Fully automatic 24/7 operation in the processing of heavy metal-containing filter ash


Chiresa AG in Switzerland specializes in the ecological and economical utilization of hazardous waste. With the assistance of our AQUACHEM filter presses, heavy metal-containing filter ashes from industrial plants are pressed into recyclable filter cakes. 



About our customer 


Chiresa AG, headquartered in Turgi, Switzerland, is a modern integrated waste management company. In the field of hazardous waste, it develops environmentally and economically viable solutions for the reduction, utilization, recycling, and disposal of hazardous waste. 



Processing of heavy metal-containing filter ash 


Since 2020, Chiresa AG has been using four of our fully automatic membrane filter presses of the type AF1200 (Smart Filter Press) to support the processing of heavy metal-containing filter ash from incineration plants. 

To achieve this, the filter ash is initially dissolved in hydrochloric acid. A subsequent precipitation reaction separates the dissolved components into water and settling hydroxide sludge. The resulting sludge is neutralized and either pressed into solid filter cakes and disposed of using AQUACHEM's fully automatic filter presses or processed for recycling. The water collected during the filtration process is returned to the cycle. 


"The filter presses used at Chiresa AG operate continuously, literally around the clock, producing and discharging solid filter cakes," says James Babbé, Managing Director of AQUACHEM. 



Machine availability of up to 98 percent


Approximately 95,500 tonnes of suspension are conveyed through the four filter presses every year. That is almost 37 tankers per day. The presence of an operator is not required, as our fully automatic filter presses can guarantee a machine availability of up to 98 percent. By using chamber and membrane plates, operating parameters can be optimally adjusted to strike a balance between economy and ecology. Additionally, the leakage of suspension during the filtration cycle can be avoided with these systems, as all filter presses in our portfolio are completely sealed. "These are all features we are very proud of," adds James Babbé, Managing Director of AQUACHEM. 



Reliable operation with the help of sensors 


To enable optimal process flow and energy management, numerous ifm sensors support our fully automatic filter presses. For example, inductive sensors monitor the end position of the filter press. This means that when the plate pack is closing, the motor operates until the preset end position is reached. 


Capacitive sensors, on the other hand, are used for limit value monitoring at the washing and rinsing station. The 700-litre rinsing station is used to clean the filter press. Filling it with acid dissolves suspension residues, regenerates the filter cloths and thus increases their service life. 


In addition to an analogue pressure sensor that detects the closing pressure (up to 350 bar) of the hydraulics, another digital pressure sensor monitors the compressed air supply within the filter press to ensure functional and safety-relevant operation. This ensures that the air supply is within the specifications and that the valves installed on the filter press also switch correctly. The so-called pressure switches are installed both on the rinsing and washing station and on each individual filter press. 

Below the filter presses there are platforms for two containers in which the filter cakes are collected for removal. Laser distance and inclination sensors support an angle-adjustable rocker that ensures that the container is filled evenly. 



Cooperation between AQUACHEM and ifm 


AQUACHEM and ifm have been working together as partners for many years. AQUACHEM supports a wide variety of customers with different requirements. A special challenge in the project implemented for Chiresa AG was to establish the cake discharge by means of a rocker, and to safeguard the container room in order to avoid endangering the employees at all costs. 

AQUACHEM has been represented with its filter presses in flue gas scrubbing for many years and supports a large number of waste incineration plants. Setting the ideal positions, both rocker and containers, was a task they were happy to solve. In cooperation with ifm and its sensors, AQUACHEM was able to master the challenge. 


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