Water Ejectors

In light of rising energy costs, saving electrical energy through energy-efficient equipment and installations has become increasingly important. Where heating water would usually be distributed to secondary circuits using a control valve and a pump for each circuit, Baelz North America uses controlled ejector technology. This equipment offers long-term energy and cost savings in heating and ventilation systems. 

Many of our systems have been in operation for over 30 years. Made from durable materials like stainless steel, steel, or bronze, these units are vacuum pumps that run on highly pressurized steam or liquids like water. They rely on driving medium-generated kinetic energy to create the suction that pulls liquid in, ultimately releasing the resultant mixture against a counter pressure. 

Read on to learn more about common ejector applications, their functionality and benefits, and how Baelz NA can support your pumping, mixing, ventilating, and heating operations with high-performance Baelz-Jetomat^® water ejectors.

Applications of Water Ejectors

Water ejectors perform four main functions:

1. Temperature control
2. Flow-variable recirculation
3. Differential pressure control
4. Unwanted circulation prevention

These devices can serve as a replacement for any water control valves as long as the main pump generates a sufficient amount of differential pressure. By switching out water control valves with water ejectors, you can decrease operational and maintenance costs while increasing energy efficiency. The initial investment may be high, but it can lead to more than 15% savings over time.

Some examples of typical applications for these energy-saving pieces of equipment include: 

• Cooling of thermal fluid (hot oil cooling) within the wood industry
• Research and development operations in the educational sector
• Heating, hot water, and ventilation operations in the building utilities sector
• Pumping and mixing operations in the pneumatic conveyance sector

How Do Water Ejectors Work?

Water jet ejectors are commonplace across industries to facilitate mixing and pumping applications. They’re an integral part of a system’s control loop, the components of which interact to create optimized system technology that consumes minimal electrical power. Water acts as the motive force in these ejectors, and they utilize motive liquid’s kinetic energy to entrain a second fluid, mix these liquids, and ultimately expel the mixture against a back pressure.

Within water distribution systems, these units recycle purposefully generated or existing differential pressure. This differential pressure builds up from inlets’ network pressure, surmounting any system resistance. With the help of circulation pumps and three-way valves, ejectors maintain a constant heating supply temperature in conventional control systems (or regulate it based on external temperatures). 

Components of Water Ejectors

Water Ejectors rely on five major components to function:

• Motive Chest: The motive chest allows high-pressure fluid to be introduced into the system. 
• Suction Chamber: The suction chamber contains the appropriate connections for the suction inlet, diffuser, and motive nozzle.
• Motive Nozzle: Typically consisting of Monel or high-grade stainless steel, the motive nozzle converts the pressure energy to velocity and directs the motive media flow into the diffuser.
• Diffuser: The diffuser consists of three sections: the converging inlet diffuser, the throat, and the diverging outlet diffuser. In the inlet diffuser, the mixing of motive and load fluids is completed, and the conversion of velocity to pressure starts. The throat section serves as a connection between the converging inlet diffuser section and the diverging outlet diffuser section. In the outlet diffuser, the conversion of velocity to pressure is completed.
• Actuator: The actuator controls the operation of the ejector. Baelz ejectors come with pneumatic and electric actuator options.

As motive fluid flows through the converging-diverging nozzle, adiabatic expansion from the motive fluid supply pressure to the suction load pressure occurs. This process converts the motive fluid’s pressure energy (i.e., potential energy) into velocity (i.e., kinetic energy), which can then be used to draw in and discharge other fluids effectively and efficiently in single-pump applications that generate a sufficient amount of differential pressure.

For optimal efficiency under your application’s unique operating conditions, it’s necessary to utilize a specialty combination of the geometry for the diffuser, mixing zone, and nozzle. You’ll achieve the highest level of efficiency in particular counter and suction pressures when you find the ideal motive pressure and flow pairing, with the motive pressure aligning with the needs of your specific application.

Advantages of Water Ejectors

Baelz-Jetomat^® water ejectors are ideal solutions for pumping applications because of their:

• Design Simplicity: Serving essentially as simplistic, low-maintenance control valves, these durable ejectors simplify a system’s hydraulics. They’re designed so that consumer circuits won’t require differential pressure controllers or electric circulation pumps with their data points for superordinate HVAC systems and check valves. The volume of water going to the consumer — heat exchanger, static heating, ventilation register, and so on — is adjusted per thermal demand.
• Lack of Moving Parts: Water ejectors have no moving parts to break or incur wear, so you only have to inspect them for maintenance periodically. This is true even if they have float mechanisms, snap valves, regulating spindles, or various other accessories.
• Better Load Stability/Control: They offer controllability across the entire load range, providing precise and accurate water distribution over dozens of circuits.
• Automatic Control: Using a float and snap-valve arrangement, a pressure liquid-regulating spindle, or other accessories, you can adjust water jet ejector systems to enable automatic control.
• Safety: Water ejectors are safe to operate in hazardous settings without requiring costly explosion-proofing, unlike electric alternatives. 
• Greater Energy Efficiency: They ensure the efficient flow of energy through heat transfer fluids and, because of Bernoulli’s equation and the Venturi principle, conservation of the kinetic energy of water (unlike typical three-way valves). You can further improve energy efficiency by using the right control equipment.
• Lower Energy and Maintenance Costs: These devices allow systems to rely on a single pump to distribute fluids, reducing the total amount of energy directed toward pumping operations. By serving as a single-component replacement for multiple circulation pumps, they reduce the amount of time and money spent on equipment installation and maintenance over time.
• Corrosion and Erosion Resistance: Water ejectors are quite flexible in their material construction, as manufacturers can use virtually any workable option. If a material isn’t sufficiently resistant on its own, they can apply corrosion-resistant coatings to better safeguard ejectors against harsh environmental conditions and liquids.
• Ease of Installation: Water ejectors fit well even in areas with limited space and, as they’re typically lightweight, they aren’t too heavy for the pipes that support them. You can make connections based on the needs of your specific piping system.

Water Ejectors From Baelz North America

At Baelz NA, we are a premier supplier of high-quality controllable ejectors designed for durability and dependability. All of our products, including Baelz-Jetomat^® water ejectors, are available at competitive prices and with short lead times. To learn more about our products and the ejectors we offer, you can download our datasheets.

Contact us to discuss your requirements with one of our experts, or request a quote today.