WO1994009431A1

WO1994009431A1 - System for adding gaseous materials to combustion system

Info

Publication number: WO1994009431A1
Application number: PCT/US1993/009981
Authority: WO
Inventors: Eugene Shustorovich; Richard Montano; Konstantin Solntsev; Yuri Buslaev; Vaniamin Kalner; Nikolai Moiseev; Aleksandr Bragin
Original assignee: Blue Planet Technologies Co., L.P.
Priority date: 1992-10-19
Filing date: 1993-10-19
Publication date: 1994-04-28
Also published as: AU5537694A

Abstract

There is disclosed a system for providing gaseous material to a combustion system comprising control means (50, 52) for detecting change of the rate of combustion in the system and for initiating admission of gaseous material into the system; and means (20) responsive to said control means for drawing gaseous material from a source of gaseous material and admitting the gaseous material into the system at a position downstream of a carburetor (44) in the system. There is also disclosed a method for providing gaseous material to a combustion system comprising detecting a change in the rate of combustion in the system and in response thereto admitting gaseous materials to the system at a position downstream of the carburetor (44).

Description

SYSTEM FOR ADDING GASEOUS MATERIALS TO COMBUSTION SYSTEM

FIELD OF THE INVENTION

This invention relates to systems for adding materials to combustion systems, and^more particularly to systems for providing gaseous materials to combustion systems.

BACKGROUND OF THE INVENTION There has long been a need to reduce undesirable emissions from combustion chambers, such as emission of carbon monoxide, unburned hydrocarbons, and nitrogen oxides (NOx) from automotive engines and the like. Carbon monoxide and unburned hydrocarbons typically are emitted from a combustion chamber, and then oxidized in a catalytic converter to C0 and H₂0, typically using a solid stratum of catalyst material, such as honeycombed ceramic structures, which are placed in the exhaust section of the automobile. However, in some instances CO and unburned hydrocarbons are not converted to C0₂ and H₂0 in sufficiently high proportions prior to being released from the-combustion system. In such instances, unsuitable high levels of CO and unburned hydrocarbons may be released into the atmosphere. Alternatively, it may be necessary to employ catalytic conversion systems which are both large in size and economically expensive, in order to reduce CO and unburned hydrocarbons emitted from combustion chambers to acceptable levels. Such structures generally are complex and relatively expensive to manufacture. Additionally, high levels of CO and unburned hydrocarbon emissions from combustion chambers contributes to catalytic converters becoming spent, which leads to removal and replacement in the exhaust portion of the engine.

Accordingly, there is a need for systems for reducing the levels of CO and unburned hydrocarbons from combustion chambers.

OBJECTS AND SUMMARY OF THE INVENTION

In light of the foregoing, it is an object of the invention to provide a system for reducing the levels of CO and unburned hydrocarbons emitted from combustion chambers.

This and other objects of the invention are accomplished by a system for providing gaseous material to a combustion system comprising control means for detecting change of the rate of combustion in the system and for initiating admission of gaseous material into the system; and means responsive to said control means for drawing gaseous material from a source of gaseous material and admitting the gaseous material into the system at a position downstream of a carburetor in the system.

The invention further comprises a method for reducing CO and unburned hydrocarbons levels emitted from a combustion engine comprising detecting a change in the rate of combustion in the engine and in response thereto admitting a gaseous material to the system at a position downstream of the carburetor.

The invention further comprises a method for providing gaseous material to a combustion system comprising detecting a change in the rate of combustion in the system and in response thereto admitting gaseous materials to the system at a position downstream of the carburetor.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic of a system for providing gaseous material to combustion chambers of the present invention. Figure 2 is a plot of substance concentration versus time for engine runs employing and not employing a system of the invention.

Figure 3 is a plot of substance concentration versus time for engine runs employing and not employing a system of the invention.

Figure 4 is a plot of substance concentration versus time for engine runs employing and not employing a system of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to Figure 1, there is shown a system of the invention in combination with an automotive engine. The system comprises a diaphragm mechanism 10 containing a valve 12, and connected to conduits 14, 16, 18. Conduit 14 leads to the intake manifold 22 of a combustion system. Conduit 16 leads to a solenoid- operated valve 20. Conduit 18 leads to a position upstream in the combustion system from the intake manifold, such as to air filter 24. Located between air filter 24 and intake manifold 22 of the combustion system is a drive throttle lever 26. Downstream of the intake manifold 22 is a combustion chamber 28.

A control unit 30 is coupled via line 32 to solenoid-operated valve 20. Control unit 30 can be any processor capable of receiving input signals and generating output signals. Preferably, control unit 30 is a conventional microprocessor. Control unit 30 is capable of receiving input from the ignition system (not shown) through line 34. Control unit 30 is also connected to contact pickup 50, through line 54.

Solenoid-operated valve 20 is coupled to conduit 36, which leads to atmosphere. Conduit 36 is capable of drawing air from the atmosphere into the system through valve 20. Valve 20 is also coupled to conduit 38, which branches into conduits 40, 42. Conduit 40 leads to the combustion system, preferably at a point in proximity to carburetor 44. Conduit 42 preferable leads to a vacuum control unit having components 46, 48. The vacuum control unit, with components 46 and 48, is connected to a second control lever 52, and is capable of operating second control lever 52. In place of, or in addition to, the vacuum control unit, the system can include any means capable of controlling lever 52, such as a pressure operated actuator. Second lever 52 is coupled to valve 20 via line 60. In operation, the system performs as follows.

When the automotive system enters a deceleration mode, throttle drive lever 26 contacts pickup 50, which is moved against second lever 52. This closes a circuit formed with lines 54, 60, and causes control unit 30 to operate valve 20. Valve 20, in turn, draws vacuum pressure through conduit 16, and thereby opens valve 12 by releasing the diaphragm of mechanism 10.

When valve 12 is open, air is drawn from air filter 24, through conduit 18, to conduits 14, 16 by passing through open valve 12. Air is then fed through conduits 14, 16 to intake manifold 22. Air fed through conduit 14 passes directly to intake manifold 22, while air fed through conduit 16 passes through solenoid- operated valve 20, conduit 38, and conduit 40 to intake manifold 22. Preferably, addition of air into intake manifold 22 lasts for less than about 15 seconds, and more preferably for about 5 to 6 seconds. When pickup 50 is moved away from second lever 52, the circuit formed with lines 54, 60 opens, thereby causing control unit 30 to close valve 20 and halt air flow through conduits 14, 16 to intake manifold 22.

In a preferred embodiment of the invention, control unit 30 is programmed to operate valve 20 in order to provide pulsed air addition into intake manifold 22. It is preferred that valve 12 operate at a frequency of about 0.5 to 5.0 Hz. In a particularly preferred embodiment, valve 20 pulses such that valve 12 is opened at a frequency of about 1 to 2 Hz.

In another embodiment of the invention, exhaust gases exiting from the combustion chamber and catalytic conversion system can be recirculated through the system in order to further increase the efficiency of conversion of unburned hydrocarbons and carbon monoxide.

It has been found that a system such as those described herein can desirably increase the burning of CO and unburned hydrocarbons in the combustion chamber. Additional air, with its attendant increase in oxygen content in the system, serves to increase the efficiency of the combustion process, thereby burning a higher percentage of hydrocarbons and oxidizing a greater amount of CO to C0₂. A significant advantage of systems of the present invention is that increased air intake can be predicated upon, and controlled in relation to, engine load. It has been found that when an engine changes from a load mode, such as in acceleration or maintenance of engine speed, to a deceleration mode (referred to herein as a period of motored engine operation) , CO and unburned hydrocarbon levels can increase beyond acceptable limits. With the present invention, upon change of engine mode from load to deceleration, the system operates to add air to the intake manifold, below the carburetor.

Systems of the present invention can be utilized in combination with combustion and catalytic conversion systems. In particular, systems of the present invention can be used in combination with catalytic conversion systems such as those described in co-pending applications U.S. Serial Nos. 840,860, 841,356, and 841,357, each filed February 25, 1992, whose disclosures are incorporated herein by reference.

The following examples are illustrative of the system of the invention.

EXAMPLE 1

A system such as that depicted in Figure 1 was employed. The internal diameter of conduits 14, 16, 18 was 6 mm. A Volkswagen engine, employing a catalytic conversion system and muffler such as those described in U.S. Serial Nos. 840,860, 841,356, and 841,357, each filed February 25, 1992, was employed.

The engine was thermostatically controlled at about 72°F for a period of about 24 hours prior to testing. Three runs wer,e made. In one run, the engine was started and run for a period of about 7 minutes without any additional air feeding. In a second run, the engine was started and run in a simulation including motored periods of operation. After about 20 seconds air feeding was commenced and fed to the system continuously during simulated motored operation. The simulation lasted about 7 minutes. In a third run, the engine was started and run in a simulation including motored periods of operation. After about 20 seconds air feeding was commenced and fed to the system at a frequency of about 1 Hz during simulated motored operation. The simulation lasted about 7 minutes.

A plot of substance concentrations present in the system exhaust over time is given in Figure 2. From the Figure, it can be seen that the levels of CO and unburned hydrocarbons are generally lower when additional air is added to the system.

EXAMPLE 2

The effects of pulsing the air feed into the intake manifold were studied. A system similar to that described in Example 1 was employed. Three runs were made. In one run, the engine was started and run for a period of about 8 1/2 minutes without any additional air feeding. In a second run, the engine was started and after about 20 seconds air feeding was commenced and fed to the system during simulated engine motoring at a frequency of about 1 Hz for about 8 1/2 minutes. In a third run, the engine was started and after about 20 seconds air feeding was commenced and fed to the system during simulated engine motoring at a frequency of about 2 Hz for about 8 1/2 minutes.

A plot of substance concentrations present in the system exhaust over time on scales such as those given in Figure 2 is shown in Figure 3. From Figure 3, it can be seen that the levels of CO and unburned hydrocarbons are generally lower when additional air is added to the system. Air fed at a frequency of about 2 Hz led to improved performance over air fed at about 1 Hz, particularly with respect to CO content in the first three minutes of the run.

EXAMPLE 3

The effects of pulsing the air feed into the intake manifold were again studied. A system similar to that described in Example 1 was employed. Two runs were made. In one run, the engine was started and run for a period of about 8 1/2 minutes without any additional air feeding. In a second run, the engine was started and after about 20 seconds air feeding was commenced and fed to the system at a frequency of about 2 Hz during simulated engine motoring for about 8 1/2 minutes. A plot of substance concentrations present in the system exhaust over time is given in Figure 4. From the Figure, it can be seen that the levels of CO and unburned hydrocarbons are generally lower when additional air is added to the system.

Claims

WHAT IS CLAIMED IS:

1. A system for providing gaseous material a combustion system comprising:

(a) control means for detecting change of the rate of combustion in the system and for initiating admission of gaseous material into the system; and

(b) means responsive to said control means for drawing gaseous material from a source of gaseous material and admitting the gaseous material into the system at a position downstream of a carburetor in the system.

2. A system according to claim 1 wherein the control means includes a drive throttle lever adapted to contact a contact pickup in order to signal a change in the rate of combustion in the system.

3. A system according to claim 2 wherein the control means further includes a microprocessor capable of initiating admission of gaseous material into the system through a conduit connected at a first end to a source of gaseous material and at a second end to the system.

4. A system according to claim 1 wherein the responsive means includes a valve adapted to be opened by said control means.

5. A system according to claim 4 wherein the valve is a solenoid-operated valve.

6. A system according to claim 5 further comprising a diaphragm valve responsive to the solenoid- operated valve and positioned in the conduit.

7. A method for providing gaseous material to a combustion system comprising detecting a change in the rate of combustion in the system and in response thereto admitting gaseous materials to the system at a position downstream of the carburetor.

8. A method according to claim 7 wherein the step of detecting change in the rate of combustion in the system comprises moving a drive throttle lever in contact with a contact pickup to close a circuit formed with the contact pickup and thereby sending a signal to a control means for detecting change of the rate of combustion in the system.

9. A method according to claim 8 wherein in response to detection of change in the rate of combustion in the system the control means activates a solenoid- operated valve to initiate admission of gaseous material to the system.

10. A method according to claim 9 wherein activation of the solenoid-operated valve opens a diaphragm valve responsive to the solenoid-operated valve and which is positioned in a conduit connected at a first end to a source of gaseous material and at a second end to the system.

11. A method according to claim 7 wherein the gaseous material admitted to the system includes oxygen.

12. A method according to claim 11 wherein the levels of CO and unburned hydrocarbons levels emitted from the system are reduced by at least about 95 and 80 percent, respectively.

13. A method for reducing the emissions of CO and unburned hydrocarbons from a combustion engine comprising detecting a change in the rate of combustion in the engine and in response thereto admitting a gaseous material to the system at a position downstream of the carburetor.