Croll Reynolds Co., Inc.

Steam Jet Ejector Vacuum System

Steam Jet Ejector Vacuum System

Ejector vacuum systems offer a reliable and economical means of handling and compressing low to high flow gas streams at high, medium, and low levels of vacuum. A vacuum system usually consists of two main components: Ejectors and Condensers. The most critical component of a vacuum system is the ejector, and it consists of four main parts: the steam chest, steam nozzle/s, suction head, and diffuser.  

Condensers are heat transfer device that promotes condensation. Condensers are designed for removing/exchanging heat between a hot fluid and coolant. There are two main types of condensers used in vacuum systems: Direct contact condensers (aka “mixing” or “Barometric”) and Surface condensers (aka “non-mixing” or “shell and tube”). Condensers are normally situated between ejector stages to collect and capture condensable liquid and particles in the stream. This reduces the vapor load handled by each successive ejector, thereby improving overall system efficiency. The number of ejector stages in each design can range from one to six, the number of stages is determined by the level of vacuum required. The number of condenser stages in each design is dependent on the temperature of the cooling fluid at the inlet of the first stage’s condenser.

Advantages

These are the primary advantages of installing ejectors versus mechanical pumps for high-volume, low-pressure applications.

• Reliable, consistent service and outputHandles high volumes of gasses and vapors
• Handles condensable loads that contain liquids and particulate
• No moving parts
• Low initial cost (compared to mechanical pumps)Easy to install and maintain
• Easy to retrofit or upgrade
• Long-lasting and durable equipment
• Can be constructed from a wide variety of steel, alloy, and composite materials including thermoplastics such as PP, PTFE, and PVDF.