Industrial, Inline, Process Refractometers

Industrial inline refractometers use of the principle of refractometry to assess the physical qualities of fluid. Using the device, the refractive index of the fluid is measured, which indicates whether the product is according to specification. The fundamental physical property helps in determining the purity and composition of fluids. 

Refractometers: An Overview

Refractometers are based on the principle of refractometry. The device measures the speed of a ray of light as it crosses from one medium to another. When light travels across two different media, its density and direction change. The change in direction is known as refraction. 

Every material has a different refractive index (RI) that refers to the ratio of the velocity of light in a vacuum to the velocity in a specific medium. 

Light travels faster in a medium with a lower optical density, resulting in a low reflective index. The lower the optical density of the medium, the lower will be the refractive index due to the higher speed of light. This principle of refractometry is used in various industrial processes for measuring different characteristics of a fluid such as: 

• Hydrocarbon content 
• Salinity
• Sugar concentration
• Protein concentration

Application of Refractometry in Industries 

Refractometry is used in many different industries. Let’s look at the application of the technique of different industrial processes.

Food and Beverage Industry 

Refractometry is commonly used in the beverage and food industry for quality control purposes. The technique helps in determining the purity and consistency of processed foods such as vegetables, jams, coffee, and dairy products.

The three important parameters that are assessed by refractometers in food processing. They include sugar percentage, acidity, and gelling agent concentration. These parameters are assessed to ensure the right mix that results in maximum shelf life.

The device is used for the measurement of percentage by weight of sugar in fruit juice. The measurement is also known as Brix. Accurate Brix measurement is critical for quality and cost control. The measurement can be carried out by assessing the density and refractive index. Both the parameters provide valuable insight into the content of the fruit. 

Chemical Industry 

Refractometry is also used for assessing the concentration of a range of chemicals in industries other than food and beverage. Sensors on refractometers installed on large tank, pipes, and reactor can determine the concentration of dissolved solids by optical measurement of the refractive index. The measurement is not influenced by bubbles, particles, temperature changes, or color of the liquid. 

Oil Refineries

Oil refineries also rely on refractometers to determine the quality of the oil. Refractive index is used to know the identity of the oil immediately. This method helps in quickly checking the oil that is transferred to the storage facility. 

Fertilizer Industry

Fertilizer industry also uses refractometry for assessing the quality of fertilizer solution. Density and refractive index are analyzed to find out the nitrogen concentration in the fertilizer. The method can help in assessing the quality of fertilizers easily, safely,  and cost-effectively as compared to the manual method. 

Pulp and Paper

Pulp and paper mills use industrial refractometers for green liquor and black liquor processing. Green liquor and black liquor are both part of the Kraft Process whereby wood chips are broken down into their chemical constituents and wood pulp.

Other Users of Refractometry 

Refractometry is used in many other industries such as the perfume industry, coolants, lubricants industry, and the milk industry. The process helps in determining the quality and concentration of fluids in different industries. 

Contact Alliance Technical Sales with any questions about the application of process refractometers. They can be reached by phone at 630-321-9646 or by visiting https://alliancets.com.

Alliance Technical Sales Products

By combining world-class products, application expertise, and unsurpassed customer service, Alliance Technical Sales enables its clients to increase manufacturing efficiency, reduce production costs, and improve product quality and value. Each of the manufacturers we represent has extensive experience solving critical service applications with the products they manufacture.

Alliance Technical Sales, Inc.
https://alliancets.com
630-321-9646

Understanding Refraction

This pencil appears to bend when it enters
the water because of the change in the light
ray speed as the medium changes.

Refraction is the directional change of wave propagation caused by a change in the light beams transmission medium.

Light rays travel through space in a straight line at approximately 300,000 km/s. As light passes through a transparent medium, such as water or glass, its speed is decreased.

For glass, its reduced to 200,000 kilometers per second, and for water the speed is 225,000 kilometers per second.

If the light enters into a medium perpendicular to the surface, it passes straight through but at a slower speed. However if the light beam arrives at the medium surface at an angle, not only will it speed be reduced, but it will bend due to a process called refraction.

As a beam of light reaches the surface of a medium the lower portion enters first and is slow down. However, the upper portion is still traveling at the speed of light until it arrives at the surface and enters. This speed difference at the top and bottom aspects of the light path causes it to pivot, bending toward what is referred to as the normal. This is an imaginary line drawn perpendicularly to the surface of the material.
 
Transparent materials have what is called a refractive index. This is the speed at which light travels in a medium compared to like traveling in a vacuum.
   
For example, typical glass has a refractive index of 1.33. This is calculated by dividing the speed of light in a vacuum (300,000 km/s) by the speed of light in glass (225,000 km/s).
   
The refractive index of air is 1.0003. Anytime a light beam travels from a medium with a low index of refraction, like air, to a medium with a higher index of refraction, like glass, the beam of light will bend toward the normal.
   
Likewise when the beam of light exits a highly refractive medium into a medium with the low index of refraction, the process is reversed.
   
The bottom portion of the beam of light exits first, and resumes at the speed of light, with the top portion still at the speed determined by the medium. This causes the beam to pivot away from the normal line.

Instruments used to measure the refractive index are called refractometers. Refractometers used in industrial automated systems are referred to as inline refractometers.

Process Refractometers Used in Industry

Technician adjusts process refractometer in plant.
(Electron Machine)

Process refractometers provide the analysis to quickly, reliably, and very accurately identify a sample and determine it's concentration and purity levels. They measure the refractive index and temperature of flowing liquids, and apply mathematical functions to determine the concentration of dissolved solids.

Part physics, part material science and part chemistry, refractometry is the process which measures the composition of known substances by means of calculating their respective refractive indexes (RI).  Light bends and changes velocity as it travels from one media into another through the media interface. When light traveling through air enters liquid, the light rays change direction by an amount determined by the liquid's density. RIs are evaluated via a refractometer, a device which measures the curve, or refraction. The
unitless number given by the refractometer, usually between 1.3000 and 1.7000, is the RI. The composition of substances is then determined when the RI is compared to a standard curve specific to the material of the substance. Standard tables are available that correlate RI to a variety of materials. These same tables also correlate RI to varying concentrations of particular liquid media at a particular temperature. Take corn syrup for example. Different refractive indexes are observed for different corn syrup samples of different concentrations. Therefore, by using a process refractometer to observe the RI of a particular corn syrup sample, a determination of the concentration of that particular sample can be made. By referring to the table or scale that correlates the RI to concentration at a particular fixed temperature, liquid concentration can be determined.

Common industrial refractometer applications are:

Process refractometer with flanged spool adapter.
(Electron Machine)

• Calculating amount of sugar dissolved in juices and beverages.
• In commercial food applications such as juice production or tomato processing, refractometers are used to measure degrees Brix (the Brix scale relates refractive index to sugar concentration, and is a key way to maintain consistency).
• In the pharmaceutical industry, process refractometers are used to monitor and control concentration levels during supersaturation, a critical process in crystallization.
• In pulp and paper production, process refractometers for measuring dissolved solids in black and green liquor during the chemical recovery process.

Equipment manufacturers have developed numerous refractometer configurations tailored to specific each use and application. Each has a set of features making it the advantageous choice for its intended application. Product specialists are invaluable sources of information and assistance to potential refractometer users seeking to match the best equipment to their application or process.

For more information on industrial refractometers, contact Alliance Technical Sales by visiting https://alliancets.com or by calling 630-321-9646.

Process Refractometers for Food and Pharmaceutical Use

Process refractometer with sanitary adapter
for food and pharmaceutical. (Electron Machine)

There are many industrial applications for process refractometers; particularly useful in the food and pharmaceutical industries, where there is a need for solids content measurement. Process refractometers are used to optimize production processes, ensure consistency and purity, and in managing quality control. Process refractometers and inline process refractometers, are types of refractometers designed for the continuous measurement of a fluid flowing through a pipe or inside a tank. They provide analysis to quickly, dependably, and to accurately identify a sample to determine its concentration and purity levels. By measuring the refractive index and temperature of flowing liquids, refractometers can then apply a mathematical function to determine the precise concentration of dissolved solids.

In commercial food applications such as jam or jelly production or the processing of soft drinks or wine, refractometers are used to measure degrees Brix. Bix is a graduated scale, used on a hydrometer, that indicates the weight of sugar per volume of solution at a given temperature. The Brix scale relates refractive index to sugar concentration, and is a method of maintaining consistency. For example, process refractometers are used for the concentration process of fruit juices. The concentration process is normally achieved by removing water through evaporation, and by measuring Brix, the evaporation process can be controlled and related to the desired juice concentration.

Process refractometers are also used in pharmaceutical processing where there is the need to monitor and control concentration levels during supersaturation, a critical process in crystallization. Crystallization is a critical element in the purification of solids in pharmaceutical production. The process refractometer guarantees precise monitoring and a high degree of measurement accuracy and reliability, towards the production of a pure product.

For more information on the application of process refractometers, contact Alliance Technical Sales by visiting https://alliancets.com or by calling 630-321-9646

Some Recent Literature Updates for Electron Machine Corporation

MPR E-Scan is a rugged, industrialized
in-line process refractometer.
Image courtesy Electron Machine Corp.

Electron Machine Corporation, manufacturer of industrial process refractometers, recently updated some of their product, application and support literature. The new documents are described and linked below. Share your process measurement challenges, and any questions you may have about the Electron Machine process refractometers, with a product specialist. Leverage your own knowledge and experience with their product application expertise to develop effective solutions.

Operating and Service Manual for MPR E-Scan
Service manual for the MPR E-Scan, a hybrid-digital critical angle in-line process refractometer. It is used to measure the refractive index of process fluids.

MDS (Monitor Divert System) Color Manual
Service manual for the Monitor Divert System, a BLRBAC (Black Liquor Recovery Boiler Advisory Committee) compliant Black Liquor solids monitoring system designed specifically for Black Liquor recovery boilers.

Refractometers for Food Industry

Brochure for refractometers used to detect sugar levels and properties of jams juices, beverages, dairy products and much more.

Refractometers for Chemical Industry

Brochure for the MPR E-Scan used for measuring the strength of a chemical when diluted with water or with another chemical.

MPR E-Scan Sales Brochure

The MPR E-Scan is a rugged, industrialized, in-line process refractometer. It directly measures the refractive index of process fluids and then displays the reading in any number of customer-desired units (Brix, Percent Solids, Dissolved Solids, SGU, R.I., etc.).

Applying Process Refractometers in Sugar Cane Processing

In-line process refractometer
Image courtesy Electron Machine Corp.

Sugar cane, after harvesting, requires processing within a limited time window to avoid sugar loss by inversion to glucose and fructose. The traditional two stage process, milling and processing, may be combined in a single modern production facility. Process refractometers can be found in both operations, making an optical measurement of a solution’s refractive index used to determine the concentration of dissolved solids.

To achieve high quality liquid and crystal sugars and contain production cost, refractometers are employed to deliver accurate in-line Brix and other measurements in the cane sugar refining and milling processes.

Specific uses of refractometers in sugar production are:

• Product flow adaptation to evaporator capacity to achieve energy savings.
• Extraction process optimization, minimizing the use of water that will need to be removed at the evaporator.
• Separation column feed juice control to adjust concentration to match capacity.
• Quality assurance check on liquid bulk sugar and molasses.
• Vacuum pan automatic and accurate seeding.
• Monitor supersaturation over complete strike of crystallization.

Share your process analytic and measurement challenges with the experts at application specialists, leveraging your own process knowledge and experience with their product application expertise to develop an effective solution.