Dust explosions in sugar-producing plants were always common, and unfortunately there are still dust explosions every year which can have quite serious consequences. In terms of safety, the grinding of potentially dust-explosive products is associated with special demands with regard to technology, quality and the execution of a grinding plant.
The up to 10 bar (g) pressure-shock-resistant design of the grinding system is the most common one, but needs, however, a significantly higher effort for the quality and durability of components.
Sugarplex SX – the economic and compact pin mill for the sugar industry
Since more than 120 years, Hosokawa Alpine has been a specialist and is well-known in the market of fine grinding. The oldest known Alpine sugar mill started production in 1934. In 1969, the oldest known mill still running in the food industry started production. Since 2009, ALPINE has sold more than 30 special-design pin mills called Sugarplex.
The Sugarplex was especially tailored to the needs of the sugar industry (e.g. baking, beverages) and is based on the tried-and-tested milling principle of the Alpine Ultraplex fine impact mill. The Alpine Sugarplex SX is an extremely compact system that needs neither additional filters and fans nor the air cooling units that are standard with traditional system designs for sugar milling. This means that operation of the plant equates to lower investment costs, reduced space requirements and lower cleaning and maintenance costs. The cylindrical design of the mill includes a container with a conical product discharge and can be easily integrated into an existing system or building.
The effective mechanism of Sugarplex SX
The crystallised sugar is fed via a rotary valve through the mill door directly into the center of the milling mechanism. The milling mechanism, consisting of 2 pin discs, is completely integrated into the mill door. The door can be opened quickly and easily and can be swung wide open so that the user can inspect or clean the milling tools at any time without problem. The mill is driven by a direct motor that is suitable for the European explosion-protection regulation ATEX Zone 22. The inner pin disc sits directly on the motor shaft and rotates with speeds of more than 120 m/sec. A special seal prevents oil from penetrating the product area and sugar or washing water going in the opposite direction. Via a frequency inverter, the rpm of the motor is infinitely variable and the desired fineness can be set. As the Sugarplex was developed exclusively for the food industry, it meets all the basic safety and health regulations of the EC Machinery Directive 98/37 EC Annex II and all the safety and accident prevention regulations of the Federal Republic of Germany. The design and construction of the mill corresponds to all harmonised EC standards that must be taken into consideration and the applicable national German DIN standards. The Sugarplex conforms to ATEX and is suitable for interior zone 20 and exterior zone 22.
The Sugarplex 315 SX achieves throughputs of 2.8 t/h at a fineness of 99% < 450 μm (35 mesh) or 1.0 t/h at a fineness of 99% < 125 μm (120 mesh). With up to 10 t/h and 5 different machine models, the Sugarplex can be used in almost every industrial sugar plant. This makes it a very variable and cost-effective solution.
Sugarplex SX – used even in the manufacture of powdered sugar
Powdered sugar, also known as confectioner’s sugar, is used in the beverages, biscuits, confectionery and several other industries. Due to the fine particle size, it will give a smoother mouthfeel in, e.g. fillings and icing, and will often be used to decorate bakery products. If a customer is looking for finer products such as icing sugar, then this can only be achieved with a classifier mill.
Mikro ACM classifier mill – superfine grinding
The Mikro ACM was launched on the market in 1962 as the first classifier mill and has been continuously improved since then to accommodate changing market needs. It is suitable for the size reduction of a great variety of products such as cocoa, chocolate mixes, lactose, fish food, etc. The combination of impact grinding with the integrated dynamic classifier constitutes the perfect solution especially for the fine and ultrafine comminution of soft to medium-hard products. The crystallised sugar is fed into the Mikro ACM pneumatically.
Size reduction is a result of the feed product impacting against the rotating grinding elements and against the stationary liner. At beater tip speeds of more than 130 m/s, fineness values of d99 < 20 µm (635 mesh) can be achieved for icing sugar. The product becomes entrained in the cooling, conveying and classifying air drawn through the mill by the downstream fan. Characteristic for the Mikro ACM is the integrated dynamic classifier. The product/air mixture is distributed uniformly by the guide vane ring to the rotating classifying wheel. Because of the two opposing forces and the different masses of the particles, the product is separated in the classifying zone into a coarse fraction and a fine fraction. The coarse material is rejected by the classifying wheel and returned to the grinding zone for further comminution. The fines pass through the classifying wheel and exit the mill. The cut point is a function of the classifying wheel speed, which can be steplessly adjusted even during operation.
The Mikro ACM is available in almost 20 sizes with drive capacities ranging between 3 and 450 kW.
The ALPINE technology center meets the requirements of today’s world
Sugar comes in many more varieties and can be used in many different food applications. Due to its unique properties, sugar will remain an important ingredient in modern food production. Due to the natural variations of food products, tests at the ALPINE technology centre are recommended. With more than 3,000 m2 and over 65 machines and complete systems, ALPINE in Augsburg has one of the largest testing centres for wet and dry powder processing in the world. In 2016 and in collaboration with Dynamic Air, one of the largest powder technology centres in South America opened to provide the best support for customers. Furthermore in the same year, a centre with the capability for lab tests was opened at Hosokawa Micron India in Chennai.
Innovative technologies for powder production and powder processing as well as blown film extrusion: These are the core strengths of Hosokawa Alpine AG, one of the world’s leading machine and plant manufacturers. The company is headquartered in Augsburg, Bavaria, with a branch in Leingarten, Baden-Württemberg. Together with several subsidiaries in ...