This undesirable condition would result in a loss of air density and power, a higher temperature within the cylinder, and a higher exhaust gas temperature. In some installations, roots blowers and turbo-chargers are used together within one system. These two components serve to compress the air more efficiently than would be possible if only a blower or a turbocharger were to be used separately. As we discuss this type of system, refer to figure 6-12. In operation, air is drawn into the blower section of the turbocharger through the air cleaner.
Air is compressed and the temperature is increased.
The cooled dense charge of air is then routed to the roots blower inlet. The roots blower further compresses the air and delivers it to the engine. After the combustion and power event are completed, the exhaust valves open and the hot exhaust gases are discharged to the exhaust manifold. The hot, high-velocity exhaust gases are directed to the turbine section of the turbochargers where they drive the turbine wheel at high speed. During this process, the pressure and the temperature of the exhaust gases are reduced and some of the energy that would otherwise be lost is used to drive the turbocharger.