FIELD OF THE INVENTION:
This invention relates to an apparatus and device for enriching the
low calorific value fuel with high calorific value fuel.
BACKGROUND OF THE INVENTION:
The furnaces in HPBP, Trichy operate on low calorific fuel-producer
gas (PG). The Heat treatment cycles are carried out in these
furnaces. Due to deficit of PG in gas plant, the minimum quantity of
heat required to carry out the heat treatment cycles is not fulfilled.
The enthalpy balance of the furnace is not allayed by the supplied
quantity of PG. The set temperature is attained tardily due to the low
calorific value of PG. Therefore in order to compensate the shortfall
of PG, it was proposed to supplement the PG with calorific fuel
liquefied Petroleum Gas (LPG) to satiate the net heat balance. Since
the physical and chemical properties of PG and LPG, an apparatus is
required for supplementation. The apparatus/device blends LPG with
PG to appropriate amount to achieve the desired result.

OBJECTS OF THE INVENTION:
An object of this invention is to propose an apparatus/device for
supplementing the low calorific fuel with high calorific fuel.
Another object of this invention is to propose an apparatus for
supplementing PG with high calorific fuel.
Further object of this invention is to propose an apparatus for
enriching the calorific value of producer gas by venturi arrangement.
Still further object of this invention is to propose an apparatus which
is capable of attaining the set temperature quickly.
Still another object of this invention is to prepare an apparatus which
reduces the cyclic time of heat treatment cycle considerably.

SUMMARY OF THE INVENTION:
The present invention is provided with a device for enriching calorific
value producer gas by LPG, PG comprises a cylindrical pipe shaped
part having a curvature contour inside the cylindrical pipe such that a
small diameter orifice exists at the inside centre to create a venturi
function for flow of gaseous medium and an inlet for PG gas and an
inlet for LPG are provided at the first end of the device and an outlet
for mixed gas is provided at the second end of the device;
characterized in that the incoming petroleum gas having high
pressure head and low velocity head and incoming LPG having high
velocity head and low pressure are allowed to pass through orifice
wherein a venturi arrangement is curved based on the Bernoulli's
theorem and law of conservation ensuring transient flow of mixed
gas with a uniform pressure at the burner inlet.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Fig - 1 shows a schematic diagram of invented device.
Fig - 2 shows a schematic diagram of flow of mixed gas through the
venturi.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF
THE INVENTION:
The present invention is provided with a device mountable on line
with fuel supply line to cater gaseous fuel to the burner.
As shown in Fig - (1) the device (1) comprises a cylindrical pipe
shape (2) parts having a curvature (3) contour inside the cylindrical
pipe (2) such that a small diameter hole (4) exists at the inside
centre to create a venturi function during the flow of gaseous
materials. One Petroleum gas (PG) inlet (5) and one Liquid Petroleum

Gas (LPG) inlet (6) are provided at one first end of the device. One
outlet (7) for mixed gas is provided at the second end of the device
(1) to cater mixed gas to the burner inlet.
The incoming PG (5) having high pressure head and low velocity
head combines with the incoming LPG (6) having a high velocity head
and low pressure head are allowed to pass through the orifice (4)
wherein a venturi arrangement is curved (3) based on the Bernoulli's
theorem and law of conservation ensuring a transient flow of mixed
gas (7) and uniform pressure at the burner inlet. The device is made
of a steel material (Fig. 2), shows a flow diagram of mixed gas before
entering in the burner inlet.
The furnace operates on PG (5). Due to deficit of PG (5) in gas plant,
the minimum quantity of heat required to carry out the heat
treatment cycles is not fulfilled. The shortfall of PG (5) is
compensated by supplementing LPG (6). Since the properties of both

the gases are different, by designing suitable venturi/nozzle (4) the
required pressure at burner inlet is obtained. The venturi (4)
arrangement is carved (3) based on Bernoulli's theorem and law of
conservation ensuring transient flow of the mixed gas and uniform
pressure at burner inlet. To compliment better mixing of fuel, venturi
arrangement (4) was configured accounting the pressure head,
velocity head, static head and calorific values of both gases. By
considering dynamic pressure and piezometric head of PG (5), the
dimensions of venturi's (4) inlet, outlet and differential pressure is
derived.
Depending on the volume of PG (5), the volume of LPG (6) is
regulated by enthalpy balance. Prior to the impregnation LPG (6) into
PG (5), the LPG (6) pressure has to be suitably regulated and safety
precautions need to be assured. This is achieved by suitable gas train
consisting of safely relief valve, solenoid valve and pressure regulator
etc. when the furnace is deficit with minimum amount of PG (5), it is
supplemented by LPG (6) depending on the enthalpy balance.

The fluid velocity increases at the constriction to satisfy the equation
of continuity, while its pressure decreases due to conservation of
energy: the gain in kinetic energy is balanced by a drop in pressure
of a pressure gradient force. An equation for the drop in pressure
due to venturi (4) effect is derived from a combination of Bernoulli's
principle and the continuity equation.
Mass flow for compressible fluid can increase with increased
upstream pressure, which will increase the density of the fluid
through the constriction (though the velocity will remain constant).
A combination of PG and LPG and Mixed gas along with their
respective pressure are mentioned herewith.


The invention as narrated with an exemplary embodiment should not
be read and construed in a restrictive manner as various
modifications of test evaluations, alternations of parameter and
condition of furnace operation and appropriate adaptations
accordingly are possible within the scope and ambit of the invention
as defined in the appended claims.

WE CLAIM:
1. A device for enriching the low calorific value fuel with high
calorific fuel like LPG, PG gases comprises:
- a cylindrical pipe (2) shaped part having a curvature
contour (3) inside the cylindrical pipe such that a small
diameter orifice (4) exists at the inside centre to create a
venturi function for flow of gaseous medium;
- an inlet (5) for PG gas and an inlet (6) for LPG are
provided at the first end of the device (1);
- an outlet (7) for mixed gas is provided at the second end
of the device (1);
characterized in that the incoming petroleum gas having high pressure head and low velocity head and incoming LPG having high velocity head and low pressure are allowed to pass through orifice wherein a venturi
arrangement is curved based on the Bernoulli's theorem and law of conservation ensuring transient flow of mixed
gas with a uniform pressure at the burner inlet.
2. The device as claimed in claim 1 wherein the device as made of
steel material.

ABSTRACT

The present invention is provided with a device for enriching the low calorific value fuel with high calorific fuel like LPG, PG gases
comprises a cylindrical pipe shaped part having a curvature contour inside the cylindrical pipe such that a small diameter orifice exists at
the inside centre to create a venturi function for flow of gaseous medium and an inlet for PG gas and an inlet for LPG are provided at
the first end of the device and an outlet for mixed gas is provided at the second end of the device; characterized in that the incoming
petroleum gas having high pressure head and low velocity head and incoming LPG having high velocity head and low pressure are allowed
to pass through orifice wherein a venturi arrangement is curved based on the Bernoulli's theorem and law of conservation ensuring
transient flow of mixed gas with a uniform pressure at the burner inlet.