Bokela Revamping Disc Filter Header
Bokela Revamping Disc Filter Header

Filter ReVamping

Optimization & upgrading of operating disc, drum & pan filters

Low throughput, too high residual moisture, low filter availability, high filter operating costs – filters which have been in operation for years often fail to achieve the desired results. With the BOKELA filter revamping program we bring your old filter system up to the latest state of the art.

Filter revamps from BOKELA are the best way to benefit from our unique know-how when using filter equipment from other OEMs. Filter revamping is a specialist program for filter optimization and a very economical alternative to a new filter investment. Filter revamps enable you to optimize the process and operation of your running filter system in the fastest and most economical way. Inadequate filter performance, excessive maintenance and high operating costs of existing filters are eliminated quickly and at low cost. In this way you can achieve higher production goals, meet higher product quality requirements and improve the reliability, operational safety and reduce the operating cost of your filter system.

Our filter revamping program has already demonstrated its feasibility and cost-effectiveness 100 times in various reference applications. Disc, drum and pan filters from numerous OEMs have been successfully optimized in many areas of application. Increase of filter performance of up to 150 % has been achieved.


  • 30 % up to 150 % solids capacity increase
  • reduced cake moisture
  • improved filter operation, maintainability and safety
  • higher filter availability
  • significant savings in investment – only 10 % to 30 % of costs for new filter investment
  • fast realization covered often under the maintenance or operational budget with no need for capital expenditure approvals


vacuum disc filter EIMCO, Dorr Oliver, KHD, Krauss Maffei, Thune, Denver
vacuum pan filter EIMCO, Dorr Oliver
vacuum drum filter EIMCO, Dorr Oliver, KHD, Krauss Maffei, Bird Young, Jord, Envirotech, Chemical Plant & Eng., Nivoba, BHS, Amafilter


  • Al-Hydrate (fine & coarse seed, product)
  • coal
  • base metal concentrates
  • iron ore concentrate
  • tailings
  • potash
  • sodium chloride
  • sodium bicarbonate
  • terephtalic acid
  • pigments
  • and many others


Example: Disc Filter Revamping

Depending on your target and available funds, a filter revamp can be carried out from a smaller up to a larger package of modifications.

Economy of filter revamps

The costs of a filter revamping range from 25 % to 75 % of the price for a new filter. However, it has to be taken into account that the total costs of a new filter investment requires 3 to 4 times the price of the new filter itself due to the additional costs for building, piping, electrics, auxiliary services and engineering.

Modifications Cost for revamping related to purchase of new filter Cost for revamping related to costs for new filter incl. building, installation and commissioning
Small Package 25 % approx. 10 %
Large Package 75 % 20–30 %


Example: revamping of 5 disc filters in an Alumina refinery

In an Alumina refinery five disc filters are operated for Al-hydrate seed filtration. Due to a planned increase in production, the filter capacity needed to be increased by 40 %. This corresponded to an additional capacity of two new disc filters of the same type. Instead of installing two new filters, the customer engaged BOKELA to optimize the five existing disc filters with the target to achieve 40% increase in solids throughput.

Engineering by BOKELA 17 %
Optimization of 4 filters with a small package 32 %
Optimization of 1 filter with a large package 29 %
Additional costs for modification at customer installation 22 %
Total cost for revamping 100 %


The necessary increase in performance has been achieved by optimizing four disc filters with a small optimization package and 1 filter with a large optimization package of modifications. The costs for this optimization were only 23 % compared to the total costs for installation of 2 new filters.

2 new filters 150 %
Building, piping, auxiliary units & engineering 280 %
Total cost for new invest 430 %

* related to total cost for revamping which is set to 100 %


Revamping Potential

The aim of a filter revamp is to improve the filter performance in terms of throughput and residual moisture, to solve operating and maintenance problems, to reduce maintenance and operating costs, and to increase availability and operational reliability. In order to exploit the existing potential, all relevant filter components and auxiliary equipment are analyzed. Depending on the objective, most of the filter components can be converted so that they correspond to the latest BOKELA design.

Most of these modifications are made to address capacity and performance issues related to hardware bottlenecks and poor hardware design which results in high vacuum loss.

At the same time, the main problems for the operation and maintenance of the filters are eliminated, such as high wear on many components, poor lubrication, poor access for work during filter operation or for maintenance work.

New invest means …

  • a lengthy pre-planning phase
  • technology and market research (screening)
  • OEM research
  • complex engineering (new filter systems usually require a new building with new piping, cabling, auxiliary units ...)
  • acceptance problems by operating personnel, since new & unknown equipment
  • etc.

Filter revamping means …

  • reduced planning and engineering efforts
  • short-termed, fast realisation (plug & play)
  • use of of customer's own know-how and plant technologies
  • use of the well known and operator-accepted equipment
  • minimal costs for peripheral & supplementary equipment

The economic way to get old filters back on track – step by step

Assessment of the improvement potential through BOKELA expert

BOKELA offer for the appropriate revamp package to meet customers requirement

Order placed by customer

Engineering and manufacturing of optimization package

Delivery of optimization package

Installation of optimization package

Re-commissioning of optimized filter(s)

Performance test to verify customer's requirements are met

Disc Filter Revamping

Cake discharge before …

… and after revamping from BOKELA

Drum Filter Revamping

… and after revamping from BOKELA

Pan Filter Revamping

Al-Hydrate Filtration with Vacuum Disc Filter after Revamp

Do you have any questions?

Benefit from our expertise – get in touch with us.

We would be happy to help you out and support you with regard to analyzing and taking a look at implementation issues, optimization potential and other aspects of your filtration system.

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