Dosing Ejectors
Dosing Ejectors are essentially Liquid Eductors that operate on the basis of the jet Venturi principle.
Dosing Ejectors typically have 3 connections
- 1. High Pressure(HP) Liquid Inlet
- 2. Suction
- 3. Outlet
During operation Dosing Ejectors are able to create a pressure differential across its Suction and outlet. Dosing Ejectors utilize the energy in pumped liquid entering from the HP liquid inlet to create this pressure differential.
This enables Dosing Ejectors to be used for creating low pressure at its suction. The low pressure allows the Dosing Ejectors to suck liquids through the suction. The suction liquid mixes with the HP liquid inside the eductor and gets pumped out from the Outlet. The discharge contains the mixture of HP liquid and suction liquid.
This phenomenon allows the Dosing Ejectors to be used to suck and deliver a controlled amount of media (liquids ,powders)
By controlling the amount of media sucked and the HP liquid flow, accurate dosing can be obtained through the Dosing ejector. Further the operating flows can be controlled by regulating the HP Liquid, Suction & Outlet Pressures and thus a control on extent of Dosing can also be obtained.
Additionally the Dosing Ejector can also be used for pumping the diluted media thus eliminating any need for an additional pump.
Typical Applications
- Acid Dosing (Sulphuric Acid, Hydrochloric acid)
- Alkali Dosing
- Caustic Dosing
- Lime Dosing
- Powder Dosing (Activated Carbon, Lime Powder, Calcium Carbonate)
Features of Dosing Ejectors
- 4 Serves dual purpose of Dosing and pumping
- 4 Ability to regulate the precise amount of dosage for the application
- 4 Ability to handle powders, granules and lumpy solid matter
- 3 Custom designed models – ensures perfect fit for your application.
- 2 Self Priming mode of operation
- Availability in multiple type of end connections – Flanged, Threaded
- Available in a large variety of materials
| Metallic | Non Metallic |
|---|---|
| Stainless Steels SS 304 / SS 316 | PVC (Poly-vinyl-chloride) |
| Duplex & Super Duplex Stainless Steel | PP (Poly-propylene) |
| Exotic metals (Hastelloy, Inconel, Titanium) | PTFE (Poly-tetra-fluoro-ethylene) |
Benefits of Dosing Ejectors
- Static Device without any moving parts – ensure long reliability and maintenance free operation.
- Tolerate entry of solids particles into the ejector – avoids abrupt breakdowns.
- Small & compact size – allows installation in tight spaces & difficult to access areas.
- Silent Operation
- Non sparking operation – can be safely used in hazardous & flammable areas
- Manufactured in multiple materials – allows using the most cost-effective & chemically compliant materials for the application.
Frequently asked questions (FAQs) about Dosing Ejectors:
A dosing ejector is a type of eductor pump designed to accurately inject chemicals, additives, or other substances into a liquid stream.
A dosing ejector uses a high-pressure motive liquid (such as water) that passes through a nozzle at high velocity. This creates a low-pressure area around the nozzle, allowing the dosing material (liquid chemical or powder) to be drawn into the motive liquid stream. The mixed liquid then exits the ejector, effectively dosing the chemical or powders into the main process stream.
Dosing ejectors are commonly used in water treatment plants, chemical processing industries, wastewater treatment facilities, and in various industrial processes where accurate dosing of chemicals is critical. They are used for adding disinfectants, pH adjusters, coagulants, flocculants, and other additives into process streams.
Dosing ejectors are simple in design, have no moving parts, and are capable of handling corrosive chemicals and abrasive slurries. They provide accurate and proportional dosing without the need for electricity or mechanical pumps.
One limitation is that dosing ejectors require a source of high-pressure motive liquid, which can add to operational costs. They may also have limitations in achieving extremely precise dosing compared to metering pumps in certain applications.
Sizing a dosing ejector involves determining the required motive liquid flow rate and pressure drop across the ejector to achieve the desired dosing rate of the chemical or additive into the process stream. Factors such as chemical concentration, flow rates, and system pressure requirements influence the sizing process.
Dosing ejectors generally require minimal maintenance due to their simple construction and lack of moving parts. Periodic inspection and cleaning of nozzles, diffusers is recommended to ensure accurate dosing and prevent clogging.
Dosing ejectors are designed to handle a wide range of chemicals, including liquids, slurries, and powders. They are suitable for corrosive chemicals and can handle additives with varying viscosities and concentrations.
