Introduction

Ejectors are used extensively in the fine chemical and pharmaceutical industries as part of a simple and reliable process system for batch sampling corrosive liquids and solvents. There are two options available a Direct Transfer System or an Indirect Transfer System as shown below:

Direct Transfer System

In operation an Ejector uses motive gas (typically air or nitrogen) to create a vacuum to entrain process liquid from a reactor. The resulting mixture is discharged into a transfer pot where the two fluids separate. Gas leaves the transfer pot via a demister pad to atmosphere or to the plant pollution control system. Once the volume of liquid reaches the preset level in the transfer pot the Ejector is switched off. The process liquid sample is simply drained by gravity from the transfer pot and any excess liquid returned to the reactor.

Indirect Transfer System

The Ejector uses motive gas (typically air or nitrogen) to create a vacuum within the transfer pot to draw in process liquid. Gas from the Ejector can be discharged to atmosphere or to the plant pollution control system. Once the volume of liquid reaches the preset level in the transfer pot the Ejector is switched off. The process liquid sample is simply drained by gravity from the transfer pot and any excess liquid returned to the reactor.

Advantages

• No moving parts
• Maintenance free
• Simple to operate
• Easy to install
• Compact
• Custom designed
• Suitable for hazardous areas
• Available in most materials
• Contact parts to suit process fluids

Design

Each TRANSVAC GAS-JET Ejector is custom designed with materials of construction and motive gas selected to suit the process conditions. Single units or packaged systems can be supplied including transfer pot, level controls and local pipework.

Construction

For this application, standard materials of construction include PTFE, polypropylene and stainless steel, but we can offer hastelloy, titanium and other suitable materials with flanged or screwed connections. PTFE and polypropylene units can also be supplied with carbon steel support shells. The units are designed to comply with the latest European standards and CE marked where applicable.