Gala tempered water systems are an integral part of a pelletizing system. The TWS conveys and cools pellets from the pelletizer cutting chamber to the resin outlet of the centrifugal dryer. The TWS is a closed loop system.
The individual components relevant for the process are selected according to the specific application requirements. Gala’s tempered water systems are typically used in pelletizing process at rates up to 15.000 kg/h.
The MB500® Tempered Water System is a result of a cooperative effort between Gala and its Customers to develop a machine which directly addresses the need for the Custom Compounder to thoroughly clean the system between products. Small color masterbatch runs require frequent changeover. The MB500 targets this speciﬁc Customer need.
The process water system BF fulfils the following functions:
- Collecting of the process water and feeding it at the required pressure to the individual locations of consumption
- Cooling of the process water
- Separating dust and contaminations from the process waterProcess water systems BF can be retrofitted into existing pelletizing systems.
The process water treatment unit PWA serves for filtering, tempering, and circulating the process water in compound and masterbatch production and can be integrated into the base frame of the cooling trough or positioned externally. Using a heat exchanger, the PWA separates the contaminated process water circuit from the primary cooling circuit from the central water supply.
Gala’s IS (Integrated Sieve) Tempered Water System features a V-wire screen mounted directly under the dryer water outlet to ﬁlter solids from the process water prior to recirculation to the pelletizer. The screen is easy to remove for cleaning, reducing downtime between product changes. TWS 20 – 80 systems are skid mounted.
The Gala Continuous Band Filtration (CBF) is also designed as a retrofit for the pellet production line where there are fines created regularly on some products and operator attendance would normally be required to clean the IS drawer in the production frequently. After installation of the CBF, the operator does not have to monitor the system anymore. The advance of the filter media is continuous and does not need any activation in order to catch fines larger than 150 µm. The process water contamination is in most cases eliminated. The fines are continuously separated from the process water and collected in a mud cart.
The Gala Band Filtration System (BF) is designed for the pellet production line where there are several color changes throughout the day, and for the system used for cutting a product that creates fines resulting in contamination in the process water system. The operator do not have to monitor the system, the advance of the filter media is automatically activated in order to catch all fines down to 20 µm created before the process water becomes contaminated. In most of the cases, the water does not need to be replaced as it stays perfectly clean. The fines are continuously separated from the process water and collected in a mud cart.
The Gala FRS removes fine particles >0.15 mm from the process water. Clean process water prevents product contamination and the settling of fines in key system components. The curved screen and collection basin are made of stainless steel. A self-priming pump and internal piping may be used to convey process water from the dryer and over the curved screen. If the gradient is appropriate, gravity feeding will be sufficient. The process water contaminated with particles is first conducted into a holding chamber and then flows evenly over the curved screen. The fines >0.15 mm are separated and collected in a collection basin. The filtered water is recirculated.
The Gala DFRS removes particles down to 0.14 mm from the process water. Clean process water avoids the contamination of the product and the settling of fines in key system components.The entire volume of process water separated from the pellets in the centrifugal dryer is conveyed by a self-priming waste water pump to a vibrating screen where it is continuously filtered. The fines are automatically separated from the circulating water and collected in a container outside the water tank. The water dripping from the container is recycled into the process. By actuating a valve, the vibrating screen can be by-passed so the process water is conveyed directly into the tank.
The dual canister filter provides extra process water filtration in high production situations where shutdowns are kept to a minimum or when processing highly filled products that create fine particulates not caught by a standard fines removal screen. The dual canister filter assembly is located after the process water pump in the tempered water system. Its purpose is to filter any fine particulates that may not have been caught in the standard water system filtration screen. Most customers requesting this feature wish to eliminate unnecessary downtime for cleaning or for extra protection when pelletizing heavily filled products that cause fine dust. This system is typically used on pellet production lines running 250 gpm (60 m³/h) or greater. The system consists of two stainless steel cylindrical housings, each containing a screen basket with 100 – 200 micron mesh bag. Valves and piping complete the system, as well as appropriate electrical controls. This filtration system can be programmed for an alarm to sound for manual filter changing or, in most cases, fully automated changing from one filter to another. One canister is in operation while the second is being prepared or ready for use.
The control system for the Gala LPU® is designed to meet the requirements of a laboratory system with low throughput. Compact design, clear separation of possible options, and the use of standardized software, standard components, and documentation permit short delivery times and a cost-effective solution.
The control system for the Gala MB500® is pelletizing rates up to 500 kg/h. Compact design, clear separation of possible options, and the use of standardized software, standard components, and documentation permit short delivery times and a cost-effective solution.
These control systems are designed to provide total control of Gala's polymer processing systems. Components used are of high quality to ensure superior control and operating safety and can be customized to meet specific customer requirements.
Gala can provide custom control systems based on the customer's needs. Gala uses standardized PLC based control systems; however, in most cases we are able to implement customer-specified controllers and other components upon request. Gala provides capabilities so the customer can easily pull information from the Gala Control System to an existing plant data acquisition system.
The E-type control system was developed for a defined machine configuration and is an affordable and compact control system for larger pelletizing systems. It also includes upgrade options.
The H-type control system can be customized to meet specific requirements and permits virtually unlimited options. It offers the highest level of operating and control comfort with separate control panel and integrated user interface.
In additional to the standard user interface of the E and H-type controls, Gala offers several options for the visual representation of processes, such as formulation / run program, alarm screen, configuration screen, history / trending and password protection. The communication between the PLC and the data acquisition system is implemented via the PROWAY DP interface. An optional PC permits visual monitoring of the underwater pelletizing system. All data can be acquired, stored and subsequently evaluated. Formulation data can be loaded from hard disk or floppy disk. The operator control of the line is made via the PC keyboard (function keys) and the formulation inputs (run programs). Line screens permit monitoring the operation. Faults are displayed in separate fault screens in clear and together with an indication of the times of occurring, acknowledging and resetting of individual faults. The acquired line data can be historically processed and printed. The control, data acquisition and visualization concept proposed by Gala is characterized by a clear separation between the control level (PLC) and the operator control and data acquisition level (PC visualization). In addition to customized solutions, we also offer Intouch OEM-1, a low-cost standardized visualization.
Maag diverter valves (DV) are based on the proven single-piston design that operates without any additional seals. The diverter valves type DV are used in Plastics manufacture, pelletizing, and compounding applications where they function as deflection, safety, and start-up valves. Their sturdy construction guarantees reliable and leak-free operation for many years, e.g. as start-up support for underwater pelletizing or for discharging start-up material in pelletizing applications.
With the multidirectional polymer diverter valve (Gala Model MdPoDV), the melt is diverted sequentially into different directions during production. The MdPoDV is designed to allow a continuous operation of the production machine and to increase output without interruptions from a defined minimum throughput up to the maximum line throughput. The machine does not have to be stopped and no throughput related modifications are required, so only minimum start-up waste is generated. At least one additional diverting operation is integrated, in addition to diverting to the floor or production position, allowing faster changeover between two product flow directions or the sequential operation of multiple pelletizers connected to the same diverter valve.
With the bidirectional polymer diverter valve ( Model BiPoDV), the melt is diverted sequentially into different directions. This means that, depending on the requirements of the job, the machine operator can work with two pelletizing heads that can be individually configured. The operator can prepare the machine for the next task and assemble, heat and tighten the ideal pelletizing tools under full production conditions. All connecting channels are freely accessible so the most recently used channels can be thoroughly cleaned. For product change, the polymer diverter valve housing is rotated and lifted into the new production position so melt flow is directed to the new fully prepared tool. The change of melt direction for the next production job can be readied in very little time and without tools. A lift-and-rotate mechanism makes it possible to change to a fully prepared and heated die plate at the operative machine within minutes.
Fitted with a screen pack, the quick opening clamp is situated between an extruder or melt pump and the pelletizer die plate. The QOC is used to filter particles from the melt before entering the die. In applications where screen changers would not be fully utilized to their potential, the QOC offers an economical solution.
Gala has been manufacturing precision die plates for its underwater pelletizers since the late 1970s. The die plate is the heart of the Gala underwater pelletizing system. All Gala dies are custom designed to fit each customer’s specific polymer requirements. The material of construction and wear face material are determined by the specifications of the Customer’s application. All die face surface materials provide maximum life before resurfacing is required. Gala’s standard electrically heated die is suitable for most applications; however, oil or steam heating can be utilized. The dies are available in one-piece design or in our patented two-piece design. The advantage of the two-piece design is the center (Insert) of the die can be quickly removed from the main body for routine maintenance or simply a need to change to a different die configuration. This is especially beneficial with frequent product changes in that you do not have to remove your heaters in order to make the die plate insert change. Continuous research and development is being invested in our dies to ensure our customers have the most energy efficient, operator friendly pellet production system available.
Gala’s die grinding tool gives you the option of grinding the die plate without removing it by simply threading the tool onto the cutter hub holder in place of the cutter hub. This unique tool is an effective method of removing small irregularities and grooves that can adversely affect pellet quality. High quality design and diamond material of construction provide the user with a superior and affordable die grinding tool.
Gala’s patented self-aligning cutter hub provides precise positioning between die plate and pelletizer shaft, ensuring alignment of all cutter blades against the die face. This results in uniform pellet quality and reduced blade and die face wear.
D2 is the material of construction known as the benchmark of the industry. Much like steel belted radial tires you get on a new car, this material will usually get the job done at a low price. The primary element is 12% Chrome which gives the blade good toughness and rust resistance. M-2 material is a member of the high speed family of tool steels. M-2 is primarily used to produce metal cutting high speed drill bits. Due to a high amount of “Moly” (Molybdenum) in its composition, this material resists break down under high heat. Under most circumstances, M-2 should last 1.5 times longer than D-2. PM(Powdered Metal) is the racing tire for a producer who wants output and is willing to pay the price. This material has a 9% Vanadium content which gives it a huge advantages in both wear and toughness. Depending on conditions, this material should last 3x to 5x longer over D-2. Note: In addition to the Vanadium content, PM material is made in a different fashion than other tool steels. In the powdered metal method the elements are all introduced in powdered form into a big furnace. The elements are then detonated so they are very evenly dispersed. Under these conditions the final product has a very uniform grain structure with little or no clumps of carbides that can chip away. 440A Stainless Steel (available on special request only) has an 18% Chrome content and is part of the stainless steel family of tool steels. This is the best tool steel offering for knives that are used in very corrosive conditions. This very special grade of stainless is able to be hardened to 54 / 56 Hrc. Specialty blades, such as half thick or half length, or various materials of construction, are available for specially pelletizing applications. Please ask our spare parts sales staff for more information.
Developed by Gala to simplify the start-up phase of the underwater pelletizing process.
The cutting chamber is the housing in which the pellets are actually cut. The pelletizer is coupled to the cutting chamber, which places the cutter blades inside the cutting chamber (often referred to as the water box), where the blades will contact the die face. As the process water enters the inlet of the cutting chamber, molten polymer is simultaneously cut into pellets by the rotating cutter blades. At this point the pellets begin to solidify and are carried by the process water from the cutting chamber to the dewatering system. From the dewatering system or centrifugal dryer, the pellets are ready for downstream processing or packaging. The Gala cutting chamber is designed to provide maximum service life. The Gala design can be rotated 180˚ so that once pellet abrasion has occurred at the exiting side of the cutting chamber, it can be rotated 180˚ to the less worn pellet entrance. Resistance wear coatings are also for abrasive applications. For extremely sticky materials, special design features for the cutting chamber are also available.
Gala provides a number of special tools for the operator of a Gala Underwater Pelletizer. These tools are designed to allow the successful performance of specific tasks.
The flow guide provides optimization of the process water flow:
•Patented adjustable flow guide
•Water flow direct to the die plate
•Avoidance of agglomerates
•Reduction of the water flow rate
•Reduction of the pellet moisture
•Smaller dryer possible (less dewatering required)
• Designed to catch and discard oversized pellet clusters (agglomerates) before they enter the rotor area of the dryer.
• Constructed of 304 S/S and is bolted to the dryer inlet, with inclined grate and gasketed door.
• Manually operated or pneumatically actuated, depending on the size of the dryer and the requirements of the system.
• have up to 25% more utilized screen area
• have very precise openings
• are stronger and more durable
• primarily used for micropellets
• available in either slotted or punched styles
• various fastening mechanisms
• multi-layer screen (patent pending)
• greater open area for small particle drying applications
• available in 16 - 22 gauge S/S
• up to 51% open area
• perforated openings from 1 mm to 4 mm
• Modular design
• Ease of replacing individual rotor components
• One-piece solid shaft
• Easier shaft replacement without alignment problems
• Ability to improve throughput and moisture levels
• Designed specifically for hot melt adhesive (HMA) or tacky product applications
• Designed to ensure proper conveying and discharge of tacky products
• Heavy gauge materials of construction
• Abrasive resistant coatings in high wear areas
• Modular components in high wear areas for easy replacement
Most all metal components within the dryer can be coated with a durable non-stick coating. This is normally confined to product contacting areas to reduce costs but can be expanded to non-product contacting areas as needed. This is a process where a release polymer is impregnated into a coating that is essentially welded to the base metal of the part that is to be coated.
• Bolts to dryer resin outlet
• Constructed of 304 S/S
• Designed to divert product during start-up, for sampling or filling containers
• Manually or pneumatically operated