RHEWUM GmbH

Dewatering machines series WAFL are the ideal dewatering sieve for fine and finest solids. Fields of application are separations in suspensions below 1 mm respective the dewatering of these.

Typically the screen achieves a dewatering ratio which is twice as good as a standard linear motion dewatering sieve. Practically it means approx. 8 wt. % residual moisture is possible whereas standard screens are reaching of 15 wt. %. This difference means easier material handling and less drying costs for you because the material is already dewatered respectively pre-dried at a high grade at the screen outlet. So RHEWUM customers can apply smaller dryer dimensions and they will save energy cost due to a less amount of water has to be evaporated. Alternatively the output of an existing dryer can be increased without exchanging it, just by applying a high performance dewatering sieve.

Functional Principle

Main characteristic of the dewatering sieve WAFL is the combination of two screening principles – the direct and the indirect excitation of the screen cloth. On the one hand a high-frequency linear movement of the housing of the dewatering sieve is generated by out-of-balance motors. This vibration transports the product along the screen mesh. On the other hand side magnetic vibrators are generating high-frequency oscillations which lead to a very high separation efficiency, especially in de-watering.

The dewatering sieve type WAFL is equipped with a supporting mesh for de-loading the overlaying finer separation mesh. Additionally a feed bin and a water spraying system are part of the scope of supply.

Strengths of the concept

• High vertical acceleration of the material due to direct excitation
• Higher throughput
• Higher product quality
• Dewatering ratio twice as good as standard linear motion screen
• 8 wt. % residual moisture in contrast
  to 15 wt. % (compared to usual screens)

High performance-screening machine for medium and coarse separation range.

Function principle

The drive principle of the DF type screeners is based on the use of two out-of-balance motors running with different speeds. The motor with the lower speed and higher out of balance weight is positioned at the inlet, whereas the motor with the higher speed and lower out of balance weight is positioned at the outlet.

At the inlet part, the higher amplitude accomplishes loosening and mixing of the feed product. At the outlet part, the high motor frequency along with higher accelerations ensures that critical materials are screened. By changing the direction of rotation the transport speed of the product can be specifically influenced.

Strengths

• Due to the driving principle nearly no vibrations will be carried into the building
• The easy machine accessibility reduces shut-down periods.
• The maintenance free drive by two out of balance motors minimizes the service costs
• The out of balance drives positioned outside the screening aggregate allow to operate on high product temperatures (max. 450° C!)

Overview

• The vibrating screening unit is encapsulated by a static housing allowing rigid connection of on- and off-going chutework
• Two counter-rotating drives with widely separated positions create double frequency vibrations
  • Inlet drive with a 6-pole motor
  • Outlet drive with a 4-pole motor

For segregation and transport of material

• Fast, efficient and precise screening with high throughput
• Standard machine sizes: Between 3.0 and 72 m³ per screening deck or machine (custom-made designs possible)
• Electrical capacity for these machine sizes: Between 2.5 and 19 kW

The RHEWUM screening machine type WAF is a combination of direct excitated WA screen and a linear motion vibrating conveyor.

Two counter rotating unbalance motors generate a linear motion, which ensures the transport of the material. In addition, the screen cloth is excited by magnetic actuators which mechanically stimulate the high-frequency oscillations. This combination as well ensures that also for sticky material the screen cloth is kept free reliably.

This additional and innovative drive excitation combination enables a separation of material, which usually cannot be classified on linear motion vibrating screens. In this process the material is classified precisely and with high-capacity. In the range of fine and fines particles with the machine type WAF much better screening results are achieved than with conventional linear motion screens.

Conveying technology for vertical transportation of bulk solids.

The sturdy vibrating spiral conveyors are suitable for the transportation of bulk solids from different production processes. These solids may be powdery, fine-grained or even coarse-grained. They are used in the chemical and food industry, but also in the raw materials industry. With the double bottom of the conveyor a product handling can be realized. It is possible to either heat, dry or cool the products during transportation. If desired, the conveyors can be manufactured in stainless steel.

With the easy-to-clean RHEWUM Spiral Conveyor you achieve a transportation that is gentle to the material and saves energy and space. Its design is modular: In addition to the spiral top part we also have a bolted vibratory drive with base or a hanging version with overhead drive as well as an optional inflow plate for the variable feeding. Also a multichannel conveying can be realized when desired.

Designs

•           Diameter:                      500 – 1400 (outside), 250 – 700 (inside)

•           Conveying capacity:       0.5 – 14.0 m3/h

•           Maximum head:             up to approx. 7,500 mm

•           Space requirement:        1.0 x 1.0 m – 1.8 x 1.8 m

•           Drive power:                   3.0 – 14.5 kW

It should be noted that the final construction of the machine depends on the transported material, the delivery height, the desired additional requirements (cooling/ heating) and the operating conditions. Because of the many potential influences it is necessary to conduct conveying tests in RHEWUM’s testing facilities.

The spiral conveyor is a special type of vibrating channel that allows a vertical transportation on the basis of vibration feeder technology. The conveyor path runs helically under increase around a torque tube.

The general use of vibrating spiral conveyors is one of the standard solutions for handling bulk materials. Granules from rubber or plastic, chemical respectively pharmaceutical products, metal salts, welding powder, catalysts and abrasives as well as milk powder, powdered coffee, tea, nuts and cereals are transported, dried and cooled with this conveyor.

Screening machines type WA are used for classification of bulk material in the finest- to medium grain size range.

This screen type employs direct excitation of screen mesh; thus the screen housing only takes a statical function. Vibration is imparted into the screen cloth by high speed movement of a transversally mounted rocker shaft, located beneath the screen cloth. Therefore the velocity down the screen is determined by the angle of the screen deck.

Outside the screen housing rugged electromagnetic drives rock the knocker shafts, conveying the high frequent oscillation directly into the screen mesh, allowing to overcome the adhesive particle forces within the product, loosening the product bed and segregating the product mixture by throwing big particles above the finer ones and separating them by comparison with the mesh apertures.

Executions 

RHEWUM screening machines Type WA can be built in a wide variety of versions in order to custom tailor them to your particular demand.

• Screening areas of 1,7 to 21 m² (18 to 226 sq ft) per deck
• Single or multideck configuration including screen angle adjustment as per requirement.
• Multi-deck-execution optional with increased deck distance and inspection openings in side walls allowing easy product control and service access if necessary
• Different feeding and distributing devices are available
• Optional machine support frame for flexible positioning
• Wide variety of different screen meshes available
• Special designs such as gas sealed, pressure surge proof or stainless steel manufacturing on request. 

Particular features of the direct excited RHEWUM design:

• Excellent screening results even with critical products
• Gentle product treatment
• Sharp seperations even with high specific screen loads
• Dust tight design, no flexible machine connections, no vibrations induced due to static screen housing
• No increase of dynamic load factors for the building due to vibrations
• Easy and fast screen change due to high accessability
• Drive by rugged electromagnetic drives, therefore low service requirements
• Very low specific drive powers due to efficient screen deck excitation
• Low noise emission
• Adaptability of every single drive/knocker system onto product requirements
• Easy adaption onto your building layout due to modular design