By Walter Eugster
The highest costs in grain processing are incurred right at the start of all process operations when purchasing the raw material: wheat. A higher yield or better flours have a considerable impact on the profitability of a flour mill.
In the grain milling industry, people know how important wheat conditioning is. To condition wheat means to bring the grain into the condition most favorable for a particular grinding process. At the same time, the wheat moisture also determines the moisture content of the finished product. Correctly conditioned wheat forms the basis for achieving optimal flour yields with a low ash (mineral) content. The conditioning of wheat is a function of the specific wheat variety, the grinding system, the kernel hardness, and the initial moisture content of the raw wheat. But the main requirement for this operation is reliable, high-precision machines and systems.
There are several moisture control systems on the market now. The equipment offered by Buhler is a three-part system — the automatic moisture controller, the liquids flow rate controller, and the Turbolizer dampener ensure that the grist going to the first break rolls has the desired moisture content and that the moisture is uniformly distributed throughout the individual grain kernels.
Today, the moisture content in many facilities is controlled fully automatically. Over the past few years, microwave technology has been found to be a particularly dependable method for measuring moisture and is applied in the Buhler moisture tester. The automatic moisture controller uses an integrated flow rate meter in addition to the microwave technology.
The Buhler moisture controller is an automatic, continuous measurement and control unit for controlling the moisture content of wheat, enabling an efficient and uniform grinding process. Its capacity range is from two tonnes per hour to 60 tonnes per hour.
The sophisticated system consists
of two units. The moisture controller continuously determines the initial moisture of the wheat and the flow rate by means of a flow balancer. On the basis of these values, the controller calculates the precise amount of water needed to achieve the required finished product moisture. A liquids flow rate controller meters the calculated quantity of water to be added to the stream
The water addition rate is 20 to 4,500 liters per hour. Even in the presence of water pressure fluctuations, which may occur very frequently, a consistent water addition rate is ensured. The water throughput is also controlled and monitored.
The system can be easily integrated in any existing wheat cleaning system. The automatic moisture controller with the liquid flow rate controller operates as a stand-alone system, or it can be incorporated in a master process control system. The moisture tester and controller can be applied for dry or pre-dampened tempered grain.
The Turbolizer dampener is used for intensive dampening of the wheat. The newly developed twin-rotor whirling system ensures uniform dispersion of the water through-out the wheat kernel, resulting in thorough penetration of the water into the wheat. Water addition rates up to 7% are possible. The Turbolizer spans capacities from 1 to 48 tonnes per hour.
The performance of the Turbolizer features excellent dampening efficiency, compact design, low power consumption, low maintenance requirements, and outstanding sanitation, due to the fact that all parts in contact with the product are of stainless steel.
The uniform distribution of the moisture throughout the grain kernel and the penetration of the accurately calculated water volume throughout the individual grain kernels, allows consistent achievement of the desired final moisture content. This, in turn, produces optimal mellowing of the grain and excellent grinding characteristics.
Walter Eugster heads the Technology department in the Milling/Bakery business unit at Bühler AG, headquartered in Uzwil, Switzerland.