MULTI Kühlsysteme has been building cooling water recooling plants of various designs for industrial customers for around 25 years. The focus is on concepts using evaporative cooling towers. Operators of such plants are facing special requirements regarding their hygienic safety. The following frequently asked questions deal with the details of these and the ways in which we can help you implement the applicable hygiene standards.
The technical rules for manufacturers and operators of evaporative cooling systems have been tightened considerably. The current state of the art is VDI 2047 Sheet 2, a guideline of the Association of German Engineers. Recooling plants can spread germs and bacteria via the air. The operators of the plants are responsible for minimising this risk. The VDI guideline helps them to do this. It contains information on “Ensuring the hygienic operation of evaporative cooling systems”.
Furthermore, the legislator provides a binding legal framework. The 42nd Ordinance on the Implementation of the Federal Immission Control Act entered into effect on 19 August 2017. This “Ordinance on Evaporative Cooling Systems, Cooling Towers and Wet Separators – 42. BImSchV” contains, among other things, the following obligation: The operator must periodically check whether their plant emits any concentrations of legionella and germs that are harmful to health. Legionella is a strain of bacteria that can cause life-threatening pneumonia. They prefer to reproduce in water at temperatures of 20 °C to 50 °C. We have summarised the most important contents of the regulation for you in the next frequently asked question.
The 42nd Ordinance on the Implementation of the Federal Immission Control Act literally states: Plants “shall be designed, constructed, and operated to avoid contamination of the service water by microorganisms, in particular legionella, in accordance with the state of the art” (§ 3 (1) 42. BImSchV). The operator also must prepare a risk assessment for the plant in question before (re)commissioning. A hygienically competent person must be consulted for this.
In addition to these general requirements, the text of the law specifies particular demands the legislator places on the operation of, e.g., evaporative cooling systems and cooling towers. An internal inspections and laboratory tests are required, among other things. The following applies to cooling towers: “The operator shall ensure the hygienic quality of the service water by regular internal inspections of chemical, physical or microbiological parameters at least every two weeks” (§ 7 (1) 42. BImSchV). The service water also must be tested for legionella and other microorganisms in a laboratory at least every three months.
Furthermore, the ordinance demands measures to be taken if certain test values are exceeded or if any operating fault occurs. If the circulation water is severely contaminated, the authority may even order the affected evaporating unit to be shut down. The text of the law addresses monitoring requirements. Accordingly, the operator of a plant must keep an operations log and to have proper plant operation checked every five years. This verification must be performed by a sworn expert.
Legionella infections have occurred in Germany in recent years, presumably spread via cooling tower exhaust air. Outbreaks of the disease in Ulm at the turn of the year 2009/2010, in Warstein in 2013, and in Bremen in 2016 drew great media attention.
Since then, safe control of hygienic conditions of use has been given greater attention. Hygiene safety is of enormous importance, in particular with open evaporative cooling towers. After all: Contaminated plants may cause legionella infections in a radius of more than ten kilometres.
The risk of human exposure through inhalation of polluted exhaust air (e.g., due to aerosols containing legionella) has been known for a long time. Sources providing information on this have existed for decades. The potential danger is not new to experts in cooling tower construction and water-treatment technology, nor to operators. However, it is also known that the risk can be effectively reduced through targeted measures. Thus, regular maintenance is indispensable to ensure perfect hygiene in cooling systems.
We have always paid great attention to the conditioning of cooling water. Raw water quality is analysed and solutions for effective and environmentally friendly treatment of the circulating water are developed. Use of conductivity-controlled desalination and dosing systems or softening plants has long been the state-of-the-art for us. We also supply special systems such as reverse osmosis or deferrisation plants at need.
MULTI Kühlsysteme has specifically built up an after-sales service for supplied cooling systems in the last 15 years. Maintenance plans have been developed and a team of trained service staff has been assembled. As a result, we can offer a comprehensive programme for the maintenance of recooling plants today. This includes all the usual components such as evaporative cooling towers of various designs, pump-tank stations, filter technology, heat exchangers, fittings, and pipes. Inspection of the control and regulation systems with sensors, control cabinet, electrical wiring, and programmable logic controller (PLC) is a central component of every maintenance.
Our service staff are working in Germany, Austria, Poland, Luxembourg, and Switzerland. We are planning to expand their action radius soon.
Perfect quality of the cooling water is essential for the safe operation of a cooling system and thus for a smoothly running production process. Our technicians are aware of this right away when taking recooling plants into operation, but also when processing maintenance orders. Cooling water quality is an important factor for low operating costs and high availability.
Because of this, the project engineers at MULTI Kühlsysteme have intensively studied and trained in the subject of water treatment from a hygienic point of view. We have long recommended that our customers actively implement the “Notes and recommendations for the effective and safe operation of evaporative cooling systems” contained in the VDMA standard sheet VDMA 24649:2005-05 in our operating instructions. This guideline is currently undergoing revision (see hyperlink).
Furthermore, we have been referring to the application of EUROVENT 9/5 – 2000 “Guidelines for the Prevention of. Uncontrolled Bacteriological Contamination, including Legionella Pheumophila, in Cooling Towers and Evaporative Condensers” for many years. These subjects are always on the agenda in advisory meetings with customers.
MULTI Kühlsysteme is expanding its service with immediate effect in order to meet the current developments in the market for recooling plants. We can now offer our customers the following services in addition to our proven portfolio:
The right cooling system will save time, money, and nerves for you. We will help you find the optimal solution for your plant.
MULTI Kühlsysteme is your one-stop shop for taking inventory, overall planning, technical processing, manufacture, assembly, control with programming, commissioning, and after-sales service from delivery of individual components to the implementation of complete projects.
