DASAG Powder Pump – news and advancements

Within the last years conventional double membrane pumps have been employed increasingly for the pumping of powdery bulk materials. The relatively slow and gentle discharge with a small air share and, at least partly, the suction mode of these pumps account decisively for this development. The pumping of bulk materials with simple membrane pumps, which are mainly employed with liquids, does usually only work with fine powders with a relatively low bulk density. But a multitude of powders and mixtures show bulk densities of > 300 kg/m³ and partly bulk characteristics which do not allow discharge via simple membrane pumps.

The clear advantages of being able to pump even such bulk materials were the initial point to develop a special pump for powdery and granular bulk materials based on the system of the membrane pump. electro-pneumatically actuated valves were installed at the in- and outlets of the pump chambers and the pump cycle was controlled. Connections for controlled air supply and pressure control were esta- blished at suitable positions at the pump chambers and in the outlet area. The general flow direction through the pump was set from top to bottom in gravity direction in order to reach a certain self-flui- disation of the material when in free fall. The entire system is controlled by a programmable control system. Various adaptable programmes allow an optimal adjustment to the respective materials and conditions. This is state of the art today.

The DASAG Pump systems have conquered a remarkable position on the market within the last years. Simultaneously the powder pump has been enhanced according to the very special requirements of the customers. This is subject of the following considerations. A controlled air supply is given in order to keep the materials in a state where they can be pumped. The gas share of the flow is to be kept as small as possible. This is especially important with materials which are to convey with inert gas and subsequent preparation procedures of the gas phase.

If required you can separate the driving air from the fluidising air or inert gas. This could be important for customers with poor air supply because they can feed in with two different pressures. Moreover you can agitate complicated bulk material by special pneumatic or mechanical devices so that it flows into the pump chambers. In a lot of cases it is verified that the powder pump is the perfect conveyer for complicated bulk material such as structure-sensitive, bridging, fragile, cohesive and adhesive. The flow volume of these versatile compact pumps is approx. 2 – 5 m³/h for distances up to approx. 40 m with powdery bulk materials with bulk densities of approx. 1,000 kg/m³. With optimal bulk materials and transport systems higher flow rates and longer distances are possible.

To increase the capacity the “Duo Pump” was developed with two identical pump blocks. This unit has further advantages such as:

• The possible simultaneous feed of two receivers, as the piping can consist of two separate pipes or hoses.
• One duo pump is more competitive than two separate pumps.
• Easy spares inventory, as there is only one installation size.
• Operation reliability, as in case of failure of one pump block the other keeps working.

Meantime there are various designs of the powder pump, e.g.

• with suction amplifier to suck material from several stations and pump it into other stations.
• Pump combined with container weigher
• With variable product inward transfer (smallest components)
• Pump as tie-in point, especially in metering plants
• Equipped for explosive regions
• Combined with sac-, bin- or IBC-discharger
• As above, additionally the complete unit is designed as a metering device (see adjoining picture).
• Application for IBC or container filling

Powder pumps are often a part of complete systems for the transport of bulk material in dosing, mixing, packaging and recycling plants from the building materials industry over the chemical to the food industry.