Seam-type air-flow lead-jetting device
Technical field
The present invention relates to a kind of device that utilizes pressurized gas to obtain vacuum, especially a kind of airflow injection device.
Background technique
At present, utilize pressurized gas to obtain the device of vacuum, its air flow jetting passage (being equivalent to jet of the present invention chamber) adopts pipe, and this device can satisfy the degree of vacuum requirement of low-pressure cavity when vacuum injection flow is less.But, when required vacuum injection flow is big,, must increase the quantity (being a plurality of pipes of horizontal Tile) of pipe diameter or increase pipe in order to guarantee the degree of vacuum of low-pressure cavity.Yet if increase the diameter of pipe, the distance at pipe center to edge also correspondingly increases, and makes the pressurized gas at center be difficult to carry out energy interchange with the low-pressure gas at edge, causes the air consumption of pressurized gas sharply to increase; If increase the quantity of pipe, then can cause whole apparatus structure complexity, cost improves, and the degree of vacuum of low-pressure cavity also is difficult to guarantee
Summary of the invention
Purpose of the present invention is intended to overcome above-mentioned the deficiencies in the prior art, proposes the airflow injection device that a kind of air consumption is few, vacuum injection flow is big.
For achieving the above object, the present invention proposes a kind of seam-type air-flow lead-jetting device, comprise hyperbaric chamber 1, jet chamber 3 and low-pressure cavity 2, one end in jet chamber 3 communicates with hyperbaric chamber 1 through passage 17, the other end in jet chamber 3 is provided with relief opening 14, hyperbaric chamber 1 feeds pressurized gas through passage 17 to jet chamber 3, the sidewall in jet chamber 3 is provided with passway 18, jet chamber 3 18 communicates with low-pressure cavity 2 through the passway, the gas of jet chamber 3 in 18 draws low pressure chambeies 2, passway, jet chamber 3 is through relief opening 14 discharging jet gases, it is characterized in that: described passage 17 is made up of rectangular slot 1700 and the wedgy passage that changes from small to big 170 that communicates with it, gas expands through rectangular slot 1700 and wedgy passage 170 post acceleration that communicate with it, and the cross section in described jet chamber 3 is a rectangle.
Described passway 18 is at least two-stage passway 181,182, first order passway 181 is positioned at wedge shape acceleration channel 170 outlet ports, two-stage passway 181,182 communicates with low-pressure cavity 2 by passage respectively, from first order passway 181 to the jet chamber 3 the passway, the second level 182 via from large to small a wedgy passage 171 and a rectangular channel 191.
Described passway 18 also comprises third level passway 183, third level passway 183 communicates with low-pressure cavity 2 by a passage, from passway, the second level 182 to the jet chamber 3 the third level passway 183 via from large to small a wedgy passage 172 and a rectangular channel 192.
From described third level passway 183 to the jet chamber 3 the relief opening 14 via from large to small a wedgy passage 173 and a rectangular channel 193.
At least described third level passway 183 is provided with one-way valve 6.
Described passway 18 is the rectangular channel mouth
The width of described rectangular slot 1700 is: A=0.5 ± 0.03mm, the length of described wedgy passage 170 is: E=5.2 ± 0.1mm.
The width of described rectangular slot 1700 is: A=0.5 ± 0.03mm.
The length of described wedgy passage 170 is: E=5.2 ± 0.1mm.
The width of described rectangular channel 191 is: B=2.2 ± 0.05mm.
The width of described rectangular channel 192 is: C=4.5mm.
The width of described rectangular channel 193 is: D=11mm.
Adopted above scheme, the technological progress that the present invention gives prominence to is:
Because cross section, slit, passage and the passway in jet chamber all are rectangle, neither increase the distance of center, jet chamber to the edge, help the energy interchange of the low-pressure gas at the pressurized gas at center, jet chamber and edge again, thereby obtain higher vacuum injection flow with less pressurized gas; When required vacuum injection flow is big, in order to guarantee the degree of vacuum of low-pressure cavity, can under the constant prerequisite in horizontal section, jet chamber, increase the height in jet chamber, be equivalent to do not increasing center, jet chamber under the prerequisite of the distance at edge, increase the quantity in jet chamber, more help the energy interchange of the low-pressure gas at the pressurized gas at center, jet chamber and edge, and further reduce pressurized gas air consumption, increase the vacuum injection flow of lead-jetting device;
The shape of wedgy passage is through strict design, with the shock wave quantity that reduces air-flow in the passage with weaken shock strength, and can not produce vortex shedding, air-flow keeps high as far as possible flowing velocity and suction capactity in the passage thereby make, and obtains big as far as possible vacuum flow type pump with injection amount and high as far as possible degree of vacuum;
Simultaneously in jet chamber and passage that low-pressure cavity communicates, increased one-way valve, when having only the gas pressure in jet chamber to be lower than the gas pressure of low-pressure cavity, one-way valve is just opened, help the high velocity air in the jet chamber and the energy interchange of the low speed flow in the low-pressure cavity, reduce pressurized gas air consumption, increase the vacuum injection flow of lead-jetting device;
Whole seam-type air-flow lead-jetting device can obtain higher vacuum injection flow with a spot of pressurized gas under the situation of the highest acquisition the-0.092Mpa degree of vacuum, air consumption is low, degree of vacuum is high, vacuum injection flow is big, simple in structure, cost is low.
Description of drawings
Fig. 1 is seam-type air-flow lead-jetting device air cavity annexation figure.
Fig. 2 is the cavity horizontal section partial enlarged drawing in jet chamber 3 among Fig. 1.
Embodiment
Also the present invention is described in further detail in conjunction with the accompanying drawings below by specific embodiment.
Embodiment, as Fig. 1, shown in 2, a kind of seam-type air-flow lead-jetting device, comprise hyperbaric chamber 1, jet chamber 3 and low-pressure cavity 2, one end in jet chamber 3 communicates with hyperbaric chamber 1 through passage 17, the other end in jet chamber 3 is provided with relief opening 14, hyperbaric chamber 1 feeds pressurized gas through passage 17 to jet chamber 3, the sidewall in jet chamber 3 is provided with rectangular channel mouth 18, rectangular channel mouth 18 is divided into third order moment shape passway 181,182,183, jet chamber 3 is by third order moment shape passway 181,182,183 communicate with low-pressure cavity 2 respectively, passage 17 is made up of rectangular slot 1700 and the wedgy passage that changes from small to big 170 that communicates with it, width A=0.5 ± the 0.03mm of rectangular slot 1700, the length E=5.2 of wedgy passage 170 ± 0.1mm, gas expands through rectangular slot 1700 and wedgy passage 170 post acceleration that communicate with it; First order rectangular channel mouth 181 is positioned at wedge shape acceleration channel 170 outlet ports, from first order rectangular channel mouth 181 to the jet chamber 3 the second level rectangular channel mouth 182 via from large to small a wedgy passage 171 and a rectangular channel 191, the width B of rectangular channel 191=2.2 ± 0.05mm; From second level rectangular channel mouth 182 to the jet chamber 3 the third level rectangular channel mouth 183 via from large to small a wedgy passage 172 and a rectangular channel 192, the width C=4.5mm of rectangular channel 192; From third level rectangular channel mouth 183 to the jet chamber 3 the relief opening 14 via from large to small a wedgy passage 173 and a rectangular channel 193, the width D=11mm of rectangular channel 193; Jet chamber 3 is through relief opening 14 discharging jet gases, and second level rectangular channel mouth 182 and third level rectangular channel mouth 183 are provided with gas pressure valve 6.
The cross section in jet chamber 3 is a rectangle, and is high highly more, and the vacuum injection flow that then obtains is big more.
Enter the high pressure draught in jet chamber 3 by hyperbaric chamber 1, become seam-type air-flow via rectangular slot 1700, be convenient to control the consumption of pressurized gas, rectangular slot 1700 is narrow more, the consumption of pressurized gas is just few more, but when passing through rectangular slot 1700 owing to high pressure draught, air-flow can form boundary layer on rectangular slot 1700 left and right sides inwalls, if rectangular slot 1700 is narrow, cause thickness proportion in rectangular slot 1700 of boundary layer excessive, then the flow field of high pressure draught will become unstable near the rectangular slot 1700, thereby influence the degree of vacuum of seam-type air-flow lead-jetting device, therefore the width A of rectangular slot 1700 should make the thickness of boundary layer account for the ratio of rectangular slot 1700 width<30%, through repeatedly test, and the first-selected A=0.5 ± 0.03mm of the present invention.
High pressure draught is through rectangular slot 1700, in the wedgy passage 170 that changes from small to big, expand and quicken, wedgy passage 170 is long more, the high velocity air speed that expands is fast more, but high pressure draught is through behind the wedgy passage 170, some is reflected into compressional wave on the border of wedgy passage 170 air outlets, the high pressure draught of compressional wave and expansion intersects the air-flow axial velocity that makes in the wedgy passage 170 outlet port certain distances and fluctuation occurs, growth along with wedgy passage 170, the compressional wave that produces is strong (may become shock wave) more and more, the air-flow axial velocity enters the decling phase, therefore, quicken the highest speed of back generation (being the ideal length of air-flow axial velocity decay) for obtaining high pressure draught, the length E of wedgy passage 170 is among the present invention: when the width A=0.5 of rectangular slot 1700 ± 0.03mm, and the length E=5.2 of wedgy passage 170 ± 0.1mm.
Rectangular channel 191 is wide more, the vacuum injection flow of the first order is big more, but rectangular channel 191 is wide, go out to produce shock wave on the border, air outlet of rectangular channel 191, therefore rectangular channel 191 air outlets do not produce shock wave and obtain maximum high velocity air flow and are of a size of among the present invention: when the width A=0.5 ± 0.03mm of rectangular slot 1700, the length E=5.2 of wedgy passage 170 ± 0.1mm, and the width B of rectangular channel 191=2.2 ± 0.05mm.
Rectangular channel 192 is wide more, partial vacuum injection flow is big more, but rectangular channel 192 is wide, in rectangular channel 192, can produce vortex shedding, therefore do not produce vortex shedding and obtain maximum high velocity air flow in the rectangular channel 192 among the present invention and be of a size of: when the length E=5.2 ± 0.1mm of the width A=0.5 ± 0.03mm of rectangular slot 1700, wedgy passage 170, the width B of rectangular channel 191=2.2 ± 0.05mm, the width of rectangular channel 192: C=4.5mm.
Rectangular channel 193 is wide more, the vacuum injection flow of the third level is big more, but rectangular channel 193 is wide, in rectangular channel 193, can produce vortex shedding, therefore do not produce vortex shedding among the present invention in the rectangular channel 193 and obtain max vacuum injection flow and be of a size of: when the width B=2.2 ± 0.05mm of the length E=5.2 ± 0.1mm of the width A=0.5 ± 0.03mm of rectangular slot 1700, wedgy passage 170, rectangular channel 191, the width C of rectangular channel 192=4.5mm, the width of rectangular channel 193: D=11mm.
The working procedure of seam-type air-flow lead-jetting device is as follows:
Pressurized gas enter hyperbaric chamber 1 by suction port 8, be to become seam-type air-flow after the rectangular slot 1700 of A by width, length be expand in the wedgy passage that changes from small to big 170 of E quicken after, airspeed reaches peak (approximate local velocity of sound 3 times), corresponding stream pressure reaches minimum, gas pressure in the jet chamber 3 is lower than the gas pressure in the low-pressure cavity 2, and the gas in the low-pressure cavity 2 enters jet chamber 3 by rectangular channel 181, is siphoned away by high velocity air.
High velocity air is slowed down by shock wave in wedgy passage 171 from large to small, after being the rectangular channel 191 of B by the rear end width, airspeed is about 1.5 times of local velocity of sound, when the gas pressure of the gas-pressure controlling valve door 61 low-pressure cavity sides in the rectangular channel 182 during greater than the gas pressure of jet chamber side, gas-pressure controlling valve door 61 is opened, and the gas in the low-pressure cavity 2 is siphoned away by high velocity air in jet chamber 3 by rectangular channel 182; When the gas pressure of gas-pressure controlling valve door 61 low-pressure cavity sides was lower than the gas pressure of jet chamber side, gas-pressure controlling valve door 61 was closed, and avoided the gas in the jet chamber 3 to enter in the low-pressure cavity 2.
High velocity air continues to slow down in wedgy passage 172 from large to small, after being the rectangular channel 192 of C by the rear end width, airspeed is about 0.5 times of local velocity of sound, when the gas pressure of the gas-pressure controlling valve door 62 low-pressure cavity sides in the rectangular channel 183 during greater than the gas pressure of jet chamber side, gas-pressure controlling valve door 62 is opened, and the gas in the low-pressure cavity 2 is siphoned away by high velocity air in jet chamber 2 by rectangular channel 183; When the gas pressure of gas-pressure controlling valve door 62 low-pressure cavity sides was lower than the gas pressure of jet chamber side, gas-pressure controlling valve door 62 was closed, and avoided the gas in the jet chamber 3 to enter in the low-pressure cavity 2.
High velocity air continues to slow down in wedgy passage 173 from large to small, be the rectangular channel 193 of D by the rear end width after, through relief opening 14 discharging jet chambeies 3.
Low-pressure cavity 2 connects other by vacuum interface 9 need use the device of vacuum, and the gas in the device of use vacuum is taken away by the high velocity air in the jet chamber 3 through low-pressure cavity 2.