Integrierte Vermeidung und Verminderung der Umweltverschmutzung

Chapter 2
2.1.9.1.3 Description of techniques, methods and equipment
Before starting the cleaning process, equipment is emptied as far as possible. Cleaning and
disinfection can be carried out in various ways. Traditionally, it has been carried out manually.
Cleaning in place (CIP), washing in place (WIP) and, cleaning out of place are all expressions
used for different ways of cleaning. Cleaning agents are delivered in a variety of ways, e.g. in
bags, e.g. powdered cleaning agents, drums or bulk tankers. Many cleaning agents are
potentially hazardous to the health and safety of the operator and systems can be provided to
minimise the risk during the storage, handling, use and disposal.
CIP is used especially for closed process equipment and tanks, whether stationary or small
mobile, processing units. The cleaning solution is pumped through the equipment and
distributed by sprayers in vessels, tanks and reactors. The cleaning programme is mostly run
automatically, and applies the following steps; pre-rinse with water, circulation with a cleaning
solution, intermediate rinse, disinfection, and final rinse with water. In automatic CIP systems,
the final rinse-water is often re-used for pre-rinsing or may be recycled/re-used in the process.
In CIP, high temperatures of up to 90 ºC are used, together with strong cleaning agents. CIP
systems used for open systems like freezers are almost entirely automatic, except for some dry
clean-up and opening of hatches. Temperatures for medium pressure systems are normally
below 50 ºC and the pressure is 10 to 15 bar.
Cleaning out of place is used when several of the machine’s components need to be dismantled,
usually before the manual or automated cleaning of the machine is started. The dismantled
components are cleaned separately outside the machine. Forming machines are one example of
this. There are augers, pistons, valves, forming plates and seals which all have to be dismantled
before cleaning the machine. High pressure jet cleaning, using gels and foams can be carried out
manually or automatically. The appropriate cleaning method is an appropriate combination of
cleaning factors such as water, temperature of the cleaning solution, cleaning agents, i.e.
chemicals, and mechanical forces. Only mild conditions, with regard to temperature and
cleaning agents, can be used for manual cleaning.
High pressure jet cleaning and foam cleaning are generally applied for open equipment, walls
and floors. Water is sprayed at the surface to be cleaned usually at a pressure of
about 40 to 65 bar. Cleaning agents are injected into the water, at moderate temperatures of up
to 60 ºC. An important part of the cleaning action takes place due to mechanical forces.
In foam cleaning, a foaming cleaning solution is sprayed onto the surface to be cleaned. The
foam adheres to the surface. It stays on the surface for about 10 to 20 minutes and is then rinsed
away with water. Foaming can be carried out both manually and automatically. Gel cleaning is
similar to foam cleaning.
In some cases, cleaning is undertaken using hot water only, however, this depends on the nature
of the product and the process, nevertheless, cleaning agents are normally used in the FDM
sector. Cleaning agents are typically alkalis, i.e. sodium and potassium hydroxide, metasilicate
and sodium carbonate; acids, i.e. nitric acid, phosphoric acid, citric acid and gluconic acid;
composed cleaning agents containing chelating agents, i.e. EDTA, NTA, phosphates,
polyphosphates; and phosphonates, surface active agents, and/or enzymes. Disinfectants, such
as hypochlorites, iodophors, hydrogen peroxide, peracetic acid and quaternary ammonium
compounds (QACs), can be used.
2.1.9.2 Energy generation and consumption (U.2)
2.1.9.2.1 Objective
FDM manufacturing requires electrical and thermal energy for virtually every step of the
process. Electricity is needed for lighting, for process control of the installation, for heating, for
refrigeration and as the driving power for machinery. It is usually generated and supplied by
utility companies. When steam and electricity are generated on site, the efficiency factor can be
considerably higher.
52 January 2006 RHC/EIPPCB/FDM_BREF_FINAL