71results about How to "Ease of production and maintenance" patented technology

The invention discloses an ore benefication process for low-grade fine particle grade embedded distribution refractory iron ore. The process comprises the following steps that crushed ore products are firstly subjected to one-stage ore grinding and one-stage grading, underflow after the grading is returned for re-grinding, and overflow is subjected to two-stage grading; underflow after the second-stage grading is subjected to second-stage ore grinding, ore grinding discharge materials are returned to the second-stage grading, and overflow is subjected to one-stage desliming; underflow after the desliming is subjected to three-stage grading and three-stage ore grinding, ore grading discharge materials are returned to three-stage grading, and overflow is subjected to second-stage desliming; next, three-section, four-section or five-section or more-section desliming is sequentially carried out; underflow after the desliming starts to be subjected to reverse flotation after the stirring, rougher flotation is firstly carried out, products in a groove after the rougher flotation are subjected to fine selection, foam products after the fine selection are returned to a rougher flotation groove, and products in a groove after the fine selection are concentrated and filtered to obtain ore concrete; and concentration machines and selective flocculation desliming processes are respectively adopted for each stage of desliming. The process provided by the invention has the advantages that the investment cost is low, the occupied area is small, the production and the maintenance are simple and convenient, the adaptability is high, the fine grinding desliming effect is good, and the like.

The invention relates to a multi-module parallel DC power supply and a control method of the DC power supply. The multi-module parallel DC power supply comprises a monitor system and N DC power supply modules, wherein the monitor system includes a serial communication system, human-machine interaction equipment, and a digital control circuit; and the digital control circuit is respectively connected with the serial communication system and the human-machine interaction equipment. The control method comprises subjecting the output parameters and the set output parameters of all of the working DC power supply modules in each control period to corresponding control computation to make each DC power supply module to output current according to requirement and to realize current equalization. The multi-module parallel DC power supply provided by the invention can realize constant voltage or constant current function according to requirement, and is simple in process, few in wiring, easy in maintenance and so on. The control method of the power supply is simple in operation and reliable in control by adopting digital control. In constant voltage model, the dynamic performance of the multi-module parallel DC power supply is improved greatly, so that the multi-module parallel DC power supply can be directly applied in the digital DC power supply parallel connection system.

The invention discloses a movable and rotatable lifting platform used for picking agricultural products. The movable and rotatable lifting platform comprises a walking mechanism, a rotating mechanism, a lifting platform body and a control system. The rotating mechanism comprises a rotating machine frame, a main shaft, a bearing set, a bearing seat board set, a gear set and a rotating driving motor, wherein the main shaft is connected with the bearing set in a matched mode, the bearing set is fixed on the bearing seat board set, the rotating driving motor transmits rotating power to the main shaft through the gear set, the rotating driving motor is installed on the rotating machine frame, the top end of the main shaft is fixedly connected with the lifting platform body, the bottom of the rotating machine frame is connected with the walking mechanism, and the control system is in signal connection with the rotating driving motor and the lifting platform body. The movable and rotatable lifting platform has the advantages of being capable of bearing larger loads and capsizing moment, small in motion resistance, high in motion precision, large in motion stroke, strong in universality of parts, convenient to produce and maintain, low in manufacturing cost, and the like. Large-load and mass mechanized harvesting of crops can be achieved only through that a corresponding agricultural harvesting operation device is arranged on the movable and rotatable lifting platform.

The invention discloses a fine grinding process for micro fine grain ore. The fine grinding process comprises first-stage ore grinding, second-stage ore grinding and a third-stage ore grinding in sequence, wherein ball mills are adopted in the first-stage ore grinding, the second-stage ore grinding and the third-stage ore grinding for ore grinding, and swirlers are adopted for grading; the draw ratio of the ball mills adopted in the three stages of ore grinding is 2.5-3.0; a ore grinding medium adopted in the three stages of ore grinding is preferably a steel section, and the filling quantity of the steel section is 20%-40% of the volume of a barrel body of the ball mills. The process provided by the invention has the advantages of being low in investment cost, small in space area, simple and convenient to produce and maintain, efficient and low in consumption, easy to implement, produce and operate and the like.

The invention provides a biomass gasification system. The biomass gasification system comprises a multi-section fixed bed biomass gasification furnace, wherein the multi-section fixed bed biomass gasification furnace comprises a furnace body which is arranged in the longitudinal direction, the furnace body comprises a conical-hopper tail ash section which is arranged on the bottom and at least two gas production sections which are arranged on the tail ash section, the two gas production sections are arranged in the longitudinal direction and connected with each other in an end-to-end manner, and a fire grate is arranged between the tail ash section and the gas production section on the bottom; the side part of each gas production section is provided with a gas outlet; each gas outlet is connected with a gas branch pipeline, and a plurality of gas branch pipelines are connected to a gas main pipeline; the bottom of the tail ash section is provided with a slag outlet, and the side part of the tail ash section is provided with an air inlet; the upper side surface or the top end of the gas production section on the top is provided with a fuel inlet. The gasification furnace is compact in structure; the biomass raw material moisture applicability is high, and the strict requirement of the conventional gasification furnace on the moisture can be broken through; the produced gas is controllable in nature, and the appropriate biomass gas can be adjusted according to different requirements of the user; the biomass gasification system is applicable to the multi-section gas production process, so that the gasification efficiency is higher than that of the conventional gasification furnace.

The invention relates to a full-automation biochemical analyzer liquor relief arm combination device, which is characterized in that: the device consists of a liquor relief arm and a liquor relief arm rotary disc; the liquor relief arm is embedded at the upper end of the liquor relief arm rotary disc, and comprises a linear motor; a lifting loop bar is arranged on the axis of the linear motor; a cover shell is fixed at the top end of a liquor relief arm holder; a liquor relief lower arm is connected with the cover shell; a silicone tube is arranged inside the liquor relief lower arm with the top end provided with a needle wiper; a liquor relief upper arm is arranged at the top end of the lifting loop bar; a loading needle is arranged at the top end of the liquor relief upper arm, and the lower end of the loading needle passes through the needle wiper; a sleeve pipe is connected with the liquor relief upper arm; a plastic capillary tube is arranged inside the sleeve pipe with the upper end connected with the loading needle; a mounting bottom plate of the liquor relief arm rotary disc is arranged at the upper end of a bearing pedestal; a rotary shaft sleeve is arranged at the upper end of the mounting bottom plate; and a step motor is connected with the rotary shaft sleeve. The full-automation biochemical analyzer liquor relief arm combination device has the advantages that: the device has simple and compact structure, high positioning precision and furthest reduced kinematic error, and can save testing time.

The invention relates to a direct-current power supply asynchronous parallel digital control system and a control method thereof. The direct-current power supply asynchronous parallel digital control system comprises a monitoring system and N direct-current power supply modules, wherein N is greater than or equal to 2. The monitoring system comprises a DSP control circuit, a serial communication circuit, man-machine interaction equipment, an asynchronous control circuit and a feedback circuit, wherein the DSP control circuit is respectively connected with the serial communication circuit, the man-machine interaction equipment, the asynchronous control circuit and the feedback circuit. The direct-current power supply asynchronous parallel digital control system of the invention can enable asynchronous and orderly work of the multiple power supply modules to be realized as required, actually control parallel output waveform and enable constant-voltage, constant-current or constant-power control of a power supply system to be quickly realized; the system has the advantages of simple process, less wiring, convenient maintenance and the like; and the system adopts a digital control method which is simple to operate and reliable in control, greatly improves the dynamic performance of the system in a constant-voltage mode and can be directly applied to a digital direct-current power supply parallel system.

The invention provides a three-phase direct-current brushless deep-water motor, comprising a motor housing composed of a front shroud, a back shroud and a housing, wherein a main shaft is installed on the front shroud and the back shroud via a bearing, magnetic steel rotor disks and coil stator disks are installed inside the motor housing, a water inlet and a water outlet are installed on the housing, the magnetic steel rotor disks are fixedly installed on the main shaft, the coil stator disks are fixed on the motor housing, and the magnetic steel rotor disks and the coil stator disks are in alternative arrangement. The three-phase direct-current brushless deep-water motor in the invention has simple structure, easy processing and low cost, and the biggest feature is that a waterproof housing does not be needed. The internal structure of the motor and the structure of the existing submersible motor are completely different. The invention can be applied to small submarine, submarine mine, diving pusher and other deepwater machines.

The invention provides a novel double-motor mixing head control system and method for KR molten iron desulfuration. The double-motor mixing head control system comprises a PLC (Programmable Logic Controller), a mixing motor No.1 and a corresponding frequency converter No.1, a mixing motor No.2 and a corresponding frequency converter No.2, wherein the mixing motor No.1 and the mixing motor No.2 are rigidly connected by a gearbox; a speed closed-loop PID (Proportion Integration Differentiation) controller and a torque filter are arranged in the PLC; the output end of the speed closed-ring PID controller is connected with the input end of the torque filter; the output end of the torque filter is connected with the input ends of the frequency converter No.1 and the frequency converter No.2, respectively; the frequency converter No.1 and the frequency converter No.2 are torque control type frequency converters; the output end of the frequency converter No.1 and the output end of the frequency converter No.2 are connected with the input end of the mixing motor No.1 and the input end of the mixing motor No.2, respectively; and the practical speed value of the motor No.1 at the output end of the mixing motor No.1 is fed back to the input end of the speed closed-ring PID controller. The double-motor mixing head control system has the beneficial effects of eliminating the synchronization time difference of the two motors and being high in synchronism; moreover, the production and maintenance are convenient, the debugging is simpler and the application range is wider.

The present invention provides a constant voltage source. The constant voltage source comprises a housing which is internally provided with a circuit board, the circuit board is integrated with an alternating current input interface, the alternating current passes through the alternating current input interface and is connected with a rectification filtering circuit, a pulse width regulation power switch, an MOS bridge-type inversion circuit, an intermediate frequency high-voltage transformer, a voltage doubling regulation circuit and a high-voltage current-limiting resistor in order to output direct current high voltage through the direct current high-voltage output end; and the pulse width regulation power switch is connected with a controller through a feedback circuit, and the processor is electrically connected with an energy storage device, a temperature detection unit, an alarm unit, an illumination unit and an interface unit. The constant voltage source is low in design cost, small in wiring, rapid in production maintenance, high in efficiency, simple in structure, convenient to operate, high in accuracy and small in space usage.

The invention discloses a method for debugging a BMS lower computer by utilizing an upper computer. The method comprises the following steps: data are monitored; a function of periodically transmitting the data of the lower computer is debugged; the data are calibrated; the functions of receiving ID data and transmitting the ID data of the lower computer are debugged; the data are processed; the periodically transmitted data and calibrated data are processed, and when information of the data is confirmed to be correct, the data of the lower computer are normal; hardware is controlled; and a relay, a data input port and an output port are controlled, and normality of the data of the functional relay, the data input port and the output port are judged. A BUG of the lower computer can be more comprehensively tested by the test scheme, and repairing can be performed before publishing so that subsequent program writing, production and maintenance are more facilitated, troubles of program re-writing are reduced for clients, and thus specialty of companies in such aspect can be greatly enhanced.

The invention discloses a cement production process, and in particular relates to a process for producing cement clinkers by straws instead of partial fuel coals, belonging to the technical field of cement production. The straws are input through a predecomposition kiln after mechanically crushed and processed, and the cement clinkers are produced by the straws instead of partial fuel coals; and smoke gas generated by burning the fuel coals and the straws in a mixing mode, a part of which is processed and exhausted through a novel wet-process cement kiln clinker production process route, and the other part of which is exhausted by virtue of cooling and dust removal through air exhaustion of a bypass air exhaustion pipeline arranged on a smoke chamber between the predecomposition kiln and a rotary kiln. By using the process, rich straw resources are fully utilized, so that the straw utilization rate is improved, precious coal resources are reduced, and an adverse effect that a poor cement production system is caused by substances such as potassium sulphate, sodium sulfate and potassium chloride generated by virtue of reaction of chlor-alkali compounds of the straws serving as a part of fuels is overcome.

The invention discloses a cam bottom plate of a fully-automatic computer multifunctional flat knitting machine. The cam bottom plate of the fully-automatic computer multifunctional flat knitting machine comprises a bottom plate, a knitting cam, a cam control device and a multifunctional stitch cam control device, the kitting cam is distributed on the bottom plate to form a knitting area, a transfer area and a tuck area. The knitting area and a transfer transition area are fixed on the lower portion of the cam bottom plate, a transition cam is a switchable device cam, a needle selection device is arranged on the left and on the right of the knitting cam respectively, the needle selection device comprises a needle selector and a jacquard needle reset device which is arranged under the needle selector and can translate in a left-right mode, a transfer cam is arranged at the top of the cam bottom plate, a tuck cam and back stitch cams are arranged under the transfer cam, and the working conditions of the tuck cam and the back stitch cams can be switched through a switching device. According to the cam bottom plate of the fully-automatic computer multifunctional flat knitting machine, the complexity of cams is reduced, complexity requirements of knitting of a full-computer multifunctional flat knitting machine can be met, the instability of stitch density control is reduced, the failure rate of the machine is reduced, a low-cost multifunctional cam bottom plate technology is developed for the technical field of flat knitting machine.

The invention relates to the technical field of automatic equipment and in particular relates to an automatic candy supply system of a cotton candy machine. The automatic candy supply system comprisesa fixed frame mechanism, a supporting frame mechanism, a humidifier candy box module, a candy amount control mechanism, a candy output device control mechanism, a fan mechanism, a microwave emitter module and a control electric box; microwave heating is adopted so that the heating temprature of candy is prone to be consistent and the control on candy melting is more fine and smooth; the size anduniformity of candy filaments are controlled and a sugar burning phenomenon is avoided; a separation type design of the fan and a candy output utensil is utilized and the utensil is easy to detach andconvenient to wash, so that the maintenance cost of a cotton candy output system can be greatly reduced and the transportation of the candy is realized through self gravity of the candy; the candy supply system is simplified and is convenient to produce and maintain; meanwhile, the viscosity of the candy also can be regulated and controlled, different cotton candy shapes can be convenient to design and so on.

The invention discloses a novel wool yarn covering nozzle device used for a computerized flat knitting machine. The novel wool yarn covering nozzle device used for the computerized flat knitting machine comprises a yarn nozzle base and a yarn nozzle handle, wherein a guiding groove is formed in the middle part of the yarn nozzle base, a claw groove is formed in the top of the yarn nozzle base, limit step surfaces are arranged at the two sides in the claw groove respectively, the yarn nozzle handle is movably embedded in the guiding groove, the yarn nozzle handle is covered by virtue of a fixedplate, a sliding plate which can slide left and right sheathes the yarn nozzle base, a sliding groove corresponding to the claw groove in position is formed above the sliding plate, a mandril telescopic device is arranged above the yarn nozzle base, the yarn nozzle handle is driven to move up and down, replace the state and alternately change working width state of the claw groove while working width state change of the yarn nozzle base is adjusted on the whole, alternate change of a main yarn and a secondary yarn and a yarn reverse covering function are realized, structure is simple, production and maintenance are convenient, cost is low, and the novel wool yarn covering nozzle device is applicable to being widely used.

The invention discloses a combined intelligent printer. The combined intelligent printer comprises an intelligent printer; a connecting mechanism and a cushion block are bonded on the upper surface ofthe left side of the intelligent printer; the connecting mechanism and the cushion block are arranged left and right and bonded with the intelligent printer; the two ends of an inkpad barrel, a printing forme barrel and a rubber printing barrel are fixedly connected with side plates; a forme barrel fixed frame is arranged on the left side of the printing forme barrel; the forme barrel fixed frameis sleeved with the two side plates, and is fixed with the two side plates through fixing pieces; a holding mechanism is bonded on the upper surface of the inkpad barrel; and the holding mechanism iswelded with the two side plates. The cushion block, the connecting mechanism, the side plates, the rubber printing barrel, the printing forme barrel, the forme barrel fixed frame, the fixing pieces,the holding mechanism, the inkpad barrel, an adjusting bolt and a slide rod form a module unit, so that the printing forme barrel and the holding mechanism can be completely replaced more quickly, thereplacement and cleaning time is greatly reduced, and the working efficiency is improved.

The invention relates to a high-voltage three-pole AC vacuum contactor which can be frequently operated by closing and separating and is suitable for a power supply and a distribution system with a rated voltage of 24KV. The high-voltage three-pole AC vacuum contactor adopts the technical scheme that a static guide rod and an electrokinetic guide rod are arranged in a vacuum arc extinguish chamber; the upper end of the static guide rod is connected with a fixed conducting bar fixed on the upper part of an insulation frame; a moving contact welded at the upper end of the electrokinetic guide rod is vertically opposite to a fixed contact welded at the lower end of the static guide rod, and the two contacts can be contacted and separated; the lower end of the electrokinetic guide rod extends out of the vacuum arc extinguish chamber and is connected with a moving conducting bar; and the extending end of the electrokinetic guide rod is connected with an insulator. The high-voltage three-pole AC vacuum contactor is characterized in that the lower end of the insulator is connected with a moving iron plate; the moving iron plate is connected with one end of a tripping spring, while the other end of the tripping spring is connected with a fixed iron plate; the fixed iron plate is fixed on the insulation frame, and the lower part of the fixed iron plate is connected with a fixed iron core; the upper part of the moving iron plate is connected with a moving iron core, and the moving iron core and the fixed iron core are vertically opposite to each other and a certain distance is reserved between the moving iron core and the fixed iron core; and a coil is sleeved outside the moving iron core and the fixed iron core. The invention has the advantages of skillful structure, reliable working, high response speed and wide application range.

The invention relates to a rolling grouser method and a rolling grouser structure. The rolling grouser method is adopted, rolling friction matching between a grouser and wheel bodies replaces traditional sliding friction matching, rollers capable of rotating transversely are fixedly disposed at the positions, where the grouser and the wheel bodies transversely and mutually butt against, on a crawler device, the rollers are matched with the side faces of the crawler wheel bodies in a rolling manner, and through rolling and butting against matching, transverse force on various wheel bodies on the crawler device is transmitted to a crawler to guide a moving direction of the crawler. The rolling grouser structure designed with the rolling grouser method is adopted to match with the wheel bodies of the crawler device, so that friction force between the grouser and the various wheel bodies can be reduced effectively, and particularly internal molecular structure heat effect caused by sliding friction of a rubber crawler is reduced, and internal molecular structural collapse caused by heat effect temperature rising of the rubber crawler is avoided effectively.

The invention relates to a vacuum pumping system, a vacuum refining system adopting the vacuum pumping system and a use method of the vacuum pumping system. The vacuum pumping system comprises a steamjet pump assembly sequentially connected in series through a pumping pipeline and a liquid ring pump, wherein the steam jet pump assembly comprises at least one grade of steam jet pump sequentially connected in series in the pumping direction and is further configured with at least one auxiliary pumping pipe used for preventing the steam jet pump from producing a laval nozzle effect; and at leastone auxiliary pumping pipe is connected to the side of the corresponding pumping pipeline between the steam jet pump and the former grade of steam jet pump, the outlet end of the auxiliary pumping pipe communicates with the liquid ring pump, and a control valve is arranged one each auxiliary pumping pipe. According to the vacuum pumping system provided by the embodiment, as the auxiliary pumpingpipe is adopted for dividing air flow entering the corresponding steam jet pump, the steam jet pump can be effectively prevented from producing the laval nozzle effect.

The invention discloses a vegetable transplanter shock absorption system and shock absorption system based on an STF and ultrasonic wave. The system is based on the characteristics of the STF and ultrasonic wave, causes by the vibration of a liquid medium through the transmission of ultrasonic wave in shear thickening fluid, ensures that the consistency of the fluid is increased and the hardness is increased, so that sufficient counter-acting force is brought to a piston, and damping effect is achieved; moreover, the system utilizes the organic combination of a displacement sensor, an operational amplifier, a sampling holder and A / D conversion, and utilizes impact force applied to displacement change reaction between upper and lower supporting plates of a damping device, thereby outputtingvoltage signals, converting the voltage signals into current values corresponding all moments, and finally converting the voltage signals into ultrasonic wave with corresponding frequencies; as the ultrasonic wave frequencies are different, hardness and viscosity of the shear thickening fluid are different, the counter-acting force is further different, and one-to-one correspondence between the impact force and the counter-acting force is accurately realized.

The invention discloses a water supply integrated module of a dishwasher and a dishwasher with the water supply integrated module. The water supply integrated module comprises a disinfection module including a first container chamber connected with the water inlet of the water supply integrated module and a disinfector arranged in the first container chamber. The water supply integrated module further comprises water supply circuit connected with the disinfection module, and transporting the disinfected water source to the dishwasher through the water outlet of the water supply integration module. The washing consumable module comprises a second container cavity for storing detergent, and delivers detergent to the water supply channel when washing dishes, thereby solving the problem in theprior art that the dishwasher only filters the water source through the PP cotton filter element, the PP cotton filter element is unable to sterilize the water source, and the filter element needs tobe frequently replaced by a user.

The invention discloses a wind-driven fan blade pitch adjusting device, and relates to the field of wind power generation equipment. The aim is to solve the problem of low power generation efficiency caused by non-adjustable fan blade pitch of the existing wind power generation equipment, the device comprises a rotating seat, fan blades are arranged on the outer wall of the rotating seat, a pitch changing mechanism used for controlling pitch changing of the fan blades is arranged in the rotating seat, the pitch changing mechanism comprises a rotary bearing, an annular table is arranged on the outer wall of the rotating seat, an outer ring of the rotary bearing is fixedly connected with the table top of the annular table, a first flange is arranged at the root of each fan blade, the first flange is fixedly connected with an inner ring of the rotary bearing, a rotary table is arranged at the end, away from the first flange, of the inner ring of the rotary bearing, and one end of the rotary table extends into the rotating seat. The device is novel in structure, and the problem that the power generation efficiency is low due to the fact that the fan blade pitch of the existing wind power generation equipment cannot be adjusted is effectively solved.

The invention discloses an air-cooling milk and coffee display cabinet. The air-cooling milk and coffee display cabinet comprises a refrigerating system, a box body liner, a glass door structure, an air baffle plate and a decorative side plate structure, wherein the glass door structure comprises a door sealing strip and a glass door; a screw cap assembly comprises a screw cap, a screw and a stud;the decorative side plate structure comprises decorative side plates which are fixedly mounted at the left side, right side and rear side of a box body of the milk and coffee display cabinet respectively; the refrigerating system is located at the rear side of the box body liner. The air-cooling milk and coffee display cabinet disclosed by the invention has the beneficial effects that a plastic end cover and a screw cap structure of a sleeve structure are adopted; a semicircular-structure screw cap is changed into a cylindrical-structure screw cap; the screw is isolated from the box body andthe screw cap and the problem that the screw is easy to lean in a utilization process is avoided; the door sealing strip, which is mounted on the glass door before, is mounted on the box body; an adsorption manner is changed into a manner of adsorbing the glass door through magnets from a manner of adsorbing the door sealing strip through a magnetic strip, so that the problem that the door sealingstrip is released, caused by the fact that the glass door is frequently opened and closed, is solved; the decorative side plates are additionally arranged so that the air-cooling milk and coffee display cabinet is more beautiful and has a better display effect.

The invention discloses a plastic extruder heating control system, which comprises a main control module, a signal conditioning module, a power supply module, a driving module, a current detection module and a unit over-temperature detection module, and the modules are respectively distributed in a heating control unit and a heating driving unit. The plastic extruder heating control system provided by the invention has the advantages of simple structure, cost saving, convenient wiring and precise control. The problems of complex wiring, low standardization, poor operability, poor control precision, low safety and the like in the industry are solved. And moreover, an expansion interface is provided for intelligent and informationized development of equipment in the future, and the difficulty and the cost of upgrading an enterprise to the industry 4.0 are greatly reduced.

The invention relates to a material conveying horizontal main machine using an elastic force reset wheel tooth drive wheel. The material conveying horizontal main machine structurally comprises a driver and a tensioner, the driver comprises a driver housing, a driving motor and a speed reducer are arranged in the driver housing, and an output shaft of the speed reducer is provided with the elasticforce reset wheel tooth drive wheel; and the elastic force reset wheel tooth drive wheel comprises a wheel disc, a retaining ring, movable wheel teeth and an elastic reset element, the multiple movable wheel teeth are distributed on the outer circumference of the wheel disc, the movable wheel teeth are in shaft connection to the wheel disc, the retaining ring is arranged on a disc surface of thewheel disc and is used for limiting the rotational positions of the movable wheel teeth, and the elastic reset element is used for resetting the rotated movable wheel teeth. The elastic reset elementincludes an elastic piece, a tension spring and the like. The material conveying horizontal main machine has the large conveying amount and high conveying efficiency, is simple in structure and convenient to produce and maintain and is suitable for serving as a driving main machine of an external conveying system.

The invention relates to the technical field of furniture, and discloses a drawer which comprises a drawer body and a sliding rail assembly, the drawer body is connected with an upper rail of the sliding rail assembly through a first limiting piece, a second limiting piece and a lock catch, and when the lock catch rotates to the position below the upper rail, the drawer body and the upper rail arelocked by the lock catch and cannot be detached. When the lock catch rotates to be not located below the upper rail, the drawer body and the upper rail are not locked by the lock catch and can be separated. Based on the structure, the drawer body and the sliding rail assembly are firmly, safely and reliably connected, meanwhile, disassembly and assembly are convenient, and production, overhaul and maintenance are facilitated. In addition, the invention further discloses a cabinet, and due to the fact that the drawer is adopted, the cabinet has the advantages of being convenient to produce andoverhaul, large in storage capacity, low in noise, good in quality and the like.

The invention relates to a vacuum pumping system, a vacuum refining system adopting the vacuum pumping system and a use method of the vacuum pumping system. The vacuum pumping system comprises a steamjet pump assembly sequentially connected in series through a pumping pipeline and a liquid ring pump, wherein the steam jet pump assembly comprises at least one grade of steam jet pump sequentially connected in series in the pumping direction and is further configured with at least one auxiliary pumping pipe used for preventing the steam jet pump from producing a laval nozzle effect; and at leastone auxiliary pumping pipe is connected to the side of the corresponding pumping pipeline between the steam jet pump and the former grade of steam jet pump, the outlet end of the auxiliary pumping pipe communicates with the liquid ring pump, and a control valve is arranged one each auxiliary pumping pipe. According to the vacuum pumping system provided by the embodiment, as the auxiliary pumpingpipe is adopted for dividing air flow entering the corresponding steam jet pump, the steam jet pump can be effectively prevented from producing the laval nozzle effect.