Navigating Fire Code Issues
One of the huge benefits of using an inline blending skid for the manufacture of windshield washer fluid is the reduction of methanol volume present at any time. With batch mixing tanks, you will transfer high volumes of methanol to a large tank. Therefore, the tank will have to be installed in a hazardous rated area meeting class 1 div 1 requirements.
A continuous system that draws raw material from their respective sources, usually outside the building, can be installed in a lesser classified area because it holds much less volume of the methanol than a batch tank. The methanol is now transferred in a diluted state, as it is combined with the water and dye, to the filler or hold tank. The methanol no longer needs to be handled in large volumes by itself, reducing fire code requirements that would otherwise have to be followed in a batch mixing situation.
The skid features full PLC automation control to automatically keep pace with a filler line or fill a hold tank on demand based on level switch indication. The automated scheme maintains proper feed ratio via PID loop control between VFD and flow meter per PD pump. Pump starvation is avoided through inlet-side pressure detection. Batch counters are used for filling to guarantee vessels are not over filled.