MACHINES AND PLANTS FOR THE FOOD AND TOBACCO INDUSTRY
MACRODOSING
BIG-BAG PRODUCTS
‘Special’ products are increasingly required in the formulation of production recipes. These special ingredients are supplied in big bags both for economic reasons and to facilitate storage and handling at the user’s premises.
The pictures above show a configuration with two rows of big bags.
The 7-metre width refers to a dosing station with two rows of big bags. In the case of a station with a single row of big bags, the occupied space is reduced to 4 metres.
The height (H) varies according to the main features of the project: a. big bag size (1 or 2 cubic metres); b. the capacity of the buffer hopper 4; c. the capacity of the weighing hopper; d. the existence and possible capacity of the service hopper 7; the type of conveyor used for handling the finished recipe 8.
Referring to the diagram above:
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METAL SUPPORT STRUCTURE. Fully bolted steel structure manufactured with hot-drawn sections compliant with UNI standards or cold formed welded structural hollow sections UNI 10219. Hot dip galvanized surface finish EN ISO 1461. The supply is always accompanied by a structural calculation report drawn up according to Eurocode 3 standards. For economic reasons it is possible to provide technical drawings of each single component in addition to the calculation report, so that components can be produced by local suppliers.
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ELECTRIC CHAIN HOIST EUROCHAIN VERLINDE. .Load: 2,000 Kg. Motor-driven translation. Low voltage push-button panel. Self-closing hook. Chain length suitable for intended use.
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BIG BAG EMPTYING HOPPER. See specific documentation attached
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BUFFER TANK FOR DOSING DURING BIG BAG CHANGE. Made of stainless steel AISI 304. Capacity adapted to the intended use: it will contain the product to be dosed during the entire time required to replace an empty big bag with a full one.
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DOSING SCREW. Size suitable to the amount and features of the product to be dosed. Progressive cavity screw. Butterfly valve located at discharge point.
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WEIGHING HOPPER. Capacity and features adapted to the dosing operations to be performed.
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SERVICE HOPPER. Features adapted to the dosing operation to be performed. Its useful capacity needs to be at least equal to that of the weighing hopper 6. The service hopper, thanks to the double butterfly valve located between the two hoppers, allows to perfectly isolate the weighing process from interferences due to any leaks from the rotary valve in the pneumatic circuit, as well as to separate the weighing and the service cycles, so as to save time for the batch execution time: while the dosing process is carried out, the system conveys the previously dosed recipe, which is transferred by gravity from the weighing hopper into the service hopper.
8. CONVEYOR SYSTEM FOR THE HANDLING OF THE FINISHED RECIPE. The diagram shows a rotary valve for product loading on a pneumatic conveying line; this is the most commonly used solution, as it ensures flexibility and hygiene.
1. METAL SUPPORT STRUCTURE
2. ELECTRIC CHAIN HOIST
EUROCHAIN VERLINDE
3. BIG BAG EMPTYING HOPPER
4. BUFFER HOPPER FOR DOSAGE
DURING BIG BAG CHANGE
6,7,8. WEIGHING AND SERVICE GROUP
WEIGHING
HOPPER
SERVICE
HOPPER
DOUBLE VALVE FOR ISOLATING WEIGHING FROM PNEUMATIC CONVEYING
ROTARY VALVE FOR THE INTRODUCTION OF
THE PRODUCT INTO A CONVEYING
AIR STREAM
RETENTION INSIDE A PNEUMATIC CONVEYING PIPE
DEHUMIFICATION AND TEMPERATURE CONTROL SYSTEM ‘MUNTERS’ FOR THE PREMISES WHERE THE EQUIPMENT IS LOCATED
When hygroscopic or heat-sensitive products are dosed or pneumatically conveyed, it is necessary to take some extremely important measures to prevent production to be blocked due to product agglomeration or retention, which lead in turn to cross-contamination processes.
DEHUMIDIFICATION SYSTEM ‘MUNTERS’ FOR DEHUMIDIFICATION OF THE AIR IN THE PNEUMATIC CONVEYOR.
BIG BAG EMPTYING HOPPER
Equipment designed for the emptying and introduction into production of granules or powders packaged in woven propylene bags. These big bags have 4 loops and are equipped with a Ø 300 o Ø 400 mm sleeve discharge valve.
Available in carbon steel with epoxy surface finish fired at high temperature or in entirely stainless steel AISI 304/316.
With internal 2B or glossy 2P surface finish and external Scotch-Brite satin finish.
The equipment has been developed in collaboration with the users, in order to make it fully functional and compliant with operators’ safety standards, food hygiene and ergonomics regulations.
Dimensions are adapted to the big bags standardly used in Europe: the size of the base can be 90 x 90 cm or 95 x 95 cm.
On request, the hopper can be supplied with increased dimensions suitable to the big bags standardly used in America, or to any other customized sizes to be submitted when requesting a commercial offer.
2
4
3
5
1
The equipment is provided with a large opening, closed by means of a hinged lid (1) for internal access which allows to unfasten the big bag discharge valve. The hatch is located on the cylindrical discharge section.
The effectiveness of the dust-proof lid is guaranteed by a gasket made of extruded closed cell rubber placed around the entire perimetre (2) and by a closing tool adjustable up to 3,200 N.(3)
The internal part of the lid is equipped with a raised profile (4), which, when closed, reconstitutes the internal cylindrical surface and minimizes product retention.
The opening of the cover is signalled by an inductive sensor (5). The signal can be used at will, e.g. to activate suction when opening the big bag discharge valve.
During emptying operations, the bottom of the big bag rests stably on a white food-grade rubber plate which acts as a seal to prevent dust from escaping.
The inlet mouth of the big bag discharge valve is reinforced by a stainless steel double flange.
The whole of the hopper rests on 4 double elastic elements with a hardness of 65 Shore A, which allow the vibration of the hopper, ensuring the emptying of the big bag and of the conical part of the hopper.
The vibration is produced by a 0.18 kW motor with adjustable eccentric weights that develops a centrifugal force up to 190 Kgf.
Pneumatic cylinders are installed on the four corners of the hopper; these cylinders have the function of shaking the bottom of the big bag and preventing the formation of lumps or mouse holes inside the big bag when powders, especially those with very small particle size, are discharged.
The cylinders are protected by a sheet metal casing for the safety of the operators.
A grate placed on the unloading outlet retains large foreign bodies or the polyethylene sack inside the big bag.
B
A
The big bag emptying hopper is equipped with a suction socket (A) to prevent the operator from inhaling dust during the opening of the discharge valve and the first filling. The suction inlet is intercepted by a butterfly valve (B) in case more hoppers are connected to a single suction system.
