Thermal Mass Flow Meter for Nitrogen Tank Blanketing

by Amara Korpi April 06, 2018

Thermal Mass Flow Meter for Nitrogen Tank Blanketing

Nitrogen Blanketing is used in the production of chemicals such as methanol, acetone and benzene and foodstuffs, such as wine and edible oils. When such chemicals come in contract with oxygen, the substance oxidizes and degrades, or can even potentially create a hazardous condition. Hence, the need for Nitrogen Blanketing.

In all instances the user is concerned in maintaining a prescribed level of oxygen to prevent hazardous conditions or to prevent oxidation.

Frequently the COST of providing the nitrogen blanketing is necessary. Using a nitrogen flow meter that can be in series with a pressure regulator, can provide this information. Hence, the need for a Nitrogen Mass Flow Meter.

As well, some more sophisticated systems utilize mass flow controllers to control the flow rate of the nitrogen to ensure a suffficient blanket for the process or system where pressure regulators are not effective, in this case a Nitrogen Mass Flow Controller is appropriate. At issue is these have typically been expensive, until NOW… Tactical Flow Meter introduces the low cost high flow Mass Flow Controller for Nitrogen Blanketing.

Per Wikipedia…. Common practices..

The most common gas used in blanketing is nitrogen. Nitrogen is widely used due to its inert properties, as well as its availability and relatively low cost. Tank blanketing is used for a variety of products including cooking oils, volatile combustible products, and purified water. These applications also cover a wide variety of storage containers, ranging from as large as a tank containing millions of gallons of vegetable oil down to a quart-size container or smaller. Nitrogen is appropriate for use at any of these scales.

The use of an inert blanketing gas for food products helps to keep oxygen levels low in and around the product. Low levels of oxygen surrounding the product help to reduce the amount of oxidation that may occur, and increases shelf life. In the case of cooking oils, lipid oxidation can cause the oil to change its color, flavor, or aroma. It also decreases the nutrient levels in the food and can even generate toxic substances. Tank blanketing strategies are also implemented to prepare the product for transit (railcar or truck) and for final packaging before sealing the product.

When considering the application for combustible products, the greatest benefit is process safety. Since fuels require oxygen to combust, reduced oxygen content in the vapor space lowers the risk of unwanted combustion.

Tank blanketing is also used to keep contaminants out of a storage space. This is accomplished by creating positive pressure inside the container. This positive pressure ensures that if a leak should occur, the gas will leak out rather than having the contaminants infiltrate the container. Some examples include its use on purified water to keep unwanted minerals out and its use on food products to keep contaminants out.

To ensure their safety, gas-blanketing systems for food use are regulated by the U.S. Food and Drug Administration (FDA) and must adhere to strict maintenance schedules and follow all product-contact regulations with regards to purity, toxicity, and filter specs.