Embodiments relate to a hydraulic fracturing system that includes a blender unit. The system includes an auger and hopper assembly to receive proppant from a proppant source and feed the proppant to the blender unit for mixing with a fluid. A first power source is used to power the blender unit in order to mix the proppant with the fluid and prepare a fracturing slurry. A second power source independently powers the auger and hopper assembly in order to align the hopper of the auger and hopper assembly with a proppant feed from the proppant source. Thus, the auger and hopper assembly can be stowed or deployed without use of the first power source, which is the main power supply to the blender unit.

The disclosed systems and methods are related to a positive displacement compression for use in various applications including gas processing, air conditioning, refrigeration, etc., to produce an isothermal compression to enhance the compression efficiency. The heat exchange enhanced compression is conducted by the use of cylinders partially filled with incompressible fluid (e.g., oil) acting as a piston compressing working fluid (e.g., CO.sub.2). The isothermal compression is contemplated in various modifications. A variety of heat exchange (cooling) techniques may be arranged either within the compression chamber or the compression process may be embedded in the heat exchanger to cool down the working fluid (for example, CO.sub.2).

Embodiments relate to a hydraulic fracturing system that includes a blender unit. The system includes an auger and hopper assembly to receive proppant from a proppant source and feed the proppant to the blender unit for mixing with a fluid. A first power source is used to power the blender unit in order to mix the proppant with the fluid and prepare a fracturing slurry. A second power source independently powers the auger and hopper assembly in order to align the hopper of the auger and hopper assembly with a proppant feed from the proppant source. Thus, the auger and hopper assembly can be stowed or deployed without use of the first power source, which is the main power supply to the blender unit.

Embodiments relate to a hydraulic fracturing system that includes a blender unit. The system includes an auger and hopper assembly to receive proppant from a proppant source and feed the proppant to the blender unit for mixing with a fluid. A first power source is used to power the blender unit in order to mix the proppant with the fluid and prepare a fracturing slurry. A second power source independently powers the auger and hopper assembly in order to align the hopper of the auger and hopper assembly with a proppant feed from the proppant source. Thus, the auger and hopper assembly can be stowed or deployed without use of the first power source, which is the main power supply to the blender unit.

A hydraulic fracturing system includes a turbine generator for producing electricity at a well site, the turbine generator producing electrical energy at a voltage. The system also includes an electric pump electrically coupled to the turbine generator and receiving operative power from the turbine generator. The system further includes switch gear arranged between the electric pump and the turbine generator, the switch gear distributing electrical energy from the turbine generator to the electric pump, wherein the voltage remains substantially constant from the turbine generator to the electric pump.

A hydraulic fracturing system includes a turbine generator for producing electricity at a well site, the turbine generator producing electrical energy at a voltage. The system also includes an electric pump electrically coupled to the turbine generator and receiving operative power from the turbine generator. The system further includes switch gear arranged between the electric pump and the turbine generator, the switch gear distributing electrical energy from the turbine generator to the electric pump, wherein the voltage remains substantially constant from the turbine generator to the electric pump.

A liquid delivery device includes at least one liquid delivery pump that delivers liquid, at least one main channel communicating with an outlet of the liquid delivery pump, at least one branch channel branched from the main channel, and a switching valve that has, as a port for connecting channels, at least a port to which the main channel is connected, a port to which the branch channel is connected, at least one output port for outputting liquid delivered by the liquid delivery pump through the main channel, and at least one drain port leading to a drain, and is configured to be selectively switched to a first state, in which the main channel is connected to the output port while the branch channel is not connected to any channel, and a second state in which the branch channel is connected to the drain port while the main channel is not connected to any channel.

A mobile fracking pump trailer 100 includes a gas turbine engine 102 and fracking pump 104, and torque converter 114 that fluidly couples the gas turbine engine 102 to the fracking pump 104. The mobile fracking pump trailer 100 further includes a first reduction gearing 118 connected between the gas turbine engine 102 and the torque converter 114 and a first power takeoff 120 connected to first reduction gearing 118. An electrical machine 128 is connected to the first power takeoff 120 for selectively starting the gas turbine engine 102 and generating electrical power to power the mobile fracking pump trailer 100 after the gas turbine engine 102 has been started.

A nut of a helical gear of a piston pump of a hydraulic vehicle power brake system. The nut has a plastic body that is covered by a metal sleeve. The plastic body has a through hole having a nut thread.

A nut of a helical gear of a piston pump of a hydraulic vehicle power brake system. The nut has a plastic body that is covered by a metal sleeve. The plastic body has a through hole having a nut thread.