Pharmaceutical Industry

• Cleaning glass lined reactors, bioreactors and fermentation tanks
• Antimicrobial spraying
• Blister pack cooling

Sinner’s Circle

The Sinner’s circle illustrates the interplay between the four main factors for successful cleaning:

• Chemistry (choice of cleaning agent)
• Mechanical (removal of soil via pressure or friction)
• Temperature (at which cleaning is performed)
• Time (duration of the total cleaning processes)

The proportion of the individual factors as a part of the entire cleaning can be varied, provided that the total is 100 per cent. This results in significant savings potentials. As a result, the intensification of mechanical cleaning enables the consumption of cleaning agents or the duration of cleaning to be reduced. Consequently, the mechanical factor takes up a greater part of the Sinner‘s circle, while the other factors can end up being reduced.

Cost Reduction by Efficient Cleaning Processes

This is precisely where our nozzles and rotating cleaning nozzles come into play, having been specially developed for delivering a high mechanical cleaning action. Their greater efficiency helps to permanently reduce on going costs for energy and cleaning agents, and also the duration of cleaning. Consequently a one-off investment in improved nozzle technology pays for itself after only a short time.

Mechanical Cleaning

Rotating cleaning nozzles deliver the greatest impact when cleaning the surface area of the tank. To achieve this, large droplets must strike at high speed. This enables thick soil to be removed that cannot dissolve in the cleaning fluid. Important influencing factors are the distance between the nozzle and wall, and the operating pressure.

If either are too great the fluid will break down into smaller droplets and the impact will be reduced.

Besides the impact, the fluid running down the tank wall also has a significant cleaning effect. If the formed film is thick enough, the resulting shear stresses can remove light to moderate soil. In that case, unsprayed patches are less of an issue than is the case during impact cleaning.

Impact

The force of impact when using a liquid jet on a surface plays an important role in cleaning technology. The ratio of the force (F) to the surface (A) is referred to as the Impact (I).

It can be controlled via the following parameters:

• Impact surface and spray angle: The impact surface is the area where the droplet strikes. The smaller the surface area, the greater the impact values. Nozzles with high impact are, for example, solid stream nozzles and flat fan nozzles with a narrow spray angle.
• Flow rate: Increasing the flow rate by using a larger nozzle increases the impact, assuming that the other parameters (spray angle, pressure and medium) remain the same.
• Pressure: In contrast to static cleaning nozzles, there is no linear relationship between pressure and impact for rotating nozzles. With rotating nozzles, the supply pressure normally influences the rotation speed. The higher the rotation speed, the greater the tendency of rotating nozzles to atomize the fluid into much smaller droplets. This effect has a negative influence on impact. Lechler rotating cleaning nozzles should therefore be used at the recommended operating pressure range.
• Comparison of rotating cleaning nozzles and static spray balls: Due to their simple construction, static spray balls are economical and are likely to miss important areas. Whereas rotating cleaning nozzles spray the entire tank wall in a fan-like pattern, the jets from spray balls strike only in concentrated spots. The remaining surface is simply cleaned by the shear stresses of the fluid running off. The fluid consumption is therefore significantly greater in comparison to rotating cleaning nozzles.
• Influence of chemistry and temperature: The chemical cleaning effect takes part in almost all tank cleaning applications when the soil is dissolved in the cleaning medium or the bonding between soil and tank surface is reduced. Higher temperatures can support the chemical cleaning effect.
• Foam cleaning with nozzles: Foam cleaning is primarily based on the chemical cleaning effect. Since the foam sticks more firmly to the surface, it can be more effective than cleaning fluids that drip off quickly. The mechanical cleaning effect plays a correspondingly subordinate role. Here, the task of the nozzle is to distribute the foam evenly. Your end result for this application depends on the type of foam.
• CIP- and SIP-cleaning: Cleaning in Place (CIP) is one of the standard cleaning methods in the food and pharmaceutical industries. This is a process where the cleaning and disinfectant solutions circulate in the production systems during the cleaning process. The nozzles are installed in the system and do not need to be dismounted during the process. The correct combination of steps from Sinner’s circle leads to a reliable and reproducible process. Almost all Lechler rotating cleaning nozzles and static spray nozzles are capable of CIP. If sterilization is performed after CIP-cleaning with hot water or saturated steam, this is referred to as SIP-cleaning (Sterilization in Place).

Operating Principles

• Static: Static spray balls do not rotate and therefore require considerably more fluid. They are used primarily for rinsing tanks. They are inexpensive to purchase and are very robust (trouble-free).
• Free-Spinning: The cleaning fluid drives the spray head by means of specially positioned orifices. The rapidly repeated impact removes the soil and rinses it from the tank surface. This results in optimum cleaning efficiency at low pressures in small to medium-sized tanks.
• Controlled Rotation: The rotating head is driven by the fluid. A turbine wheel with an internal gear is used to control the rotation. This ensures that the speed remains in the optimum range even at higher pressures. The droplets produced are larger and strike the tank wall at higher speed. These rotating cleaning nozzles achieve an even higher impact which is especially important for large tanks.
• Gear-Controlled: The cleaning fluid drives an internal gear by means of a turbine wheel so that the spray head rotates by two axes. The solid jet nozzles mounted on the spray head produce powerful jets. These jets sweep the entire tank surface in a pre-programmed, modelspecific pattern during a spray cycle. This requires a certain minimum time. These models generate the highest impact and are therefore ideal for very large tanks and the toughest cleaning tasks.

Connection Options

Lechler offers various options for connecting the rotating cleaning nozzles to the supply line:

• Threaded Connection: Most nozzles have a female thread that is screwed onto a male thread on the pipe.
• Slip-On Connection: Slip-on connections without threads are often preferred in applications with high sanitary requirements. Here, the nozzle is slipped onto the outer pipe and secured through a horizontal hole by a pin or clamp.
• Tti-Clamp: Tri-Clamp fittings are frequently used in the food and beverage industry. Some rotating cleaning nozzles can be supplied with a compatible adapter.
• Welded Connection: Welded connections are particularly suitable for applications where sanitary requirements have to be taken into account. Please contact us for further information.

Materials

Lechler tank and equipment cleaning nozzles are made of extremely high-grade materials that are designed to meet requirements such as resistance to cleaning chemicals or temperature influences. The large choice of different materials — e.g. stainless steel AISI 316L, PVDF, PEEK or PTFE — allows nozzle selection customized to the individual application and operating conditions. In addition, the materials used for the tank and equipment cleaning nozzles are perfectly matched to each other and are thus characterized by very low wear.

The product pages for the individual nozzles provide information on the materials available for the different nozzle types. 

In addition to the requirements for material resistance and wear, the materials must also be food grade for use in the beverage, food and pharmaceutical industries. Depending on the application area, the materials must meet different demands.

A large number of the materials used for Lechler tank and equipment cleaning nozzles comply with the requirements of the FDA or conform to (EC) 1935/2004. 

Further information on conformity is provided on the product pages. 

The FDA, the U.S. Food & Drug Administration, is a federal agency which overseas those two industries. Materials used in making Some of Lechler’s products comply with the requirements of FDA regulation 21 CFR for use in food applications.

The regulation (EC) No. 1935/ 2004 of the European Parliament regulates general safety requirements to all food and beverage contact materials.

Within this regulation, it is additionally stipulated that plastics must comply with (EU) 10/2011.

Hygiene Requirements

Lechler’s tank and equipment cleaning nozzles are designed so that they meet hygiene requirements.

This is reflected, for example, in the self-draining function, minimized dead space in the nozzles as well as an external design without unnecessary gaps and edges. At the same time, the nozzles are designed with the lowest possible surface roughness.

Lechler also offers specially certified nozzles for particular hygiene requirements. For example, the “PTFE Whirly” and 527 series are 3A-certified.

3-A® Sanitary Symbol Council Administrative Council for Spray Cleaning Devices (78-01) 3-A® SSI is an independent, not-for-profit corporation dedicated to advancing hygienic equipment design for the food, beverage, and pharmaceutical industries. The display of the 3-A symbol requires that processing equipment meets certain material, design, and fabrication standards for cleanability and inspection.

Nozzle Wear

Nozzle wear depends mainly on the operating conditions. Like with all rotating parts, the bearing assembly is subjected to the highest amount of stress. The following operating conditions accelerate wear:

• Solids in the fluid and hard particles
• Use in a chemically aggressive environment
• Spraying of chemically aggressive substances
• Operating the nozzle above the recommended pressure range or temperature

Material Certificates

Material certificates in accordance with DIN EN 10204 can be issued on request for almost all Lechler tank and equipment cleaning nozzles.

ATEX

Lechler offers specially designed nozzle series for use in explosive atmospheres. The “MicroWhirly” and “Whirly” series have an ATEX approval that was issued by an external certification institute.