39results about How to "No surge" patented technology

The invention relates to a double-head claw pump rotor and its molded line. The molded line comprises an equidistance curve of a point meshing epicycloid, a modified arc segment, a tooth top arc segment, an intermediate connecting arc segment, an arc conjugate curve segment, and a tooth root arc segment. Two rotors adopt a central symmetrical structure. By setting the modified arc segment, the sharp points are eliminated, and severe wearing phenomenon of the rotors during operation can be avoided. The equidistance curve of the point meshing epicycloid and the modified arc segment are always spaced apart to avoid the formation of suction and exhaust closed volume, and a design parameter space of the rotor molded line is increased, the power consumption is reduced, and the pump efficiency isimproved. The molded line is designed in the double-head claw pump, compared with the other conventional pumps, the pump in the invention has the advantages of less wearing parts, compact structure,high pumping rate, no surge, and low vibration noise.

The invention discloses a variable frequency centrifuge and a control method of a hot gas bypass valve in the variable frequency centrifuge. The variable frequency centrifuge includes a compressor, and the hot gas bypass valve is disposed between an air suction pipe and an air exhaust pipe of the compressor. The method comprises the following steps of when the variable frequency centrifuge is in an operating state, obtaining a guide vane opening degree, an operating pressure ratio and the upper limit of the operating frequency of the compressor, wherein the operating pressure ratio is a ratioof an air exhaust absolute pressure value to an air suction absolute pressure value of the compressor; calculating the critical frequency of the variable frequency centrifuge according to the guide vane opening degree and the operating pressure ratio; controlling the opening degree of the hot gas bypass valve according to the critical frequency and the upper limit of the operating frequency. By controlling the opening degree of the hot gas bypass valve, the variable frequency centrifuge can safely operate with a small load under high ambient temperature and large pressure ratio, and at the same time, the compressor surging phenomenon does not occur under small load operation, so that the operation reliability of the variable frequency centrifuge is improved.

The invention discloses a forward-curved multi-wing type centrifugal fan. The forward-curved multi-wing type centrifugal fan comprises a volute casing and an impeller, wherein the volute casing comprises a volute tongue as well as a first curved surface, a second curved surface and a third curved surface which are sequentially tangential and are smoothly connected, wherein the impeller and the volute casing are arranged in an eccentric manner for increasing the diameter of the impeller. According to the forward-curved multi-wing type centrifugal fan, the impeller is mounted in the eccentric manner relative to the volute casing, so that the diameter of the impeller is increased, parameters such as air quantity, air pressure and the like are obviously improved, noises are reduced, fan surge is avoided, and the performances of the fan are improved; and meanwhile, three sections of cambered surfaces form the volute casting, so that the profile of the volute casting is simplified, the space volume is saved, the structural form is simple, a welding process is avoided and the processing cost is low, and therefore, the volute casting is more convenient to manufacture.

Disclosed is a double-screw vacuum pump rotor profile. One rotor comprises a first involute ab, an addendum circle arc action bc, a point engagement cycloid cd, a second involute de, a first point engagement epicycloid ef, a dedendum circle arc section fg and a second point engagement epicycloid ga which are sequentially connected in an end-to-end mode, and the other rotor has the same structure,wherein a point a is located on the pitch circle, during rotation, the point a is engaged with a cycloid section c'd', the involute ab is engaged with the involute d'e', a point b is engaged with an epicycloid section e'f', the addendum circle arc section bc is engaged with a dedendum circle arc section f'g', a point c is engaged with an epicycloid section g'a', the cycloid section cd is engaged with a point a', the involute de is engaged with an involute a'b', the epicycloid section ef is engaged with a point b', the dedendum circle arc section fg is engaged with the addendum circle arc section b'c', and the epicycloid section ga is engaged with a profile point c'. The structures of the two rotors are the same, and the machining cost is low.

The invention discloses a whole ellipse and ellipse envelope type double-screw rotor, a compressor and an expansion machine. The rotor comprises a male rotor and a female rotor capable of realizing mutual meshing during the rotating process; the tooth profile of the single tooth of a male rotor profile line is composed of a tooth root circular arc section, an ellipse envelope line segment, an ellipse arc segment, the ellipse arc segment and the ellipse envelope line segment sequentially connected end to end; the tooth profile of the single tooth of the male rotor profile line is composed of atooth tip circular arc segment, the ellipse arc segment, the ellipse envelope line segment, the ellipse envelope line segment and the ellipse segment sequentially connected end to end; the adjacent curve segments of the male rotor profile line and the female rotor profile line are continuous at the intersected point and are also continuous in slope; according to the teeth number of the male and female rotor profile lines, rotation is carried out to generate the tooth profile of the single tooth is generated, and the tooth profiles are sequentially connected end to end to generate a complete female and male rotor profile line. The rotor profile lines are composed of ellipses and envelope lines of the ellipses, cusps are eliminated, and according to the demand of the design working condition, the rotor shape is flexible and adjustable to improve the performance.

The invention relates to a protection control system of an air compressor. The protection control system of the air compressor comprises the air compressor; an air compressor outlet valve is arrangedon an outlet pipeline at the top end of the air compressor; the air compressor outlet valve is connected to a freezing dryer through a pipeline; a freezing dryer inlet valve is arranged on the pipeline and near the position of the freezing dryer; a buffer tank is arranged on the pipeline between the air compressor outlet valve and the freezing dryer inlet valve and near the position of the air compressor outlet valve; a water discharging pipeline is arranged at the bottom of the buffer tank; a leading-out pipeline is arranged on the pipeline between the freezing dryer inlet valve and the buffer tank and near the freezing dryer inlet valve; the leading-out pipeline is connected to an industrial air pipe network; an outlet pipeline of the freezing dryer is connected to the leading-out pipeline, and the outlet pipeline of the freezing dryer and the leading-out pipeline are jointly connected to the industrial air pipe network; the protection control system of the air compressor overcomes the defect of no buffer device when the compressed gas in the original air compressor system enters the industrial air pipe network through the freezing dryer; and the buffer tank is arranged at the compressor outlet, so the water of the gas can be discharged out of the buffer tank and the corrosion phenomenon of the outlet pipeline is reduced.

The invention provides a narrow flow channel turbine. The narrow flow channel turbine comprises a shell and a turbine rotor, wherein a sealing retaining wall is arranged on the circumference of the turbine rotor, and small holes are distributed in the sealing retaining wall, so that fluid sucked by the turbine rotor at high rotating speed is sealed in the rotor; and the fluid is compressed and filled in the radial direction under the action of centrifugal force, cavitation or surge is avoided, and the fluid is sprayed into the shell only through the small holes, so that high lift under small flow is achieved. The efficiency of a centrifugal pump can be improved under the working condition of the small flow and the high lift, and meanwhile, the cavitation is not generated at high speed so that the centrifugal compressor can reach the high pressure ratio at the small flow, and meanwhile, the surge is not generated at the high speed; and the application range of an impeller type fluid conveying mechanism is widened, and energy consumption is reduced.

The invention discloses a concrete mixing system based on an integrated operational amplifier processing technology design. The system comprises a central processing unit, a wind pressure circuit, anair quantity circuit and a surge-preventing circuit; an air volume sensor and an I/U conversion circuit are arranged in the air quantity circuit; a preceding stage scaling operation amplification circuit and a post amplification circuit which are connected with each other are arranged in the I/U conversion circuit, an operational amplifier A3, a resistor R3, a resistor R5, a resistor R6 and a resistor R7 are arranged in the post amplification circuit, input ends of the operational amplifier A3 are connected with an output end of the preceding stage scaling operation amplification circuit through the resistor R3 and the resistor R5 respectively, an out put end of the operational amplifier A3 is connected with a first input end of the operational amplifier A3 through the resistor R6, and a second input end of the operational amplifier A3 is connected with the ground through the resistor R7. According to the system, a flowing pressure conversion circuit is cooperatively formed by the scaling operation amplification circuit and the post amplification circuit to achieve conversion from an electric current signal to a voltage signal, so that collected air volume information is safely andreliably transmitted to the central processing unit.

The invention provides a variable-line double-screw rotor structure. The variable-line double-screw rotor structure comprises a male rotor and a female rotor, the male rotor is provided with three teeth, the female rotor is provided with five teeth, and a molded line of the male rotor comprises an arc section D1C1, an arc envelope line section C1B1, an arc section B1A1, an arc section A1E1 and a point meshing cycloid section E1H1 which are connected in sequence; a molded line of the female rotor comprises an arc section D2C2, an arc section C2B2, an arc envelope section B2A2 and an arc envelope section A2E2 which are connected in sequence; the radius of the arc section B1A1 is rAB, the radius of the arc section C2B2 is rBC, and the values of the rAB and the rBC are linearly increased along with the increase of the axial position of the rotor from the air suction side to the air exhaust side. The defects in the prior art are overcome, the sizes of leakage triangles on the air suction side and the air exhaust side are reasonably configured by controlling the sizes of the leakage triangles on the air suction side and the air exhaust side of the double-screw rotor structure, the effects of reducing air exhaust pressure pulsation and reducing leakage on the air suction side and the air exhaust side are achieved, the thermodynamic efficiency of the rotor is improved, and the operation noise of the rotors is reduced.

The invention discloses a current-to-voltage conversion circuit applied to a commercial concrete production management system. The current-to-voltage conversion circuit applied to the commercial concrete production management system is provided with a central processing unit, an air pressure circuit, an air volume circuit and an anti-surge circuit; an air pressure sensor and an I/U converter are arranged in the air pressure circuit; the I/U converter comprises a front-stage current-to-voltage conversion circuit and a rear-stage current-to-voltage conversion circuit, which are connected with each other; a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a potentiometer W1 and an integrated operational amplifier A1 are arranged in the front-stage current-to-voltage conversion circuit; the resistor R1 is connected with the input end of the integrated operational amplifier A1 through the resistor R2 and the resistor R3 separately; one input end of the integrated operational amplifier A1 is connected with the output end of the integrated operational amplifier A1 through the resistor R5 and the potentiometer W1, which are mutually connected in series; another input end of the integrated operational amplifier A1 is grounded through the resistor R4; the output end of the integrated operational amplifier A1 is connected with the input end of the rear-stage current-to-voltage conversion circuit; and conversion from current to voltage is carried out by utilization of the I/U converter, which is composed of two-stage current-to-voltage conversion circuits.