244 results about "Pressure equilibrium" patented technology

A hearing aid includes a first half shell and a second shell attached to the first shell. A microphone, battery, electronics, a receiver and a flexible tip are mounted within a housing formed by the first half shell and the second half shell. A mechanical securing mechanism, located on the first half shell and the second half shell, attaches the first half shell to the second half shell. A flexible tip for a hearing aid includes a tip portion, a sound port attached to the tip portion and a vent formed in the flexible tip. The vent provides static pressure equilibrium between an ear canal and an ambient pressure.

The invention discloses a method for evaluating shale gas adsorption through a coal/shale ultrahigh pressure gas absorption and seepage experiment. The method comprises the steps that a core is selected and put in a sample cylinder, a confining pressure pump is started to make the sample cylinder reach an experimental confining pressure, and vacuumizing is performed; the temperatures of the sample cylinder and a reference cylinder are stabilized at experimental temperature; helium gas is injected into the reference cylinder, and the pressure of the reference cylinder is measured; after the reference cylinder and the sample cylinder are balanced in pressure, the pressure of the sample cylinder is measured; the pressure of the reference cylinder is increased sequentially, and free space volume measurement of the sample cylinder is completed; systematic vacuumizing is performed; water steam is injected into the sample cylinder; methane having set pressure is injected into the reference cylinder, and the pressure of the reference cylinder is acquired; a balancing valve is turned on, and the pressure of the sample cylinder is acquired; the pressure of the reference cylinder is increased sequentially, and the shale gas adsorption experiment is completed under certain water saturation. By adopting the method, the porosity, the permeability, the adsorbing capacity and gas-water seepage of the experimental core, electrical resistivity change of the core in the experimental process and the influence of different water saturations on absorption and desorption amounts can be respectively measured.

A new adiabatic scanning calorimeter allows the thermal mass of a high-pressure reaction vessel to be dynamically compensated during a test. This allows the effective Φ factor for the experiment to be reduced to 1.0 without the use of complex pressure balancing equipment. Endothermic events can be quantified and sample specific heats can be measured. The time required for test completion is much shorter than for conventional adiabatic calorimeters, thus considerably improving apparatus productivity. The sensitivity to exotherm detection is at least as good as existing adiabatic calorimeters employing the Heat-Wait-Search strategy, but does depend on the temperature-scanning rate. In addition, the heat of reaction is obtained without reference to the heat capacity of the sample, pressure is measured continuously, reactants may be injected into the test vessel and the sample can be mixed during the test.

A waterproof electronic device that is waterproof and has pressure-equilibrium functions is provided. The waterproof electronic device includes a housing, a microphone, an elastic element, and a waterproof element. The housing has a chamber and an acoustic hole communicating with the chamber. The microphone is disposed in the chamber. The elastic element is disposed on the microphone. The elastic element includes a through hole facing the microphone, and a ventilation groove communicating with the through hole. The waterproof element is connected to the elastic element and the housing, and is configured to block liquid. The waterproof element includes pores communicating with the acoustic hole and the through hole.

The invention discloses a pressure sensor dielectric medium isolation packaging structure and a packaging method of the pressure sensor dielectric medium isolation packaging structure. The pressure sensor dielectric medium isolation packaging structure comprises a substrate, a cover body made of soft low-elasticity-modulus materials and a pressure sensor chip. The cover body and the substrate form an airtight cavity body together in order to accommodate the pressure sensor chip. When the pressure of a dielectric medium to be measured is acted on the cover body, the cover body deforms and accordingly compresses gas in the airtight cavity body to achieve balanced internal and external pressure. In the process, the dielectric medium to be measured is transmitted to a pressure sensitive membrane of the pressure sensor chip and accordingly the purpose that the pressure of pressure sensor chip and the pressure of the dielectric medium to be measured are separated is achieved. According to the pressure sensor dielectric medium isolation packaging structure and the packaging method of the pressure sensor dielectric medium isolation packaging structure, the pressure is transmitted by compressing the gas, and accordingly complex silicone oil filling procedures in a traditional silicone oil filling stainless steel packaging technology are avoided and manufacturing cost is greatly reduced.

The present invention is directed to a pressure balanced fluid control device. In one illustrative embodiment, the device comprises a body, a bonnet coupled to the body, a valve stem operatively coupled to a gate positioned in the body, a valve stem seal positioned between the valve stem and the bonnet, wherein a sealed cavity exists above the valve stem seal, and an opening through the bonnet that is adapted to allow a pressure of a working fluid flowing through the valve to be exerted in the sealed cavity above the valve stem seal. In another illustrative embodiment, the device comprises a body, a bonnet coupled to the body, a valve stem operatively coupled to a gate positioned in the body, a valve stem seal positioned between the valve stem and the bonnet, wherein a sealed cavity exists above the valve stem seal, and an opening through the bonnet, the opening being in fluid communication with the sealed cavity and an interior region of the body. In a further illustrative embodiment, the device comprises a body, a bonnet coupled to the body, a valve stem operatively coupled to a gate positioned in the body, a valve stem seal positioned between the valve stem and the bonnet, wherein a sealed cavity exists above the valve stem seal, a piston chamber formed in the bonnet, the piston chamber being in fluid communication with the sealed cavity and an interior region of the body, and a piston positioned in the piston chamber.

A method of refrigeration control through a refrigeration system of a refrigerated transport container includes performing a defrost cycle on the refrigeration system by activating a heat source; and restarting the refrigeration system after the defrost cycle has completed, wherein restarting the refrigeration system includes performing a liquid slugging avoidance process including: initiating a compressor of the refrigeration system at a speed; opening a pressure equalization valve in parallel with the compressor in response to the initiating; opening a liquid valve in series between a condenser and an evaporator after opening of the pressure equalization valve; and closing the pressure equalization valve after a period of time.

The invention provides a coal/shale isothermal adsorption experiment method. The method is carried out by a reference kettle, a sample kettle and a middle region of an experiment device; a sample to be detected is placed in the sample kettle and an experiment temperature is set to be constant according to actual stratum conditions; the sample kettle is calibrated to obtain a free space volume of the sample kettle; the reference kettle and the sample kettle are vacuumized to obtain the initial pressure of the sample kettle; the middle region is communicated with the reference kettle and the middle region is separated from the sample kettle; enough amount of adsorbate gas is injected into the reference kettle one time; after the pressure in the middle region is balanced with the pressure in the reference kettle, the initial pressure of the reference kettle is obtained; an adsorption experiment is carried out to obtain the pressure of the reference kettle and the pressure of the sample kettle after adsorption is balanced; according to a mass conservation principle before and after each time of adsorption, the adsorption amounts under different sample kettle pressures after a plurality of times of adsorption balance are obtained by using the initial pressure of the sample kettle, the initial pressure of the reference kettle, the free space volume of the sample kettle and the pressure of the reference kettle and the pressure of the sample kettle in an adsorption process.

The invention discloses an in-built middle through-hole dynamic throttling element flow meter, belonging to the technical field of automatic detection of a throttling flow meter. The flow meter is characterized in that an in-built middle through-hole dynamic throttling element is adopted; the internal and external pressures of the dynamic throttling element are balanced; the measured fluid pressure is born by a flow meter pressure hull, thus, a thin wall thick dynamic throttling element can be used; the main boy of an anti-blocking mechanism is a flexible filter medium or a filter membrane with a simple structure; compared with the used pore plates of a differential pressure flow meter, the flow meter provided by the invention mainly uses a dynamic venturi tube; the venturi tube has the advantages of small flowing resistance loss, long service life, high precision, and the tube is hard to block and the like. The flow meter provided by the invention is simple in structure, easiness in manufacturing, high in performance cost ratio, less in energy consumption for measurement, thus, the flow meter can be used for measuring the flow of small pipe diameter and dirty fluid, and has a development prospect for replacing differential pressure flow meters and partial small pipe diameter ultrasonic flow meters.

The invention relates to a method and a device for obtaining the volume leakage speed under the standard condition of a gas well, wherein the method comprises the following steps that: the depth of a leakage point, the gas pressure at the leakage point in an oil pipe and the corresponding temperature are obtained according to a condition that the annular pressure in the position of the leakage point under the well is balanced with the pressure in the oil pipe; the flowing state of the leakage is judged according to the gas pressure at the leakage point in the oil pipe and the annular pressure in the position of the leakage point in different moments; a mass leakage speed expression in the position of the leakage point is converted to obtain a volume leakage speed expression in the position of the leakage point; the volume leakage speed expression in the position of the leakage point is subjected to time integration to obtain a volume leakage speed expression in the position of the leakage point in the corresponding time; the leakage area of the position of the leakage point in the corresponding time is obtained; the leakage area of the position of the leakage point in any pressure relief time period is determined according to the volume leakage speed in the position of the leakage point; and the volume leakage speed of the gas well oil jacket annular leakage gas under the standard condition is obtained according to the leakage area of the position of the leakage point in any pressure relief time.

A housing block for a hydraulic unit of a vehicle brake system that retaining a piston pump and an eccentric element that rotates the piston. A motor drives the eccentric element within an eccentric chamber. The block has a cylindrical cavity within a hydraulic leakage reservoir and a fluid leakage path that begins near a lower most portion of the eccentric element chamber and extends to a cylindrical cavity by way of a passage defined by an intersection of the eccentric chamber and cylindrical cavity. A pressure equalization path extends from the eccentric chamber upwardly to a point intermediate the housing block and motor enclosure and into the motor enclosure to a location that is substantially above the eccentric chamber. A seal intermediate the motor enclosure and housing block is formed as a closed curve of mastic material encircling the motor shaft, eccentric chamber, hydraulic leakage reservoir hydraulic fluid leakage path, and pressure equalization path.

Disclosed are an air conditioner for cooling or heating air in a room by compressing, condensing, expanding and evaporating a refrigerant, and a method for controlling an electronic expansion valve of the air conditioner. The air conditioner includes a plurality of compressors, for compressing a refrigerant, of which one or more are operated so that refrigerant compression capacity is variably changed according to the variation of a cooling/heating load; and an electronic expansion valve adapted to control the refrigerant compression capacity. The electronic expansion valve controls the flow rate of the refrigerant after one or more of the compressors are stopped, thereby rapidly achieving the pressure equilibrium at inlet and outlet pipes of the stopped compressor(s), shortening a time taken to allow the stopped compressor(s) to be re-operated, and improving reliability in operating the compressors.

The invention provides a reservoir capillary pressure curve determinator under a high temperature and a pressure. The determinator comprises a ring pressure system, an injection system, a core clamping system, a semi-permeable baffle plate, a back pressure system, a measuring system, a data automatically collecting and processing system, and a thermostat which are connected through pipelines. A semi-permeable baffle plate method is adopted to measure capillary pressure curves under a stratum condition, and the basic rationale is that a principle of balance between an impressed pressure and the capillary pressure is used to measure the capillary pressure curves under the high temperature and the pressure. Core saturated wetting phase fluid displaces a wetting phase with a nonwetting phase under a certain displacement pressure. When the impressed pressure overcomes the capillary pressure of a certain capillary in the core, the wetting phase fluid in the capillary is discharged gradually, and the wetting phase fluid saturation in the core is reduced. Pressure is increased stepwise, accumulated discharged quantity of the wetting phase fluid when the wetting phase fluid is no longer discharged and an injection pressure are measured, and the capillary pressure curves can be solved.

A pressure equalization element for a housing includes a water-impermeable membrane. The membrane is combined with either a pressure relief valve acting in two directions or with a corresponding combination of two pressure relief valves such that a volume of air exchange is reduced. An amount of moisture transported into the housing is thus also reduced.

The invention belongs to the technical field of water drainage and gas recovery of a gas well, and particularly provides a method for removing gas well accumulated liquid by means of the oil jacket pressure balancing method. The method mainly comprises the steps of bottom hole accumulated liquid diagnosis, formation pressure prediction, flow inducing with the oil jacket balancing method, foam drainage and the like. The feasibility of the technique is determined through accumulated liquid diagnosis and formation pressure prediction. Liquid in a well and foaming agents can be well mixed through accumulated liquid flowing caused by the oil jacket balancing method, and liquid drainage effect is promoted cooperatively. The method is suitable for wells with certain stratum energy and reduced productivity due to liquid accumulation or dead wells. The method is not limited by well deflection, gas-liquid ratio, ground environment and the like and has the advantages of being simple, economical and practical.

A diaphragm/spring operated pressure relief valve having a sensing passage of substantially the same flow area as the outlet orifice of the valve whereby failure of either diaphragm results in "fail open" configuration with the addition of a sensing inlet shroud located to capture the total pressure at the inlet and channel it to the sensing chamber to allow the valve to relieve full rated capacity in the event the sensing diaphragm is ruptured.