Trading and engineering company focusing on process pumps
Engineering project and project management, hydraulically actuated diaphragm pump for chamber filter press at Stjerne-Chrom A/S.
Stjerne-Chrom A/S is a Danish company specializing in surface treatment located in Næstved. The company is environmentally certified and therefore takes the handling of industrial wastewater from the factory very seriously.
An industrial filter press suitable for the purpose is used for purification. The factory wastewater is collected and flocculated with lime before being pumped to pressurize the filter press.
In Denmark, process water from production companies must be cleaned of harmful particles before it can be discharged to urban wastewater for further treatment. Copenhagen Pump was contacted in 2023 to replace existing peristaltic pumps on a chamber filter press for process water treatment.
Click on drawing to zoom
The choice fell on a Special type pump, which is a hydraulically activated diaphragm dosing pump, also known as a piston diaphragm pump. The Josef Emmerich pump is designed to operate chamber filter presses and, in addition to the built-in safety valve, also has a bypass valve. Together, the two valves regulate and protect the pump. The capacity, which is designed for 1500 l/h, is regulated downwards with increasing pressure until the pump finally only pressurizes the filter press just before the safety valve opens.
The pump has the great advantage of being self-protected while performing a complicated control task. The pump is 1 cylinder, which would normally give a strong pulsating flow. However, the Josef Emmerich pump has 2 pulsation dampers, which are designed as wind boilers. This means that there are no membranes in the pulsation damper. On the other hand, a small amount of air is supplied 0.5 l/min into the suction side.
The small amount of air serves to dampen but also maintain a gas cushion in the pulsation damper. The resulting flow is a smoothed, almost pulsation-free flow. The pressure varies in the application between 15.0 and 15.2 bar, corresponding to a damping of approximately 99%.
The pictures show the pump installed and commissioned.
The video shows part of the commissioning (i.e. starting up and checking the operating parameters) of the pump.
The pump noise is almost completely silenced when the covers are fitted. The hydraulic fluid is water-based and similar to cutting oil.
Pump data:
Pressure 15 bar
Capacity 0-1500 l/h
Speed 68 rpm
