10 results about "Back pressure" patented technology

An engine air brake device for a 4-stroke reciprocating-piston internal combustion engine is provided and has at least one intake valve and two exhaust valves per cylinder. The exhaust train incorporates a throttling device actuatable for engine deceleration so that an exhaust back pressure builds up in the accumulated exhaust gas upstream of the throttling device and becomes effective in conjunction with an engine-internal braking device associated to only one of the two exhaust valves for each cylinder, the other exhaust valve being controlled conventionally. The engine-internal braking device comprises a control piston installed in the valve bridge and pressed in the direction of the exhaust valve from a control pressure chamber supplied with pressurized oil and possibly also by means of an additional control compression spring.

The present invention relates to an apparatus for field-flow fractionation and to a method for separating samples by means of field-flow fractionation using this apparatus. The apparatuses of the invention comprise one or more reservoirs, a pump, a first flow volume splitting device, two valves for flow control, an injector, a separation channel having a first connector at a first end and a second connector at a second end or an AF4 separation channel having a first connector at a first end, a second connector at a second end and a third connector between the first and the second ends, optionally a second flow volume splitting device, a back-pressure element, one or more detector(s), a flow volume control device and one or more waste container(s). The apparatuses of the invention are characterized in that they comprise a valve for flow control in a first flow path and a second flow path which connect the pump to the first or the second or the third connector of the separation channel and that these valves are switched alternately in a controllable time ratio.

An exhaust gas treatment device comprises a casing and a tail gas treatment module located inside the casing, wherein the casing comprises a mixing cavity, a splitting cavity and a distributing cavity; the exhaust gas treatment device further comprises a conical mixer located inside the mixing cavity and a mixing pipe located in the splitting cavity, and the conical mixer comprises a plurality of conical swirl plates and a plurality of openings corresponding to the conical swirl plates. Therefore, on one hand, urea can be laid on the pipe wall of the mixing cavity so as to increase the evaporation area and dwelling time of the urea and improve the mixing effect; on the other hand, exhaust gas can flow more smoothly, the local pressure loss can be reduced, and the back pressure can be reduced.

The present invention relates to a method for protecting a ventilation device of a ventilator against backflowing exhaled air, and to a ventilator. A respiratory gas flow is generated by a blower device and is guided via a flow connection to a breathing interface. The respiratory gas flow is adjusted with the aid of a control device to a first ventilation pressure during an inhalation phase of the patient and to a second ventilation pressure during an exhalation phase. A characteristic variable for a flow within the flow connection is detected in this case by means of a monitoring device for monitoring backflowing exhaled air. And, in this case, a back pressure with respect to the backflowing expiratory flow is adjusted by means of a specific increase of the ventilation pressure with consideration for the characteristic variable, whereby an undesirable rebreathing into the ventilation device is counteracted by means of the back pressure.

The invention discloses a low pressure drop check valve. The low pressure drop check valve comprises a tubular valve body and a valve clack. A lug is arranged on one end of the upper surface of the valve clack; the lug is connected to a bracket rod arranged on the upper wall of an inner cavity of the valve body through a horizontally arranged pin roll; the axis of the pin roll is vertical to a vertical plane of the axis of the valve body; a valve clack seat is arranged in the inner cavity of the valve body; the outer edge of the valve clack seat is hermetically connected to the wall of the inner cavity of the valve body in a surrounding manner; a through hole is formed in the middle of the valve clack seat; the valve clack rotates around the pin roll to hermetically close or open the through hole; the plane of the valve clack seat inclines to the horizontal plane of the axis of the valve body and is vertical to the vertical plane of the axis of the valve body; and the valve clack seat inclines toward the inlet end of the valve body. Compared with the prior art, the low pressure drop check valve disclosed by the invention has the advantages of simple and compact structure and good sealing property, and can be quickly opened when the front and back pressure difference of the valve is smaller.

The invention provides a turbine front-and-back pressure difference control type low-pressure circulating system in the technical field of mechanical design. The turbine front-and-back pressure difference control type low-pressure circulating system comprises a gas compressor, an engine, a turbine, connecting pipes, a valve seat, a valve body, a rotating shaft, a containing cavity, a fixed body, penetrating pipes, a partition board, a rotating body and a connecting board. One end of the rotating body extends into the first penetrating pipe and is in sealing contact with the wall face of the first penetrating pipe, the other end of the rotating body is fixedly combined with the partition board, the two ends of the first connecting pipe are communicated with a gas inlet of the containing cavity and a gas exhausting pipe of the turbine respectively, and the two ends of the second connecting pipe are communicated with a gas outlet of the containing cavity and a gas inlet pipe of the gas compressor respectively. When the front-and-back pressure difference of the turbine is large, the rotating body drives the valve body to rotate clockwise, the low-pressure gas exhausting recirculation rate of the engine is large, and the detonation pressure of the engine is low. The turbine front-and-back pressure difference control type low-pressure circulating system is reasonable in design, simple in structure and suitable for a low-pressure gas exhausting recirculation system of a supercharged engine.

The invention provides an auto exhaust pipe with a function of internal cooling based on an airflow effect. The auto exhaust pipe is characterized in that an airflow effect pipe is added on the auto exhaust pipe; outside cold air is sucked into the auto exhaust pipe through the airflow effect pipe and mixed with high-temperature engine exhaust, so that the engine exhaust in the auto exhaust pipe can be cooled, the energy and flow rate of the engine exhaust can be reduced, and the purpose of reducing noise of the engine exhaust can be fulfilled; through additional arrangement of an appropriate silencing bags, a very good silencing effect can be achieved; due to the cooling function of the airflow effect pipe, the energy of the engine exhaust is greatly reduced; and accordingly, the sizes of the silencing bags can be very small, that is, not only the manufacturing cost but also the weight and back pressure of the auto exhaust pipe can be reduced, and the oil consumption of an auto engine can be lowered.

The invention relates to a variable capacity compressor. The compressor comprises a housing, a variable capacity cylinder and a lower flange assembly arranged below the variable capacity cylinder; thelower flange assembly is provided with a sliding hole communicating with a variable capacity chamber of the variable capacity cylinder, and the sliding hole is provided with a locking assembly that can be reciprocable in the axial direction thereof and lock a variable capacity sliding plate of the variable capacity cylinder; upper part of the locking assembly is communicated with lower part of the locking assembly through the variable capacity chamber and a variable capacity channel and with a constant pressure passage arranged on the housing. By adjusting air pressure values of the variablecapacity passage and the constant pressure passage, the variable capacity sliding plate can adhere to a lower roller under variable light operating conditions and under the action of high back pressure, which reduces fluctuation of the capacity and ticking sound; meanwhile, by reducing pressure difference between the variable capacity passage and the constant pressure passage, gas leakage from topto bottom of the locking assembly can be reduced, which reduces the impact and friction between the locking component and other components during state switching, thereby improving cooling efficiencyand cooling capacity as a whole, and increasing compressor reliability.

The invention relates to a double-damping high-pressure back pressure valve without a diaphragm. The double-damping high-pressure back pressure valve comprises a main valve body, an auxiliary valve body, a main valve core, an auxiliary valve core, a pressure reducing cylinder, a valve core pressing plate, an auxiliary spring, a main spring and a main spring gland; the auxiliary valve body is arranged in the main valve body, the lower end of the pressure reducing cylinder is connected to the main valve body, the upper end is connected to the main spring gland, and the main valve core is arranged in the pressure reducing cylinder; and the lower end of the main valve core and the auxiliary valve body are sealed or separated to open and close a back pressure valve, the upper end of the main valve core is connected with the auxiliary valve core, the upper end of the auxiliary valve core is connected with the valve core pressing plate, the main spring is arranged between the valve core pressing plate and the main spring gland, and the auxiliary spring is arranged between the auxiliary valve core and the main valve core. Compared with the prior art, the double-damping high-pressure back pressure valve without the diaphragm is provided with the auxiliary spring providing damping in addition to the main spring providing spring back for the valve core. The auxiliary spring is used for absorbing and releasing part of the energy, so that the speed of opening and closing of the valve core can be eased, and the pulse generated by a pump in the valve body is smoother and the performance of the back pressure valve is improved significantly.