Title of Invention

"AN APPARATUS FOR GENERATING SPARK WITH LOW AND HIGH ENERGY"

Abstract An apparatus for generating spark with high energy, said apparatus comprising: means for storing energy and inducing current impulse; and means for producing high voltage impulse and triggering the spark into the spark gap is connected to means for providing proper isolation which in turn is connected to means for storing energy.
Full Text FIELD OF INVENTION
The present invention relates to an electronic circuit apparatus for generating sparks with low energy or high energy and variable frequency for igniting gas based pilot burners or main burners.
Industrial furnaces use large number of pilot burners to ignite main burners. These burners are generally gas based and ignited by electric spark of sufficient energy.
DESCRIFriON OF THE RELATED ART
Currently, the apparatus which is presently known in the art has:
a step up transformer which raises input voltage from 110V, 50Hz/230V, 50Hz to about 10KV, 50Hz. The stepped up voltage provides spark, which is continuous. Spark energy is decided by the transformer parameters. The system is shown in Fig. 1. Transformer can weigh a few Kgs.
In order to increase the energy of the spark a different approach is used. A comparatively smaller transformer is used to step up the input ] 10V, 50Hz/220V, 50Hz to about 2-3kV. The stepped up AC is rectified and that charges a high voltage capacitor. Energy stored in the capacitor is 1/2 CV". where C is Capacitance in farads and V is voltage to which it is charged. A low-pressure gas filled spark gap device, which may be triggered or non-triggered type is used as a switch to connect the charged capacitor to the HT electrode. HT Electrode is connected to ground electrode at the point of spark tip through a semiconductor. Presence of semiconductor helps in generating a spark at the tip at about 2-3 kV.
However, the abovementioned apparatus have the following drawbacks:
1 As the step up transformer works on mains (i.e. 50 Hz) its size is big. It
uses large sized core as well as more Copper wire. It weighs a few
kilograms.
2. Continuous operation results in larger energy loss in the secondary resulting in frequent burning of the winding especially if output gets shorted.
3. As the spark generation is facilitated by using semi-conducting material between the electrodes, spark tip gets eroded and needs replacement from time to time.
4. Some energy is also lost in the Spark Gap Device. Spark Gap Device is also fragile and its availability is poor in India.
5. For non-triggered Spark Gap Devices capacitor is required to be charged to about 2-3kV. This requires a special step up transformer and rectifiers.
6. Energy retained in the capacitor after the discharge is considerable resulting in inefficient use of capacitor.
Accordingly, the principle object of the present invention is to overcome the abovementioned drawbacks and provide a circuit for operations on main to provide high current impulse for the induction coil which generates high voltage for spark in high tension low energy pilot ignitor.
Another object of the present invention is to provide a circuit to generate high energy spark for direct ignition of main burners using oil/gas/combustible powders.
Accordingly, there is provided an apparatus for generating sparks with
low energy for igniting gas based pilot burners or main burners, said apparatus
comprising:
means for creating current impulse directly from a mains by switching
on and off the means for allowing the passage of current; and
means for producing high voltage impulse and triggering the spark into
the spark gap connected to the said means for allowing the passage of
current.
Accordingly, there is also provided an apparatus for generating spark with high
energy, said apparatus comprising:
,,means for storing energy and inducing current impulse; and means for producing high voltage impulse and triggering the spark into the spark gap is connected to means for providing proper isolation which in turn is connected to means for storing energy.

The subject invention relates to an apparatus for generating spark with high
energy, said apparatus comprising:
means for storing energy and inducing current impulse; and
means for producing high voltage impulse and triggering the spark
into the spark gap is connected to means for providing proper isolation
which in turn is connected to means for storing energy.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
Figs. 1 8s 2 relate to prior art apparatuses
Fig. 3 relates to the apparatus in accordance with the present invention.
Fig. 4 shows the graphical representation of the charging and discharging of
the capacitor.
Fig. 5 relates to the another embodiment of the present invention.
Figures 1 and 2 have already been discussed above in the description of the
related art.
The proposed apparatus is different from both the abovementioned apparatus as mentioned in Figs. 1 & 2. The proposed apparatus is shown in Fig. 3.
The apparatus of the present invention works on mains power supply and generates a low energy current impulse for an induction coil. Current impulse is generated with the help of capacitor C1 and Phase Controlled TRIAC. When
Triac is switched ON, C1 charges rapidly. Initially current is high which
decays exponentially. When the current goes below the holding current, TRIAC
is switched off. Voltage across the TRIAC again builds up as per the equation
(Equation Removed)
Where VT is voltage across the TRIAC, Em is peak supply voltage of frequency ω and Vc1 is the Voltage to which capacitor was charged by first trigger. TRIAC is once again triggered when suitable conditions exist. In each quarter cycle there can be a number of steps in which capacitor is charged. In a similar way capacitor is charged and discharged in the next quarter cycle. 7'his is shown in Fig.-4.
When impulse of current is fed to an induction coil's primary winding a high voltage impulse is produced at the secondary. This high voltage is enough to generate a low energy spark. Spark energy of the order of few mJ can be sufficient to ignite Methane, Butane, Propane and Hydrogen gas. These gases have low ignition energies.
In order to make the circuit more reliable a Silicon Controller Rectifier (SCRI and a diode combination connected back to back can replace TRIAC. This combination helps in using low current high voltage SCR's and diodes. Operation is similar to that of TRIAC circuit. Diode helps in discharging the charged capacitor for a new current impulse to be generated.
If high-energy sparks are required then circuit must be modified 1o discharge a charged capacitor straight into the spark. This is achieved by using a HV low energy spark as a trigger and a suitable capacitor charged up to a few hundred volts, releasing its energy into the spark. Proper isolation is provided by using EHT Power diodes as shown in the Fig. 5. In the figure 'n represents the turn ratio of the coil.
Using proper circuit elements sparks having tens of Joules of energy can be generated. Capacitor charging and Trigger spark circuits can be powered from AC mains or batteries. The circuit can also be used to generate very high energy arcs directly from mains.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.




WE CLAIM-:
1. An apparatus for generating spark with high energy, said
apparatus comprising:
means for storing energy and inducing current impulse; and means for producing high voltage impulse and triggering the spark into the spark gap is connected to means for providing proper isolation which in turn is connected to means for storing energy.
2. An apparatus as claimed in claim 1 wherein said means for storing
energy is charged up to few hundred volts for releasing its energy
into spark wherein a HV spark is used as a trigger.
3 An apparatus as claimed in claim 1 wherein said means for
providing proper isolation is HT power diode.
4 An apparatus as claimed in claim 1 wherein said means for storing energy is connected to a charging circuit.
5. An apparatus as claimed in claim 1 wherein said means for producing high voltage impulse and triggering spark is connected to means to avoid negative pulses which is preferably a diode.
6. An apparatus as claimed in claim 1 wherein said means for storing energy is connected to a means for providing proper isolation wherein isolation providing means is preferably a low PIV diode.

7. An apparatus as claimed in claim 1 wherein said means for producing high voltage impulse is connected to a trigger spark circuit.
An apparatus as claimed in claim 1 for optionally generating
sparks with low energy wherein said apparatus comprises:
means for creating current impulse directly from a mains by
switching on and off the means for allowing the passage of current;
and
means for producing high voltage impulse and triggering the spark
into the spark gap connected to the said means for allowing the
passage of current.
An apparatus as claimed in claim 8 wherein means for allowing the passage of current is either a phase controlled TRIAC or SCR and diode connected back to back.
0. An apparatus as claimed in claim 1 or 8 wherein the means for creating current impulse and storing energy is a capacitor.
1. An apparatus as claimed in claim 1 or 8 wherein means for producing high voltage impulse and triggering the spark is an induction coil.
12.An electronic circuit apparatus for generating sparks with low or high energy and variable frequency for igniting gas based pilot burners or main burners substantially as herein described with reference to and as illustrated in the accompanying drawings.

13.An apparatus for generating spark with high energy substantially as herein described with reference to and illustrated in the accompanying drawings.

Documents:

597-del-2000-abstract.pdf

597-del-2000-claims.pdf

597-del-2000-complete specification (granted).pdf

597-del-2000-correspondence-others.pdf

597-del-2000-correspondence-po.pdf

597-del-2000-description (complete).pdf

597-del-2000-drawings.pdf

597-del-2000-form-1.pdf

597-del-2000-form-13.pdf

597-del-2000-form-19.pdf

597-del-2000-form-2.pdf

597-del-2000-form-3.pdf

597-del-2000-pa.pdf


Patent Number 245572
Indian Patent Application Number 597/DEL/2000
PG Journal Number 04/2011
Publication Date 28-Jan-2011
Grant Date 25-Jan-2011
Date of Filing 16-Jun-2000
Name of Patentee ENGINEERS INDIA LIMITED
Applicant Address GOVERNMENT OF INDIA UNDERTKING ENGINEERS INDIA BHAWAN, 1, BHIKAJI, CAMA PLACE, NEW DELHI-110066, INDIA.
Inventors:
# Inventor's Name Inventor's Address
1 HAR SUKHDEEP SINGH ENGINEERS INDIA LIMITED, ENGINEERS INDIA BHAWAN, 1, BHIKAJI CAMA PLACE, NEW DELHI-110066, INDIA.
2 DR. D.S.GILL ENGINEERS INDIA LIMITED, ENGINEERS INDIA BHAWAN, 1, BHIKAJI CAMA PLACE, NEW DELHI-110066, INDIA.
PCT International Classification Number G01P 3/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA