[Problems] To provide a driving method for a metering pump, a driving apparatus for a metering pump, a vaporizer and an anesthesia apparatus which are capable of suppressing a pulsation in the metering pump, and lowering the costs and reducing the sizes of the vaporizer and the anesthesia apparatus.

[Means for solving the Problems] A metering pump 16 is joined to the stepping motor 15, includes an eccentric mechanism converting a revolving motion of the stepping motor 15 into a reciprocating motion of a plunger 16A, and makes a constant liquid delivery by sucking and discharging an anesthetic agent through variations in the cubic volume of a cylinder 16D caused by the reciprocating motion of the plunger 16A. The control section 12: calculates a suction and discharge cycle T of the metering pump 16 on the basis of a set anesthetic-gas concentration and a fresh-gas flow rate; sets a discharge period T2 of the cycle T to be longer than a suction period T1 of the cycle T; and controls the revolution speed of the stepping motor 15 so that the travelling speed of the plunger 16A is kept constant during the discharge period T2.

A fluid dispenser with a fluid pump for dispensing fluid on movement of an actuator, and an air pump for delivering a stream of air through at least one sound generator on movement of the actuator. The sound generator produces at least two sounds as the actuator is moved from a first position to a second position, with each sound produced in a different time period during a cycle of operation, or differing from the other sound in respect of one or more detectable sound characteristics, such as duration, frequency, temporal alignment, amplitude, and/or timbre. The time period of each sound is a function of the relative location of the actuator between the first and second positions.

A method of probabilistically estimating a velocity of a plunger of a beam pump may comprise continuously monitoring well acoustics using a plurality of passive acoustic sensors attached to external structures of the beam pump; digitizing outputs of the plurality of passive acoustic sensors and sending the digitized outputs to a computing device for storage and processing; and using the digitized outputs of the plurality of passive acoustic sensors, estimating a probability of the velocity of the plunger using a hidden Markov model (HMM) to represent a probability of a position and the probability of the velocity of the plunger, the HMM comprising a state space model and an observational model.

A system and method for predicting failures of rod pumps using a scaled load ratio is configured to: optimize the size of a rolling window, the upper and lower bounds of the normal range of the scaled load ratio, an alert period, and an alert frequency ratio; receive data of a current maximum/minimum loads on a surface rod, and a current speed; remove outliers showing an abnormality; scale the current maximum/minimum loads on the surface rod using the maximum/minimum loads on the surface rod in normal operation; calculate a scaled load ratio; calculate the average of scaled load ratios in the rolling window; determine whether the average of scaled load ratios is in the normal range, and classify the values as normal and abnormal events; calculate the ratio of the abnormal events in the alert period, and generate an alert when the calculated ratio exceeds the alert frequency ratio; and monitor a pump state using the pump failure prediction system.

A fluid dispenser with a fluid pump for dispensing fluid on movement of an actuator, and an air pump for delivering a stream of air through at least one sound generator on movement of the actuator. The sound generator produces at least two sounds as the actuator is moved from a first position to a second position, with each sound produced in a different time period during a cycle of operation, or differing from the other sound in respect of one or more detectable sound characteristics, such as duration, frequency, temporal alignment, amplitude, and/or timbre. The time period of each sound is a function of the relative location of the actuator between the first and second positions.

The present invention relates to a liquid feeding apparatus capable of feeding a liquid with high accuracy. The liquid feeding apparatus includes a liquid feeder having a downstream side, a plunger, and a cylinder that is configured for aspirating and discharging a solvent when a plunger slides. The liquid feeding apparatus further includes a pressure sensor for the solvent to be discharged, a selector valve configured to switch between a plurality of solvents to be aspirated and discharged, and a controller configured to control the liquid feeder and the selector valve. The controller controls the selector valve in synchronization with an aspiration operation of the plunger so that a mixing ratio of the solvents changes, controls the plunger to cause the plunger to operate at first and second accelerations that are different from each other, and suppresses a fluctuation of the solvent to be aspirated by the plunger.

A pumping system includes a head having an opening and an injection port. The head is for holding content to be forced through the injection port. A bladder is within the head. The bladder is between the content and the opening. A plunger is configured to move through the opening of the head and to apply force within the bladder. The plunger may be movable in a discharge stroke to force the bladder against the content and thereby force the content through the injection port.

A linear motor compressor including a compressor housing and a cylinder housing having a plurality of opposing compression chambers. A piston freely reciprocates within the cylinder housing using a linear electric motor. A piston position feedback control system provides adaptive current output as a function of position feedback and/or velocity feedback from the piston and/or the electric motor, to directly power and control the electric motor, wherein the piston reciprocates without assistance from a mechanical spring or other equivalent centering force.

An integrated wireless data system and method for controlling and measuring operational data of a pumpjack system, for safety, health monitoring, and pump control is provided. The integrated wireless data system and method may be configured to allow for bi-directional communication with a central station to enable human intervention with pumpjack and to store pump parameters in a database for use in development of predictive maintenance techniques.

Devices and methods for operating a diaphragm compressor system provide high output pressure and high throughput. In some embodiments, modular diaphragm compressors are stacked with a clamping mechanism pressing the compressor modules together. In embodiments, multiple stacks are provided as stages of a pressurization process. In embodiments, a main stage valve controls one or more pressure circuits for one or more hydraulic actuators of compressor modules. In embodiments, orifices configured for damping are incorporated to control actuator piston movement within a compressor module.