Dragon Manufacturing and Automation Gears Co., Ltd.

This proposal is to reduce the discharge pressure of gear pump, and it will be able to realize the 30% energy saving effect of the extruder line by adapting our DEX-GP gear pump, which is designed by DMAG.

 

Fig.1：

This figure proposes how to install the screen changers, which are a bolt screen changer on the down-stream and a flat screen changer on the upper-stream of the gear pump for the pump’s protection.

Screen changer works to filter the foreign materials of carbonized and un-molten polymer and etc. in order to keep the quality of the polymer products. And screen changer is also installed to remove the big solid materials for pump protection.

 

There have been many installation cases that the screen changers are adapted on the upper-stream of gear pump so as to fulfill the above filtering conditions.

 

However DMAG propose customers to install the two filtering sections as follows,

(1) To install the screen changer on the down-stream of gear pump for the filtered product’s quality improvement.

(2) To fit the filter of #10 or #20 on breaker plate for the protection of gear pump. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

In case that the screen changer is installed on the upper-stream of the gear pump as shown in above fig.-2, the extruder must additionally execute the pressurizing function for the resistance of screen changer.

 

But the extruder is not good at pressuring, and the results are the polymer’s temperature-up by the additional pressurizing work in the extruder.  To change the screen changer to the down-stream of the gear pump is to exert gear pump’s pressurizing function, fully. And the results are to be able to lower the extruder’s discharge pressure, to contribute the energy saving of extruder line, and to make polymer’s temperature lower and stable.

 

However the conventional gear pumps, which have low volumetric efficiency, can’t pressurize enough for the screen changer, and the screen changer must be installed on the upper-stream of the gear pump.

DMAG recommends to install the screen changer on the down-stream and to adopt DEX-GP gear pump. And the energy saving can be realized more certainly and effective.