High-Viscosity Products

High-Viscosity Products Use of Yokeş® Powermill Convecta® / G - Conventional Horizontal Bead Mill with Dynamic Gap Separator in Wet Grinding of High-Viscosity Products The operating principle of horizontal wet grinding machines (bead mills), in its simplest form, works as follows: the product is pumped into the grinding chamber, enters from one side and progresses toward the outlet. As the grinding beads within the chamber move, solid particles suspended in the liquid product are crushed and broken by the impact and hammering effect created by the beads, reducing particle size and keeping them suspended in the liquid. At the end of the process, the system that ensures the ground product exits the grinding chamber while the grinding beads remain inside is called the separation system. Several different separation systems are used in horizontal-type wet grinding machines. Among these, despite being the oldest application, dynamic gap separators are the most efficient for certain products, particularly those with high viscosity. This system consists of two separators operating with rotor-stator motion, located at the outlet of the grinding chamber. In this system, where the gap spacing can be adjusted with high precision (+/-0.1mm), the ground product can pass through the separators while keeping the beads inside the grinding chamber. The separators are manufactured from sintered carbide materials and are designed to have high resistance to intense zirconia bead friction. Although simpler solutions for separation systems have been developed over time due to the high mechanical precision required, these solutions cannot provide the flow rate and problem-free operation that gap separators deliver for every product, especially at high viscosity. The screen-type separation system used in high-flow bead mills delivers highly efficient results in most wet grinding processes. However, dynamic gap separators operate with significantly fewer problems, particularly in grinding high-viscosity products such as flexographic and rotogravure printing inks and similar products. In screen systems, when the momentum provided by the agitator shaft to the grinding beads falls below the resistance caused by high viscosity, the beads lose their ability to move independently and can accumulate as a mass with the product at the outlet. This can cause the filter responsible for separation to clog and interrupt the process. This is precisely where Yokeş® Makina offers a solution: the Powermill Convecta® / G - Conventional Horizontal Bead Mill / Wet Grinding machine featuring a rotor/stator-operated dynamic gap separation system. Powermill Convecta® / G represents the most advanced version today of the first model designed by Yokeş® Makina of conventional horizontal bead mills / wet grinding machines, which the company has been manufacturing for over 25 years. Powermill series horizontal wet grinding machines have employed the dynamic gap separator system since their initial design. Although we now have highly advanced bead mill models operating with various different solutions for bead-product separation, when high viscosity is a concern, the dynamic gap separator system remains indispensable. Thanks to tungsten carbide gap separators operating in rotor-stator configuration, our Convecta® / G series models can operate 24/7 non-stop without any clogging. Due to the robust construction of the agitator disks and the specially designed separation system, high flow and grinding rates can be easily achieved even with high-viscosity products without problems.

General Features:

• Powermill Convecta® / G bead mills feature a very robust helical tank cooling system in their grinding chambers. This cooling system is designed to provide maximum heat transfer from the grinding chamber to the cooling water. This completely eliminates product heating problems that occur during the wet grinding process. • Maximum shaft sealing is ensured with a reliable, cartridge-type, double-acting mechanical seal, and seal replacement can be performed quickly and easily. The mechanical seal cooling / washing system is also water-cooled separately. The seal inner barrier fluid pressure can be adjusted according to product pressure. All of these ensure that the mechanical seal can be used problem-free for an extended period. • The main shaft has stepless speed control via a frequency converter. (This allows operation at desired speeds to achieve the most efficient results during the process. After grinding is complete, low-speed washing can be performed to clean the interior of the machine.) • Product feeding is performed reliably with a stepless speed/flow-controlled pump suitable for feeding high-viscosity products, controlled via frequency converter. Alternatively, diaphragm pump operation is also available. • Via an advanced PLC control system, all machine controls, process parameter monitoring, and machine limit value settings can be easily performed by the machine operator. • For detailed machine cleaning, a ball-bearing roller system allows easy opening and closing of the tank. • Thanks to the dynamic separator system and powerful agitator disks, any type of grinding beads can be used in the machine. (Min 0.6mm). Ultra-fine grinding values can be achieved without problems. • All materials used in the machine are selected to provide maximum wear resistance and service life in accordance with maximum quality requirements. Specific steel materials, ceramic derivatives, sintered carbide materials, and high-quality stainless steel materials are used depending on the type of product to be ground. Because: "High viscosity has never been a problem for us…."   Onur Ovalı Sales and Marketing Manager Yokeş Makina