Membrane Filter Presses

When particularly dry filter cakes and/or short cycle times are required, the membrane filter press is the optimal solution. A flexible membrane positioned between the filter plates is used to displace the remaining free liquid from the chambers in a targeted manner after primary filtration, thereby compressing the filter cake.

 

By compressing the filter cake, it is compacted and additional liquid is expelled. After successful compression, the filter cake is generally further mechanically dewatered using compressed air. The result: consistently stable filter cakes with the lowest possible residual moisture and minimal energy consumption.

 

The membrane filter press therefore combines the proven technology of the chamber filter press with an additional compression function. This results in:

• shorter filtration cycles
• consistently stable filter cakes
• lower energy costs
• drier cakes
• reduced disposal costs

Our range of membrane filter presses 

 

 

	LCM 320	AF 470	AF 630	AF 800	AF 1000	AF 1200
Plate format	320 x 320mm	470 x 470mm	630 x 630mm	800 x 800mm	1000 x 1000mm	1200 x 1200mm
Filter type	Membrane chamber filter press
Filling pressure up to	7 (15) bar	7 (10) bar	7 (10) bar	7 (10) bar	7 (10) bar	7 (10) bar
Number of chambers	1 - 8 pcs.	4 - 10 pcs.	10 pcs.	10 pcs.	10 pcs.	10 - 20 pcs.
Filter area	0.09 - 0.73m²	1.3 - 3m²	5.9m²	9.9m²	14.9m²	22.3 - 44.6m²
Max. cake thickness	32mm
Filter volume	1.5 - 12l	16 - 40l	86l	154l	238l	365 - 730l
Operation	Manually	fully automated/autonomous

 

This is what sets the AQUACHEM membrane filter press apart

 

Our AF series combines proven membrane chamber filter press technology with state-of-the-art automation systems. From filling and cake filtration to cake washing and final discharge, the entire process operates fully automatically and without any manual intervention. This significantly reduces labour requirements, prevents downtime, and ensures consistently high throughput.

 

To the best of our knowledge, the AF series is the only fully automatic and autonomously operating membrane filter press on the market. During every process design, we meticulously ensure that only the absolutely necessary technology is installed, guaranteeing maximum system availability while keeping complexity to a minimum.

 

Whether in the chemical industry, food processing, wastewater treatment, or metal processing – with a membrane filter press from AQUACHEM, you benefit from innovative technology, high cost efficiency, and minimal maintenance requirements.

Your benefits at a glance

 

• high process reliability thanks to state-of-the-art automation
• minimal labour requirements due to fully automatic and autonomous operation
• robust design for long service life
• minimum maintenance effort and ease of operation
• customisable for almost any industry and application

The design of a membrane filter press

 

A membrane chamber filter press consists of several filter plates – the so-called plate pack. The plate pack is assembled alternately with chamber plates and membrane plates. Chambers are formed between the plates, into which the medium to be separated – the suspension – is pumped.

 

The filter cloths mounted on the filter plates retain the solids, while the liquid – the filtrate – passes through the cloth and is discharged via a drainage surface and outlet ports into the filtrate collection channels.

The filtration process – Step by step

Filling of the filter chambers

The suspension (sludge) is pumped under pressure – generated by a suspension pump – into the chambers between the filter plates. It is important that all chambers are filled simultaneously and evenly.

 

Formation of the filter cake – Primary filtration

While the liquid (the filtrate) passes through the filter cloth and is discharged into the filtrate channels, the filter cake remains inside the chamber. This phase is similar to the process of a conventional chamber filter press; however, in a membrane filter press the chambers do not need to be completely filled.

 

Membrane squeezing

This is where the decisive difference occurs: the flexible membranes of the membrane plates are filled with compressed air or alternatively with water, causing them to expand.

 

As a result, the free liquid is pressed out of the chambers and the formed filter cake is strongly compressed. Additional residual liquid is squeezed out – similar to a sponge – and the filter cake is further compacted.

 

Filter cake washing

Some processes require filter cake washing, for example to remove unwanted substances such as chlorides from the filter cake. After the filter cake has been compacted by membrane squeezing, it is washed using the pressure washing plate principle with a suitable washing solution. 

 

In this pressure washing plate principle, the wash water is pumped from one chamber side to the other through the filter cake, resulting in displacement washing and/or dilution washing.

 

Cake dewatering

After membrane squeezing and any optional cake washing, the filter cake is generally further mechanically dewatered. During cake dewatering, compressed air is usually forced through the filter cake using the pressure washing plate principle, so that the free liquid in the cake pores is literally “blown out”.

 

We would be pleased to explain personally which additional measures we can implement to achieve the lowest possible residual moisture for your downstream process.
contact us!

 

Filter cake discharge

After secondary pressing and cake dewatering, the filter press is opened. Depending on the filter press type, all plates are opened simultaneously, or the plates are moved individually by a shifting mechanism.

 

When the filter press is opened, the filter cake either falls off the filter plates automatically, or – depending on the adhesive properties of the cake – must be discharged manually or with the aid of a discharge system.

 

We would be pleased to explain in a personal discussion which special systems we offer for safe and fully automatic cake dischargeWe look forward to hearing from you

 

Filter cloth cleaning/cloth regeneration

Over time, every filter cloth becomes clogged and therefore needs to be cleaned periodically. The following options are available for cloth regeneration:

• manual high-pressure cleaning: The filter cloths are cleaned manually using a high-pressure cleaner. However, this method involves a high risk of mechanical wear and damage to the cloths.
• automated washing system: The filter cloths are cleaned using a washing medium under “high pressure”, whereby a nozzle bar automatically moves across the filter surfaces and washes adhering solids from the cake side of the filter cloth.
• chemical cloth regeneration: In this process, the filter cloths are regenerated using a diluted acid or alkaline solution, depending on the application – similar to descaling a kettle. The acids/alkalis gently dissolve the solids embedded in the filter cloths. Before the flushing process, the filter press is closed and the cleaning liquid is pumped through the filter press via various flow paths. This process requires sealed filter plates with closed filtrate outlets.

Due to its high effectiveness and the gentle treatment of the filter cloths, we prefer chemical cloth regeneration for most applications.

In contrast to a conventional chamber filter press, the residual liquid in the chambers of a membrane filter press is displaced by elastic membranes after primary filtration, and the filter cake is additionally compacted. This ensures that, before every cake discharge, a consistently stable filter cake is produced, which can be discharged optimally and always exhibits uniform residual moisture.

 

Thanks to the membrane pressing technology, the cake thickness can be individually adjusted at any time to suit the specific process conditions.

 

Whenever uniform cake properties are required, maximum process reliability is essential, and the necessary labour input is to be reduced to an absolute minimum, a fully automatic membrane chamber filter press is indispensable.

Are you interested in a membrane filter press that is precisely tailored to your process? Get in touch with us – together we will find the most efficient solution for your application.

Enquire now!