Provided is a tube pump system which includes: a pair of roller units which are rotated around an axis line from a closing position to a releasing position; a pair of drive units which are configured to respectively rotate the pair of roller units; a control unit which is configured to control each of the pair of drive units; and a pressure sensor which is configured to detect a pressure of a liquid in a pipe connected to the other end of the tube, wherein the control unit controls a first rotation angle when the first roller unit passes through the closing position and a second rotation angle when the second roller unit passes through the releasing position such that fluctuation of the pressure of the liquid when the pair of roller units are rotated through at least one revolution falls within a predetermined value.

Provided is a tube pump system which includes: a pair of roller units which are rotated around an axis line from a closing position to a releasing position; a pair of drive units which are configured to respectively rotate the pair of roller units; a control unit which is configured to control each of the pair of drive units; and a pressure sensor which is configured to detect a pressure of a liquid in a pipe connected to the other end of the tube, wherein the control unit controls a first rotation angle when the first roller unit passes through the closing position and a second rotation angle when the second roller unit passes through the releasing position such that fluctuation of the pressure of the liquid when the pair of roller units are rotated through at least one revolution falls within a predetermined value.

A monitoring method and dosing pump system monitor operation of a dosing pump including a dosing chamber (2), a displacement element (4) and an electric drive (12). A position (S) of the displacement element and a pressure (P) inside the dosing chamber are continuously recorded as a curve in a pressure-stroke diagram. The method includes monitoring at least one characteristic portion (36, 38, 40, 42, B, C) of the curve in the pressure-stroke diagram by detecting a possible shift (A) of the characteristic portion over several strokes. The method further includes one or both of: adjusting a control of the electric drive based on the detected shift; and determining a trend of the shift over several strokes of the displacement element and determining based on the trend whether and/or when the shift will reach a predefined limit. A dosing pump system with the dosing pump execute the method.

A centrifuge system includes a centrifuge and a feed line fluidly connected to centrifuge with the centrifuge driven by a hydraulic system. The hydraulic system includes an electric motor driving a hydraulic pump connected to a fluid reservoir with the hydraulic pump providing hydraulic fluid to one or more hydraulic motors which in turn rotate the centrifuge. The system includes a pressure sensor for measuring fluid pressure and a speed sensor for measuring the rotational speed of the centrifuge. A controller can be in communication with the hydraulic system and the sensors and can receive measurements from the sensors and adjust the pressure of hydraulic fluid flowing to the one or more hydraulic motors to maintain a rotational speed of the centrifuge based on differing loads. The system can include one or more valves, controlled by the controller, which can also adjust the hydraulic pressure of the system.

A centrifuge system includes a centrifuge and a feed line fluidly connected to centrifuge with the centrifuge driven by a hydraulic system. The hydraulic system includes an electric motor driving a hydraulic pump connected to a fluid reservoir with the hydraulic pump providing hydraulic fluid to one or more hydraulic motors which in turn rotate the centrifuge. The system includes a pressure sensor for measuring fluid pressure and a speed sensor for measuring the rotational speed of the centrifuge. A controller can be in communication with the hydraulic system and the sensors and can receive measurements from the sensors and adjust the pressure of hydraulic fluid flowing to the one or more hydraulic motors to maintain a rotational speed of the centrifuge based on differing loads. The system can include one or more valves, controlled by the controller, which can also adjust the hydraulic pressure of the system.

A liquid proportioning machine includes at least two liquid storage mechanisms for storing liquid, pump bodies for pumping liquid from the liquid storage mechanisms, and liquid discharge locations connected with liquid outlets of the pump bodies and ejecting liquid; and the liquid storage mechanisms are respectively connected with the corresponding pump bodies, and a regulating mechanism for keeping a proportion for the liquid discharge speeds of the pump bodies is arranged between the pump bodies. The pump body includes a rotating shaft, and the rotating shaft rotates to cause the pump body to pump and discharge the liquid; and the regulating mechanism includes a driving shaft driven by a driving mechanism to rotate, and the driving shaft drives the rotating shafts of the liquid storage mechanisms to rotate through a transmission mechanism and maintains a proportion for the rotating speeds between the rotating shafts. The driving shaft drives any rotating shaft to rotate through a first transmission mechanism, and a second transmission mechanism is arranged between other rotating shafts and the rotating shaft directly driven by the driving shaft. In the present invention, an automatic proportioning manner is adopted, so the proportion of various kinds of liquid does not need to be manually regulated, which improves the working efficiency and the proportioning accuracy, and then the quality of the product is improved. The entire device has a low cost and great market competitiveness.

In a control method for construction machinery, an operation performed by the construction machinery is divided into a plurality of subordinate works. A current subordinate work currently performed by the construction machinery is determined. A maximum absorbing torque of a hydraulic pump is adjusted according to the determined subordinate work. An engine speed change map is adjusted according to the determined subordinate work.

In a control method for construction machinery, an operation performed by the construction machinery is divided into a plurality of subordinate works. A current subordinate work currently performed by the construction machinery is determined. A maximum absorbing torque of a hydraulic pump is adjusted according to the determined subordinate work. An engine speed change map is adjusted according to the determined subordinate work.

A method is provided which includes injecting a fluid into a wellbore; measuring, by a surface pressure sensor, a surface pressure; and measuring, by a downhole pressure sensor, a downhole pressure. A controller determines a true friction pressure based on a pressure differential between the surface pressure and the downhole pressure. A concentration of one or more components in the fluid is adjusted based on the true friction pressure to lower a total friction pressure loss.

A method is provided which includes injecting a fluid into a wellbore; measuring, by a surface pressure sensor, a surface pressure; and measuring, by a downhole pressure sensor, a downhole pressure. A controller determines a true friction pressure based on a pressure differential between the surface pressure and the downhole pressure. A concentration of one or more components in the fluid is adjusted based on the true friction pressure to lower a total friction pressure loss.