Vacuum filler
A vacuum filler is a filling machine for filling pasty masses. The movement of the pasty masses is generated with the aid of a vane cell conveyor under the influence of vacuum .
Problem
The weight equalization of prepackages in the food market, especially in the area of viscous or pasty products, places the highest demands on the reproducible accuracy of filling and portioning systems. In order to achieve this, technical or technological aspects, but also product-specific properties , must be taken into account. In addition to the conditions mentioned, requirements for the quality of an end product are decisive for the selection or implementation of a technical process solution. With the development of vacuum filling machines, it has been possible to harmonize the technical and qualitative requirements.
In the food sector , the movement or transport of fluids is technically implemented with the help of pumps. Colloquially, this is referred to as filling, filling or portioning. Different types of pumps are used, depending on the type of filling goods to be moved. Vacuum fillers with vane cell feeders and vacuum feed are often used for viscous masses. The masses are transported with the aid of a filling funnel with a feed device, a vane cell feed system under the influence of vacuum and the corresponding volume displacement in the pump housing. Basically, this is a volumetric delivery principle. This means that a certain weight is defined via a volume . In addition to vane cell feeders, also known as rotary vane pumps , there are also screw feeders with conveyor curves, gear conveyors or evacuated lifting cylinders. In all of them, the transport is carried out via volume displacement under the influence of vacuum.
Vacuum fillers are traditionally found in meat processing, but also in other food areas. There are also applications in the non-food sector. Generally pasty and compressible masses can be filled with vacuum fillers.
history
The first vacuum filler was probably developed in the early 1960s. Patents from the early 1970s such as that of the "hydraulically operating sausage filling and linking machine" are known. The conveyor device for the vacuum filler was patented a year earlier. And from 1972 a patent for regulating the delivery pressure is known.
Requirements / influences
The pumpability of viscous or pasty masses has a decisive influence on the reliable function of a vacuum filler. Filling goods in the food sector can be characterized with the help of different properties with regard to their pumpability (“fillability”). These can be physically measured directly or describe sensory characteristics.
Gas content / density
The gas content is also referred to as "air content". This air content of a fluid is the percentage of the air brought in during grinding or mixing processes. It can be measured with special aids and is directly related to the density of a fluid.
Compressibility
The compressibility depends on the air content of a fluid. High compressibility goes hand in hand with a high proportion of gas in the fluid.
viscosity
The viscosity is a measure of the viscosity of a fluid. The higher the viscosity, the thicker, more highly viscous (less flowable) the fluid is; the lower the viscosity, the thinner, more low-viscosity (more flowable) it is. Highly viscous filling goods in food processing are mainly found in the meat, baked goods and convenience sectors. Highly viscous media are commonly referred to as pasty.
The flowability is a basic requirement for the pumpability of a fluid. The viscosity can also be determined with appropriate rheological measuring devices . In the food sector, the viscosity is primarily dependent on the liquid content of the product.
temperature
The temperature is decisive for the pumpability, as this directly influences the viscosity but also the product quality.
Lumpiness, fibrousness, dimension of the insert particles
Specific sensory properties of a product have a great influence on the assessment of the fillability and compliance with the exact weight.
Weight accuracy
With the help of modern filling technology in the food sector, precise portioning of up to 1% deviation based on the conveyed volume of a portion is possible.
functionality
The central element of a vacuum filler is the vacuum filling principle. The filling material is fed into the conveyor system on the one hand mechanically via a funnel with an actively driven feed curve, on the other hand via a vertical "vacuum suction". Pre-evacuated chambers of a vane cell conveyor move under the hopper. The pressure difference resulting from evacuation relative to the ambient pressure (negative pressure) ensures that the chambers are filled with mass. If the conveyor moves continuously , a continuous filling flow can be generated.
The portioning is done by clocked movements of the conveyor. Each chamber of the conveyor system has a certain volume . The portion is defined by the rotation path of the rotor. The setting of a portion volume is thus carried out by multiplying the rotation path of the rotor with the number of conveyor chambers contained therein within the control. The portion weight must be determined using a scale using the portion volume parameter on the control.
Structure and technical requirements
Vacuum fillers are mainly used in the food industry and in the food industry. For the structural design of a machine in the food industry, special criteria apply due to the corresponding hygiene requirements or hygiene regulations . These include B. easy dismantling, flat surfaces, flushable seals, avoidance of dead spaces, ergonomic shapes, low number of parts or detectable or food-safe materials. In addition, there are relatively aggressive environmental conditions, such as B. reactive cleaning agents, reactive or abrasive filling media, intensive high pressure cleaning or extreme ambient temperatures.
Vacuum fillers are therefore made to a large extent from stainless steel in a very robust construction. Moving parts are easy to dismantle and can be cleaned individually.
In addition to the mechanical or structural aspects, complex electronic components must also be taken into account in a vacuum filler.
Conveyor system with hopper
The conveyor system essentially consists of a rigid pump housing with a side window that is attached to the swiveling hopper and a removable rotor with pump blades and a clamping eccentric. Depending on the machine size, there are different conveyor sizes with appropriately dimensioned parts. The funnel can be folded down to clean and dismantle the surfaces and parts that come into contact with the product. The driven rotor is located in the pump housing with a corresponding number of slots in which the pump blades form so-called chambers or cells with defined volumes when the machine is closed, supported by the clamping eccentric. Initiated by the rotor movement when the machine is started, the chambers move in the direction of the conveyor outlet and thus ensure a defined volume flow. The weight accuracy of a conveyor system depends, among other things, on the manufacturing precision of the parts and their wear.
Vacuum system
The chambers are filled by evacuating the conveyor. By applying a vacuum via a vacuum pump, the goods are gently sucked out of the funnel into the conveyor system as soon as an evacuated chamber moves under the filling funnel. The vacuum pump is protected by an integrated water separator. The vacuum level can be adjusted depending on the product.
In addition to the feed effect, the product is evacuated to a certain extent at the same time (approx. 2-4%). This means that the proportion of air in the product decreases and the product becomes denser.
Feed
Feeding in connection with vacuum fillers means the active conveyance of the filling media in the direction of the lower part of the funnel to support the vacuum build-up within the filling funnel. The feed is implemented through the use of so-called movable feed curves with scrapers or rigid counter-hold curves. The feed cam is driven synchronously with the rotation of the rotor. Due to the special geometry of both curves and the parallel rotational movement, the filling medium is moved vertically in the direction of the conveyor. The necessary intensity of the supply depends on the viscosity of the media to be filled. With low-viscosity media, less active supply is necessary than with high-viscosity media. Thus there are different combinations or designs of the feeding parts.
Machine stand
The basis of a vacuum filler is the so-called machine stand. This is made entirely of stainless steel according to hygienic criteria. The compact machine stand is designed so that it can be easily transported with lifting devices.
Lifting device
Lifting devices are used to load the hopper with standard trolleys. These can either be permanently attached to the vacuum filler or placed separately next to the vacuum filler as a mast lifting device. Lifting devices can be operated hydraulically or electrically.
Control and drives
To operate a vacuum filler, computer-aided control is necessary for various tasks. As a rule, several drives for a wide variety of applications are built into vacuum fillers . In the most modern vacuum filler generations, the drives are implemented via servomotors and corresponding bus systems .
Locking devices
For the production of individual portions from a homogeneous mass via a conveyor system, a portion-separating "closing device" at the conveyor system outlet that is controlled synchronously with the portion output is always required. These can be twist-off devices for sausages, clip machines for portion sausages, metering valves for cups or cans, cutting devices for dough or also shaping devices for dumplings.
Further conveyor principles
Vacuum fillers can generally be equipped with different conveyors. The basic machine structure with funnel, vacuum system, feed device, machine stand, lifting device, control and locking device is, however, very similar in principle. Depending on the application, the conveyor types have advantages and disadvantages.
Screw conveyor with conveyor curves
In a screw conveyor system, two counter-rotating screws form chambers within a housing, which are moved in the pumping direction when the screws rotate. The filling material is also moved into the screw conveyor with the aid of a vacuum and mechanical feed devices.
Gear conveyor
An external ring gear is driven and rotates an internal gear. The gears form chamber segments against one another. The chamber contents are transported through the teeth and displaced and expelled in the outlet area.
Promotion via lifting cylinder
Conveying via alternating lifting cylinders is the simplest conveyor principle. The volume is defined by the geometry of the cylinder, with the portion size being determined by the number of strokes.
Funnel vacuum systems
The additional application of a funnel vacuum is a modification of the vacuum filler. The vacuum system is expanded by an additional vacuum pump especially for the funnel. The filling funnel is closed and has a connection to an upstream reservoir . Due to the vacuum in the filling funnel, filling material can be sucked out of the reservoir into the filling machine. The contents are also intensively evacuated.
Examples of viscous or pasty masses
- Food
- Meat products
- Scalding - raw - and cooked sausage ( meat )
- Raw and cooked cured products
- Dairy products
- butter
- Cream cheese or cream cheese preparations
- Cheese curd
- Processed cheese preparations
- yogurt
- Fishery products
- Fish meat
- caviar
- Herbal products
- Potato products
- Bakery products
- Bread with fruits
- Cake batter
- pasta
- Dumplings
- pasta dough
- confectionery
- marzipan
- Chocolate products
- pudding-like products
- Delicatessen products
- Soups
- Sauces
- Spices marinades
- Deli salads
- Raw food products with fibrous insert material
- All kinds of fillings
- Meat products
- Chemicals or non-food
- Trinitrotoluene (TNT)
- Technical sealants
Problems and their solutions
Many problems can arise when filling viscous media. Often these are product-related and show up in the creation of an atypical appearance of the goods to be filled. Examples of this are inhomogeneous sectional images in sausage products or excessive shredding of deposits during the pumping process.
But economic or legal problems can also arise in the form of weight deviations or breaches of the specified quality guidelines (e.g. guidelines for meat products).
These problems are caused by various influences, such as, for example, excessively high air content, excessively high viscosity, insufficient supply to the conveyor system, temperature or mechanical influences such as friction or fragmentation.
The problems mentioned can be eliminated by adapting upstream process steps, adapting the recipe, but also by making technical modifications.
Attachments
Holding devices
Holding devices in the case of sausage production are used to automatically twist sausages. A holding device consists of a rotating twist- off spout and an associated sausage casing brake . The movement of the twist-off nozzle is implemented by a drive integrated in the vacuum filler. The sausage casing brake ensures that the sausage casings are withdrawn evenly and therefore portioning is even.
Hanging lines
Suspension lines in the sausage production application are attachments for linking and hanging sausage portions. In principle, the application is the same as with a holding device. However, much higher filling capacities can be achieved. Suspension lines are implemented in different degrees of automation .
Cutting lines
Cutting lines in the case of sausage production basically have the same basic structure as hanging lines. With cutting lines, twisted sausage strands can be separated into portion sausages.
Clipping machines
Clip machines for the production of portion sausages are used in combination with vacuum fillers. The filling material is portioned into corresponding casings by the vacuum filler via a filling tube connected to the clipping machine and the associated sausage casing brake. The portion is then closed by the clip machine with the help of metal clips. Sometimes loops to hang up the portions are also attached at the same time. Sausage chains, but also individual portions, can be produced.
Molding devices
Molding devices are used to manufacture molded products such as dumplings or burgers .
- Devices for free shaping
- The filling material is filled via piping with an attached separating device. The separating device and the portion output are coordinated with one another so that the filling flow can be shaped. The separating devices can be diaphragms (function similar to a photo- iris diaphragm ; opening and closing creates a round shape during portioning), form knives that can be moved relative to one another or else simple wire cutters or blades. The portion is ejected synchronously with the opening of the separating device. At the end of the portion, the separating devices close again synchronously. This synchronized, adjustable sequence allows different shapes to be created. The products can be fed directly to the packaging or thermal treatment via belts.
- Thermal treatment ( drying , freezing , cooking , sterilizing , maturing, steaming , smoking , etc.) in the food sector is an umbrella term for the setting and conditioning of environmental influences such as temperature , relative humidity and gas or air circulation, and possibly also air exchange the aim of making food durable or edible.
- Devices with form matrices
- With these devices, the filling material is poured into the mold matrices (plastic mold that is filled against a base). The filled mold is "moved" out of the filling area, separated from the product flow by the simultaneous shearing movement and then mechanically or pneumatically ejected onto transport containers or into media for thermal treatment.
Co-extrusion devices
Coextrusion means the synchronous conveyance of two or more volume flows with the aim of producing filled products (for example meatballs with ketchup filling, sausages with mustard filling or potato dumplings with meat filling). Basically two or more vacuum fillers are required for this. Coextrusion devices are offered in the area of molding, clipping or turning.
ConPro systems
ConPro systems (Continuous Production System) are special continuous co-extrusion systems for the production of sausages with alginate casing . Two vacuum fillers are operated synchronously, their filling flows being combined into a continuous volume flow. In the further course of the process, the continuous strand is divided into individual portions or portion chains. A vacuum filler pumps the filling material, while the second doses an alginate-containing paste as a casing over an annular gap. This is solidified by a fixing solution containing calcium ions. Depending on the degree of automation, the portions can be hung, grouped, fed to continuous thermal treatment or to packaging.
The main advantages of the ConPro systems for classic production are that no sausage casings or casings need to be changed. With a ConPro system, there are no casing change times due to the continuous coextrusion, thus maximizing the filling time.
Filling grinders
Grinders are used in meat processing to mince meat and can actually be found in product preparation before the filling process. In the case of filling grinders, a shredding grinder is integrated into the filling flow of the vacuum filler as an attachment. The process steps of filling and chopping can thus be represented in one machine. This means that the filling material is conveyed by the vacuum filler and cut to the final grain size within the mincer during filling. An important application for filling grinders is raw sausage or fresh sausage production.
Minced meat lines
Minced meat lines are combinations of vacuum fillers, filling grinders and devices for separating the minced meat flow into individual portions. A continuous, shaped volume flow is filled onto a conveyor belt, with a separating knife dividing the filling flow into portions. The portions can then be packed directly.
Filling flow divider
With a filling flow divider, a single volume flow from a pump can be divided into several equivalent flows. Conveyors similar to vane cell conveyors are built into filling flow dividers. Filling flow dividers are required, for example, for the simultaneous dosing of several containers .
Valves
Valves or cutting devices are used as closing devices at the end of piping or filling flow dividers.
Weight regulation and process documentation
To document a filling process to vacuum fillers or monitoring filling weights across machines electronic can rule - and documentation systems are used.
literature
- DIN German Institute for Standardization e. V. (Ed.): DIN EN 12463 - Food processing machines - Filling machines and attachment machines - Safety and hygiene requirements; German version EN 12463: 2004 + A1: 2011 . September 2011.
- Process large quantities gently . In: The butcher shop . No. 4 , 2011, p. 29-31 .
- Produce portion size . In: The butcher shop . No. 9 , 2011, p. 38 ff .
Individual evidence
- ↑ "Process and vacuum filler for filling a pasty mass" accessed on May 14, 2012
- ↑ filling machine . duden.de; accessed on May 29, 2020
- ^ "Vane pump" , accessed on May 14, 2012
- ↑ "Checklist for operating a filling machine" . Retrieved May 29, 2020
- ^ "Hydraulically working sausage filling and linking machine" , accessed on November 23, 2012
- ↑ "Conveyor device for pasty masses with a vane pump for sausage filling machines" , accessed on November 23, 2012
- ↑ "Control device for regulating the delivery pressure of controllable pumps by changing the delivery rate", accessed on November 23, 2012
- ↑ "Checklist for the operation of tilting and lifting devices" . Retrieved May 29, 2020
- ↑ Funding system . In: duden.de; Retrieved May 21, 2012
- ↑ vacuum pump . In: duden.de; Retrieved May 21, 2012
- ↑ "Guidelines for Meat and Meat Products" , accessed on May 15, 2012
- ↑ “Diaphragm” , accessed on May 15, 2012