The SIEBTECHNIK TEMA CONTHICK screen bowl decanter is a hybrid centrifuge consisting of a solid bowl in the product feed zone and a screen bowl fitted downstream.
Solid materials are separated by sedimentation in the solid bowl and thickened. The product can then be washed and dewatered up to the mechanically separable dewatering limit. A further special feature of the CONTHICK is its overhung mounting. This design enables easy cleaning and fast access to the parts in contact with the product. As a result, maintenance costs and maintenance times are considerably reduced.
The second stream of liquid is drained off through a separate drainhole.
All CONTHICK centrifuges are individually adapted to suit product conditions and system requirements.
Operational behaviour and mechanical characteristics
The design of this centrifuge is based on the technology of our CONTURBEX screen worm centrifuge with the addition of a pre-thickening stage. The aim is high separating efficiency, even with slightly-concentrated suspensions, and a high yield of fine contents.
The task to be perfomed by this centrifuge consists in the separation of solid matter and liquids from suspensions. The suspension is fed into the pre-thickening stage of the centrifuge through an inlet pipe and apertures in the middle of the worm body.
The main liquid content is drained off through a steplessly adjustable weir at the back of the solid bowl to obtain a clear filtrate.
The solid matter is pre-thickened and conveyed from the worm to the screening section, where residual dewatering and, if necessary, product washing takes place. The streams of liquid from the solid bowl and screening section are optionally individually or jointly drained off by means of a single- or dual-cyclone separator.
The loss of solid material here is relatively slight and can be further reduced by returning the screening filtrate to the feed. The solid matter is conveyed by the worm to the solids discharge housing via the cylindrical screening section.
The centrifuge is fitted with a special profile slotted screen cloth. Depending on the application, a special screen plate can alternatively be used. In all cases the screening elements can be very easily exchanged without having to disassemble the machine or the rotating parts.
Drives for centrifuges
The solution to a separation task depends very decisively on the centrifuge drive. The centrifugal force required for solid-liquid separation is determined by the bowl or screen speed. To achieve the right speed for optimum separating results, it is frequently necessary to keep the speeds variable. The drive control needed for this is designed by our specialists specifically to fit your application.
Furthermore, on screen worm centrifuges and in decanters the speed differential between the solid-conveying worm and the bowl is decisive. It determines the time which the solid spends in the centrifuge and so the quality of the drying. The correct speed differential for your separation task is determined by the correct choice of gear unit. The speed differential here may be constant, but may also be variable. In the latter case the back-drive, where the otherwise fixed gear input shaft is also driven, is used. If the worm speed is required to be kept completely independent of the drum speed, hydraulic drives (viscotherms) or two-stage gear units with an upstream differential planetary stage are used.
To guarantee the operational reliability of your centrifuge, the drive system is continuously monitored. Excessive speeds, overcurrent and slip are identified and reported to the machine control system and there processed.
Only a drive system specially designed for your separating task will give optimum separating results.
Explosion protection / inertising
Inertisation of our machines and systems may be necessary for various reasons. In many industrial processes it is necessary for safety reasons to reliably prevent the build-up of an explosive atmosphere through dust or gases (ATEX).
It may also be necessary to seal and overlay the product spaces with inert gas, e.g. nitrogen (N2) or carbon dioxide (CO2), to prevent oxidation and maintain product quality.
Use SIEBTECHNIK specialialists’ many decades of experience in all areas of industry to help seal and inertise the process spaces in your centrifuges.
We will be pleased to work with our customers to draw up an inertising concept for the integration of our machines into existing or scheduled plant systems.
Hygienic Design / CIP
The name SIEBTECHNIK is inseparably associated with dewatering tasks to meet the most stringent hygiene requirements. The separation of batter from frying oil at temperatures of approx. 200°C with the SHORTBOWL decanter centrifuge, the centrifuging of lactose crystals with the SHORTBOWL decanter centrifuge and the CONTURBEX screen worm centrifuge for the manufacture of baby food or the manufacture of extremely pure inorganic salts with our CONTURBEX and pusher centrifuges are some examples. Design features for this are the technical separation of the drive and processing sections of the centrifuge and highly developed sealing systems that are easy to clean by CIP.
For the optimisation of centrifuges in the hygiene sector and/or in areas where e.g. cross-contamination has to be prevented by CIP we use riboflavin tests to examine and optimise cleaning results.
Our self-developed and USDA-certified CIP nozzles, self-developed hygienic screw connections, special hygiene surfaces or our highly developed USDA-conformant sealing technology make many dewatering tasks possible only with our centriguges.
Our reliable service enables optimum operation of your machines and systems. We offer energy optimisation, machine monitoring, an on-site maintenance and & repair service, OEM spare parts, damage cause analysis, maintenance & repair kits, stock inventory analysis, machine history management, personal technical consultation, training & workshops, 24 hr service, retrofitting & upgrades and used & loan machines.
Ask us, we’re there for you.
SIEBTECHNIK/TEMA has consistently developed itself into one of the world’s most innovative manufacturer of continuous centrifuges and suppliers of system solutions in the field of mechanical and thermal solid-liquid separation since the early 1940s. SIEBTECHNIK/TEMA is your reliable partner for customer-focused, custom-built machines and system solutions.
SIEBTECHNIK/TEMA centrifuge and drier systems offer you the latest technology, customer- and product-specific special fittings and individual consultation at the pre-sales stage and reliable support in the after-sales process. For mechanical liquid separation continuously operating centrifuges are often the technically and economically best solution. They separate large volumes in closed housings with little space requirement and low energy and time costs. Also drying on the fluidised bed with fluidised bed driers and coolers has established itself in numerous branches of industry and applications.