Big-bag Emptying Stations
series SBB, SBBW, SSBEH

They are stations used for big-bag emptying of granular or powder products. The big-bag available on the market have various dimensions, so the SBB station is designed and built to be as versatile as possible. The big-bag usable can have maximum dimensions of 120x120x200 cm, they have exhaust valve and lifting suspenders.

The basic setup (SBB) is constituted by a self-supporting structure made of two overlapping modules.

The lower module is constituted by a structure made with sturdy welded square tubes and 4 main uprights with several stiffening beams. At the bottom of the uprights there are flanges properly drilled that allow to fix the entire station SBB to the floor with anchor bolts.

The upper module has 4 tubular uprights that are inserted in the ones of the lower module to form an adjustable in height telescopic structure. Once determined the total height of the structure, according to the big-bag dimension to use, the two modules are fixed together with screws and bolts. This type of construction allows in a simple and practical way to modify in any moment the Station SBB to manage the big –bags of another dimension.

The big-bag is hung to the self-supporting structure hooking its sustainers to a proper palletized frame with spring carabiners. In this way, using a forklift, the palletized frame is lifted together with the big-bag and it is placed on the structure top where there are proper centering shapes. The big-bag stays hung inside the structure leaning its bottom on a containing hopper with a poligonal reversed pyramid shape and opens in the center to let the exhaust valve pass and make it accessible to the operator.

The station SBB is dimensioned to support big-bag with a maximum weight of 2000 Kg.

In case of particularly compacted products, as it usually happens if the big-bag is stocked in a humid environment, the station SBB is equipped with one or more electro-pneumatically actioned beaters. Each beater is constituted by a wide spherical steel cap fixed on the stem of a pneumatic cylinder. The beaters, normally in number of 2 or 4 are installed on opposed walls of the containing hopper. They are placed in order to hit the bottom and the lower part of the big-bag and they are actioned alternatively according to a timed settable cyclical sequence. In this way eventual products blocks are crumbled and they can come out from the exhaust valve of the big-bag. The action area of the beaters is protected by outer panels, one for each of the 4 sides of the station SBB, in order to not access. One of the bulkheads is drop-down openable to introduce more easily the big-bag inside the supporting structure without lifting it more than necessary. There is a safety micro-switch that disables the beaters when the bulkhead is open.

The big-bag emptying station is equipped with a cylindrical collector, installed centrally under the containing hopper, to which it is connected the big-bag exhaust valve blocking it with a clamp ring. The collector acts as a discharging outlet of the big-bag and it can be eventually supplied with interception devices, such as butterfly or slide valves. It offers also the possibility to connect mechanical or pneumatic transport systems trough suitable flexible sleeves.

If the product transport occurs pneumatically the discharge collector of the big-bag ends with an extraction unit as the one present in the product intake hoppers series TPP, completed with its air-flow regulation devices and eventually of the line cleaning.

Under the discharge collector of the stations SBB it is possible to connect also rotary valves and various types of dosers such as single screw dosers series CH, CHY, BH, BHY, DFH, DFHY, vibratory channel series VF, VFY and weighbelts series NPW.

If the work ways involve the replacement of the big-bag before their complete emptying, as it happens for example for product change need, the station SBB is equipped with an exhaust valve close module ( SBBVG ) that allows to the operator to close the big-bag, even if not empty, tying again the exhaust valve without a particular effort. It is a device constituted by two opposed gates electro-pneumatically actioned whose function is to choke the exhaust valve of the big-bag until blocking the product to come out. In this way the part of the exhaust valve under the gates is free from the product. It becomes possible to tighten and tie the closing string without particular struggling.

The blades of the module SBBVG are dovetail shaped with rounded ends not to rip the bag in the closing phase. The close module SBBVG is flanged under the containing hopper of the station SBB. On the lower side of the closing module it is installed a cabin equipped with a wide front door that allows to the operator to enter with his hands to untie the exhaust valve of the big-bag and tie it again when needed. A safety microswitch ables the blades of the close module only when the door is closed. Under the cabin there is an inclined walls collector with a discharging outlet. The inside cabin dimension allows also the manual bags emptying in case of need. In this case inside the cabin there is a completely removable grid to support the bags.

The cabin is equipped with an air intake inlet, provided to connect to the centralized dedusting system or to a dedicated captation and filtering system. The air intake inlet is normally equipped with an interception gate electro-pneumatically controlled. The gate, normally closed, is actioned when the front door is open thanks to the consent of a microswitch suitably installed. The light vacuum that creates inside the cabin makes the volatile dust to be sucked by the filtering systems and not inhaled by the operator.

The big-bag emptying station SBB can be installed on load cells (serie SBBW) that are placed directly under the 4 main uprights of the structure with proper devices fit with anti-rollover safety blocks. The load cells normally used are stainless steel shear beam, available also in the Atex version when requested.

The gravimetric setup SBBW allows to keep the weight decreasing of the product under control giving indication on when go ahead with the big-bag replacement. The station SBBW allows also to unload and transfer a predefined quantity of product if properly connected to extraction and transport devices.

The station SBBW can be used as a storage hopper for dosers series CH, BH, DFH and VHF that are eventually installed on board. This setup constitutes a real gravimetric dosing system that can operates with the logic of difference of weight either in batch or continuous mode.

In the areas with poor manouvral space, and where it is not possible to move easily the big-bag with a forklift, it is suggested a version equipped with its own electric chain lifting hoist ( SBBEH ).

The hoist is motorized and moves along a beam placed on top of the station SBBH which is supported by uprights fixed to the floor and proper reinforcing girders. The hoist is manually actioned with a control keypad that allows to move it back and forth to hook the big-bag to the ground by means of a proper hooking cross, lift it and move it inside the structure placing it on the containing hopper. The translation movements of the hoist along the beam and the lifting chain run are limited by proper limit-switches.

During the emptying phase the big-bag stays always hung to its hooking cross and supported by the hoist. The hoist is certified for a maximum lifting range of 2000 Kg .

The most used construction materials are stainless steel Aisi 304 and 316L, but it is also possible to provide carbon steel on request.

The surfaces in contact with the product are pickled. It is possible to have them glass bead blasted or electro-polished on request.

The gaskets are made in dust-tight rubber , such as SBR or NBR. They are available also with FDA certification on request.

The stations SBB, SBBW and SBBEH can be set in Atex version when it is requested.