Abstract: An installation for the dosing of a powder polymer having a particle size in the range from 100 to 500 micrometers intended to feed a blender in hydraulic fracturing operations, successively including: a powder polymer supply, from a pressurized tilting truck or from big bags emptied by pneumatic conveying, a mechanism for transporting the powder polymer fed by a compressor, and provided with a polymer transportation check valve, a hopper for receiving the powder polymer having a high level and a low level, the hopper being equipped with a pulse jet cleaning dust filter, as well as with a mechanism for controlling the check valve and the compressor according to the high and low levels, a screw feeder for dosing the powder polymer, positioned at the lower end of the hopper, the screw being equipped with a variable-speed motor capable of being remotely controlled.

Abstract: An installation for the dosing of a powder polymer having a particle size in the range from 100 to 500 micrometers intended to feed a blender in hydraulic fracturing operations, successively including: a powder polymer supply, from a pressurized tilting truck or from big bags emptied by pneumatic conveying, a mechanism for transporting the powder polymer fed by a compressor, and provided with a polymer transportation check valve, a hopper for receiving the powder polymer having a high level and a low level, the hopper being equipped with a pulse jet cleaning dust filter, as well as with a mechanism for controlling the check valve and the compressor according to the high and low levels, a screw feeder for dosing the powder polymer, positioned at the lower end of the hopper, the screw being equipped with a variable-speed motor capable of being remotely controlled.

Abstract: Compact and transportable equipment that can be used for fracturing operations on gas or oil fields, includes, successively, a silo for storing polymer in powder form, a feed hopper of a polymer metering device, a device for metering out the powder polymer, a device for dispersing and grinding the polymer, and at least two volumetric pumps enabling the injection and metering of the polymer solution obtained in the mixer used for supplying at least one high-pressure fracturing pump.

Abstract: Compact and transportable equipment that can be used for fracturing operations on gas or oil fields, includes, successively, a silo for storing polymer in powder form, a feed hopper of a polymer metering device, a device for metering out the powder polymer, a device for dispersing and grinding the polymer, and at least two volumetric pumps enabling the injection and metering of the polymer solution obtained in the mixer used for supplying at least one high-pressure fracturing pump.

Abstract: An oscilloscope and a digital multimeter are combined in a single housing to provide a portable electronic measurement instrument wherein a substantial portion of circuitry is common to both measurement systems. A cathode-ray tube provides the display for both waveform and alpha-numeric information.

Abstract: A multiple-line display signal generating apparatus is disclosed in which each of a plurality of lines is generated in a normally fixed raster format, wherein any one of the plurality of lines may be selected and positioned wiith respect to the other lines. Programmed current generators provide a fixed displacement current for each line, and a variable displacement current may be selected to replace any of the fixed values.