Introduction
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Condenser Tube Cleaning Systems & Debris Filter :: Introduction
MACMET
INDIA LIMITED offers Condenser Tube Cleaning Systems (CTCS) and Debris
Filters in technical association with
TECHNOS ET COMPAGNIE, France.
TECHNOS
is one of the leading suppliers of CTCS and Debris Filters for Power
Utilities, Refineries and Process Industries with worldwide supply reference
of more than 1000 installations, capacities of the units ranging from 2 MW
to 1300 MW.
The continuous cleaning of condensers and heat exchangers
maintains their efficiency of heat transfer without mechanical or chemical
cleaning of the tubes and without increasing the number of outages.
Cleaning of internal tube surface is accomplished by continuous circulation
of sponge rubber balls with sizes slightly larger than the tube diameter.
These sponge rubber balls are injected into the cooling water inlet header.
The water flow carries these balls into the inlet water boxes, then through
the tubes and finally into the ball strainer located at the cooling water
outlet header.
From the strainer section, the balls are extracted and pumped through the
ball monitor to the ball collector and then to the cooling water inlet
header. The ball collector acts as the storage vessel for the sponge rubber
balls during backwashing of the strainer grids.
Condenser tube cleaning is necessary as raw water induces different types of
fouling which affects the inside of condenser tubes.
Settling of suspended
materials like silt, mud, slime
Biological fouling due to
the presence of bacteria / marine organisms in water
Crystallization of soluble
elements
Formation of seashell
colonies
Fouling leads to:
Corrosion under deposit
Corrosion created by the
destruction of protective film inside the tubes
Reduction in the heat
transfer capacity of the condensers
The efficiency of heat transfer in the condensers of steam turbines has a
direct effect on the power generation. Experience has shown that a reduction of 1 mbar in the condenser vacuum of a
900 MW power unit leads to a final loss of about 1 MW of power output. An
uncleaned condenser can easily lose over 10 mbar vacuum. In such a case the
use of a CTCS will increase the power output by more than 10 MW. Hence it is
extremely important to maintain the tubes of the condenser as clean as
possible using highly efficient and reliable equipment.
MACMET CTCS use
patented TECHNOS technology and equipment to ensure complete and efficient
cleaning of condenser tubes. When an obstacle is placed perpendicular to a
regular flow of fluid, a series of ‘Karman’ vortexes are generated. The
velocity of the first vortex is very high and more than 5 times the on line
velocity.
TECHNOS patented equipment utilises the full advantage of these “Karman”
vortexes. The vortex chamber design produces and maintains very effective
ball circulation in the strainer. This is a considerable improvement over
conventional ball strainer design. Due to the high velocity, balls are
immediately collected and re-injected in to the condenser inlet. The balls
do not remain in the collecting area waiting to find an outlet. The power of
the vortex also allows self cleaning of the ball collecting area. This
technology has been demonstrated in a test unit where the vortex chamber was
filled with stones and gravel. The chamber emptied in two seconds upon
starting of water circulation.
Macmet, jointly with Technos, is currently executing an order of NTPC’s 5 x 200 MW Singrauli Super Thermal Power Station for design, manufacture, supply, installation and commission of COLTCS. Macmet is also manufacturing several COLTCS equipment and assembling the system for supply to Technos for Sohar Aluminium Power Plant in Oman.
