Final Design

A final design was completed to overcome some of the problems encountered on the Mineral-Primm Fire. These changes include:

• Larger filter housings and filters. The new filter housings use filters that have 120 percent more surface area than the original prototype. This should decrease the number of filter changes, especially when washing extremely muddy vehicles.
  
  
• The flow of water to the settling tanks has been rerouted. The original washer split the flow and had the water enter both settling tanks at the same time. The new design has the settling tanks in series, so the water from the mat flows into one settling tank and the overflow goes to the second tank. We believe this should improve settling of the particulate.
  
  
• A valve on the mat sump pump helps prime it (figure 17). Opening the valve allows water to flow without the head pressure from the tank and hose.
  
  
• All the tanks and filter housings have been plumbed for easy draining. All hoses and drain fittings have cam/lever coupling fittings for easy connections.
  
  
• Hydraulic fittings have been used for the high-pressure plumbing from the pump and manifold to the wands and underbody washers. This allows operators to change the high-pressure bypass valve easily.
  
  
• The engine was increased to 25 horsepower. The sheaves used to power the pump were resized for better efficiency and an extra belt was used to prevent slipping.
  
  
• An additional underbody washer was incorporated to spray the vehicles twice.
  
  
• Other miscellaneous changes included increasing the size of the holding tank from 350 to 550 gallons, redesigning the locking mechanism on the mat reel, purchasing commercial rubber ramps to protect the hoses, and lengthening the trailer from 16 to 18 feet.

Figure 17—The mat sump pump has a valve attached to the outflow.
This valve is used to prime the pump. Opening the valve allows
water to flow through the pump without any head pressure. Once
the flow is established, the valve is closed and water is pumped to
the settling tanks.