An air starting system uses compressed air to rotate the crankshaft and initiate combustion in a diesel engine, especially during cold starts. Here are the key components:
1. Air Compressor:
* Function: Compresses atmospheric air to a high pressure, typically around 300-400 psi, for starting.
* Types:
* Reciprocating compressors: Most common type, using a piston and cylinder to compress air.
* Rotary screw compressors: More efficient than reciprocating compressors, but more expensive.
* Centrifugal compressors: Often used in large engines, requiring high airflow.
2. Air Receiver:
* Function: Stores compressed air from the compressor, acting as a buffer to ensure continuous air supply for starting.
* Features:
* Fitted with safety valves to prevent overpressurization.
* Equipped with a pressure gauge to monitor air pressure.
3. Starting Air Manifold:
* Function: Distributes compressed air from the receiver to the starting valves.
* Features:
* Contains a pressure regulator to control the air pressure delivered to the engine.
* May include an air dryer to remove moisture from the air.
4. Starting Air Valves:
* Function: Control the flow of compressed air to the cylinders during starting.
* Types:
* Solenoid valves: Electromagnetically controlled, allowing for remote starting.
* Pneumatic valves: Controlled by air pressure, often used in larger engines.
* Manual valves: Operated manually, typically used in older engines.
5. Starting Air Piping:
* Function: Connects the components of the starting system, transporting compressed air from the receiver to the cylinders.
* Features:
* Typically made of heavy-duty steel pipe.
* Must be properly sealed to prevent leaks.
6. Starting Air Motor:
* Function: Transmits compressed air to the crankshaft, rotating the engine to initiate combustion.
* Features:
* Connected to the crankshaft via a gear train.
* Consists of a piston and cylinder arrangement similar to a reciprocating compressor.
7. Air Consumption Gauge:
* Function: Monitors the amount of compressed air used during starting.
* Features:
* Typically a dial gauge located on the dashboard.
* Helps identify problems with the starting system.
8. Safety Devices:
* Function: Protect the system and operator from potential hazards.
* Types:
* Pressure relief valves: Prevent overpressurization of the receiver.
* Safety interlocks: Prevent starting the engine if safety conditions are not met.
* Fire suppression systems: Mitigate fire hazards associated with compressed air.
Note: The specific components and their arrangement may vary depending on the type and size of the diesel engine.
