Gas Turbines Cleaner
(Effective, Powerful, Secure, Clean and Economic)
Fouled turbines – lost profits
A typical 46,500KW gas turbine with normal fouling, showing just a 3% power decrease and 1% heat rate increase, can suffer a loss of performance costing more than 500,000 every year.’
Fouling refers to the accumulation of unwanted material on solid surfaces causing an undesirable roughness. In a gas turbine compressor this means deterioration in the aerodynamic form of the aerofoil blades, resulting in reduced air flow, a lower pressure ratio and lower efficiency.
These losses of performance are indicated by a decrease in power output and an increase in heat rate which means lost profits and increased environmental damage.
TYPES OF FOULING
Hydrocarbons
The worst fouling problems are caused by mixtures of liquids and oils or generally hydrocarbons, that deposit on the blades and form an oily film which catches particulate matter. This could be caused by the burnt fuel exhausts emitted from turbines, and can be particularly severe if less clean fuels such as crude oil are used. Oil leaks are another major problem and even smoke from surrounding industries, cities and vehicles contribute toward the fouling.
Salt water
As the air ingested into the compressor is heated, moisture in the air evaporates, leaving salt and dissolved constituents to deposit on the blades. When subjected to the high temperatures
temperatures inside the compressor, these deposits can become firmly baked onto the compressor surfaces. Salt also causes corrosion and rust, so it should be promptly removed. This is a major problem in coastal areas and offshore.
Other causes
Dust and sand generally cause erosion and can lead to fouling when combined with other constituents such as oily vapours. The atmosphere also contains numerous other contaminants including farming chemicals, gases from neighbouring industries, plant spores, insects and smog. Even some additives in certain cleaning products, if not rinsed off properly, can contribute to fouling.
WASHING IS THE BEST SOLUTION
Regular
washing is the most effective way to remove fouling and is the method
specified by the turbine manufacturers. It involves injecting a
cleaning fluid into the compressor to restore performance. Washing will
also halt the progression of corrosion which can cause pitting of the
blades and encourage further fouling.
The
fouling however can be made up of many different and often sticky
substances, that when subjected to high temperatures become even more
resistant to cleaning and hard to remove. To overcome this, proven
cleaning chemicals must be used.
Minco’s
next generation of cleaning fluids have been specially designed to
break-down and eliminate all types of compressor fouling, whilst still
complying with stringent OEM requirements. Even at low temperatures or
with short contact times they will effectively restore any compressor
to pristine condition.
Our
products have been designed to effectively lift dirt and then carry it
clear of the compressor. They are free rinsing and will not leave any
sticky residue when evaporated, making them ideal for both on-line and
off-line washing. They also prove washing can be safe for the
equipment, the operator and the environment.
WASHING METHODS
Off-Line (Soak or Crank) Washing
Off-line
washing is conducted with the gas turbine in a cooled state, by
injecting a cleaning solution into the compressor while it is being
turned at cranking speed
Once
the chemicals are injected into the compressor, the gas turbine is shut
off and allowed to come to a halt. The chemicals are then left to soak
for 20-30 minutes, before being rinsed with demineralised or deionised
water.
The main drawback is
the amount of time the turbine must be taken out of operation to allow
it to cool and be prepared for washing. The efficiency of crank washes
however is very high, and the power recovery is close to the original
level or the level reached after a major overhaul.
Product recommended for off-line washing is Turboklenz
On-Line (Fired) Washing
This involves regularly spraying a cleaning solution into a compressor running at full speed. High operating temperatures inside the compressor, the high centrifugal forces on the injected liquid and the short contact time of the wash solution with the fouling all limit the effectiveness of this method.
The washing fluid will however reach the inlet guide vanes and first stage compressor blades which will result in some power recovery. This improves availability by slowing the rate of loss of output and prolonging the time between off-line washes. Using a suitable detergent will improve the wetting abilities of the wash solution, improving contact with the fouling so improving the cleaning effect, and also reducing the total amount of liquid required per wash.
Product recommended for on-line washing is Protoklenz
WHEN TO WASH?
On-line washing needs to be performed regularly to decrease the fouling rate, but the timing of off-line washing is a more complex proposition and will depend on the following:
* Amount and type of Contaminants in the Air Supply.
* Acceptable Level of Power Degradation to the user.
* Time Constraints owing to demand for availability.
* The Level of Air Filtration employed.
These variables all mean there can never be one universal cleaning procedure. The most beneficial regime of on-line and off-line washing is usually developed through experience, and needs to be customised for every compressor.
Full power can be difficult to regain once significant fouling occurs so we recommend that the compressor is washed regularly to prevent the build-up of fouling deposits and maintain performance.
Minco is happy to work with operators to help them develop the best washing programme for their specific needs.
TurboKlenz normally used for most stubborn fouling
TurboKlenz is a carefully balanced blend of powerful, high boiling-point solvents and surface active agents. It is optimally used to remove the heaviest oil-borne, and most stubbornly baked-on, fouling deposits.
This is the ultimate compressor cleaning chemical that will eliminate all types of fouling, whilst still complying with the stringent requirements of the original equipment manufacturers.
Its use is recommended for off-line washing where extreme degradation of the compressor surfaces has occurred.
ProtoKlenz for regular washing requirements
ProtoKlenz GT is a detergent with a unique, non-ionic formulation of
complex grease-cutting surface active agents, coupled with ultra
low-toxicity oil stabilisers.
This is an innovative product that provides an alternative for
environmentally-aware companies who appreciate, and understand, the
need to use ecologically safe chemical cleaners.
Thanks to cutting edge technology Minco offers users a powerful and
effective product without the environmental or personal hazards
associated with traditional solvent cleaners.
For full information about MINCO's products, please download the brochures by clicking; Turboklenz-Product Sheet and Protoklenz-GT-ProductSheet
Where can you find information for our complete Product and Services ?
For further information please contact our Sales & Marketing Department, we guarantee you will get fast and satisfying services. Telephone: (021) 8873531, 8880316, 88865553-4, 88977065, 88984410 Fax : (021) 8873532 E-mail : minco@zevanya.com
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