|
AirDog Information |
||||||
|
Diesel engines, since their
inception, have suffered from lost power, unnecessary excess
fuel consumption, and increased levels of soot present in the
exhaust as the fuel filter becomes more restricted with use.
This is a sign of an inadequacy somewhere in the fuel injection
system or the fuel supply system. Additionally, the diesel
engine has a rough and wet idle that can wash the rings and
liners of oil, reducing engine life and contaminating crankcase
oil. Diesel engines also suffer a drop in torque output at the
higher operating speeds, 1200 to 1500 rpm, and, as "in use"
diesel engines accumulate operating hours, levels of NOx gases
in the exhaust increase. After-treatments such as EGR and catalytic converters treat only the effects of diesel engine problems. They do not address the cause. By eliminating the cause of the problem, peak performance and efficiency is not only obtained from your diesel engine, but consistently maintained. The actual cause of these diesel engine deficiencies has not been recognized and eliminated until now. The Untold Story Entrained air and fuel vapors are compressible. The presence of air/vapor in the fuel injector delays the pressure buildup. The effect, “Retarded Injection Timing” results in lost power, increased fuel consumption, and increased exhaust emissions, all of which increase as cavitation increases. Lost torque at higher operating rpms is a result of excessive “Retarded Injection Timing” caused by increased pump cavitations. The wet, rough idle of the diesel is also a result of “Retarded Injection Timing”. The retarding of the injection timing on the diesel engine has a similar effect on performance as that of a gasoline engine in severe need of a "tune-up". The development and widespread use of ECM and electronically controlled fuel injector is an attempt by the industry to obtain precise injection timing. The ECM, however, cannot deal with the presence of air/vapor in the fuel. Rough idle, high fuel consumption, lower than rated power, increased smelly exhaust with increased EMISSIONS are the result of the incomplete combustion of fuel. The result of “Retarded Injection Timing” is a consequence of the inadequate vacuum feed fuel filtration concept. HARD FACTS Diesel fuel contains varying degrees of entrained air! Entrained air can be in the form of foam on the surface or suspended in the bulk fluid in the form of tiny bubbles. Additionally, pumps such as the transfer pumps used on diesel engines will cavitate. Cavitation is a condition in which the fuel pressure/flow at the inlet to the pump is not sufficient to fill the pump. This allows large volumes of fuel vapor to develop within the pump to be introduced into the fuel injection system. Cavitation increases as the fuel filter plugs with use, engine rpm increase, as fuel levels drop with consumption, fuel temperature increase, and when operating at higher altitudes. These are the conditions that affect all diesel engines, today! "The most destructive fluid contaminant is air", states Milwaukee School of Engineering Handbook on Hydraulics. "it causes severe cavitation and can destroy a pump in a matter of minutes." Caterpillar® points out in their Special Instruction, 651-1250, “normally No. 2 diesel fuel contains about 10% air in solution". When explaining the low fuel level in primary fuel filters, Cummins® stated in their Service Topic 5-135, "the source of the vapor is the fuel itself". Precise metering of the fuel and exact injection timing is impossible with the presence of air/vapor in the fuel system. Without precise injection timing, consistent peak engine performance, maximum efficiency and clean exhaust is impossible. Totally Inadequate: The vacuum feed fuel filtration concept currently in use on diesel engines worldwide may remove water and particulate contaminates, however, it DOES NOT remove the #1 contaminate, entrained air/vapor, and it DOES NOT deliver fuel to the engine at a consistent, positive pressure great enough to meet the needs of the transfer pump. Rating the efficiency of the filter and/or the system by stating the pressure drop or vacuum has nothing to do with the pressure/flow requirement necessary to fill the transfer pump, especially at higher operating speeds. The vacuum feed filtration concept is inadequate as a filtration system and falls far short (as evidenced by performance issues through fuel filter plugging and cavitation) as an appropriate means to present fuel to the diesel engine. The vacuum feed filtration concept is the absolute heart of the performance, efficiency, and emission problems of the diesel engine, today. Entrained air/vapor and fuel vapor cause pitting and gaulding of the injector barrel and plunger, tip erosion of the nozzle, and metal on metal wear. Air/vapor present in diesel fuel is the single most evident source of lost diesel engine performance, lost efficiency, and increased tail pipe emissions. Test Cell vs. Real World Test cell fuel conditions lack the agitation of “in use” equipment. A large quiet storage tank equates to lower levels of entrained air present in the fuel. Also, the test cell fuel supply tank or “day tank" is usually mounted six or more feet above the floor as a convenience; this gives a positive, but limited, pressure to the engine. Less entrained air/vapor and less pump cavitation will allow the test cell engine to operate at a higher level of efficiency than the day-to-day performance of a diesel engine in "real world" operation. Thus performance problems caused by the presence of air/vapor are less noticeable in test cell engines. A new or rebuilt engine, as tested in the test cell does not have the high level of unburned hydrocarbons present in the exhaust, therefore carbon deposits have not developed in the combustion chamber nor have the ensuing levels of NOx emissions in the exhaust as does an “in use” engine. The Solution: Restoring and maintaining the performance, efficiency and emission levels of the "in use" diesel engine back to the levels intended by the designers of the engine is simple. Remove the conditions that create the problems, remove entrained air/vapor from the fuel, and meet the fuel flow needs of the pump, eliminating cavitation. This is not as easy as it might seem! In more than 100 years of the existence of the diesel engine, there have been many attempts by individuals and corporations the world over, to remove entrained air/vapor from diesel fuel. The effort to develop a working air/fuel separation system began before 1900 and has attracted big players, as evidenced through their attempted patents. For example John Deere of Waterloo, Iowa, 1940; Chicago Rawhide Manufacturing of Elgin, Illinois, 1983; The Stant Corporation of Connersville, Indiana,1985; Lucas Industries of Birmingham, England, United Kingdom, 1988; and again, in 1988 by Mannesmann Kienzle GmbH of Germany. The devices developed and patented by these groups are not commercially available today none of them had a positive air/vapor separation system or solved the problem of pump cavitation. The patented AirDog™ addresses the basic fuel filtration and delivery needs of the diesel engine. Issues that when eliminated allow the engine optimum engine performance and efficiency under virtually all operating conditions. Filtration requirements are met by removing contaminates, including water, particulates to 10 micron, and especially entrained air/vapor. Fuel flow requirements are fulfilled by maintaining a monitored pressure/flow of fuel that meets or exceeds the demand of the engine transfer pump. Eliminating pump cavitation and removing compressible entrained air/vapor restores injection timing to designed specifications; thus allowing the diesel engine to operate at test cell performance levels or better, in “real world” operation on a daily basis. A report pertaining to the AirDog™ by the University of Illinois states: "The results of the injector timing with a conventional filtering system showed that the spray timing lagged" and "the results of the spray timing with the AirDog™ was consistent every time the injector fired." Charts in the report also show that the amount of entrained air/vapor present in the fuel after 1 1/2 hours of operation was equivalent to the same volume vapors produced by a pump restriction of approximately 12 inches vacuum (hg).
Furthermore, the University of
West Virginia reported torque; off idle was increased by
approximately 100%, at peak reaching approximately 6% higher
than test results on the same engine without the AirDog™, in
addition, torque did not drop at the 1200 to 1500 rpm, as it
does with the vacuum feed system. This West Virginia report
(based on test cell conditions rather than true operating
conditions) stated that "the AirDog™ was
very effective in removing entrained air from the fuel supply
system" in addition, tests from Doe Run Company, Southeast
Missouri Mining and Milling Division; Canyon Fuel LLC., Dugout
Canyon Mine of Price, Utah; U. S. Silica Company of Berkeley
Springs, WV.; and the Metropolitan Health Department of
Nashville, TN., documented a reduction in hydro carbons of 21.6%
to 76.8%, and a reduction in NOx gases of up to 46%. |
||||||
|
|
