Comparison of Common Gluten Dewatering Methods & Equipment in Corn Starch Manufacture Industry

In recent years, corn starch industry has maintained steady growth rate and corn starch processing technology has matured and stabilized. However, protein dewatering process and equipment used tend to vary from case to case.

In corn wet milling process, after extraction of germ and fiber, centrifugal separators are normally used for separation of gluten from starch, yielding thin gluten liquid of 15-25g/l density. This in turn is thickened by gluten thickener (GT) to obtain thick gluten liquid of 80~110g/l density. Thick gluten liquid needs to be further dewatered and dried to yield final commercial gluten powder. Currently, the rotary vacuum filter (RVF) and plate and frame filter press are widely used for this application. Another alternative, tried by some processers, is the decanter centrifuge. The following part of this paper is a brief comparison between these common protein dewatering methods and related equipment.

1. Rotary Vacuum Filter (RVF)

RVF currently represents the mainstream gluten dewatering equipment for maximum separation of insoluble gluten from water.

Rotary Vacuum Filter Structure

This process is preferable for the features below:

● Long-time continuous operation mode.

● High automation level leading to simplified operation procedure, reduced human interference in the operation process, and reduced labor cost requirement.

● Clean production environment as the complete dewatering process takes place inside the enclosed equipment chamber.

Nevertheless, the RVF is not free from disadvantages. Moisture content of the discharged material moisture is relatively higher at 58%~60% and power consumption is comparatively higher.

2. Plate and Frame Filter Press

The plate and frame filter press came into use earlier than rotary vacuum filter and is currently still used in some starch factory for gluten dewatering process.

The most obvious advantages of plate and frame filter press is the relatively lower moisture content in the discharged material at 50%~55% and lower power consumption.

Plate and Frame Filter Press

The negative side of plate and frame filter press is:

● Incapable of continuous operation as it relies on pressure, which needs to be maintained for some time, to remove water from protein. The solution is to use multiple units in parallel.

● Intense work load for the operator for moving plates apart and cleaning the cloth. Although mechanical plate parting devices have been tried, human interference in this process is still required.

● Undesirable working environment due to scattering of protein particles on the operation platform.

3. Decanter Centrifuge

About 10 years ago, some corn starch processors started experiment with decanters with little success. In recently years, with the progress of technology, decanters are again used for protein dewatering.

Decanter Centrifuge Structure

The decanter centrifuge has the following advantages:

● Smaller operation space requirement than RVF and plate & frame filter.

● Capability of continuous operation.

● High level of automation and lower labor intensity.

● Clean and hygienic operation without pollution caused by scattering of protein and acid gas.

On the other hand, decanter dewatering application requires addition of chemicals into the thick gluten liquid. There is so far little sure evidence for its watering effect even though some manufacturers assure that the moisture content of the discharged material will be at 55~58%.

Conclusion: From the above comparison, it can be concluded that each of these three methods has pros and cons. The choice depends on comprehensive consideration of various factors that include availability of workshop space, initial investment, cost of steam, electricity and labor, cost of consumables, operation environment, and user-friendliness. Currently, most corn starch processors in China opt for RVF for this application.

Myande Participated in the 11th International Starch Exhibition in Shanghai

From June 21 to 23, 2016, the 11th International Starch and Starch Derivatives Conference was held in Shanghai International Expo Center. More than 3,500 companies from all around the world participated in the exhibition. Myande exhibited some core starch processing equipment, including centrifugal separator, impact mill and screw press.

Sponsored by China Starch Industry Association, this exhibition is generally recognized as a major international event in starch processing industry. During the exhibition, Myande introduced to potential customers technical performance and advantages of its complete range of starch processing equipment by means of prototype machines, brochures and multimedia visual aids. In addition, Myande team had ample technical communication with current and potential buyers on various topics relating to starch processing technology, equipment, and engineering, such as energy-saving evaporation, and sweetener processing.

Myande Elected as China Starch Industry Association Executive Director

The 8th General Assembly of China Starch Industry Association was successfully held in Shanghai Everbright Convention & Exhibition Center on 19th June, 2016. Myande was elected as the Executive Director. Myande vice-chairman Mr. Wang Mu gave a speech at the opening ceremony. Mr. Liang Yong, vice general manager of Myande’s Starch Engineering Division, delivered a speech entitled “Innovative Equipment Manufacturing Boosting Industry Upgrading” on 20th, June.

Focusing on environmental protection, and following the strategy of sustainable development, Myande is committed to providing its customers with safe, reliable and energy saving equipment in the starch professional field featuring maximal utilization of steam. Corn starch process involves closed thermal recycling process is which steam as heat source is applied for drying starch, germ, fiber and gluten. Myande corn starch technology enables corn starch processors to recycle hot exhaust air and condensate water and thereby achieves more effective and economical utilization of energy. The emission of waste vapor and water is thus reduced to the minimum. Benefits of this technology include savings on energy and water and reduced impact on the environment.

What is Full Automatic MIIM Control System?

On January 4, 2016, Myande and China Huaye Group Company signed a contract by which Myande supplied Shandong Fukuan biological Engineering Co a full automatic DCS control system to be incorporated in a corn starch processing line with capacity of 300,000 ton per year. During the tender of this automatic control system project, the owners put forward high requirements on the automatic control system of all the production line. They hope that the automation and unattended operation can be realized during the production.
Myande automatic control system designing team consists of over 30 engineers and have designed and supplied more than 200 automatic control systems for starch, oils & fats, fermentation, and energy saving & evaporation projects. Myande’s typically fully automatic MIIM control system effectively improves control efficiency with some unique features.

1. High combination of automation and process design
There is a widely recognized principle in starch industry that automation design team without sufficient understanding of starch processing technology is not in a good position to come up with effective automatic control systems for starch processing industry. Myande Group is a professional supplier of machinery & engineering services in starch, vegetable oil, and fermentation industries with strong product R&D capability and process design capability. So the control plan of each complete project is determined after many exchanges and communication between automation engineers and process engineers. Automation engineers typically participate in the process design, site installation, commissioning and other aspects of the project. Automation is a combination of technology and process, which is the essential difference of Myande automation team and general automation company.

2. Comprehensive technical ability
Myande automatic control system service covers low voltage system, PLC system, DCS system, electrical installation, electrical and automatic control system, and on-site commissioning. The team provides a full range of electrical and automation solutions for the customer. The biggest benefits for our customers include in reduced cost of communication between the suppliers of low voltage electrical components and DCS control system, shortened delivery time, and improved quality of the whole project.

3. Combination of automation and 3D design
In electrical and automation engineering, the statistics of material is a very important part. If statistic is not exact, it will result in buying more material, increasing costs and waste. In addition, it will also cause extension of construction period due to the lack of material. Myande has a professional 3D design team and typically use 3D design to resolve this problem perfectly. During the installation design, this team will model the workshop in accordance with 1: 1 proportion. In the 3D drawing, each equipment and instruments, valves can be positioned and electrical and instrument trays also will be described in detail, so as to avoid the interference between the tray and the pipeline, and also have a precise statistic material specifications and quantity of cable, cable tray and other installation materials in the generated list of materials.

4. Combination of automation and equipment
Myande has a strong mechanical design and manufacturing capacity that can provide customers with most major starch production equipment, such as, centrifugal separator, pin mill, screw press, tube bundle dryer and starch dry system, etc. The company will have all the staff to carry out the relevant training of mechanical equipment so that automation engineers can know how to utilize automation control technology to maintain equipment safety and continuous running.

5. Guarantee of reliable brand 
Myande insists on using internationally renowned brands and has entered into strategic cooperation agreements with many internationally renowned brands, such as, SIEMENS, Schneider, ABB, Danforth, E+H, Emerson, EBRO, ARI, SPIRAXSARCO, etc. By using reliable parts and components, Myande is in a good position to guarantee safety, reliability and stability of the electrical automation system.

6. Project implementation capability
All projects will have a standard project management process. After the plan of project implementation is made, relevant professional person will be responsible for each node of project implementation. At the same time, there are corresponding records, feedback about every step of the project, which can ensure timely delivery of the project with high quality.

7. Perfect after-sale service system
At present, the automatic maintenance of starch production enterprises is not particularly strong, so after-sale service is very important. At the beginning of the establishment, Myande always holds on to the purpose of “Move forward with customers”. Excellent after-sale service is Myande's solemn commitment to customers. The automation team relies on the advantages of Myande Group in order to supply durable and lifelong after-sale services for customers.