Automated tank cleaning offers many benefits: increased productivity, reduced maintenance time and labor costs, decreased chemical and water costs, improved worker safety and cleaner tanks.

Start by Selecting the Right Tank Cleaning Nozzle

Address These Factors First to Identify the Best Tank Wash Solution for your Application

Residue

Is the substance sticky or easily cleaned? Can it be dissolved by the cleaning liquid? What is the level of impact required to dissolve it and wash it away?

Level of Cleaning

• Rinsing: Majority of residue is loosened and removed with water.
• Cleaning: Remaining residue is loosened and removed with water and cleaning agent.
• High impact cleaning: Utilizes the impact of the spray to break apart difficult and stubborn residues and wash them away.
• Sanitizing: Chemical agent is applied to all surfaces to kill microorganisms to an acceptable level.
• Disinfecting: Kills most bacteria with the exception of spores.
• Sterilizing: Eliminates all forms of life.

Cleaning Solution and Required Temperature of the Cleaning Liquid

Chemical additives are typically used to remove contaminants, improve tank wettability and reduce droplet formation. Heat can improve the cleaning action of many water-based detergent chemicals.

Tank Size and Spray Distance

Spray distance is usually measured in terms of the tank diameter, however, it is important to consider the tank length and height. For example, if a tank is 20 ft. (6 m) in diameter and 40 ft. (12 m) long, use two tank washers that specify 20 ft. (6 m) or a single tank washer that can clean up to 40 ft. (12 m).

Flow Rate

Use the lowest possible flow rate to achieve your cleaning objectives. The lower the flow, the less liquid required, less effluent for disposal and less energy consumed. A general guideline is to work with a minimum of 0.2 gal/min/ft2 (7 l/min/m2).

A more moderate recommendation is 0.4 gal/min/ft2 (15 l/min/m2). This guideline generally applies to stationary nozzles where all the surfaces of the tank are sprayed at the same time. Nozzles that rotate usually contact part of the tank at one time, thus less flow rate is needed.

Spray Impact

Hard-to-clean residues require a higher level of impact than residues that are easily rinsed. It is difficult to determine the exact impact value of each tank wash nozzle.

However, a general rule of thumb can help you increase the level of impact when determining the optimum cleaning requirements for your application. Increasing flow rate is more effective than increasing pressure. As the chart below shows, doubling the flow rate increases impact as much as 100%, while doubling pressure provides only 40% more impact.