Abstract: A complete additive transport and mixing system is carried on a single vehicle. A collection of liquid additive containers, a collection of metering devices, and a mixing system are all mounted on the vehicle, as is a dry additive metering device. A selected liquid additive container can be selectively and changeably connected to a selected liquid additive metering device, and a selected liquid additive metering device can be selectably and changeably connected to a selected input into the mixing system. The metering of the liquid additives is monitored and a concentration display given so that the metering devices can be manually controlled to obtain an actual concentration equal to a desired concentration. A display indicating a desired setting for the dry additive metering device is also given so that the dry additive metering device can be manually controlled to allow a suitable amount of the dry additive to be added into the mixing system to obtain a desired concentration of the dry additive.

Abstract: A process control system for mixing a proppant with a fluid includes a remote control computer located remotely from where the process is to be performed, and a monitor computer and a local control computer both located where the process is to be performed. An LAN cable connects the remote control computer to the monitor and local control computers. The desired concentration value of the proppant in the fluid is entered into the remote control computer. The monitor computer sends measured values to the local control computer which generates a control signal to a sand screw to provide the desired concentration value.

Abstract: A complete additive transport and mixing system is carried on a single vehicle. A collection of liquid additive containers, a collection of metering devices, and a mixing system are all mounted on the vehicle, as is a dry additive metering device. A selected liquid additive container can be selectably and changeably connected to a selected liquid additive metering device, and a selected liquid additive metering device can be selectably and changeably connected to a selected input into the mixing system. The metering of the liquid additives is monitored and a concentration display given so that the metering devices can be manually controlled to obtain an actual concentration equal to a desired concentration. A display indicating a desired setting for the dry additive metering device is also given so that the dry additive metering device can be manually controlled to allow a suitable amount of the dry additive to be added into the mixing system to obtain a desired concentration of the dry additive.

Abstract: A data monitoring system includes a display unit for communicating with an operation that has characteristics which are to be monitored, a recording unit located remotely from the environment of the monitored operation, and a local area network interconnect circuit for connecting the display and recording units. The local area network circuit allows multiple display units to be connected to a single pair of electrical conductors. Each display unit has at least one dual microcomputer configuration interconnected by a shared dual port random access memory. A third microcomputer is located in the recording unit for communicating over the local area network circuit with one of the microcomputers in the display unit.