EP0162157B1 - Compresseur volumétrique à vis comportant un tiroir - Google Patents

Compresseur volumétrique à vis comportant un tiroir Download PDF

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Publication number
EP0162157B1
EP0162157B1 EP19840303436 EP84303436A EP0162157B1 EP 0162157 B1 EP0162157 B1 EP 0162157B1 EP 19840303436 EP19840303436 EP 19840303436 EP 84303436 A EP84303436 A EP 84303436A EP 0162157 B1 EP0162157 B1 EP 0162157B1
Authority
EP
European Patent Office
Prior art keywords
der
slide valve
des
steuerschieber
schraubenkompressor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19840303436
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German (de)
English (en)
Other versions
EP0162157A1 (fr
Inventor
Shoji Yoshimura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kobe Steel Ltd
Original Assignee
Kobe Steel Ltd
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Filing date
Publication date
Application filed by Kobe Steel Ltd filed Critical Kobe Steel Ltd
Priority to DE8484303436T priority Critical patent/DE3473326D1/de
Priority to EP19840303436 priority patent/EP0162157B1/fr
Publication of EP0162157A1 publication Critical patent/EP0162157A1/fr
Application granted granted Critical
Publication of EP0162157B1 publication Critical patent/EP0162157B1/fr
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/10—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by changing the positions of the inlet or outlet openings with respect to the working chamber
    • F04C28/12—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by changing the positions of the inlet or outlet openings with respect to the working chamber using sliding valves
    • F04C28/125—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by changing the positions of the inlet or outlet openings with respect to the working chamber using sliding valves with sliding valves controlled by the use of fluid other than the working fluid

Definitions

  • the present invention relates to a compressor incorporating a slide valve. Discussion of Prior Art
  • a screw compressor is generally provided with a pair of male and female screw rotors 5 and 6 (hereinafter referred to simply as "rotors" for brevity) which are rotatable in meshed state within a compression chamber 8 in a casing 7.
  • rotors screw rotors
  • One end face of the compression chamber 8 is partly cut away at a position corresponding to tooth grooves of the rotors 5 and 6 to provide an opening 10 (an axial port) in communication with a suction port 11 through a suction casing 7a.
  • the other end face is similarly provided with an opening, although different in shape, for communication with a discharge port 12.
  • a longitudinal slot in communication with the suction port 11, which mounts a slide valve 31 (of a length L,) which is slidable in the axial direction of the rotors.
  • the slide valve 31 is provided with curved surfaces each of an arcuate shape in section which form part of the inner wall surface of the compression chamber 8, and its forward movement (leftwards in Figure 1) is limited by a fixed stop 31 a which is located in a forward position.
  • the conventional slide valve 31 has the end face 33 on the side of the suction port formed by a flat surface which is disposed perpendicular to the sliding direction, so that it has been difficult to preclude an abrupt and discontinuous variation in the volume of a closed space (hereinafter referred to simply as "suction volume" for brevity) at an initial closing point even if the radial port 13 is opened little by little in the initial stage of a volumetric control.
  • Figure 5 shows at (a) to (f) varying conditions at the end of the compression chamber on the side of the suction port 11 in relation with rotation of the rotors.
  • the rotors 5 and 6 are rotated in the arrowed directions, gradually compressing a closed space 14 which is indicated by a hatched area.
  • the closed space 14 is the one which is formed when the aforementioned radial port 13 is in closed state (so that the latter does not appear in Figure 5), and, for simplification of explanation, there is shown a case where the width W of a lower projection 18 which forms the opening 10 in the end 5 face 17 or which closes the ends of the screw root ends of the rotors 5 and 6 is equal to the width w of the curved surfaces 2 of the slide valve 31 (see Fig. 2).
  • FIG. 6 Shown at (a) to (f) of Figure 6 are developed views of sections taken along line X-X of Figure 5, which correspond to phases (a) to (f) of Figure 5.
  • an end face 33 of the slide valve 31 is positioned on the side of the suction port 11 and outside the compression chamber 8, closing the radial port 13 with the curved surfaces 2.
  • the hatched areas in Figure 6 indicate a closed space 14 corresponding to the hatched areas in Figure 5, which is gradually shifted upward from phase (a) to (f) of Figure 6.
  • the closed space 14 reaches an end face 19 on the discharge side and the end of the discharging side is closed while the end face 19 is rotated through a predetermined angle, so that the volume of the closed space 14 is reduced to compress the gas gradually from phase (a) to (f) of Figure 6.
  • the slide valve 31 is shown in a position which is slightly moved from that of Figure 6 with its end face 31 located a little closer to the discharging side (the upper side in the figure) than the end face 17 of the compression chamber 8, with the radial port 13 in a slightly opened state, illustrating variations of the closed space in this position from phase (a) to (f) corresponding to the phases shown in Figure 6.
  • a portion corresponding to the closed space 14 is in communication with the suction port 11 through the radial port 13 as indicated by a dotted area in phases (a) to (d) of Figure 7, so that it is only in and after phase (e) that a closed space 15 is formed as indicated by a hatched area.
  • the lowermost point M (a closing point) of a V-shaped hatched area, at which the male and female rotors 5 and 6 contact with each other, is gradually shifted inward across the end face 17 of the compression chamber 8 and it is only when the closing point M reaches the end face 33 of the slide valve 31 that a closed space 15 is formed.
  • the suction volume corresponds to the closed space 14 in phase (a) in the position of Figure 6 and to the closed space 15 in phase (e) in the position of Figure 7.
  • the suction volume is abruptly and discontinuously varied or stepwise from the volume in phase (a) of Figure 6 to the volume in phase (e) of Figure 7 (same as that of the closed space in phase (e) of Figure 6) upon opening the radial port 13 only to a slight degree.
  • the suction volume is varied as indicated by curve II of Figure 8, in which the horizontal axis represents a distance 1 of displacement of the slide valve 31, namely, the distance between the end faces 17 and 33 in the particular embodiment shown, and the vertical axis represents the rate (%) of the suction volume at various distances 1 of displacement to the suction volume in the state shown in Figures 5 and 6 (a state in which the radial port 13 is closed).
  • curve II consists of a vertical portion AB and an inclined portion BC.
  • the point B represents a state in which opening of the radial port 13 has just been initiated or when the distance in phase (e) of Figure 7 is infinitesimal
  • the point C represents a state in which the radial port 13 has been further widened continually.
  • the curve II is varied discontinuously from point A to B.
  • a slide valve type screw compressor of the type generally shown in Figures 1 to 8 above is illustrated in French patent specification 2279951, but in addition to the above described features, this French specification shows a compressor in which the slide valve includes a part which is retractably protrudable into the suction casing. (See Figure 1).
  • the present invention has as its object the provision of a slide valve type screw compressor which can vary a suction volume theoretically in a continuous manner throughout a range of volumetric control including an initial point of the control no matter whether or not the compressing gas is a light (less dense) gas.
  • a slide valve type screw compressor having a slide valve with a generally chevron-shape transverse cross section consisting of a pair of arcuately curved surfaces forming part of the wall of a compression chamber which compression chamber accommodates a pair of intermeshed male and female screw rotors, said slide valve being slidable in the axial direction of said rotors for communicating said compression chamber with a suction port through an opening with an adjustably variable area for volumetric control of said compressor, and the fore end of said slide valve is retractably protrudable into a suction casing disposed on the side of said suction port characterised in that the opposite outer corner portions of the fore end of said curved surfaces of the slide valve are chamfered at a predetermined angle to the axis whereby the fore end of the curved surfaces of the slide valve is generally wedge shaped with an apex of the wedge facing forwards.
  • FIG. 9 there is shown a screw compressor slide valve 1 (with a length L 08) according to the present invention, which is substantially the same as the slide valve 31 of Figures 3 and 4 in construction except for its shape of the end face 33 on the suction side.
  • the slide valve 1 is provided with a surface of chevron shape in section consisting of arcuately curved surfaces 2 formed on opposite sides of an apex 26, which constitute part of the wall of the compression chamber 8 as stated hereinbefore, and has end faces 3 on the suction side shaped such that the lines of intersection 4 with the curved surfaces 2 are inclined in the direction of screw threads of rotors 5 and 6 to form a wedge shape fore end.
  • the slide valve 1 is received in a suction casing 7a which is provided with a stopper 23 to permit the valve end on the suction side (or the fore end of the valve) to protrude retractably into the suction casing 7a.
  • Figure 11 shows a screw compressor incorporating the slide valve according to the invention, which is the same in construction as the screw compressor of Figures 1 and 2 except that the slide valve 1 and stopper 23 are employed in place of the slide valve 31 and fixed valve 31 a, respectively.
  • the component parts which are common to the example shown in Figures 1 and 2 are designated by common reference numerals, and their description is omitted to avoid unnecessary repetitions.
  • the reference numeral of the slide valve 1 is indicated in brackets in Figure 2 so that the latter can serve also as a side view of the compressor of Figure 11.
  • the lines of intersection 4 are inclined in the direction of screw threads of rotors 5 and 6, so that each intersecting line 4 is disposed parallel with a line 22 of a screw thread (which comes out in a straight line in a developed view). Consequently, as the slide valve 1 is gradually shifted upward in Figure 12, a radial port 13 is opened on the opposite sides of the slide valve 1 in a manner similar to the rotor grooves which are moving toward the centre (in the direction of arrows V) on the end face 17.
  • Figures 13(a) to 13(c) Shown in Figures 13(a) to 13(c) is an example of the varying condition of the radial port 13, which is observed, for instance, when the slide valve 1 alone is moved upward in the state of Figure 12(c).
  • the radial port 13 is in fully closed state and does not appear in Figure 13(a), but it is gradually widened from Figure 13(b) to 13(c). Consequently, the closed space 16 of Figures 13(a) and 13(b) is uncovered in Figure 13(c), resuming a state prior to dosing.
  • the volume of the closed 16 space (or the suction volume) in phase (b) of Figure 12 at the initial closing point can be adjusted to approach the volume of the closed space 14 in phase (a) of Figures 5 and 6 (the maximum suction volume) by minimising the radial ports 13. That is to say, as the slide valve 1 is shifted upward in the drawing from the fully closed position to open the radial ports 13, the suction volume is continuously reduced from the maximum value at the fully closed position (the value in phase (a) of Figures 5 and 6).
  • width w of the curved surface 2 of the slide valve 1 is shown and described as being equal to the width W of the lower projection 18 on the end face 17, the invention is not limited to this particular arrangement and can produce similar effects, for example, in a case where w > W except for a change in the initial position of the slide valve 1 for the volumetric control. On the contrary, in a case where w ⁇ W, there occurs a slight discontinuous variation at an initial point of the volumetric control but it is far smaller than the discontinuous variation from point A to B of Figure 8.
  • the fore end portion as a whole of the slide valve 1 is shaped in an inclined form in the foregoing embodiment with the lines of intersection 4 of the end face 3 disposed in the direction of screw threads of the rotors 5 and 6.
  • the corner portions of the curved surfaces 2 on the side of the suction port may be partly cut off, or the intersecting lines 4 may be disposed in the same direction at an angle different from the lead angle of the screw threads of the rotors. In such a case, similarly a slight discontinuous variation occurs to the suction volume.
  • the cutting angle 13 (beta) of the end face 3 of predetermined angle is greater than the lead angle (a) of the screw threads of said rotors (5, 6).

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Rotary Pumps (AREA)

Claims (6)

1. Compresseur àvis du type àtiroir comportant un tiroir (1) ayant en section transversale une forme générale en chevrons, consistant en deux surfaces incurvées formant une partie de la paroi d'une chambre de compression (8), cette chambre de compression logeant deux rotors a vis mâle et femelle (5, 6) engrenant, ledit tiroir (1) pouvant coulisser dans la direction axiale desdits rotors (5, 6) pour faire communiquer ladite chambre de compression (8) avec un orifice d'aspiration (11) à travers un orifice (13) avec une aire variable de façon réglable pour une commande volumétrique dudit compresseur, et l'extrémité avant dudit tiroir (1) peut faire saillie de façon rétractable dans un carter d'aspiration (7a) disposé sur le côté dudit orifice d'aspiration (11), caractérise en ce que les parties (4) d'angles externes opposés de l'extrémité avant des surfaces incurvées (2) du tiroir (1) sont chanfreinées suivant un angle prédeterminé par rapport à l'axe, grâce à quoi l'extrémité avant des surfaces incurvées (2) du tiroir présente dans son ensemble une forme en coin avec un sommet (26) du coin dirigé vers l'avant.
2. Compresseur à vis du type à tiroir suivant la revendication 1, caractérise en ce que ledit angle prédétermine est plus grand que l'angle avant (33) des filets desdits rotors (5, 6.
3. Compresseur à vis du type à tiroir suivant la revendication 1, caractérisé en ce que lesdites parties d'angles (4) opposees à ladite extremite avant des surfaces incurvées (2) sont chanfreinées suivant des lignes en zig-zag.
4. Compresseur à vis du type à tiroir suivant la revendication 1, caractérisé en ce que lesdits parties d'angles (4) opposées à ladite extrémite avant desdites surfaces incurvées (2) sont chanfreinées jusqu'a un niveau situé à mi-distance de l'épaisseur dudit tiroir (1).
5. Compresseur à vis du type à tiroir suivant la revendication 1, caractérise en ce que ledit tiroir (1) comporte un prolongement avant sur l'avant de ladite section en coin.
6. Compresseur à vis de type à tiroir suivant la the slide valve 1 is determined depending upon the controllability of a compressing gas and the structural factors of the compressor. Where especially a higher controllability is required, a cutting angle β beta greater than a lead angle (alpha) of the rotor screws is employed as shown particularly in Figure 26.
The end faces 3 of the slide valve 1 which are inclined as a whole in the direction of the screw threads of the rotors 5 and 6 in the foregoing embodiment may be formed in other shapes as exemplified in Figure 14 and onwards wherein the component parts common to the foregoing embodiment are designated by common reference numerals.
In a modification shown in Figures 14 and 15, the slide valve 1A has intersecting lines 4 common to the above-described valve body 1 but it is provided with end faces which are cut obliquely from the intersecting lines 4 with a suitable gradient to present substantially a shape of trigonal pyramid, instead of the vertically cut end faces.
Referring to Figures 16 and 17, there is shown a modification wherein the slide valve 1 B has intersecting lines 4 common to the slide valve 1 but it is provided with vertically cut end faces 3 which are terminated at a halfway level to the bottom side of the valve body. According to the present invention, the apex 26 of the curved surfaces which form part of the rotor chamber is located closer to the suction port than the lateral corner portions 27, so that the shape of the fore extension 28 which contiguously extends beneath or forward (leftward in the drawing) ofthe end faces 3 is determined according to the shape of the suction casing 7a or the kind of gas to be handled.
Accordingly, the front portion of the fore extension 28 may have the same sectional shape as the body of the slide valve 1 B (except its cut portions) as seen in a modification shown in Figures 18 and 19. In this case, a groove 29 of substantially V-shape is cut on the upper side of the body of a slide valve 1 C of a length slightly greater than the length L2 indicated in Figure 11, and, as shown in Figures 18 and 19, the slide valve 1C is provided with curved surfaces 2 the same as those on the slide valve 1 and, integrally on the front side of the V-cut groove 29, a fore extension 28 which has the same sectional shape as the body of the slide valve 1C as indicated in phantom. In Figures 18 and 19, in order to distinguish the curved surfaces 2 from the fore extension 28, they are indicated by solid and chain lines, respectively.
Referring to Figures 20 and 21, there is shown a further modification employing a slide valve 1D which is inclined in the directions of screw threads only in the outer edge portions of the end faces 3.
Shown in Figures 22 to 25 are slide valves 1 E to 1 F which have the intersecting lines 4 formed in a zigzag fashion and inclined as a whole in the direction of the screw threads.
Although the end faces 3, more particularly, the intersecting lines 4 are inclined to conform with the directions of screw threads of the rotors in the foregoing embodiments, it is not always required to conform the angle of inclination with the screw threads as long as the apex 26 of the curved surfaces 2 is located closer to the suction end of the rotor chamber than the outer corner portions 27. In a case where the angle of inclination does not conform with the directions of screw threads, a slight discontinuous variation occurs to the suction volume as mentioned hereinbefore in connection with the relationship between widths w and W.
Further, the curved surfaces 2 are not neces- sarily required to be disposed symmetrically on the opposite sides of the longitudinal axis of the slide valve 1 (or any of the slide valves 1A to 1F). When the slide valve 1 is located eccentrically relative to the compression chamber 8, the apex 26 is positioned off the centre axis of the compression chamber.
As is clear from the foregoing description, the slide valve according to the present invention has outer corner portions of upper curved surfaces cut off, so that, when applied to a slide valve type screw compressor, it can control the suction volume of the compressor in such a manner as to open a radial port at or in the vicinity of a position at which a closed space is initially formed, broadening the radial port in the direction in which the closed space is moved by rotation of the rotors. Consequently, upon shifting the slide valve in an increasing degree, the suction volume of the compressor can be continuously reduced correspondingly. Thus, the present invention makes it possible to perform a smooth and continuous volumetric control from an initial stage even when the compressing gas is a light gas like hydrogen and helium gases.
EP19840303436 1984-05-21 1984-05-21 Compresseur volumétrique à vis comportant un tiroir Expired EP0162157B1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
DE8484303436T DE3473326D1 (en) 1984-05-21 1984-05-21 A screw compressor incorporating a slide valve
EP19840303436 EP0162157B1 (fr) 1984-05-21 1984-05-21 Compresseur volumétrique à vis comportant un tiroir

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19840303436 EP0162157B1 (fr) 1984-05-21 1984-05-21 Compresseur volumétrique à vis comportant un tiroir

Publications (2)

Publication Number Publication Date
EP0162157A1 EP0162157A1 (fr) 1985-11-27
EP0162157B1 true EP0162157B1 (fr) 1988-08-10

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EP19840303436 Expired EP0162157B1 (fr) 1984-05-21 1984-05-21 Compresseur volumétrique à vis comportant un tiroir

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EP (1) EP0162157B1 (fr)
DE (1) DE3473326D1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4007217A1 (de) * 1989-03-08 1990-09-13 Stal Refrigeration Ab Vorrichtung zur regelung des inneren volumenverhaeltnisses eines rotationskompressors

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5496388A (en) * 1994-07-01 1996-03-05 Air Liquide America Corporation System for compressing air and extracting nitrogen from compressed air
GB9702342D0 (en) 1997-02-05 1997-03-26 Rotary Power Couple Engines Li Rotary device
JP6385708B2 (ja) * 2014-04-18 2018-09-05 日立ジョンソンコントロールズ空調株式会社 スクリュー圧縮機
FR3034464B1 (fr) 2015-04-03 2017-03-24 Snecma Refroidissement du circuit d'huile d'une turbomachine

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1118800B (de) * 1959-06-04 1961-12-07 Svenska Rotor Maskiner Ab Einrichtung zur Umkehr der Drehrichtung einer als Expansionsmaschine arbeitenden Schraubenradmaschine
FR1258651A (fr) * 1960-06-01 1961-04-14 Svenska Rotor Maskiner Ab Dispositif de réglage pour machines à rotors en hélice
US3936239A (en) * 1974-07-26 1976-02-03 Dunham-Bush, Inc. Undercompression and overcompression free helical screw rotary compressor
DE3221849A1 (de) * 1982-06-09 1983-12-15 Aerzener Maschinenfabrik Gmbh, 3251 Aerzen Schraubenverdichter

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4007217A1 (de) * 1989-03-08 1990-09-13 Stal Refrigeration Ab Vorrichtung zur regelung des inneren volumenverhaeltnisses eines rotationskompressors
DE4007217C2 (de) * 1989-03-08 1999-08-05 Stal Refrigeration Ab Ventilvorrichtung zur Regelung des inneren Volumenverhältnisses eines Schraubenverdichters

Also Published As

Publication number Publication date
EP0162157A1 (fr) 1985-11-27
DE3473326D1 (en) 1988-09-15

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