Sulphur filtration

Sulphur filtration: Most sulphur is used for the production of sulfuric acid (H2SO4). Before elemental sulphur can be fed to the contact process, typically with a vanadium catalyst, it needs to be purified.

If sulphur is filtered in a molten sulphur process the maintenance interval of the sulphur burners, catalyst beds, and pipe reactors is significantly improved. This results in considerably lower maintenance costs.

A molten sulphur filter system typically consists of a two stage filtration system. This system consists of a horizontal pressure leaf filter followed by a polishing/safety cartridge filter.

Filtration Group Process Systems – amafilter – LFC Lochem has developed Horizontal Pressure Leaf – Retractable Bundle and Retractable Shell type filters for sulphur filtration.

Key characteristics of these filter models are a big filtration surface, easy to clean filter plates, and a heating jacket in order to maintain the high process

An additional cartridge filter is placed downstream of the horizontal pressure leaf filter.

Sulphur filters can be found in the following industries:

  • Fertilizer industry
  • Sulphuric and phosphoric acid producers.
  • Oil refineries
  • Rubber producers.
  • Mining corporations.
  • Carbon disulfide (CS2) producers.

Key advantages of Filtration Group Process Systems – amafilter – LFC Lochem sulphur filtration solutions:

  • Undisputed market leader with by far the largest installed base worldwide.
  • Several other players have copied our design, some of which with a reasonable result, but none with a better one.
  • Mechanical finish of the highest standard, leading to longevity of the filters.
  • Impact resistant and tightly assembled 5-ply filter plates with superior release properties.
  • Lower maintenance costs resulting from proprietary engineering, not just for your filters but also for the downstream protected burner nozzles.
  • Experience-based cycle algorithms to optimize your total process performance.
  • Extensive process support for commissioning and local design requirements.
  • Advanced operator training and pragmatic testing guidance.
  • Fully fledged quality assurance system and certification/compliance track record.
  • And last but not least close customer interaction, whenever you need it, wherever you are.

Pressure leaf system advantages in sulphur filtration

The Horizontal Pressure Leaf Filter is a closed filtration system and can be automated. This filter produces high filtrate clarity after the clarification run and is also suitable for most filter aids. The regeneration time between the filtration cycles is optimized and short.

Key characteristics of the Horizontal Pressure Leaf Filters for sulphur filtration are a big filtration surface, easy to clean filter plates, and use of a heating jacket in order to prevent solidification.

The pressure leaf filter itself has no rotating parts, thus keeping maintenance to a minimum. These advantages result in an economical filtration solution. For cake discharge the carriage with the filter leaves is driven outside the tank with an electric or hydraulic system. With a Retractable Shell system, the filter
leaves are exposed by moving the tank away from the bundle. The bayonet ring is opened hydraulically. The cake discharge is easily done with the filter opened.

The Retractable bundle type filter is equipped with a selfsealing quick release manifold coupling which is steam heated.

The Horizontal Pressure Leaf Filter, which we supply in the filtration cycle of liquid sulphur, can be tailor made to fit your requirements, in any of the following setups:

copyright Filtration Group BV / Amafilter / LFC Lochem

Sulphur filtration RS-horizontal-pressure-leaf-filter-filtration-group-amafilter-lfc-lochem

copyright Filtration Group BV / Amafilter / LFC Lochem


  • Retractable bundle:

The shell doesn’t move; the bundle
with filter elements moves in and out of the shell.

  • Retractable shell with an overhead suspension frame:

The bundle doesn’t move, the shell hangs from a support structure and moves over the bundle.

  • Retractable shell with a lower support frame:

The bundle doesn’t move here either, the shell is supported
by rails and moves over the bundle.

Filter elements

The leaf spacing is 125 mm to allow for precoat and longer filtration times. The filter leaves are mounted on a manifold which allows for easy removal and mounting of the filter leaves.

Features and benefits

  • Vertical position for easy cleaning
  • Rectangular filter screens, double sided
  • Five layers of wire mesh
  • Reinforced binding around the full circumference of the filter leaf to protect the rim during manual cake removal by tapping

VC Model Cartridge filter

A cartridge filter is placed downstream of the horizontal pressure leaf filter. It also has a heating jacket in order to maintain the required elevated temperature.

This filter is used for the removal of fine ash and other particles which come through even if the main filtration is 100%

  • Solid content in Sulphur 10-20 ppm.
  • Solid content in filtrate:
  • less than 5 ppm
  • particles are smaller than 5 µm

The cartridge filter is also used as a safety/police filter to prevent precoat material of passing the horizontal pressure leaf filter due to errors in switching valves, insufficient precoat or strong changes in flow.

The cartridges are suspended from a septum plate between the cover flanges. This allows for quick exchange with a spare set of cartridges.

Ceramic Filter cartridges

The ceramic PC filter cartridge is specifically designed for the polishing filtration of liquid sulphur. These rugged porous ceramic cartridges are manufactured by fusing aluminium oxide grains using a porcelain bond to form a strong, uniformly porous and homogeneous structure.

The ceramic PC cartridge is cleanable by a variety of methods, depending on the type of contaminant. Some of the methods are backwashing, oven firing, solvent cleaning, steam cleaning and ultrasonic cleaning.

Wound Fibre Glass Filter Cartridge

Glass fibre filter cartridges are ideally suited to remove solids in critical applications within the chemical industry.

Typical applications are acids, organic solvents and high temperature processes.

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