Application Stories - Sensors and Instruments in Industrial Automation

Dispensing Controls

Two Challenges in Dispensing - Creating the Dose and Delivering it to the Package

This example demonstrates both! Beverages are packaged in plastic PET containers or aluminum cans for economy and convenience. Thin walled cans and plastic containers require the contents to provide internal pressure for rigidity. Indeed, after opening a beverage container, it is easily collapsed. Carbonation provides the internal pressure making the container rigid, allowing these containers to endure handling during distribution. When you open a container of carbonated beverage, a familiar pop occurs, as the pressurized contents equalizes with atmospheric pressure. But how do non-carbonated beverages -- fruit juices, iced tea, etc make use of thin-walled containers? By adding liquid nitrogen just after filling, before capping. The cold liquid becomes a gas, expands and provides internal pressure. A side benefit - the process drives oxygen out of the package headspace, replacing it with inert nitrogen, preventing oxidation prior to consumption.

Creating the Dose and Delivering it to a moving package.

Speed and movement raise the challenges. The dose travels a fixed distance between the dispensing point and package. As the package speed changes, the dose must be released at a different time relative to package position, just like a quarterback must lead his receiver to complete a pass. When to release depends on distance and speed of the receiver or in this case, the package. And in the liquid nitrogen example, the dose size must be adjusted to compensate for variation in evaporation before the capping.

Dosing PET Bottles with Liquid Nitrogen

Scanning Devices Dispensing Controls offer a wide range of features and configurations to support a variety of dispensing applications. From speed compensated flow rate and pattern generation for liquid adhesives and liquid nitrogen dose delivery, to flavor pouches in food packages and cutting-to-length, Scanning Devices Dispensing controls put the product where you want it.

More on Pressurization with Liquid Nitrogen

Immediately after filling and just prior to capping, a container receives a measured dose of liquid nitrogen -- measured so that, when the liquid nitrogen becomes a gas, there is just enough inert nitrogen gas trapped in the containers headspace (the volume above the liquid in the can or bottle) to provide a positive pressure and keep the container rigid. How is this done? Through a sequence of carefully controlled steps to create and deliver the dose of nitrogen to the container. Scanning Devices microcontroller-based instrumentation: Allows an operator to program the rate of flow of liquid nitrogen and the time to deliver a measured dose (usually in milliseconds), Detects a container moving through a filling machine with a sensor, Measures the speed of the container, Initiates the dose so that the stream of liquid nitrogen enters the container at its mouth. As container speeds change to accommodate the requirements of filling machinery, the dosing point is advanced or retarded so that the dose arrives at the rendezvous spot at the same time as the contain. All on-line in real-time, at rates of hundreds of containers per minute. Instrumentation is used to create the dose and deliver it, adjusting for changes in the package or the process. The result: water, fruit juice or athletic drink in thin-walled containers for economy and convenience.

Vacuum Barrier Corporation Nitrodose System

For information on Liquid Nitrogen Dispensing Equipment using Scanning Devices instrumentation contact:

Vacuum Barrier Corporation
4 Barten Lane
Woburn, MA 01801
781-933-3570
VacuumBarrier.com

To learn more about Scanning Devices Dispensing Controls, contact us directly.

Home Page | Application Stories | Product Information | News | Trade Shows