JPS6337280B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pump for conveying liquid from a vacuum chamber to a chamber of higher pressure, comprising: a casing having a discharge connection mounted substantially tangentially to the supply connection; a rotor having a suction chamber rotating therein and to which liquid is axially supplied via a supply connection; a plurality of conveying mechanisms arranged on this rotor and extending between the suction chamber of the rotor and a casing wall; It relates to a type of thing that has the following.

BACKGROUND OF THE INVENTION The transfer of liquids from a vacuum chamber to a chamber with a higher pressure is of particular importance in chemical process technology. Many chemical method technology processes can only be performed under vacuum. In order to carry out this process continuously, the liquid must also be continuously transported. This removal is usually carried out against atmospheric pressure. For example, vacuum generators are known that vaporize certain components from a liquid in a vacuum chamber in order to extract these components in a pure form. While being continuously supplied to the chamber, it is necessary to continuously remove liquid from this vacuum chamber against atmospheric pressure. A particular problem with such a discharge is when the liquid to be discharged has a temperature close to its boiling point and vapor bubbles are carried away with it.

If a conventional liquid pump is used in such cases, a large supply height must be provided to compensate for the pressure difference.

Liquid ring pumps are used to reduce such large supply heights. In this case, a liquid ring rotating together with the rotor permanently seals the vacuum chamber from a chamber with a higher pressure. The rotor that generates this liquid ring is assigned one or more impellers that perform the actual transport. In such a liquid ring pump, the liquid ring rotates together with the rotor, so the liquid is heated based on frictional force, and the amount of vaporization becomes large, especially when the liquid is near its boiling point. The formation of vapor and gas bubbles results in undesirable cavitation. The vaporized liquid is replaced by fresh liquid and the liquid ring must be cooled by the supply of carrier liquid. As a result, the pump always requires a considerable minimum supply. Furthermore, such pumps require a supply height of more than 0.5 m,
It has the disadvantage that it cannot be used in a large vacuum range of several torr to 10 ^-2 torr.

Furthermore, it is known to use volumetric pumps or so-called positive pumps, such as gear pumps, threaded spindle pumps (monopumps), slider pumps or the like, for the above-mentioned purposes. In this case as well, a large minimum supply amount is required given a predetermined supply height. Otherwise, air will enter due to the intight gaps. Also, dry operation of these pumps is not allowed. For this purpose, these pumps require, in addition to a level adjustment device or regulating transmission device, a check valve arranged on the discharge side to adjust the conveyance. Although such pumps have the advantage of being able to be used in high vacuum conditions, they only have a sufficient service life if the conveying liquid has lubricating properties.

For more viscous liquids and highly concentrated suspensions, sluice gates are used, but they do not have a transport function.

The object of the present invention is to automatically and reliably change the conveying amount in accordance with the supply amount, to maintain a static pressure difference when the supply amount is zero, and to maintain a high supply level even for boiling liquids containing bubbles. To provide a pump for discharging a liquid under vacuum, which is capable of continuously conveying liquid without causing any damage and without cavitation.

The task starts from a pump of the type mentioned at the outset, in which each conveying mechanism is connected in a fluid-tight manner with the suction chamber of the rotor, and the liquid is first directed outwards in the radial direction of the rotor and then, in the radial direction, It is configured as a siphon with conveying passages deflecting radially inward towards the outlet openings located between the suction chamber of the rotor and the casing outer periphery, with the outlet openings of all conveying passages having a pressure higher than that of the vacuum chamber. and the suction chamber of the rotor is connected via a conduit to the gas cylinder above the liquid level in the vacuum chamber, and the suction chamber of the rotor is sealed against non-rotating parts of the casing. It was then resolved.

Due to the design of the individual rotating conveying channels as siphons, the axially supplied liquid accumulates in the deflection region in the same manner as in the case of a U-tube with an isometric leg. In this case, one section of the conveying channel (corresponding to the long leg of the U-tube) is provided with a certain liquid level height, and the other section of the conveying channel (corresponding to the short leg of the U-tube) (equivalent) liquid flows out.
The height difference between this outlet and the liquid level in the other section corresponds to the respective pressure difference between the vacuum chamber in which the liquid is conveyed and the higher pressure chamber in which it is received. It changes depending on. The minimum feed required by the pump of the invention is extremely small, and in practice dropwise delivery is possible. The liquid is forced radially outwards due to centrifugal force in a conveying channel that is virtually closed and opens into the casing only through the outlet, so that the pressure of the liquid is increased and the vapor bubbles present in the liquid are Condensation and gas bubbles are separated. Cavitation, which was feared, can thereby be avoided.

Furthermore, in the pump of the present invention, a rotating liquid ring is not formed inside the pump unlike in the case of a liquid-sealed pump, so the liquid is heated by friction and the amount of evaporation and deaeration increases. No defects will occur. Furthermore, the pump of the invention can be used in both low and high vacuum conditions. Also, when restarting the pump, it is sufficient to fill approximately half of the pump with liquid. This is because in this case the conveying channel is automatically filled from the suction side. Moreover, the pump of the invention automatically adjusts the output volume to any supply volume.

In one advantageous embodiment of the invention, each conveying channel consists of a tubular channel section which is attached approximately radially to the rotor and a hood-shaped channel section which covers it at a distance. This construction is particularly simple and reliable from a manufacturing and operational point of view. The advantage of positive displacement pumps is that there are no problems with gap seals, and the tight manufacturing tolerances required in positive displacement pumps are no longer an issue.

Furthermore, when using the pump of the invention for transporting liquids containing solids, it is also possible that the transport passage has a small diameter, possibly closed, in the deflection range that rotates close to the wall of the pump casing. It is advantageous to have a possible opening. In this case, the solids in the liquid accumulate in the deflection range based on centrifugal force, so
It is carried out into the casing through the opening. Of course, the diameter of this opening must be selected so that the liquid cushion within the deflection range does not flow out.

In addition, when the solid content contained in the liquid is small, it is also possible to close the opening so that it can be opened from time to time.

The invention will now be explained with reference to the drawings: FIG. 1 shows a vacuum chamber 1 and a chamber 2 which is at a relatively high pressure, for example atmospheric pressure. The vacuum chamber 1 can be, for example, a vacuum generator or the like. Between the vacuum chambers 1 and 2 there is disposed a discharge pump, generally indicated by the reference numeral 3. This delivery pump 3 has a housing 4 with a supply connection 5 and a schematically illustrated discharge connection 6. The unloading pump 3 has a shaft 9
It has a rotor 7 which is rotated by a drive motor 8 via a rotor 7. The rotor 7 or its suction chamber 11 is sealed against non-rotating parts of the casing 4 by a sealing member 20. The rotor 7 has a plurality of outwardly extending conveying passages 10. These conveyance passages 10 are based on the principle of a U-shaped tube,
In other words, it is configured as a siphon. This conveying passage 10 runs from the suction chamber 11 of the rotor 7 to the passage section 1.
It extends radially outwardly at 2 and then via deflection point 13 and radially inwardly at channel section 14 . The passage section 14 has an outflow opening 15 .

When the rotor 7 rotates, the liquid contained in the vacuum chamber 1 flows toward the suction chamber 11 via the supply connection 5 and is pumped into the conveying passage 10 based on centrifugal acceleration. As a result, a liquid column is formed in each conveyance passage 10 on the principle of a siphon. In this case, the height R of the liquid level in the passage section 14 corresponds to the outlet opening 15
, whereas the height r of the liquid level in the passage section 12 is adjusted to different values depending on the pressure difference between the vacuum chamber 1 and the chamber 2. This difference in liquid level is indicated by the symbol h in the drawings. However, in any case, there is a liquid in the conveying passage 10 that blocks it, and air is prevented from flowing from the suction chamber 11 into the chamber 2. A uniform continuous conveyance, which guarantees reliable operation, is ensured by the fact that the suction chamber 11 is connected via a conduit 16 to a gas cylinder above the liquid level in the vacuum chamber 1, so that both chambers have the same gas pressure. This is achieved by the generation of

In the embodiments described below, the reference numbers of the main parts of the pump shown in FIG. 1 are likewise used to designate the main parts of the pump. In the embodiment shown in FIGS. 2 and 3, the casing 4 of the pump 3 consists of two shell bodies 41, 42. The drive shaft 9 penetrates the shell body 41 and protrudes into the casing 4. A rotor 7 is fixed onto the shaft 9 with a screw 17. Rotor 7 is shaft 9
It has a surrounding boss 18 to which a sealing element 19 is assigned which seals the pump chamber to the drive side. The rotor 7 has a suction chamber 11 in the axial direction, into which the supply connection 5 passing through the shell body 42 is introduced. The rotor 7 of the pump is connected to the casing part 42 by means of a sealing member 20.
sealed against. Suction chamber 1 of rotor 7
1 is connected via a conduit 16 to a gas cylinder above the liquid level in a vacuum chamber, not shown in FIG.

In the illustrated embodiment, the rotor 7 has a total of six outwardly extending conveying passages 10. In this case, two different implementations are shown in FIG. In the first embodiment, each conveyance path 10
consists of a radially outwardly extending tubular passage section 101 connected to the suction chamber 11 and a passage section 102 which grips it from the outside. In this case, this channel section 102 can be fixed with a thread 103 to a corresponding cylindrical extension 104 of the rotor. The hood-like channel section 102 has a plurality of outlet openings 105 in the form of holes.

A second embodiment of the conveying path 10 is shown in the upper right corner of FIG. In this case too, the rotor 7 has a radially outwardly extending tubular passage section 106.
and a hood-like passage section 107 that grasps this from the outside.
It has This hood-shaped passage section 107
is fixed to the tubular passage section 106 only via a spacer web 108. In this case, an outflow opening 109 in the form of an open ring results. Insofar as the pump is used for conveying liquids mixed with solids, the hood-like passage section 102, whose top 110 rotates close to the wall of the casing 4, has an opening 111 of small internal diameter, so that the solids are not removed from the outside. Advantageously, it is conveyed to the outlet connection 6 by the outer surface of the rotating conveying channel 10.

In the embodiment shown in FIGS. 4 and 5,
The casing 4 is constructed in a similar manner to the previously described embodiments. However, the pressure compensation line 16 is led through the supply connection 5 and extends axially into the suction chamber 11 of the rotor 7 with a tubular line section 21 . In this embodiment, the rotor 7 is
two discs 7 connected to each other by screws 63
It consists of 1,72. These ward boards 7
1 and 72 are kept apart by a strip 112 arranged on the end face of at least one of the discs. In this embodiment, the strip 112 has legs 113, 114 which are connected to each other in a V-shape via a connecting part 115 facing the suction chamber 11, one leg 114 pointing inwards. Formerly arc-shaped top 11
It has an extension 117 bent through 6. Therefore these strips 112 and both discs 7
1 and 72, a conveying channel 10 having a rectangular cross section is created. Radial legs 113 adjacent to inwardly directed extensions 117
The space between the two is designed to allow fluid to flow out.
This strip 112 forms part of both discs 7.
1, 72 or can be cast integrally on the end face of one of the discs. Two similar embodiments are shown in FIGS. 6 and 7, one above the other. In this case as well, the rotor consists of two discs 7
It consists of 3,74. A strip forming the conveying passage 10 is integrally cast on the end face 75 of one of the disks 74. In the embodiment shown in the upper half of FIG. 7, these strips include a curved strip section 118 extending up to the outer circumference of the suction chamber 11 and a short strip section 119 extending parallel to this. and a leg portion 120 extending downwardly from the curved strip section 118 to surround the short strip section 119. In the embodiment shown in the lower half of FIG. 7, the downwardly extending leg 1
20 is extended outwardly through a bend (strip section 121). Therefore strip section 118
An outflow passage is formed between and 121.
The two discs 73, 74 are in this case connected to each other by screws 76. 8 and 9 show an embodiment in which the rotor 7 is composed of three discs 77, 78, 79. There is a space between the outer disk 77 and the center disk 78, indicated by the reference numeral 12 in FIG.
A passage section is formed extending radially outward from the suction chamber 11, indicated by A section 14 is formed. The central disc 78 has a smaller diameter than the two outer discs 77, 79, so that a passage 80 is formed at its outer periphery. This passage 80 is closed in the embodiment shown in FIG. 8 by a ring 81 which is slidable from the position shown in the upper half of FIG. 8 to the position shown in the lower half. There is. This ring 81 is moved onto the outer disk 79 as shown in the upper half of FIG. 8, and a passage 80 is opened to the outside, through which the collected solids may be carried out. You will be able to do it. In this example, the disk 7
The liquid that collects in 9 is removed via a pumping pipe 82. In the embodiment shown in FIG. 9 as well, the rotor 7 is composed of three discs 83, 84, 85 constructed in substantially the same manner as in the embodiment shown in FIG. An elastic O-ring is used as a closing member on the outer peripheral side of the passage 80. This O-ring is in fluid-tight contact with a suitably chamfered disc. The elasticity of this O-ring is selected so that when a predetermined pressure rise occurs in the conveying passage, the O-ring separates from the outer periphery of the disk, and the solid matter is carried out, resulting in automatic purification. It is advantageous.

[Brief explanation of the drawing]

The drawings show a plurality of embodiments of the present invention, in which FIG. 1 is a schematic diagram showing the working principle of the pump of the present invention, FIG. 2 is an axial sectional view of one embodiment of the pump of the present invention, 3 is a sectional view taken along the - line in FIG. 2, FIG. 4 is an axial sectional view taken along the - line in FIG. 5 of another embodiment of the present invention, and FIG. - sectional view along the line, FIG.
7 is a radial sectional view taken along the line - - of FIG. 6, with different embodiments shown in the upper and lower halves, and FIG. 8 is a closed periphery. Figure 9 showing an embodiment with possible openings
This figure is a diagram showing a modified embodiment of FIG. 8. 1...vacuum chamber, 2...chamber, 3...export pump,
4... Casing, 5... Supply connection section, 6... Discharge connection section, 7... Rotor, 8... Drive motor, 9
...shaft, 10 ... conveyance passage, 11 ... suction chamber, 1
2... Passage section, 13... Deflection point, 14... Passage section, 15... Outflow opening, 16... Conduit, 17
...Screw, 18...Boss, 19...Seal member,
20... Seal member, 21... Conduit portion, 41,
42... Shell body, 70... Screw, 71, 72,
73, 74... Disc, 75... End face, 76... Screw, 77, 78, 79... Disc, 80... Passage,
81...ring, 82...pumping pipe, 83,8
4,85... Disc, 101... Passage division, 102
... Passage section, 103 ... Thread, 104 ... Addition part, 105 ... Outflow opening, 106 ... Passage section, 107 ... Passage section, 108 ... Space web, 109 ... Outflow opening, 110 ... top, 1
11...Opening, 112...Strip, 113, 114
...Legs, 115...Joining portion, 116...Top portion, 117...Extension portion, 118...Strip section, 1
19...Strip division, 120...Legs, 121...
Strip division.

Claims (1)

Claims: 1. A pump 3 for conveying liquid from a vacuum chamber 1 to a chamber 2 with a higher pressure, a casing 4 having a supply connection 5 and a discharge connection 6 mounted approximately tangentially. a rotor 7 which rotates in this casing 4 and has a suction chamber 11 which is axially supplied with liquid via the supply connection 5; In the case of a type having a plurality of conveying mechanisms extending between the wall and the wall, each conveying mechanism is connected liquid-tightly to the suction chamber 11 of the rotor, and the liquid is first directed outward as viewed in the radial direction of the rotor 7. , which is then constructed as a siphon with a conveying channel 10 which is deflected radially inward towards an outlet opening 15 located between the suction chamber 11 of the rotor 7 and the outer periphery of the casing; opening 1
5 is connected to the chamber 2 having a higher pressure than the vacuum chamber 1, and the suction chamber 11 of the rotor 7 is connected via a conduit 16 to the gas cushion above the liquid level in the vacuum chamber 1. Pump for discharging liquid under vacuum, characterized in that 11 is sealed against non-rotating parts of the casing. 2. Pump according to claim 1, wherein the rotor 7 has an axially arranged hollow space as the suction chamber 11, into which the supply connection 5 projects axially. 3. Each conveying channel 10 consists of a tubular channel section 101 mounted substantially radially on the rotor 7 and a hood-shaped channel section 102 covering it at a distance. pump. 4. The pump according to claim 1, wherein the conveyance passage 10 is curved in a direction opposite to the rotational direction of the rotor 7. 5. The rotor 7 consists of two discs 71, 72 or 73, 74 that are joined in one plane perpendicular to the rotor axis and almost completely fill the casing 4, and these discs 71, 72 or 7
3, 74, or both of the strips 1 bent into a substantially V-shape of equal height on the end faces facing each other;
12 are provided circumferentially distributed, one leg 114 of these V-shaped strips 112 having an inwardly bent extension 117, within which the inwardly bent extension 117 The leg 113 of the V-shaped strip 112 adjacent to the V-shaped strip 112 without the extension 117 protrudes at a distance from the adjacent V-shaped strip 112 .
2. Pump according to claim 1, wherein the letter-shaped strip 112 and the mutually opposite end faces of the discs 71, 72 or 73 form a conveying channel 10 with a rectangular cross section. 6. An extension 117 of one leg 114 of the V-shaped strip 112 is bent in an arc to form an apex 116 which deflects the liquid inwardly in radial direction. Pumps listed in section. 7. The conveying passage 10 rotates close to the casing 4 of the pump 3 and has an opening 111 with a small inner diameter in a range where the liquid is deflected inward when viewed in the radial direction. pump. 8 The rotor 7 is composed of three discs 77, 78, 79, the central disc 78 is connected to the other two outer discs in order to form a passage 80 in which the liquid is deflected radially inward. Three disks 77, 78, 79, having a smaller diameter than the plates, are arranged on one of the end faces facing each other and have a conveying channel 1 between them.
both outer disks 77, held at a distance from each other via strips forming 0, 12, 14;
The pump according to claim 1, wherein the pumps 79 are sealed from each other at the outer periphery by a sealing member. 9. Pump according to claim 8, in which the sealing between the two outer discs 77, 79 is achieved by a removable sealing ring 81. 10 The sealing ring 81 is made of an elastic material and is adapted to automatically separate from the outer periphery of both outer discs 77, 79 when the pressure in the passage 80 reaches a predetermined value. A pump according to range item 9.