Spray Coverage Testing: Eliminate Spray Shadows

Agitators, mixing blades, baffles and coils can be a challenge for tank cleaning. These tank obstructions cause spray shadows, which are areas within the tank that are not properly cleaned. Some of these areas are located underneath the internal components, which can be difficult to clean.  Here are some recommendations that may help you overcome these tank obstructions:

  • Remove the obstruction before cleaning. In order to accomplish this you will need to make this part of your SOP that includes removal, reinstallation and a COP system to properly clean it.
  • Position multiple tank nozzles in different locations to avoid spray shadowing.  For these cleaning tasks, Lechler offers rotational tank cleaning nozzles.   Below is a video showing the effect of placing three rotational nozzles inside the tank.   You can see the line of spray being obstructed by the agitators but when multiple nozzles are used they  compensate for the shadowing effect to provide complete spray coverage.

Although placing multiple nozzles inside a tank helps avoid spray shadowing, greater challenges such as cleaning underneath the agitators or blades can be very difficult. Often cleaning underneath the agitators or blades can be very difficult. For this task we offer the compact PopUp Whirly rotating cleaning nozzle for cleaning in confined spaces. The unique feature of this system is that the nozzle appears only during the cleaning process. The nozzle is installed flush inside the tank wall. With a fluid pressure of approximately 15 psi in the supply line, it automatically pops out of the housing and starts to rotate spraying with flat jets. The recommended operating pressure is 30 psi. If the pressure falls as a result of the pump being switched off or a valve closing, the rotor is retracted to a closed position again by a spring. Operation with foam is also possible.

Below is an example of one of our PopUp Whirly removing chocolate sauce.

XactClean reduces cleaning cycle by 73%
XactClean HP Plus

A world leading chocolate malt beverage company produces a product that is made in wet mixing tanks approximately 10 ft. in diameter x 13 ft. tall. Each tank contains an agitator located directly in the center of the tank.

Spray coverage testing - Malt residue in mixing tank

The Challenge

The challenge for this cleaning application is to select a nozzle that will remove sticky and persistent malt residue from the tank walls and agitator as seen in Image 1.  Manual cleaning is still required for stubborn baked on stains.

Leftover residue in tank after cleaning

Spray Coverage Testing Process

  1. Fill tank with recycled water at 90°C and soak
  2. Rinse using fresh water at 90°C
  3. Run 2 static sprayballs for a total cleaning cycle of 60 minutes
  4. Manually clean left over residue inside tank and on agitator as seen in image
Spray coverage testing - Clean tank result

Improvement and results

Both static sprayballs were replaced with Lechler’s XactClean™ HP.  The total cleaning cycle time required was only 16 minutes and very little residue was left inside as seen in Image 3.

  • As a result, the total cleaning cycle was reduced by 44 minutes!
  •  The original procedure for filling and rinsing is no longer required, which reduces overall water consumption and time.   The agitator is entirely clean from any residue!
  • The XactClean™ HP provides controlled rotation of spray and requires less water and saves on time in comparison with static sprayballs.

Consult with us

We utilize a tank cleaning simulation software which allows you plan your tank cleaning. To do this, we replicate the tank geometry in the software and then simulate the spraying operation. Operation of all Lechler tank cleaning nozzles can be simulated – from the static spray ball to the high-impact tank cleaning machine. The result of the simulation is documented and provided in a PDF or video file. Simulation with TankClean can already be used as the basis for optimum cleaning in the planning phase of new tanks, but is also suitable for optimizing existing tank cleaning processes.

Are you still interested in learning more? Contact us for more information. 
Lechler's tank cleaning experts are here to help you with every step of the process.

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