EP0138927A1

EP0138927A1 - Piston pump for liquid media contaminated by solid materials.

Info

Publication number: EP0138927A1
Application number: EP84901346A
Authority: EP
Inventors: Ernst Korthaus
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-04-06
Filing date: 1984-04-03
Publication date: 1985-05-02
Also published as: DE3465761D1; DE3410943A1; US4664606A; IT1175827B; EP0138927B1; WO1984003913A1; IT8420404A0; AU2810784A

Abstract

Pompe à piston pour milieux liquides, notamment pour milieux contaminés par des matières solides. Dans le but d'avoir une pompe de ce type qui soit autonettoyante, on propose de placer la chambre d'aspiration (7), le cylindre de pompe (2) et la chambre de pression (8) l'un à côté de l'autre dans le même plan horizontal ou légèrement incliné, de placer les soupapes de non-retour (9, 10, 11, 12) l'une à côté de l'autre dans le même plan horizontal ou légèrement incliné et de faire déboucher le raccord de refoulement (20) sur la face inférieure de la chambre de pression. De plus, le raccord d'aspiration (19) débouche verticalement ou au moins approximativement verticalement à partir du fond de la chambre d'aspiration. De cette manière on obtient un parcours du liquide dans la pompe essentiellement horizontal ou légèrement montant, de façon que les matières solides qui arrivent dans le carter de la pompe soient à nouveau évacuées de la pompe.Piston pump for liquid media, especially for media contaminated with solids. In order to have a pump of this type which is self-cleaning, it is proposed to place the suction chamber (7), the pump cylinder (2) and the pressure chamber (8) one next to the '' in the same horizontal or slightly inclined plane, place the non-return valves (9, 10, 11, 12) next to each other in the same horizontal or slightly inclined plane and clear the discharge connection (20) on the underside of the pressure chamber. In addition, the suction fitting (19) opens vertically or at least approximately vertically from the bottom of the suction chamber. In this way, a substantially horizontal or slightly rising path of the liquid in the pump is obtained, so that the solid matter which arrives in the pump casing is again removed from the pump.

Description

Piston pump for liquid media, especially for media contaminated by solids

The invention relates to a piston pump for liquid

Media, in particular for media contaminated by solids, with a pump piston which can be pushed back and forth in a pump cylinder, to the interior of which, with the interposition of opposing check valves, a suction chamber having the suction port of the piston pump and a pressure chamber with the pressure port of the piston pump are connected.

In the case of piston pumps of the type mentioned which are known from the prior art, the pressure chamber is generally arranged above the pump cylinder. In particular, the check valves (pressure valves) assigned to the pressure chamber are always arranged at the highest point of the interior. In addition, the pressure port on the pressure chamber usually opens above the pump cylinder out. This design was previously considered mandatory because it can prevent air bubbles from remaining inside the pump. The air bubbles emerging or directly sucked in from the sucked-in liquid cannot collect in the pump housing, but are discharged through the higher pressure valves. In this way, in the event of counterpressure, the danger should be countered that the piston pump compresses the air drawn in without performing any pumping work.

A disadvantage of the known piston pumps of the type mentioned, however, is that they are relatively easily clogged by solid particles carried in the liquid to be pumped. This is particularly disadvantageous when dirty media, e.g. Dirty water on construction sites or the like should be promoted. The solid particles get relatively easily through the intake valves with the intake flow and then remain in the space between the intake valves and the pressure valves because they cannot follow the rapidly increasing delivery flow. This applies in particular to those solid parts that are specifically significantly heavier than the pumped medium, e.g. stones, sand or the like contained in the dirty water. For this reason, the piston pumps mentioned above

Typically built into the suction line separator for stones or other coarse dirt. However, such stone separators easily clog, for example due to leaves or the like floating in the dirty water, and cannot hold back small stones or solid particles which can also clog the pump. In contrast, it would be better to design the piston pump to be self-cleaning, so that blockages caused by solid particles carried along cannot occur. It is therefore an object of the invention to further develop the piston pump of the type mentioned at the outset such that solid parts carried in the conveying medium and which have passed through the suction valve are reliably discharged from the pump via the pressure valves, the pressure chamber and the pressure nozzle.

To achieve this object, the invention proposes, starting from a piston pump of the type mentioned, that the suction chamber, the pump cylinder and the pressure chamber are arranged side by side in a horizontal or only slightly inclined plane, that the check valves are arranged next to one another in the same horizontal or slightly inclined plane and that the pressure port opens at the bottom of the pressure chamber.

In the piston pump according to the invention, the medium flows through the paths through the suction chamber to the suction valve, from the suction valve to the delivery cylinder, from the delivery cylinder to the pressure valve and through the pressure chamber to the pressure port, essentially horizontal or only gently rising delivery paths, so that it is ensured that the solid parts be conveyed on the floor of the horizontal conveying paths on a rolling or sliding basis. Even if solid parts with a particularly high specific weight should be deposited on the bottom of the conveying path, the conveying capacity and the self-cleaning ability of the piston pump according to the invention are not impaired because the flow rate increases due to the narrowing of the conveying paths due to the deposition, so that at least the solid parts subsequently entering the pump are entrained on the horizontal conveying paths and thus a complete one

Blockage of the pump is impossible. Air bubbles can form in the pump cylinder of the piston pump according to the invention only above the upper edge of the pressure valve. Appropriate design measures can therefore be taken to keep the air bubble that is formed as a function of the maximum possible back pressure so small that it is not possible to suspend the liquid delivery by compressing and expanding the air bubble in the pump cylinder.

A preferred embodiment of the piston pump according to the invention provides that the pressure port extends from the underside of the pressure chamber to its top and is provided in the area of the top with a small cross-section vent opening opening into the pressure chamber. In this embodiment of the piston pump, the vent opening at the top of the pressure chamber prevents air from accumulating in the pressure chamber, which could enter the pump cylinder due to leaks in the pressure valves. The pressure port naturally has a cross-section that is smaller or at least not larger than that of the suction port, so that, despite the increasing conveying path, proper removal of solids sucked in and conveyed by the pump is guaranteed.

An alternative embodiment provides that the pressure port runs from the bottom of the pressure chamber falling, horizontally or slightly rising and the pressure chamber at the top with a

Vent valve is provided. In this embodiment of the piston pump, the vent valve ensures that the air is removed from the pressure chamber. Because the pressure port runs horizontally, falling or at least only slightly rising, the solids contained in the medium are conveyed away even better. An advantageous V / eiterb ildung the piston pump according to the invention provides that the suction port opens into the suction chamber from below vertically or at least rising steeply. In this way it is ensured that such solid parts are retained in front of the suction chamber, the sinking speed of which is greater than the flow rate of the conveying medium due to a particularly high specific weight. With solid parts that have passed the vertically or steeply rising intake manifold, it can be assumed that they will then easily pass the horizontal or only gently rising delivery paths in the piston pump.

In order to avoid that floating solids, such as sheets, threads or the like floating in the pumped medium, get stuck in the area of the check valves of the pump, it is further provided that the check valves are designed as diaphragm valves with an uninterrupted circular cross section, the membrane of which is on the outside Has a rigid bulge which lies against the valve seat, is bulged in a ring shape in the direction of pressure and is attached centrally to a fixed holding shaft. Membrane valves designed in this way have a particularly large stroke and accordingly release large through-flow cross sections without the valve body needing any supporting webs or support grids constricting the through-flow cross section. The diaphragm, which bulges out in the direction of pressure in connection with the stiff bead, makes the diaphragm valve also suitable for relatively high pressures. The middle held by the holding shaft and externally connected to the rigid bead, pre-shaped in the pressure direction domed membrane causes the pressure load on the

Valve according to membrane theory, d. H. is absorbed by tensile stresses, but not by bending stresses. Since elastic materials can absorb much stronger tensile stresses than bending stresses, it is possible to make the membrane relatively thin, so that it can be easily bent back when the valve is opened and opens a large opening cross-section, and yet can absorb high liquid pressures in the closed position.

The diaphragm and the bead of the check valves are expediently made of rubber-elastic material, a steel ring being incorporated into the bead at higher liquid pressures. As a result, the bead can have a relatively small cross section with great rigidity, so that only small mass forces occur when the valve is actuated. The built-in steel ring prevents the bead from folding under the influence of the tensile forces of the membrane attacking it at one point on the circumference and in this way making the valve leaky.

In order to be able to easily clean the pump housing and the check valves if necessary, the check valves are fastened to housing covers of the pump housing, which are detachably connected to the pump housing. Suitable detachable fasteners can be used for the releasable fastening of the housing cover, so that the valves and the interior of the pump are accessible in a few simple steps.

In order to avoid dead spaces in the conveying path to the pressure chamber, the housing covers assigned to the check valves of the pressure chamber with filler pieces are expedient see that fill the dead corners in the supply channels of the pressure chamber in front of these check valves and form run-up ramps that extend to the level of the lower edge of the valve passage. These filler pieces fill out the dead spaces in which solid particles could accumulate and, in addition, direct the solid parts rolling or sliding on the bottom of the conveying path to the pressure valve so that they can pass the pressure valve without obstruction.

An embodiment of the invention is explained below with reference to the drawing. Show it:

Fig. 1 shows a vertical section through a

Piston pump according to the invention in a first embodiment along the line A - B in Fig. 2, Fig. 2 shows a horizontal section through the piston pump shown in Fig. 1 along the line C - D in Fig. 1, Fig. 3 shows a horizontal section 4 shows a vertical section through a piston pump according to the invention in a second embodiment along the line EF in FIG. 5,

5 shows a horizontal section through the piston pump shown in FIG. 4 along the line G - H in FIG. 4.

In the drawing, the pump housing is designated in its entirety by reference number 1. A pump cylinder 2 is arranged in the pump housing 1, in the interior of which a double-acting pump piston 3 is arranged so that it can be pushed back and forth. The pump piston 3 is connected to a piston rod 4, for example with a pump drive, not shown a driving hydraulic cylinder or a crank mechanism is connected. A suction chamber 7 and a pressure chamber 8 are connected to the interior of the pump cylinder 2 via narrow connecting channels 5 and 6 and, like the pump cylinder 2, are located next to one another in the horizontal plane in the pump housing 1. The connecting duct 5 is connected to the part of the interior of the pump cylinder 2 facing the full surface of the pump piston 3, while the connecting duct 6 is connected to the part of the interior of the pump cylinder 2 facing the annular surface of the pump piston 3. In the connecting channels 5 and 6 there are check valves 9 and 10 assigned to the suction chamber 7, which allow the flow of the medium from the suction chamber 7 into the connecting channels 5 and 6, and a backflow of the medium from the connecting channels 5 and 6 into the suction chamber 7 prevent however. In the same way, non-return valves 11 and 12 are assigned to the pressure chamber 8, which allow the flow of the delivery medium from the connecting channels 5 and 5 into the pressure chamber 8, but prevent a backflow of the delivery medium from the pressure chamber 8 into the connection channels 5 and 6, respectively.

The check valves 9, 10, 11 and 12 are each located on housing covers 13, 14, 15 and 16, which are detachably connected to the pump housing 1. The connection between the housing covers 13, 14, 15, 16 and the housing 1 is made by screws or by suitable ones

Quick fasteners. The housing covers 15 and 16 assigned to the pressure chamber 8 are each provided with filler pieces 17 and 18 which fill the dead corners in the connecting channels 5 and 6 to the pressure chamber 8 and form sliding ramps which extend to the level of the lower edges of the valve passage of the check valves 12 or 13 are enough. At the bottom of the suction chamber 7 a vertically opening intake 19 is connected from below. In the exemplary embodiment according to FIGS. 1 and 2, on the pressure chamber 8 there is a horizontally opening pressure connection 20 at the bottom at the side. In addition, in this exemplary embodiment, a vent valve 21 is provided on the upper side of the pressure chamber 8.

As can be seen from the drawing, the pump cylinder 2, the suction chamber 7, the pressure chamber 8, the connecting channels 5 and 6 and all check valves 9, 1o, 11, 12 are arranged in the same horizontal plane, so that they are vertical within the pump housing behind the arranged intake manifold 19 result in essentially horizontal conveying paths, which enable self-cleaning of the pump in the manner described.

The check valve 9 is shown enlarged in detail in FIG. 3. Like the other check valves 1o, 11 and 12, this check valve 9 has a curved diaphragm 3o made of rubber-elastic material, which is fastened in the middle to a holding shaft 31. On the outer circumference, the membrane 3o is provided with a rigid bead 32 made of rubber-elastic material, into which a steel ring 33 serving for stiffening is incorporated. In the closed position of the valve, the bead 32 bears against an annular valve seat 34 of the pump housing 1 and, in the open position, lifts off from this valve seat 34 over the entire circumference.

The membrane 3o is curved in a ring shape in the pressure direction, such that the membrane fixed on the one hand on the bead 32 and on the other hand on the holding shaft 31 3o the pressure load according to the membrane theory can only be absorbed by tensile stresses. In the event of the reverse action, the bead 32, on the other hand, can easily be lifted off the valve seat 34 by bending the membrane 3o and releases a large passage cross section which is not restricted by any supporting webs or the like.

The holding shaft 31 is fastened to the housing cover 13, which in turn is connected to the pump housing 1. As can be seen, the entire check valve 9 can be removed in a simple manner by simply removing the housing cover 13.

The check valve 10 is constructed in the same way as the check valve 9. The check valves 11 and 12 are constructed in principle in the same way as the check valve 9 shown in detail in FIG. 3, but because they are assigned to the pressure chamber 8 they have a reverse direction of action. So that these check valves 11 and 12 can also be easily removed, there the valve seats 34 are connected to the housing covers 15 and 16 and are removed together with them, so that the bulge in the pressure chamber 8 cannot hinder the expansion of the check valve.

In Fig. 1 is finally indicated that the air bubble forming in the pump housing 1 can only extend to the upper edge of the valve passage of the check valves associated with the pressure chamber 11 and 12. The resulting air-filled space in the connecting channels 5 and 6 and in the pump cylinder 2 is so small that it cannot interfere with the proper functioning of the pump. (M aaaa -O 01 01 o: Φ a <a ω 3 <α HJ F- <<G

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Claims

1. Piston pump for liquid media, in particular for media contaminated by solids, with a pump piston which can be pushed back and forth in a pump cylinder, on the interior of which, with the interposition of counter-rotating check valves, a suction chamber having the suction nozzle of the piston pump and the pressure nozzle of the piston pump Pressure chamber are connected, characterized in that the suction chamber (7), the pump cylinder (2) and the pressure chamber (8) are arranged side by side in a horizontal or only slightly inclined plane, that the check valves (9,1o, 11,12) in the same horizontal or slightly inclined plane are arranged side by side and that the pressure port (2o, 22) opens out on the underside of the pressure chamber (8).

2. Piston pump according to claim 1, characterized in that the pressure port (23) from the underside of the pressure chamber (8) extends up to its top and in the region of the top with a vent opening (23) opening into the pressure chamber (8) of small cross-section is provided.

3. Piston pump according to claim 1, characterized in that the pressure port (2o) from the bottom of the pressure chamber (8) is falling, horizontal or slightly rising and the pressure chamber (8) is provided on the top with a vent valve (21).

4. Piston pump according to one of claims 1 to 3, characterized in that the suction nozzle (19) opens into the suction chamber (7) from below vertically or at least rising steeply.

5. Piston pump according to one of claims 1 to 4, characterized in that the check valves (9, 1o, 11, 12) are designed as diaphragm valves with an uninterrupted annular cross section, the diaphragm (3o) of which is rigid on the outer circumference and adheres to the Has bead (32) bearing valve seat (34), is bulged in a ring shape in the direction of pressure and is fastened in the center to a fixed holding shaft (31).

Piston pump according to claim 5, characterized in that the diaphragm (3o) and the bulge (32) of each check valve (9,1o, 11,12) consist of rubber-elastic material, a steel ring (33) being worked into the bulge (32) is.

7. Piston pump according to claims 5 to 6, characterized in that the

Check valves (9, 01, 11, 12) are attached to housing covers (13, 14, 15, 16) of the pump housing (1), which are detachably connected to the pump housing (1).

8. Piston pump according to claim 7, characterized in that the check valves (11, 12) of the pressure chamber (8) assigned to the housing cover (15, 16) are provided with filler pieces (17, 18) which are in front of these check valves (11, 12). fill in the dead corners in the connecting channels (5, 6) to the pressure chamber (8) and form sliding ramps that extend to the level of the lower edge of the valve passage of the check valves (11, 12).