Screw Presses
Latest know-how in application
Screw presses made by Harburg-Freudenberger are used as pre- or fullpresses in oilseed processing as well as for the mechanical fat separation in the rendering process. Our latest generation of screw presses has been developed on basis of the most advanced mechanical engineering technology and the latest know-how in application.
Data from its own research and development department with pilot plant facilities played an important role in the adaption of screw presses to the demands of practical pressing.
Shaft and worm design
The worm shafts of the EP-series presses are free floating in the cages without bearing at the cake discharge end, with self-centering provided by the surrounding press material during operation. This results in a continuous balancing of the radial forces acting on the cage support structure.
Depending on the application the screw press will be equipped with a 'conventional' worm configuration with gradually decreasing free volume over the length of the shaft. For other products we have developed a worm design which is based on pressure build-up by pressure worms alternating with pressure equalization and relaxation via conical throttle rings. The fixed throttle ring system replaces the complicated mechanical system of adjustable cake discharge choke rings. Furthermore the worm geometry allows operation of the press without forcefeeding device.
Power transmission system
The EP-series screw presses are equipped with planetary gear reducers flanged directly onto the press housing. These heavy duty reducers are small in size and operate with high efficiency due to low friction losses at a very low noise level. The splash – lubricated reducers have a double jacket for water cooling. The cooling water flow is controlled by a thermostat valve. The oil temperature is monitored continuously and high-temperature switch contacts are interlocked with the screw press control system. A shearpin coupling between the driven belt pulley and the reducer helps to prevent damage to the reducer if the shaft is blocked.
The power transmission drive speed (screw shaft speed) can be varied by modifying the gearing ratio of the belt pulley drive.
Replacement of wear parts
One of the major objectives of the mechanical design of our EP presses is to reduce down times, thus increasing production time. Apart from using high quality wear parts this is achieved by minimizing the number of mechanically complicated components. Furthermore, great emphasis has been placed on easy access to all wear parts in combination with the special tools necessary for maintenance.
The strainer cage consists of two vertically divided halves which are hinged onto the press housing. After removing the interlocking bolts and opening the cage, cage and knife bars can be replaced with the cage halves in place. The worm shaft is designed as a stub shaft and can be easily removed from the key-way joint on the gear box and taken out of the press housing sideways. Thus no excessive free space for maintenance has to be considered in the plant lay out. It is not necessary to remove the shaft in order to apply the necessary prestress to the worm elements on the shaft using the hydraulic nut or when replacing the worm elements.
Wear parts quality
Worm and cage parts are protected against abrasion and corrosion by a 3 - 4 mm thick armoured double-layer. The armouring consists of an iron alloy (free from heavy metals Ni and Co) with a hardness of 60 - 62 HR. Numerically controlled welding machines in combination with continuous quality control (ultrasonic testing) help to maintain the very high quality standards of the wear parts.
Optional attachments
The cake discharge chambers of the press housings are designed for the installation of knife roll cake breakers. Pre-grinding of pre-press cakes helps to improve extractability in the solvent extraction process. In the full-pressing process, this reduced particle size leads to improved cooling and conveying behaviour. The EP-series full-presses can also be equipped with shaft cooling to avoid excessive heat on the shaft and consequently to maintain high product quality.
Control systems
Depending on individual requirements, different control systems with varying degrees of automation can be provided. The extensive system consists of two independent control circuits. One circuit monitors the filling level in the press inlet chute and controls the dosing screw speed to maintain a constant product level. The second circuit monitors the main drive amperage and controls the dosing screw speed to maintain a constant motor load. Both circuits are linked to obtain optimal screw press performance by avoiding overfilling or overloading.
EP-Series Screw Presses for the Oilseed Processing Industry
| Technical data Unit Pre-press Full-press | ||||||
|---|---|---|---|---|---|---|
| Type | EP-07 | EP-09 | EP-20 | EP-08 | EP-16 | EP-22 |
| Capacity MT/24 h | 130-175 | 200-275 | 450-650 | 25-35 | 60-75 | 100-120 |
| Residual oil in cake % | 17-21 | 17-21 | 17-21 | 5-8 | 5-8 | 5-8 |
| Required drive rating kW | 110-160 | 160-250 | 400-600 | 75-110 | 160-250 | 250-400 |
| Approx. weight MT | 11 | 12 | 18 | 10 | 15 | 17 |
| Dimensions approx. Unit Pre-press Full-press | ||||||
|---|---|---|---|---|---|---|
| Type | EP-07 | EP-09 | EP-20 | EP-08 | EP-16 | EP-22 |
| a mm | 4550 | 4550 | 5900 | 4550 | 5900 | 5900 |
| b mm | 3700 | 3700 | 5000 | 3700 | 5000 | 5000 |
| c mm | 1500 | 1500 | 1650 | 1500 | 1650 | 1650 |
| d mm | 800 | 800 | 900 | 800 | 900 | 900 |
| e mm | 900 | 900 | 1000 | 900 | 1000 | 1000 |
| f mm | 1360 | 1360 | 1460 | 1360 | 1460 | 1460 |
| g mm | 350 | 350 | 400 | 350 | 350 | 350 |
| h (for maintenance) mm | min. 1200 | min. 1200 | min. 1200 | min. 1200 | min. 1200 |
min. 1200 |
| i (for maintenance) mm | 800 | 800 | 900 | 800 | 850 | 850 |
Capacities, residual oil contents in cake and required drive ratings vary with the type and quality of seed to be processed. The arrangement of the driving system and the dosing screw may differ from the one shown here.
EP-Series Screw Presses for the Rendering Industry
| Technical data Unit Presses | |||
|---|---|---|---|
| Type | EP-19 | EP-07 | EP-09 |
| Input MT/h | 1.0 - 1.9 | 2.0 - 2.8 | 3.1 - 6.2 |
| Output (cake) MT/h | 0.6 - 1.2 | 1.3 - 1.8 | 2.0 - 4.0 |
| Residual fat in cake % | 10 - 12 | 10 - 12 | 10 - 12 |
| Required drive rating kW | 30 - 45 | 90 - 110 | 110 - 132 |
| Approx. weight MT | 5 | 11 | 12 |
| Dimensions approx. Unit Presses | |||
|---|---|---|---|
| Type | EP-19 | EP-07 | EP-09 |
| a mm | 3440 | 4550 | 4550 |
| b mm | 2745 | 3700 | 3700 |
| c mm | 1250 | 1500 | 1500 |
| d mm | 700 | 800 | 800 |
| e mm | 700 | 900 | 900 |
| f mm | 1160 | 1360 | 1360 |
| g mm | 320 | 350 | 350 |
| h (for maintenance) mm | min.1200 | min.1200 | min.1200 |
| i (for maintenance) mm | 690 | 800 | 800 |
Capacities, residual fat contents in cake and required drive ratings vary with the type, composition and quality of raw material to be processed. The stated input and output figures apply to a raw material composition of 65 % water, 15 % fat and 20 % solids. The arrangement of the driving system and the dosing screw may be different to the one shown here.
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Screw presses EP09 for animal fodder production |
Press shop for secondary expelling of oil seeds |
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Screw shaft of an EP09 expeller |
Screw presses |
