FIELD OF INVENTION
The invention relates to a device for lube oil conservation in lube oil ventilation
system for Gas turbine application.
BACKGROUND OF INVENTION
Large high speed rotation equipment like Gas Turbines, Steam Turbines, Axial
and Centrifugal compressors, requires a large volume of oil for lubrication,
cooling, and sealing of the bearings. The lubricating oil can be either mineral
based or synthetic.
During the operation, the bearings become very hot and the bearing surfaces
that the oil comes in contact with are rotating at high speeds. The high
temperature and shearing action generates a large volume of very fine oil mist
and a considerable amount of vapor. When this oil mist and oil vapor is vented
from the lube oil tank, it causes a visible plume at the outlet. This oil plume falls
under the purview of the stringent environmental laws and regulations at all
government levels throughout the world.
Lube Oil Systems:
A Typical Lube Oil System consists of
i) Lube Oil Tank
ii) Lube Oil Pumps
iii) Lube Oil Filters
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iv) Lube oil feed lines from the tank to the bearings
v) Lube oil return lines from the bearings to the tank
The basic operation of a lube oil system is similar for all designs. Lubricating oil
(mineral or synthetic) is pumped to the bearings to lubricate and cool the metal
to metal surface contacts. The high speed shearing and heat that occurs at the
metal to metal contact causes droplet formation and vaporization of some of the
oil.
Therefore the return lines to the lube oil tank contain not only hot oil but also
mist and vapor.
Once back in the tank, most of the larger droplets fall out; however the tank
must be vented or open to atmosphere. This is accomplished by connecting the
suction side of a blower to the top of the tank, thus creating a slight vacuum in
the tank as compared to atmosphere. In this case much of the generated oil mist
and vapor will escape through the vent of the tank, resulting in financial loss,
damage to the environment, and a safety hazard.
The Gas turbine lubricating system vents through a mist eliminator. This vessel
contains of one or more coalescing filter elements used to remove oil from the
air. The blower also maintains a slight negative pressure in the tank.
During the maintenance / breakdown period of mist eliminator, the oil mist is
allowed to directly discharge to the atmosphere. This oil mist forms a visible
plume at the out let of the mist eliminator, thus causing environment pollution
and loss of lube oil.
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OBJECT JOF INVENTION
It is therefore an object of the invention to propose a device for lube oil
conservation in the lube oil ventilation system of a gas turbine system which
reduces the load on mist eliminator blower.
Another object of the invention is to propose a device for lube oil conservation in
the lube oil ventilation system of a gas turbine system which provides improved
economy in recovery of wastable lube oil.
A further object of the invention is to propose a device for lube oil conservation
in the lube oil ventilation system of a gas turbine system which increases the life
of the coalescing filters provided in the lubricating system.
A still further object of the invention is to propose a device for lube oil
conservation in the lube oil ventilation system of a gas turbine system which
reduces the possible environmental pollution generated by the oil plume.
DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
1. Figure 01 is a block diagram of a device according to invention.
2. Figure 02 is the schematic diagram of a typical lube oil vent system.
3. Figure 03 is the schematic diagram of a device disposed in plurality within
the lube oil vent system according to the present invention.
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DETAILED DESCRIPTION OF INVENTION
Figure 01 shows a device of the invention which is basically an heat exchanger.
At least one pipe (1) is provided with a plurality of fins (2) and these fins (2) get
cooled with water circulated in a jacket (3) provided around the fins (2). The
heat exchanger has an water inlet (7), an water outlet (8), and a drain plug (9).
The characterizing feature of the device resides in the fins (2) that the oil mist
gets condensed while passing through the device (c).
A number of device (c) can be installed in the suction line (5) of a mist eliminator
(4). The water jackets (3) are connected to the water supply and return lines
(10,11).
Mist being sucked from a lube oil tank (6) which get cooled the mist eliminator
(4) and most of the vapor will get condensed, and the recovered oil can directly
return to the tank (6), minimizing oil loss and environmental damage.
Figure 02 is the schematic diagram of the standard lube oil vent system.
To assist the mist eliminator (4) during the maintenance or breakdown period
and to improve the performance of the mist eliminator (4), the device (c) can be
employed in the Lube oil venting systems (Lovs). Figure 03 is a schematic for
installation of multiple device (c) in the piping depending on the temperature of
the lube oil vapor and the cooling media.
This also reduces the capacity of the blower and loads on the coalescing pads of
the mist eliminator.
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WE CLAIM
1. A device for oil conservation in a lube oil ventilation system adaptable in
particular to gas turbines, the tube oil ventilation system accommodating
the device and comprising at least one lube oil tank, a mist eliminator
blower connected to the tank-upper via its suction side, a lube oil feed
line, and a lube oil return line, the device comprising:
- at least one tube provided with a plurality of fins to form a heat
exchanger;
- one each water inlet, water outlet, and drain plug provided to the at least
one tube; and
- a plurality of water jackets disposed around the fins and being connected
to the lube oil feed line, and the lube oil return lines.
2. A device for oil conservation in a lube oil ventilation system adaptable in
particular to gas turbines as substantially described and illustrated herein
with reference to the accompanying drawings.

The invention relates to a device for oil conservation in lube oil ventilation
system uses which is provided with a finned cooler in a water jacket for cooling
the lube oil mist being sucked by mist eliminator and condenses the lube oil
vapor to form droplets and these droplets fall back in to the lube oil tank. It also
reduces the burden on mist eliminator to handle large volumes of lube oil vapor. This invention can be used in lube oil vent system of Gas Turbines, Steam Turbines, Axial and Centrifugal compressors applications.