weighing and metering technology - solid system

solids Weighing- and metering-technology - the complete programme for every accuracy

pneumatic bulk feed dosing

hopper scale with dosing screws

solids Big-Bag Filling Device

Type BFA

S.S.T.-Schüttguttechnik Maschinenbau GmbH Lechwiesenstr. 21, 86899 Landsberg / Lech

Tel. 0049 (0)8191-3359-50 / Fax 0049 (0)8191-3359-55 E-mail [email protected]

Dust-free filling of all types of big-bags, optional modules such as table lift, compacting device, dustproof docking, scale and control unit.

Advantages:

• Fail-safe due to built-in controller and weighing; as a result, constant and reproducible filling quantities

• Easy-to-operate due to ergonomic, movable suspension device

• Fully automatable, complete electrical and pneumatic installation

• Dust-free due to the solids special docking system

• Low maintenance


Type BFA



Characteristics:

Dustproof docking with a blowing seal

Load cell

Suspension device for big-bag loops, pneumatically movable, pneumatically pivoted hooks

The vibrating table squeezes out air from the filled product

Table lift: for big-bags having different heights, and lifting when vibrating / suspending

Sturdy weighing frame

Connection for suction


Type BFA



General functional description: This device is used to fill the big-bags. Normal position:

• Lifting table down.

• Pneumatic, pivoted suspension hooks in the normal position, i.e. vertical as shown in the drawing.

• The two rear suspension hooks, seen from the operator side, can be moved pneumatically and suspended in the front position.

The Big-Bag is attached to suspension hooks using four loops. The loops remain attached to these suspension hooks during the entire filling process.


Type BFA



Procedure for docking and filling:

• Move the two rear suspension hooks, seen from the operator side, to the rear position

• Move the big-bag inlet over the docking connection

• Press the blowing hose at the big-bag inlet pneumatically by actuating the pneumatic switch

• Switch-on the on-site suction system

• Start the filling process by switching on the metering equipment

• On reaching the first desired weight mark, use load cells for measuring. Stop the filling process by switching off the metering equipment

• Raise the lifting table up to the big-bag on which the vibrating table rests

• Switch on the vibrating table and condense the filled material by vibrating until adequate air escapes from the material so that additional material can be filled in

• Lower the lifting table (up to the lowermost end position)

• Continue the filling process up to the second desired weight mark by switching on the metering equipment = final weight

• Stop the filling process by switching off the metering equipment

• Relieve the blowing hose

• Raise the lifting table until the suspension loops are relieved

• Use the pneumatic rotary drive to rotate all four suspension hooks by 90° upwards to place them in the horizontal position so that the loops of the big-bag can be lowered freely

• Lower the lifting table (up to the lowermost end position)

• Use a forklift to transport the pallet containing the big-bag • All devices in the normal position, see above.

solids Drum Filling Device

Type DBF



Gravimetric dustproof filling of drums and other packages; Transporting the drums using a conveyor belt; Drum on the conveyor belt is weighed using a platform scale.

Advantages:

• Reliable due to the universal discharging and metering system

• High operational safety due to the sturdy design of the components

• Quick product change and therefore low cleaning costs • Dustproof drum docking


Type DBF



Storage tank

solids vibrating hopper type EVS

solids vibration dosing screw type DSV

solids drum docking type FAD

Cask

Scale Pneumatic installation


Type DBF



Roller track

solids drum docking type FAD

solids Agitator

Type BAR



Homogenisation and discharge, improved metering accuracy, optimum adaptation of agitator geometry to the product properties

Advantages: • No segregation

• Perfect mass flow without dead zones

• Complete emptying

• No bridging • Improved metering accuracy due to constant filling of the metering equipment

• Homogeneous bulk solid

• Agitator geometry has been optimally adapted to the product properties, which ensures versatility and operational safety

• Low maintenance • Energy-saving and gentle product handling due to slow rotary movement

solids Agitator

Type BAR



Function: The mechanical movement exerts relative forces on particles and loosens or disintegrates the bonding mechanisms. As a result, the bulk solid becomes capable of flowing. The structural design of agitator elements depends on the properties of bulk solids.

Sizes: Ø1000, 1300, 1800 mm

Characteristics:

Controlable drive

Vertical agitator

Pressure-tight shaft feedthrough

Product inlet

Product outlet with a connection for the metering equipment

Overhung bearing

solids Rotary Valves

Type ZRS



Discharge and metering rotary valve, for continuous discharge of silos and/or feed into pressure or vacuum conveying pipelines ; even for dust explosion hazardous products

Advantages:

• Sturdy and less wear

• Cost-effective and low maintenance due to simple assembly

• Space-saving

• Gas-tight from outside

• Protection against spreading of dust explosions and effective flame trap

• Safety for operators, with a DMT certificate


Type ZRS



Functions and operating modes of a rotary valve Generally a rotary valve has two basic functions: Discharging and metering. Both the functions have an additional task to establish an air lock point between two sections of the system. Absolute air lock is however not possible at the given pressure difference. The flow of the leakage air can only be minimised. Discharge The basic function of pure discharging is executed by the well-known basic rotary valve: In the housing the rotor is revolving by constant speed. Due to gravity the product comes out from the container or the hopper from the top and falls in the chambers of the rotor. Due to the revolving rotor the product is transported to the discharge opening, from where it again moves down by gravity. The rotary valve itself does not affect the flow capacity of bulk solids. It depends on the chamber volume, filling ratio and rotation speed. Metering The rotary valve for metering is characterised by a variable speed, e.g. using a variable-pitch geared motor or a frequency converter drive. The metering is purely volumetric in such a case: A specific volumetric flow per time unit is set as the desired value in dm ³/s or m³/h. It is however not measured so that there is an undefined deviation between the desired and actual values. The mass flow capacity is not measured and regulated, and therefore the term, "metering" is actually incorrect in the strict sense; a constant and reproducible volumetric flow can however be set. The condition is, that a) the density of bulk solids is always constant, b) the rotor is always fed with the same filling ratio. This can be achieved, e.g. using an

agitator or a pneumatic discharge aid in the pre-hopper over the rotary valve, c) the chambers are emptied completely.


Type ZRS



Volumetric metering using solids rotary valves

Standard rotary valve, type ZRS:

• Housing with inlet and outlet

• Horizontal rotor with chambers (see rotor versions)

• Filling the chambers at the inlet

• Downward transport by rotation

• Emptying due to gravity; free discharge at the outlet

• Setting the volumetric flow by changing the speed

• Sizes from entry-∅ 150 to 500 x 1000 mm

• Capacity range: from 100 dm³/h to 200 m³/h

Conditions: The maximum particle size must be determined depending on the pressure difference and other product properties.

Most important rotor versions:

a) Basic version: - Fixed bars - For non-wearing

products

b) Replaceable, adjustable sealing strips - made of

elastomer or cutting strip

- for moderately wearing products

c) Rounded chambers - with/without

replaceable sealing strips

- for slightly accumulating products

- with coated chamber surface

d) Towing vane made of elastomer

- for granular, sticky and fibrous products


Type ZRS



Characteristics (here as an example of a pressure-shock-resistant rotary valve):

Optional: radial shaft sealing rings with a sealing gas connection

Cast housing; with pressure test on request

pressur-shock-resistant rotor

Pressure-tight shaft seal Packing gland up to 200 °C

Rotor for dust explosion class ST1

Adjustable and replaceable rotor strips

Rotor for dust explosion class ST3

External bearing

Solid rotor design

Rounded chambers


Type ZRS



Foodstuffs version:

Complete with a leakage air collector and a blowing shoe:

Rounded chambers

Slip-on gear


Type ZRS



Accessories: Leakage air collector for optimised diversion of leakage air from the pressure conveying by the solids rotary valve; inclusive of the granulate inlet for granular products

Advantages: • Space-saving

• Fail-safe; prevents coarse grains from clamping

• Cost-effective

• Increases the conveying capacity

Characteristics: • Welded steel design; all commonly available steel and stainless steel qualities

• For pressure conveying

• Nominal widths 150 to 350 mm corresponding to the rotary valve

Product inlet

Leakage air diversion


Type ZRS



Blowing shoe below the metering equipment for filling a pneumatic conveying pipeline

Advantages: • Space-saving

• Fail-safe

• Cost-effective

• Can be connected to all metering equipment

Characteristics: • Welded steel design; all commonly available steel and stainless steel qualities

• Pressure-resistant

• For suction and pressure conveying

• Conveying pipe nominal widths 50 to 150 mm

Product inlet

Air inlet

Product + conveying air

solids Microfeeding Rotary Valve

Type MDS



Pulsation-free metering of products that tend to spurt or stick; with high accuracy; for small and smallest capacities as a volumetric metering device in combination with a pre-vessel and load cells (differential metering scale); as an entry device for a pneumatic conveying system.

Advantages: • Extremely accurate metering due to the complete

filling and emptying of the chambers

• Metering and air lock in one device

• Space-saving, less installation height

• Smallest volumes from 1 dm³/h onwards

• For poorly flowing to interleaving products

• Low-pulsation flow Detail:

forced scraping device

solids Microfeeding Rotary Valve

Type MDS



Characteristics • Sizes: ∅ 150, 250, 250x400 mm

• Metering volume capacities from 1 to 4000 dm³/h

• Pressure-tight up to 1 bar

• 1) Robust cast housing made of GG, 1.4308, 1.4408

• 2) Precision welded rotor with small chambers; arranged in multiple rows that are offset with each other; this ensures low-pulsation mass flow

• 3) Forced scraping device in the outlet area to empty the rotor chambers completely

• 4) Shaft seal using adjustable packing glands, optional with radial shaft sealing rings and sealing air connection

• 5) External flange bearings on both sides

• Slip-on worm geared motor with manual adjustment, optional with frequency converter operation

• Combination with the solids agitator vessel type BAR above the MDS

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2

3

4 5

solids Dosing Screw

Type DSC



Continuous metering with high accuracy and constancy, can be used globally, horizontal or angular, measurement fabrication

Advantages:

• Can be used globally, even for difficult bulk solids

• High accuracy and constancy

• Suitable for the smallest of volumes

• Adaptable to all vessel outlets

• Can be combined with multiple metering screws for exact and reproducible recipe preparation

• Extendable with weighing

• Complete solution with a control unit

• Low maintenance

solids Dosing Screw

Type DSC



Characteristics:

Sizes: Nominal diameter of flight: 80, 100, 150 mm Conveying lengths: 500 - 2000 mm Volumetric metering rate: approximately 10 - 3000 dm³/h

Product inlet

Product outlet

Screw flight with progressive pitch

Bearing in the gear

The screw flight and the gear can be dismantled and pulled out easily

The flap valve prevents the product from trickling down after stopping the metering

Detail: Shaft seal:

Radial shaft sealing rings

Sealing/purge air connection

solids Dosing Screw

Type DSC



Metering screw with release and a horizontal agitator: 1. Screw flight with progressive pitch and a

coaxial release near the inlet 2. Horizontal agitator in the inlet, for uniform

filling of spiral channels and to avoid bridging

3. Overhung bearing with external pedestal bearings

4. Common drive of the screw and the agitator using a chain and sprocket wheel drive and laterally (space-saving) attached geared motor

5. Shaft seal with radial shaft sealing rings 6. Pneumatic quick-action flap valve at the

outlet: prevents the product from trickling down after stopping the metering

1

2

3 4 5 6

Detail: Inlet with agitator

solids Vibration Dosing Screw

Type DSV



Safe metering with optimum filling, low-pulsation, high accuracy, no bridging in the inlet area

Advantages:


• High accuracy and constancy




• Low maintenance


Type DSV



Characteristics:

Sizes: Nominal diameter of flight: 80, 100, 150 mm Conveying lengths: 500 - 2000 mm Volumetric metering rate: approximately 10 - 3000 dm³/h

Product inlet

Detail: Shaft seal:

Radial shaft sealing rings

Entry in the pneumatic conveying pipeline

Screw flight with progressive pitch

The flap valve prevents the product from trickling down after stopping the metering

The screw flight and the gear can be dismantled and pulled out easily

Bearing in the gear

Product outlet


Type DSV



Discharge from a vessel or a silo, and continuous volumetric or gravimetric metering of bulk solids. Drums, containers or other casks can be filled. Advantages:

• Reliable and universal discharging and metering system

• High operational safety due to the sturdy design of components and avoidance of bridging

• Quick product change and therefore low cleaning cost

• Excellent metering constancy due to the optimum filling of the metering equipment

• Low-pulsation metering flow

• Optimised outlet using electronic control


Type DSV



Combination of the vibrating cone type EVS with the vibration metering screw Type DSV: • Vibrated using a vibrating cone, therefore better filling in the inlet area of the screw, and

constant and reliable metering

• Can be dismantled quickly and cleaned easily

Characteristics of the vibrating cone, type EVS: • Vibration resistant angular ring design

• Optional for bolting at the vessel

• Nominal diameter 600, 900 mm or higher

• Flexible suspensions prevent the transmission of vibrations to the supporting structure

Dosing screw

Quick-action flap valve

Vibrating cone

solids Precision Dosing Equipment

Type DSA PreciDos



Metering with highest accuracy, easy-to-dismantle, easy-to-clean, suitable for the smallest of volumes

Advantages:


• Highest metering accuracy and constancy without pulsation

• Easy-to-dismantle, easy-to-clean in case of frequent product changes




• Low maintenance


Type DSA PreciDos



Characteristics of the basic version:

1. Screw flight with progressive pitch 2. Horizontal agitator in the inlet, for uniform

filling of spiral channels and to avoid bridging

3. The screw and the agitator are driven using geared motors

4. Shaft seal with radial shaft sealing rings Sizes: Nominal diameter of flight: 65, 80, 100 mm

Detail: Inlet with agitator

1 2 3

4


Type DSA PreciDos



Optional modules:

1. Pneumatic quick-action flap valve at the outlet: prevents the product from trickling down after stopping the metering

2. Metering star: also increases metering constancy, prevents pulsation 3. Extractor device for the screw and the agitator, with a rail, for easy cleaning

2

3

1


Type DSA PreciDos



Operation sequence, e.g. batch-wise filling of a container or a scale:

1. Dosing in the coarse flow at the nominal speed, for short filling periods. The pneumatic quick-action flap valve is fully opened while doing so.

2. At the end of the metering process: Dosing in the fine flow at reduced speed. The quick-action flap valve is driven up to a short distance before the screw outlet in order to enable the shortest possible closing time after stopping the metering. The optional, concurrently rotating metering star is fitted flush at the outlet. It completely prevents pulsation.

3. The screw stops after reaching the desired weight, and the quick-action flap valve closes with an extremely short closing time. This ensures an extremely negligible deviation from the desired value.

1. Coarse flow 2. Fine flow

solids The fine art of Fine dosing

Fine dosing – product overview

Loss-in-weight-scales

Micro feeders with high accuracy

Linear powdering machines

Multi-heads feeders

Accurate filling machines

solids The fine art of Fine dosing

Technical Advantages of Fine dosing feeders

Technical advantages Batch process Continuous process

Short reaction time

Short dosing time :

From 0.2 sec in volumetric feeding.

Good relationship

between flow rate and motor rotation speed.

Very accurate mass flow regulation.

Low overshoot

High accuracy with good

repeatability and short dosing time.

Powdering capacity (up to 2000 mm ...)

Good powdering profile and stability.

Flexibility

The same feeder can cope with extremely fine powders or coarse and abrasive granulates.

Good capacity of extraction

Good efficiency with ingredients with poor flowing properties (dyes, starch...)

Respect of ingredient

Suitable for: pills, capsules…

No particle size segregation

Particle size distribution is respected during whole process.

Sewage

Complete sewage of ingredient: easier cleaning works

and change of ingredients.

Short cleaning time

Few seconds, no tools requested Compliant with GMP/ EHEDG guidelines

Safety

Thanks to the limited stroke of the parts in movement (< 3 mm), feeder operation is safe for operators.

Reliability

Design without wearing parts.

The feeders can’t be damaged with unwanted parts coming with ingredient. Made with high brand stainless

steel


Tel. 0049 (0)8191-3359-50 Fax 0049 (0)8191-3359-55 e-mail: [email protected]

www.solids.de

solids Rotating Bowl Scale

Type GSC GiroScale



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The weighing vessel is designed as a rotating bowl that is turned by 180° for emptying. This simple concept enables a compact assembly and high accuracy at a weighing capacity of up to 60 kg.

Advantages: • High accuracy • Simple, compact and robust design • Suitable for foodstuffs • Complete emptying • Automatable for up to 9 components • Suitable for recipe compilation


Type GSC GiroScale




Function and Assembly

The rotating bowl scale is designed for weighing the batches of small/smallest components with high accuracy. It has a simple and robust design. It can weigh bulk solids as well as liq-uids. It consists of a housing with a weighing device, a rotating drive and a plugable rotating bowl as a weighing vessel that can be mounted/dismantled without any tool.

The extremely compact shape and the nearly quadratic design of the weighing vessel with a pivot pin attached at the centre ensure minimum installation space. In the filling position (nor-mal position), the opening of the rotating bowl faces upwards. It is turned by 180° (opening faces downwards) for emptying. The positions are checked using initiators.

A test weight is provided for functional check. It is placed on the weighing device using a pneumatic cylinder. An error message is generated if the weight is not in the prescribed toler-ance zone. This check is executed fully automatically, and ensures the correct functioning of the scale. A transportation lock is provided for the test weight.

The scale is pressure and vibration-resistant, and has high accuracy since there is no me-chanical coupling with the metering or following equipment, and since the tare/net ratio is ex-cellent due to the design.

A gasket is provided between the housing and the slip-on pin to protect the inner side of the scale housing from the dust of bulk solids. In addition, a small overpressure can be generated and be kept in the housing.

The scale series comprises three main sizes for different weighing capabilities. They are equipped with rotating bowls whose volume is adapted to the density of bulk solids.

All actuations are electropneumatic.

Outer housing walls, rotating bowl and the slip-on pin are made of stainless steel 1.4301, and so are the parts of the taper that come in contact with the product. Special vessels with lining or flexible walls are available for special bulk solids.

Small rotating bowl scales (GSC10, GSC20) are preferably directly bolted onto the dust hous-ing using a flange coupling. The large scale (GSC60) requires a separate base. The housings of GSC10 and GSC20 are identical, and differ slightly from that of GSC60 (see dimension sheet).


Type GSC GiroScale




Scale Series Scale type Weighing

capability Numeric

step Weighing

signal Accuracy Vessel

volume Dead

weight

kg (max.) g (recom-mended)

µV/d (at US10

V)

g Litre kg

GSC10 10 0.5 0.66 ±1,5 10 15

GSC20 20 1 0.66 ±3 10 20

GSC20 20 1 0.66 ±3 16 20

GSC20 25 1 0.66 ±3 25 20

GSC50 50 5 1.33 ±15 32 30

GSC50 50 5 1.33 ±15 50 30

The following weighing capabilities can be implemented additionally:

- GSC10: 2 and 5 kg

- GSC50: 30 and 50 kg Intermediate values can also be implemented. Technical specifications:

- Power supply for solenoid valves, initiators and weighing terminal: 24 V DC approxi-mately 10 W

- DMS readings recorder: 2 mV/V max. 15 V DC supply voltage C3 as per OIML

- An overload protection is integrated for weighing capability of up to 20 kg

- Ambient temperature: -10 °C to 40 °C

- Compressed air supply: 6 bar


Type GSC GiroScale




Example for a control concept with many recipes and components. The OP can be omitted if a process control system is available, unless manual operation is desired on the site, e.g. since a large number of metering equipment has been installed or due to other reasons.

Switch cabinet with fre-quency converter, power elements and separately illustrated PLC. Profibus is used for communication.

OP for recipe management, simple visualisation, auto-matic and manual opera-tion, error messages. Can be mounted on the switch cabinet doors or sepa-rately.

Weighing terminal as com-plex metering controller with a direct control of me-tering elements is inte-grated into the rotating bowl scale or separated.

solids Vacuum Scale

Type SVN



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Vacuum scale for large product batches to implementation in combination with: • Product delivery using silo trucks, in big-bags and sacks • Storage of large components in silos • Completely dust-free emptying of big-bags and sacks

Technical data (example):

• Delivery rate 9 t/h • Conveying route 30 m verti-

cal / 38 m horizontal • Poorly flowing product • Vessel size 2.5 m³ • Metering accuracy: ± 1.0 kg • Metering accuracy with fine

dosing ± 100 gr

solids Vacuum Scale

Type SVN



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Your Advantages: • Exact gravimetric metering

as per the recipe • Residue-free discharge from

vacuum hybrid scales • Fail-safe due to proven sys-

tem • Efficient operation • Fully automatic sequence • Space-saving assembly • Absolutely dust-free unload-

ing, metering and conveying • More accuracy due to the

hybrid scale • Process accuracy achieved

using precise interplay be-tween the system compo-nents

Your Benefits: • Less cost due to reduced

handling effort • Improved quality due to

more metering accuracy • More output due to large

production volumes • More cleanliness in the sys-

Suction scale with tare compensation

2

solids Weighing- and metering-technology Taking out a certain quantity of material from a feed bin under control of a weighing unit and the transfer of this quantity to a downstream process is called gravimetric metering of batches. This has to be realized within a preset period of time at a preset velocity. This process is oftenly jeopardized by the wide spectrum of bulk material properties and the usually unfavorable ambient conditions for the weighing process, in which the scale has to work properly. The equipment necessary for metering is comprising the metering device, the scale and the pertinent control. For optimum results these units must be compatible and have to be suitable for the bulk material and also for the ambient conditions. However, the function of this assembly depends also on the proper design of the process interfaces at the intake and the discharge. Small components batches

• rotary bowl scale

• bin scale

• loss-in weight scale

• suction scale

Middle and large components batches

• bin scale

• suction scale

• silo scale

• big-bag scale

3

Liquids

• dosing cabinet

• bin scale

• pipe loop scale

Loss-in-weight-feeders

• High-precision hybrid bin scale on a parallel

guide bars system with mechanical tare compensation

• Bin scale with direct induction of tare and

net weight to the load cells

weighing and metering technology - solid system

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