it dries. Only when the product is damp or wet is it stable.

In such a circumstance it might be that product recovery of the high value residue left in the tank is very important. It might also be vital to ensure that after the initial production process is finished, the cleaning device needs to use very low volumes of liquid to keep the remaining residues damp to prevent any explosion risk.

A tank cleaning nozzle with low liquid consumption makes it less costly to recycle the product. In this example, the tank cleaning nozzle fulfils two functions in a single wash cycle.