Vented conveyor diverter valves
One feature that we put onto our vented conveyors is a diverter valve. Depending on the design, these can sometimes be called “Y” or “K” valves due to their shape which can resemble these respective letters. In addition to being called Y or K valves, they are oftentimes called two-way or three-way valves, respectively, due to their ability to divert product two or three different ways. A couple of questions we often get are what is the purpose of these valves and are they necessary?
What are they used for?
In the ExPress® system, the extruded product is conveyed to the oil press by the vented conveyor. Under normal operation, this is a continuous and steady process. If there are variations in product composition or material flow, the oil press performance can be affected. We monitor the performance of the oil press by noting the operating amps of the main motor. If this goes too high, the press can stall or the motor will be overworked and could eventually fail. To prevent this, there is some logic built into our control panels that monitors the press amps. If the amps reach a certain value, the diverter valve is engaged and directs product away from the oil press inlet until the amps return to a safe level. This valve is designed to reduce the chance of the oil press plugging by diverting product away from the inlet. Additionally, it is also nice to have the ability to bypass the oil press during startup if needed and using a valve is a simple way to achieve this.
Y vs K valves
In some situations, customers want to produce both full fat soy and ExPress® soy meal. To create full fat soy, the product from the extruders needs to be diverted away from the oil press. Using a K valve with three different positions allows for bypass, full fat, and ExPress® product streams. For full fat applications, the valve diverts product into a separate conveyor which goes to a cooler like in the picture. For regular ExPress ® applications, a Y valve is sufficient.
The final decision of which valve to use will ultimately depend on what the final products need to be. K valves give the most versatility, but routing and wiring can be somewhat tricky. In some instances, a Y valve is used for full fat production as well. The “bypass” position goes into a full fat conveyor regardless if it is truly for full fat production or just to bypass the press. This may be another option to run full fat in the future without having to use a K valve.