Dust collectors are key elements of bulk solid loading bellows. They collect any fugitive dust during bulk solid loading and prevent dust emission to the environment. Several loading bellow dust collector models are available depending on application requirements.
In Line Dust Collector
If there exists enough height below discharge unit (silo, hopper, conveyor etc) in line dust collectors can be used in loading bellows. Filter units are installed at the top. Bulk material flows through the space between filters. Dusty air is collected through these filters. Dust content in the air is trapped by filter units. Automatically operated pulse jet filters are used for supplying air shocks to the filters and sending dust back to the stockpile downside.
Offset Type Dust Collector
Offset type dust collectors of loading bellows are installed at the edge of top flange with an angle. A vacuum fan is utilized to supply required vacuum air. During material discharge, fan unit vacuums the air from the discharge point of loading bellow. This vacuumed air passes through the passage between inner and outer bellows. Dust content in the air is trapped by filter units. Automatically operated pulse jet filters are used for supplying air shocks to the filters and sending dust back to the stockpile downside. The inclined design occupies less height and provides easier installation below hoppers and silos.
Separate Dust Collector
Loading bellows have outlet for dust collection system connection. Any external fan, dust collector or bag house filter can directly be connected to built in outlet. If the loading bellow installation area does not have enough space, separate dust collectors can be utilized. These dust collection units are independent systems that have their own fans, filters and discharge hoppers.
Central Dust Collector
If central dust collection systems exist in the plant, they can be connected to loading bellows. Air outlet of the loading bellow is used for connection. Air flow speed is to be adjusted with respect to operation conditions. Collected dust is stored in external dust collector. This configuration is suitable for applications where several loading bellows are to be used together at the same place. Single central dust collector can be used for collecting fugitive dust from all loading bellow systems.
Bottom Closure and Sealing Cone
Bottom closure and sealing cone is used in tanker loading bellows to prevent any product spillage after loading. The conical shaped valve can move in vertical direction. It normally closes the outlet port of loading bellow at the bottom. When the loading bellow is placed on the tanker inlet flange, the conical valve moves downward and opens the product discharge passage. After tanker loading is finished, the loading bellow is retracted. Bellow retraction moves the bottom closure cone upwards and closes the outlet. Any remaining product within the loading bellow is kept inside during retraction and spillage is prevented.
Material composition, moisture, particle size etc are some of the important attributes of bulk solids and it may be needed to check these values before loading. Bulk solid sampling systems are used to get a sample from free flowing bulk materials. In loading bellow applications, a manual or automatic sampler is installed above the loading bellow. During loading, sampler takes out some amount of material from the material flow.
Loading Bellows For High Temperature Applications
In case of high temperature bulk solid loading needs like fly ash handling systems, high temperature resistant loading bellows are to be utilized. Mechanical components including electrical motors, sensors etc. are selected from high temperature resistant models. Loading bellow and skirt fabrics are chosen from high temperature fabrics. Bulk solids having temperatures up to 300OC can be discharged with high temperature resistant loading bellows
Level sensors of open and closed loading bellows have different functions.
In closed vehicle loading, (i.e tanker trucks) level sensor is used for giving signal when the product reaches the tanker inlet level. Loading operation is stopped when the tanker truck is full.
In open loading bellows, level sensors are used for controlling the vertical position of loading bellow. Flexible dust skirt of the bellow should cover the product discharging region to prevent any fugitive dust and also keep enough space for rapid product discharge. When the product level increases, flexible dust skirt should raise accordingly to provide dust-free and fast loading.
Handling of explosive and flammable raw materials in hazardous explosive atmosphere need special care both in design and manufacturing of bulk solid loading bellows. Overheating, dust leakage, static electricity and electrical spark generation should be prevented during material discharge. Bellow fabrics are made of antistatic materials to prevent any static electricity build up. Atex certified and ex-proof equipment are used in such working conditions.
Food Grade Loading Bellows
Food grade loading bellow systems are available on request. All surfaces that have contact with food are made of food grade materials as stainless steel, silicone etc. All parts are designed and manufactured carefully to prevent any contamination and bacterial growth. Bellow fabrics, filter bags, valves and other mechanisms are selected from food certified equipment.
Handheld Control Pendant
Standard loading bellows are controlled by built in electrical control panel. Depending on application requirements, handheld remote control units can be utilized to increase operational efficiency. Wired and wireless remote controls are available upon request.
Communication With Other Systems
Electrical panel of loading bellows can send signals to other automation systems in the plant and can receive signals from them. Operation of loading bellow can be controlled from external systems. i.e truck weighing scale can send stop signal when the desired amount of product is filled. And loading bellow can give signals and operate related equipment from its own panel. Silo discharge valves, conveyors etc can be ran from loading bellow control unit.
Loading bellows can be coupled with weighing systems. Weighing hoppers, dosing belt scales, silo weighing systems can be utilized to feed loading bellows. For tanker truck or open truck loading, truck weighing scales can also be used for directly measuring of loaded weight. These systems can send signal to command loading bellow to start or stop loading.
3 or 4 Lifting Cables
Loading bellows can be manufactured with 3 cable or 4 cable configuration. 2 cable design is applicable for standard truck loadings with wide range of bulk materials. 3 or 4 cables are needed for high capacities, long bellows and environments with high side winds. This design increases rigidity of loading bellows and ensures problem-free bulk material loading.
Vibration motors are used for discharging residues of bulk solids from the inner bellow parts. They can be operated during or after loading.
Depending on the flowing properties, bulk materials cannot be completely filled into the tank. For materials which have low flowability, the tanker cannot be filled up to its maximum carrying capacity. Material spreading systems are developed to solve this issue. The spreader is positioned near the outlet spout in loaders for loading to tanks. Rotating paddles distribute the material uniformly inside the tanker allowing entry of a larger quantity of material. Since the filling efficiency of the tanker is increased, the overall transportation cost will decrease.
Poliurethane Coated Outlet Cone
Closed type tanker loading bellows incorporate poliurethane coated outlet cone that fit vessel inlet to prevent any dust emission during vehicle loading. Abrasion resistant poliurethane coating provides flexible sealing to prevent dust leakage. Conical shape makes it easy to fit different tanker inlet diameters.
Manual Winch Mechanism
For low duty applications, tanker truck and open truck loading bellows are available with manual winch mechanism. In this configuration a handwheel operated winch mechanism is used instead of electrically controlled motor, gearbox and pulley system. Handwheel unit can be installed to any location for easier access.
Loading Bellow PositionersLoading bellow positioning systems ensure efficient loading of trucks and railcar wagons. Instead of repositioning vehicle for loading of entire volume, positioning system moves the loading bellow when needed. Loading bellow is installed below the positioner unit. Remote controlled loading bellow positioner moves the bellow to the desired location rapidly and accurately. Bulk material transfer is started in very short time, eliminating the time needed for moving the vehicle forward and backwards to be in the precise center of the loading bellow. Depending on application requirements, single axis loading bellow positioners, double axis loading bellow positioners and articulating arm positioners are available.
Single Axis Loading Bellow Positioners
The single axis loading bellow positioner has the capability of moving forward and backwards over the vehicle. A single axis linear motion mechanism is used.
Double Axis Loading Bellow Positioners
The double axis loading bellow positioner has the capability of moving longitudinal or a lateral directions over the vehicle. A double axis linear motion mechanism is used.
Articulating Arm Loading Bellow Positioners
Two screw or airslide conveyors connected by rotating joints are incorporated in articulating arm positioners. Discharged product is transfered within these closed conveyors. At the end of articulated arm conveyor, product is discharged directly into the vehicle through loading bellow.
Loading Bellow Vehicle Access Platform
For opening tanker inlets, guiding loading bellows, maintenance operations and similar tasks above the vehicles, operators should have easy and safe access to loading region. Vehicle access platforms provide safe and fast solution for these tasks. Each application and loading environment has its own structure and arrangement. Vehicle access locations, silo discharge heights, conveyor types are designed with respect to plant needs. Though, loading bellow access platforms are custom designed for each application needs.
Custom Designed Loading Bellows
In addition to standard series, loading bellows can be custom designed to conform wide range of application needs. For efficient and dust-free loading, loading bellow should be designed carefully. Type and physical properties of handled bulk solid, loading capacity, loading environment, installation limitations are key factors that have effect on loading bellow design.
Bulk material loading bellows manufactured by Polimak are designed to conform human and environment safety regulations. Being CE certified, all safety measures are taken to prevent work accidents in sack handling systems. Mechanical and electrical locks, alarm systems exist on machinery with respect to work conditions.