Title of Invention

SELF (PARTIAL) EVACUTING FOR INTERNAL COMBUSTION ENGINE

Abstract An acoustic muffler whose gas flow conduit is such that it is capable of utilizing the energy in the exhaust gases of a four stroke, internal combustion engine for partially evacuating the exhaust. The Evacuating process Improves with no. of cylinder in the engine. The presented invention significantly reduces / eliminates the negative work done by the engine during exhaust stroke therefore also increases the net output of the engine without any increase in fuel consumption, optionally minor adjustment on engine can also yield lower fuel consumption i.e. improve mileage.
Full Text An acoustic muffler whose gas flow conduit is such that it is capable of utilizing the energy in the exhaust gases of a four stroke, internal combustion engine for partially evacuating the exhaust. The Evacuating process Improves with no. Of cylinder in the engine.
The presented invention significantly reduces / eliminates the negative work done by the engine during exhaust stroke therefore also increases the net output of the engine without any increase in fuel consumption, optionally minor adjustment on engine can also yield lower fuel consumption i.e. improve mileage.

EXISTING MUFFLERS (PRIOR ARTS)
All acoustic mufflers reduce acoustic power / noise either by suppression or by absorption in porous material. The Process involves significant flow energy losses / total pressure losses. Higher the total pressure losses lower is the net output of the engine, as the exhaust has to be forced out of muffler by piston action, flow losses are due to the bends, baffles, restrictions, sudden expansion, contraction in the muffler which the main flow has to navigate
ADVANTAGE OF PRESENTED INVENTION
This invention is capable of presenting a moving wall of fluid / gas to the incoming exhaust gas from the engine during exhaust stroke. The circulation effect is present during the exhaust stroke, which drastically reduces flow resistance associated with the flow in the muffler and also provides a degree of suction.
DETAILED DESCRIPTION: -
In all four stroke, internal combustion engines; the expansion of gases during the power stroke is never complete.
Generally the exhaust valve opens an approximately 40 degree crank angle* before the bottom dead center (BDC) at this Instant* the total pressure ratio (W. R. T. ambient Pressure, 101325 N/m2) is usually above two, which reduces to unity within next few degrees (~ 60 degree) as gas flow commences. The above process is termed as blowdown
The presented invention / exhaust device aims to utilize the blowdown process to assist the engine to evacuate the gases from the cylinder. Action of exhaust device: As the blowdown begins from the engine; the gas / fluid in the exhaust device between section " CC " and " DD " (SEE SECTIONAL VIEW "BB" (Fig 2)) is pushed towards the exit and also in to the circulation conduit. (1) Fig. 2.
The fluid flow is established in Recirculation conduit which gets accelerated due to friction during its travel from section "DD"To CC and further accelerated by the presence or application of a co - axial / concentric converging nozzle (2) fig.2. The typical front view of section "CC is as shown in Fig. 3, right half The exit section indicated by view on section "DD" has been shown in Fig. 3 left half
The blow down process lasts for approximately 60 crank revolution time. The nozzle also provides high velocity Co- axial, concentric stream of gas for the same duration of time. The nozzle is dimensioned so as to keep this velocity higher than the exhaust gas velocity in the exhaust pipe furnished by the piston action, while the exhaust stroke is in progress.

The gas / fluid from the nozzle entrains the exhaust flow (between section CC & DD Fig 2) and carries /accelerates it out of the muffler, giving rise to a degree of suction serving to convert a portion of exhaust stroke in to a weak power stroke.
In rest of the exhaust stroke the concentric gas stream velocity from the nozzle remains approximately same as that of exhaust gas velocity in the exhaust pif)e /inlet pipe, (7) / (5) Fig 2 this serves only to eliminate the flow resistance across the muffler.
The above-described invention is not suitable for two stroke internal combustion engines BECAUSE the suction effect of this muffler can remove charge from the cylinder of a two stroke -engine, due to late closure of exhaust ports. The muffler is at its best with 4 stroke engines having fuel injection device although it can be used for carbureted 4 stroke engines as well.
The circulation of a gases (as shown by arrows in Fig 2; 3; 4) helps to utilize the energy in the exhaust gas (By increase in pressure expansion ratio)
For continuous flow system like gas turbine engines where exhaust pressure ratio is above 2 (i.e. Po / pa > 2.0) convergent divergent nozzle (8), (Fig - 4) is proposed instead of converging nozzle alone. This would give supersonic co - Axial and concentric gas stream around the circumference of the exhaust line at the inlet to muffler in effect the total pressure ratio across the turbine would increase.
Acoustically this device works by expanding the noise / sound wave as soon as it arrives into the acoustic expansion chamber (3) Fig - 2 and then by filtering it at section DD noise wave that remains inside are suppressed by repeated reflections. The exhaust device may also be provided with a short conical extension on the pipe (6) Fig - 2 (pipe has orifices on it, as shown in the sectional view BB (Fig - 2)) to additionally muffle the noise if necessary.
The invention described above functions as acoustic muffler and increases the net output of the engine.
EXPERIMENTAL OBSERVATIONS: -
Test runs were carried out with four stroke, single cylinder, diesel engine (injection pressure = 200 bar, RPM = 3600). Pressure measurements were made at locations indicated by numbers on Fig. 5 & 6 concerning two types of silencer configurations, using a" U " Tube water manometer for studying the relative performances.
Abbreviations: -
Po_ - Total Pressure, p_ - static pressures at respective locations.
Pj 1 - static pressure at location 1, for atmospheric air ejector\aspirator type of
Muffler (Fig. 6). Pr2 - static pressure at typical location 1, for commercially available muffler.

Approximate values:
Po2 = 103280 N/m2, Po5 = 103780 N/m2, pi = 103290 N/m2, p3 = 102210 N/m2,p4= 101025 N/m2.
Other observations: -
1) Increased fuel efficiency\ mileage by ~ 10%.
2) Lesser carbon deposit in intake manifold & around intake valve.
3) Better acceleration on throttling (subjective).
4) Less emissions.
5) Pl/pjl Based on the above experimental observations and analysis I recommend that this exhaust device can be brought into action simply by a leak proof connection to the exhaust line as shown in the sectional view "BB" or by leak proof flange type connection the muffler may be provided with additional external anchorage if necessary. The device is to be manufactured using metal tubes / sheet metal based on scheme shown in figure 1,2,3. The recirculation conduit may be anchored using an independent member (4), as shown in figure 3.
While above specification describes the preferred embodiment of the invention. The invention is not to be deemed to be limited to precise details of construction disclosed here by the way of example. It is to be understood that the invention includes all changes and modification in parts, construction and combinations shall come within the preview of claims.



I CLAIM;
(1) An acoustic muffler system containing a circulation conduit to accelerate fluid flow by staged or progressive reduction of concentric fluid passage area starting from around muffler exit conduit and ending around muffler inlet conduit.
(2) An acoustic muffler system as claimed in claim one with a diffusing inlet conduit serving as nozzle for circulation conduit.
(3) An acoustic muffler as claimed in claim one with a convergent divergent nozzle arranged concentrically around inlet conduit.
(4) An acoustic muffler as claimed in any one of the preceding claims wherein a side branch resonator and or a diffuser box element is included for additional noise and harshness reduction depending on specific requirements.

Documents:

2386-mas-1997 abstract.pdf

2386-mas-1997 claims duplicate.pdf

2386-mas-1997 claims.pdf

2386-mas-1997 correspondence others.pdf

2386-mas-1997 correspondence po.pdf

2386-mas-1997 description (complete) duplicate.pdf

2386-mas-1997 description (complete).pdf

2386-mas-1997 drawings duplicate.pdf

2386-mas-1997 drawings.pdf

2386-mas-1997 form-1.pdf

2386-mas-1997 form-13.pdf

2386-mas-1997 form-19.pdf

2386-mas-1997 others.pdf


Patent Number 203514
Indian Patent Application Number 2386/MAS/1997
PG Journal Number 05/2007
Publication Date 02-Feb-2007
Grant Date 01-Dec-2006
Date of Filing 23-Oct-1997
Name of Patentee SHRI. UTTARKAR MAHABALA MUKESH
Applicant Address NO.85, 2ND CROSS, KADUGODI PLANTATION, G.K. NAGAR, (BEHIND KADUGODI POLICE STATION) BANGALORE 560 067
Inventors:
# Inventor's Name Inventor's Address
1 UTTARKAR MAHABALA MUKESH NO.85, 2ND CROSS, KADUGODI PLANTATION, G.K. NAGAR, (BEHIND KADUGODI POLICE STATION) BANGALORE 560 067
PCT International Classification Number F01N 5/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA