FIELD OF THE INVENTION
The present invention generally relates to a high viscous crude firing system in a
corner fired boiler. More particularly, the present invention relates to a
transmission and firing system for high viscous crude adapted as a stabilizing
and/or load carrying fuel in a corner fired boiler for power generation. The
invention further relates to a method to fire a high viscous crude oil adapted as a
stabilizing and/or load carrying fuel in a corner fired boiler.
BACKGROUND OF THE INVENTION
In a typical thermal power plant, furnace oils are used as a source of energy
input. The furnace oil is commercially graded as No.2 oil and No.6 oil. No.2 oil is
used as a start up fuel and No.6 oil is used as stabilizing and or load carrying fuel
depending on the types of fuels used in the power plant. The furnace oil
transported to the power stations in railway wagons or oil tankers and stored in
tanks. The oil is pumped from the tanks to the burners mounted on the boilers.
Heaters are employed in case of No.6 oil.
A known oil firing system comprises pumping means, heating means, and
burners with control means, and an isolation and bye pass device. Such a system
is enabled to cater for a variable load and a continuous operation by suitably
handling the fuel oils. However, handling of high viscous crude generally used as
the stabilizing and/or load carrying fuel and firing of the crude in a corner fired
boiler requires arrangement to cope up with the extremities is necessary. The
extremities being evolution of vapours from the lower end crude fractions due to
heating and also the solidification of the crude in the isolation and bye pass sides
of the crude supply lines, the supply lines leading to the burners corresponding
to a varying fuel cut off frequency, or burner load demands.

US patent No.5,295,817 discloses an apparatus and a method of combusting
crude oil during oil well production tests comprising atomizing and spraying a
primary feed of the crude oil into a combustion chamber, igniting the primary
feeding in the combustion chamber, heating a secondary feed in a heat
exchanger provided to a combustion chamber before the secondary feed is
sprayed into the combustion chamber in order to reduce the viscosity and
decrease the droplet size of the crude oil in the secondary feed.
US patent 3,622,071 discloses a crude petroleum transmission system, where a
heater having an oil or gas burner is shown, tubes are extended through the
heater to conduct crude petroleum through the heating zone and lower the
viscosity of the petroleum.
US patent 7,037,435 B2 discloses a process for burning off oil spills, especially on
lakes, seas and marginal seas or in the soil, wherein, prior to ignition, the oil slick
is sprayed with an incendiary material containing a readily combustible mixture
of saturated and or unsaturated hydrocarbons.
US patent application publication No: US 2002/0100500A1 dated 01.08.2002
discloses a method and a system for treating crude oil to improve its flowability
by employing internal combustion engine exhaust gas.
Accordingly, a need exists for development of a transmission and firing system
for high viscous crude adaptable as a stabilizing and/or a load carrying fuel in a
comer fired boiler for power generation.
OBJECTS OF THE INVENTION
Accordingly, it is an object of the present invention to propose a transmission
and firing system for high viscous crude adapted as a stabilizing and/or load
carrying fuel in a corner fired boiler for power generation, which is enabled to
heat the crude in stages by employing a steam jacketed valve body including
steam traced lines and fittings.
Another object of the present invention is to propose a transmission and firing
system for high viscous crude adapted as a stabilizing and/or load carrying fuel
in a corner fired boiler for power generation, which is enabled to deploy positive
displacement pumps for pressurization of the crude by shifting the vaporization
point.
A still another object of the invention is to propose a transmission and firing
system for high viscous crude adapted as a stabilizing and/or load carrying fuel
in a corner fired boiler for power generation, which reduces the viscosity of the
crude to achieve effective atomization of crude in burners by a staged heating
device.
Yet another object of the invention is to propose a transmission and firing
system for high viscous crude adapted as a stabilizing and/or load carrying fuel
in a corner fired boiler for power generation, which is enabled to avoid the loss
of heat from the heated crude and eliminates the possibility of choking of the
supply lines.

A further object of the invention is to propose a transmission and firing system
for high viscous crude adapted as a stabilizing and/or load carrying fuel in a
corner fired boiler for power generation, in which the burners are connected by
duplex type flexible stainless steel braided hoses with an annular space so as to
allow monitoring by means of transmitters in respect of any leakage of vapour or
oil.
A still further object of the present invention is to propose a transmission and
firing system for high viscous crude adapted as a stabilizing and/or load carrying
fuel in a corner fired boiler for power generation, in which a crude oil flow
control valve having anti cavitation trims are provided to eliminate formation of
vapours due to pressure drop in the control valves capable to meet varying load
demand of the boilers.
Yet further object of the invention is to propose a transmission and firing system
for high viscous crude adapted as a stabilizing and/or load carrying fuel in a
corner fired boiler for power generation, which allows recirculation of a selected
quantity of heavy crude to the tank after pumping to maintain a continuous
agitation by means of a recirculation device.
Another object of present invention is to propose a transmission and firing
system for high viscous crude adapted as a stabilizing and/or load carrying fuel
in a corner fired boiler for power generation, which resorts to heating of the
crude oil at two or more stages, a first Stage of heating near the tank to facilitate
effective transmission-of heavy crude to the boiler area, and a second or further
heating stages to meet the proper atomization criteria near the burner station.

Another object of invention to propose a transmission and firing system for high
viscous crude adapted as a stabilizing and/or load carrying fuel in a corner fired
boiler for power generation, which resorts to cooling of the crude in the return
lines from the boiler to the crude oil tank to prevent the crude in the tank from
being overheated and suppress the vapour formation at the lower end fractions
of the oil in the tank.
Another object of the invention is to propose a method to fire a high viscous
crude oil adapted as a stabilizing and/or load carrying fuel in a corner fired
boiler.
SUMMARY OF THE INVENTION
Accordingly in a first aspect of the invention, hence is provided a transmission
and firing system for high viscous crude adapted as stabilizing and/or load-
carrying fuel in a corner fired boiler for power generation, comprising a positive
displacement pump for pressurizing the high viscous crude oil stored in a storage
tank; a piping network connecting the positive displacement pump and a burner
station via a first stage heater, at base one strainer being disposed between the
tank and the piping network ; a steam supply source providing regulated flow of
steam to the first stage heater via a control valve, the steam flow being
regulated corresponding to a temperature of the crude oil discharged from the
outlet of the first stage heater measured in a control link ; a steam-traced pipe
line being an intermediate part of the piping network provided with a plurality of
intermediate pumps, strainers, and valves each having in-built steam jacket
means transporting the heated curde to the boiler area; a second stage heater
receiving a regulated supply of the crude oil via a flow control device, and a

temperature control means; the burner station having one each crude oil trip
valve and a steam trip valve intended to cut off the supply of crude oil when the
oil trip valve is activated to safeguard the furnace; the burner station having at
least one burner, and receiving regulated supply of heated crude oil from the
second stage heater for firing the boiler; at least one stainless steel braided
duplex hose is connectingly disposed between the burner station and at least
one burner; and a return crude oil line having a cooler for transferring back a
portion of the high viscous crude oil via a recirculation means to the crude oil
tank for continuous agitation of the crude.
In a second aspect of the invention, there is provided a method to fire a high
viscous crude oil adapted as a stabilizing and/or load carrying fuel in a corner
fired boiler in which heating of the crude is done in two or more stages. The
heating of the crude is accomplished after pressurizing the crude to shift the
vapourization point of crude which eliminates the possibility of vapor lock in the
flow control means. Release of any vapour in the annular space provided for
burner connections, of the duplex hose is sensed by a monitoring means.
A first stage of heating is provided near the pumping unit located near the tank
area. The steam admission to the tube bundles of the heat exchanger is
regulated by monitoring the temperature of the heater outlet. The heating
temperature is limited to facilitate efficient and effective transmission of the
crude up to the burner station. A second stage of heating is accomplished at a
location between the flow control means and the trip station. As the trip valves
operating for full shut off or full open conditions, even the presence of vapour do
not affect function of trip devices, (i.e.) trip valves.

The outlet temperature of the second or further stage of the heating device is
selected for efficient atomization of the crude in the crude oil at the burners. The
crude oil is atomized with saturated steam to form a fine mist through oil guns
and the ignition of the spray is done by an ignition source mounted in the
burners.
The formation of vapour due to cavitation arising out of pressure drop in control
valves is eliminated through the control devices which are provided with anti-
cavitation trims. The solidification of heavy crude in the oil lines which leads to
choking of the crude of lines is avoided by providing the pumps, valves, and
other fittings with inbuilt steam jacketing means including saturated steam
connections.
The temperature of the crude oil is reduced in the return lines from the firing
temperature to just above crude oil tank temperature to avoid overheating of the
crude oil and vapour formation in the crude oil tanks.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
Figure 1 shows a schematic diagram of heavy crude transmission and firing
system from a tank up to a burner according to the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
The drawing predominantly features a pipe line (1) which transports heavy crude
from a tank (2) through a strainer (3), the Strainer (3) filters out the dirt and
sediments present in the crude, to a positive displacement pump (4). The pump
(4) pressurizes the crude and pushes the crude to a first stage heater (5).
Steam is admitted to the tube bundles of the first stage heater (5) through a
steam flow control valve, which regulates the quantity of steam to the heaters
(5,9). An automatic regulation of the steam is ensured by measuring
temperature of crude oil from the outlet of the heater (5) by means of a control
link (7). The heated crude is transported to the boiler area through a steam
traced pipe line (20). A plurality of pumps, strainers, valves and fittings are each
fitted with an integrated steam jacket means (8).
One each main trip and flow control valve (15) are located in the boiler operating
floor before a second stage heater (9) and the burner station (10). The second
stage heater (9) is provided with a steam control means (12) which admits the
desired quantity of steam to the secondary stage heater (9) and is regulated by
monitoring outlet temperature of the crude oil, to ensure an effective atomization
of the crude oil at the burners (17).

The control device (11,12) is provided with a steam jacket (8) and anti-cavitation
trims (11,12). The burner station (10) includes the crude oil trip valve (11) and
the atomizing steam trip valve (12). The trip valves (11,12) intended to cut off
crude oil supply to the burners (17) when the fuel trip valve (11) is activated to
safeguard the furnace.
A cooler (14) is provided in the return crude oil line (21) from the boiler to
maintain the temperature of the returned crude to maintain the tank
temperature which avoids overheating of the tank and vapour formation in the
lower end fraction of the crude in the tank.
A flow control device (15) is provided to regulate the crude oil supply to the
burners (17) based on the load demand. A temperature control means (16) is
provided for the second stage heater (9). The crude oil supplied to the burners
(17) through a plurality of Stainless steel braided duplex hoses (18).
A recirculation means (19) is provided to ensure a portion of the high viscous
crude pumped back to the crude oil tank (2) for continuous agitation of the high
viscous crude.
WE CLAIM :
1. A transmission and firing system for high viscous crude adapted as
stabilizing and/or load-carrying fuel in a corner fired boiler for power
generation, comprising :
- a positive displacement pump (4) for pressurizing the high viscons
crude oil stored in a storage tank (2);
- a piping network (1) connecting the positive displacement pump (4)
and a burner station (10) via a first stage heater (5), at base one
strainer (3) being disposed between the tank (2) and the piping
network (1);
- a steam supply source providing a regulated flow of steam to the first
stage heater (5) via a control valve, the steam flow being regulated
corresponding to a temperature of the crude oil discharged from the
outlet of the first stage heater (5) measured in a control link (7);
- a steam-traced pipe line (20) being an intermediate part of the piping
network (1) provided with a plurality of intermediate pumps, strainers,
and valves each having in-built steam jacket means (8) for
transporting the heated crude to the boiler area;
- a second stage heater (9) receiving a regulated supply of the crude oil
via a flow control device (15), and a temperature control means (16);
the burner station (10) having one each crude oil trip valve (11) and a
steam trip valve (12) intendended to cut off the supply of crude oil
when the oil trip valve (11) is activated to safeguard the furnace;
- the burner station (10) having at least one burner (17), and receiving
regulated supply of heated crude oil from the second stage heater (9)
for firing the boiler;
- at least one stainless steel braided duplex hose (18) is connectably
disposed between the burner station (10) and at least one burner
(17); and
a return crude oil line (21) having a cooler (14) for transferring back a
portion of the high viscous crude oil via a recirculation means (19) to
the crude oil tank (2) for continuous agitation of the crude.
2. A method to fire a high viscous crude oil adapted as a stabilizing
and/or load carrying fuel in a corner fired boiler, comprising in steps
of :-
- shifting the vapourization point of a crude oil by pressurizing and
heating the crude in a first stage heater, the crude being supplied to
the first stage heater from a tank via a strainer though a piping
network;
- allowing a regulated steam input to the first stage heater to heat the
crude oil, the steam input being regulated corresponding to a
measured temperature at the outlet of the first stage heater;
- transferring the heated crude oil from the first stage heater to a
second stage heater via an intermediate portion of the piping network
having a plurality of intermediate pumps, valves, strainers and pipe
fittings each having in-built steam jacket means, the flow of crude oil
from the first stage to the second stage heater being regulated in
respect of load demand and temperature of the crude oil;
- heating the crude oil further in the second stage heater corresponding
to an atomization temperature of the crude with saturated steam to a
burner;
- transporting the further heated crude to a burner station with a
regulated flow;
- transferring the regulated crude oil from the burner station via at least
one stainless steel braided duplex hose to atleast one burner for firing
into a corner fired boiler; and
- recirculating back a portion of the crude from the second stage heater
via a return pipe line to the crude oil tank for agitation, the return pipe
line having a cooling means.
3. A transmission and firing system for high viscous crude adapted as
stabilizing and/or load-carrying fuel in a corner fired boiler for power
generation as substantially described and illustrated herein with
reference to the accompanying drawings.
4. A method to fire a high viscous crude oil adapted as a stabilizing
and/or load carrying fuel in a corner fired boiler as substantially
described and illustrated herein with reference to the accompanying
drawings.

The invention relates to a transmission and firing system for high viscous
crude adapted as stabilizing and/or load-carrying fuel in a corner fired boiler
for power generation, comprising a positive displacement pump (4) for
pressurizing the high viscous crude oil stored in a storage tank (2); a piping
network (1) connecting the positive displacement pump (4) and a burner
station (10) via a first stage heater (5), at base one strainer (3) being
disposed between the tank (2) and the piping network (1); a steam supply
source providing a regulated flow of steam to the first stage heater (5) via a
control valve, the steam flow being regulated corresponding to a temperature
of the crude oil discharged from the outlet of the first stage heater (5)
measured in a control link (7); a steam-traced pipe line (20) being an
intermediate part of the piping network (1) provided with a plurality of
intermediate pumps, strainers, and valves each having in-built steam jacket
means (8) for transporting the heated curde to the boiler area; a second
stage heater (9) receiving a regulated supply of the crude oil via a flow
control device (15), and a temperature control means (16); the burner
station (10) having one each crude oil trip valve (11) and a steam trip valve
(12) intendended to cut off the supply of crude oil when the oil trip valve

(11) is activated to safeguard the furnace; the burner station (10) having at
least one burner (17), and receiving regulated supply of heated crude oil from
the second stage heater (9) for firing the boiler; at least one stainless steel
braided duplex hose (18) is connectably disposed between the burner station
(10) and at least one burner (17); and a return crude oil line (21) having a
cooler (14) for transferring back a portion of the high viscous crude oil via a
recirculation means (19) to the crude oil tank (2) for continuous agitation of
the crude.