Feeding systems

VacuDry® is very flexible with regard to the feeding – find your solution

Working in the field of industrial waste treatment poses one major challenge: a permanent change of composition of the input materials, and a change in their physical and chemical properties. For some of our clients, waste materials may transform from powder to sludge within one day. Therefore the handling of these incoming waste streams is as important to us as the actual thermal processing itself. Based on 20 years of experience with industrial wastes, we are able to offer a unique variety of material handling systems. econ industries provides the most flexible and versatile feeding solutions for thermal desorption units worldwide.

Finding a suitable material feeding process depends on the type, variety and properties of the waste, as well as the general waste-handling and logistics management conditions at the client´s premises. Therefore the process of selecting the appropriate feeding technology for a particular waste stream is always a cooperative decision with the client.

A VacuDry® unit can also be delivered with two or three different feeding systems to allow maximum flexibility for future waste streams. Below you will find a short summary of the material handling technology most frequently used with our VacuDry® units.

Screw conveyor

Almost every VacuDry® unit consists of screw conveyors as a part of the feeding process, either for dosing or conveying. These screw conveyors are designed to ensure a clean and economic feeding process of the material into the VacuDry® units, including the option for enclosed transporting of materials under nitrogen atmosphere. In addition to the standard trough-type screw conveyors, econ industries also supplies various other feeding bunkers, e.g. a five-fold screw feeder up to a size of 30 m3, used for refinery oily wastes.

Application:

Almost all kinds of sludge, filter-cakes and centrifuge cake; dry fines incl. powder; wet contaminated soils

Advantages:

Enclosed, odour and dust-free transport; mild steel as well as stainless steel for corrosive matters available

Limitations:

Wear resistance against abrasive or coarse materials (e.g. large stones) is to be considered; possible risks when conveying thixotropic sludge

  • Solid pump for oily waste
  • Solid pump for oily waste
  • Solid pump for oily waste

Solid pump

For certain feed materials up to approx. 60 % mineral solid content, heavy piston pumps can be used. Materials enter the pump via an appropriate feeding bunker, where the operator controls an overhead crane / wheel loader for dumping. Due to the fully enclosed system solid pumps allow a very clean and safe handling process, and do not require a large amount of space.  Handling highly toxic or volatile substances (e.g. high mercury level, VOCs, etc.) under explosion protection regulation is not an issue for these systems.  Piston pumps are especially relevant to clients that have almost consistent waste streams.  econ´s largest pump used for feeding oily wastes is a 90 kW hydraulically-driven, double piston pump; able to deliver 70 m³/h at up to 60 bar pressure.

Application:

Oil sludge, wet drill cuttings, filter cake, centrifuge cake, incl. mercury containing sludge

Advantages:

  • Enclosed system – Clean and safe handling (even of highly toxic or volatile wastes)
  • Compact design – Low space demand

Limitations:

Mineral solid content limited to approximately 60 %; the sophisticated design of the hydraulic system means special skills are required for undertaking maintenance; explosion protection issues to be considered while designing the pump system

  • Belt conveyor for mercury contaminated soil and building rubble
  • Belt conveyor for oily wastes and oil contaminated soil
  • Belt conveyor for oily sludge and oil contaminated soil

Belt conveyor

For bulk material as well as feed materials that are not overly sticky, a belt conveyor is a cost effective and reliable solution. econ industries has already designed such conveyors for many different applications, incl. contaminated soils, building rubble, highly-viscous oily sludge, etc. When it comes to sticky hydrocarbon feed materials, econ industries has the required knowledge for appropriate belt-cleaning and dosing facilities. Typically feeding belt conveyors are 30 meters long and 800 mm wide, and include sophisticated belt cleaning devices, all necessary maintenance platforms and a magnetic separator to remove massive ferrous parts (e.g. from soils and building rubble).

Application:

Highly-viscous drill cuttings with a high solid content, contaminated soils, crushed building rubble, pre-conditioned sludge, relatively dry filter-cake

Advantages:

Simple to operate; low wear and tear; low demand for maintenance; low investment cost

Limitations:

Not a fully enclosed system – dust and vapour emissions (Not suitable for highly toxic wastes); requires a large amount of space; clean operation can be challenging with sticky feed materials

Double belt conveyor

In case of limited space, a double belt conveyor is a suitable alternative to a standard belt conveyor. This equipment can be used for the same feed material range, but the design is a little more sophisticated; it requires additional dosing devices in front of the conveyor. econ industries has already designed and installed such conveyors up to a height of 15 meters, needing only 10 m² space on the ground.

Application:

Highly-viscous drill cuttings with a high solid content, contaminated soils, crushed building rubble, pre-conditioned sludge, relatively dry filter-cake

Advantages:

Compact, space saving design; flexible regarding feed materials; compared to the standard belt conveyor, almost fully enclosed system with less vapour emissions

Limitation:

Clean operation challenging with sticky feed materials; higher invest compared to belt conveyor

Chain conveyor

A broad range of chain conveyors is available; typically used when there are no space limitations and when the feed material tends to be wet. This conveyor type also works fully enclosed, allowing nitrogen blanketing during the feeding process to be straightforward. Feeding heights of up to 14 meters have already been put into operation by econ, with feeding capacities of up to 50 m³/h of sludge.

Application:

Oil sludge, wet drill cuttings, filter cake, centrifuge cake, incl. mercury containing sludge; incl. thixotropic sludge

Advantages:

Proven technology with easy maintenance; low wear due to slowly moving parts

Limitations:

Can be sensitive to foreign parts/stones, proper sieving of input material is required; alternative feeding systems to be added when sludge gets too dry