/ep_edm/en/contect_116.html SHINI PLASTICS TECHNOLOGIES, INC.

Experience Sharing

2010 Quarter 1 Issue 2

Solution for High Dew-point of SDL-80U-HD-D

Share to:


Problem Description

The dew-point can not meet customers requirement, and material drying effect is not ideal.

SDL-80U-HD-D


Analysis

Check the machine of serial number 2LU08060006: First we observe the front filter. If there were too much oil-water mixture in the oil leveler, it indicated that no check and maintenance were taken, and also the air source was in a poor quality. Then we knew the air source pressure is 6~7kgf/cm2 after inquiring customers. Secondly, we checked the air exhaust of the heatless regeneration dryer. We found there were some oil spots at the connection and the silencer was in a bad air permeability after took it down. Thirdly, we took down the two silencers. The silencers were changed when we found the regeneration air exhaust has greater differential pressure which indicated the silencer was in a bad air permeability. Finally, we checked the dew-point when the silencer was taken down, if the dew-point reach -43℃ after about 20 minutes, it will meet customers requirement.

Check the machine of serial number 2LU08060016:First we checked the front filter and found no water-oil mixture, then checked the air exhaust of heatless regeneration dryer. After the silencer was taken down, we found there were no oil spots, little dust and much displacement at the connection. Secondly we checked air regeneration control valve. We found it was in a full open status, which cause reduction of pressure, pressure difference, and poor regeneration effect in drying bin. Thirdly, we turned down air regeneration control valve, meanwhile took down the two exhaust silencers. Then we checked dew-point. If the dew-point reach -41℃ after 20 minutes, it will meet customers requirement.

Check the machine of serial number 2LU08120004: First we checked the front filter and found no water-oil mixture. Then check the air exhaust of heatless regeneration dryer. After the silencer was took down, we found there was no oil spots, little dust at the connection, but only one group of solenoid valve exhausted. Secondly we adjusted regeneration control valve and checked the connection of solenoid valve. We found the connection is right, then checked the dew-point. If the dew-point reach -41℃ about 20 minutes later, it will meet customers requirement.


Solution

We should check machine completely before operation, the key point is: 

• There is no more water and oil for front filter.
• Check the availability of oil and dust beside regenerative exhaust port, molecular sieve should be replaced if there are oil and water. (2LU08060006 should replace molecular sieve).
• The regeneration air is adjusted based on the equipment of lowest dew-point with the best effect, too much or too little will affect dew-point.
• Check whether the dryer and the pipes is leakage, if any problem, it should be improved immediately.
• Maintainer should be advised not to adjust regenerative air control valve, do need to adjust the machine based on the instruction if needed.