JP5202512B2

JP5202512B2 - Piston pump for concentrated material

Info

Publication number: JP5202512B2
Application number: JP2009503453A
Authority: JP
Inventors: マティアスシュターベル
Original assignee: プッツマイスターゾリートプンプスゲーエムベーハー
Priority date: 2006-04-04
Filing date: 2007-03-23
Publication date: 2013-06-05
Anticipated expiration: 2027-03-23
Also published as: DE502007005346D1; EP2002121B1; EP2002121A1; DE102006016083A1; CA2647794A1; ATE484676T1; CN101410619A; US20100232996A1; JP2009532616A; WO2007115665A1

Abstract

The invention relates to a piston pump for thick matter, in particular for high-solids sewage sludge, coal sludge and concrete. The piston pump has at least one delivery cylinder (16) which contains a motor-driven or hydraulically driven delivery piston (20) and which has an orifice (12) which communicates alternately with the interior of a material feed container (10) and with a pressure delivery line (30) in a slide-controlled manner in accordance with the movement of the delivery piston (20). In order to significantly increase the degree of filling of the at least one delivery cylinder (16), an annular nozzle (32) opening into the delivery cylinder (16) in the region of the orifice (12) is provided, and this annular nozzle (32) is connected to an external pressure line (34) to which a lubricant can be admitted.

Description

本発明は、モータ駆動又は液圧駆動の供給ピストンを含む少なくとも１つの供給シリンダを有する濃厚物質（高粘性物質）用ピストンポンプに関している。上記供給シリンダは、材料充填容器の内部とプレッシャ供給ラインに交互に連通するオリフィス開口部を有している。上記オリフィス開口部は、供給ピストンの動きに応じてスライド制御される。 The present invention relates to a piston pump for dense substances (high viscosity substances) having at least one supply cylinder comprising a motor-driven or hydraulically driven supply piston. The supply cylinder has an orifice opening communicating alternately with the inside of the material filling container and the pressure supply line. The orifice opening is slide-controlled according to the movement of the supply piston.

この種のピストンポンプは、例えば下水汚泥、石炭スラリー、バイオマス又はコンクリートの様な固体の割合が多い固液混合物を搬送するために、使用される。そのような濃厚物質は大きな内部摩擦を有するので、吸引ストロークの間に供給シリンダの充填度は頻繁に所望されるものを残してしまう。他方でこの種のピストンポンプの場合、プレッシャ供給ラインの位置口で、壁面摩擦を減少するために、濃厚物質のストランドとプレッシャ供給ラインの壁の間に潤滑剤を導くことが公知である（特許文献１）。これは通常、連続して、また供給流れに比例し計量された量において行われ、パイプの内壁と濃厚物質ストランドの間に境界層が形成される結果となる。上記境界層によって、供給圧力は減少され得る。潤滑層が、供給区間に沿って徐々になくなるので、或る程度の間隔で追加の潤滑剤をプレッシャ供給ラインへ注入しなければならない。供給シリンダの充填程度を高めるために、材料充填容器の領域に予圧装置（プリプレッシング装置）を通常設けている。上記予圧装置を用いて、充填圧力を少なくとも１ｂａｒまで高めることができる。しかしながら多くの場合、これは十分ではない。 This type of piston pump is used for conveying solid-liquid mixtures with a high proportion of solids such as, for example, sewage sludge, coal slurry, biomass or concrete. Such concentrated materials have large internal friction, so that the filling degree of the supply cylinder frequently leaves what is desired during the suction stroke. On the other hand, in the case of this kind of piston pump, it is known to introduce a lubricant between the concentrated material strand and the pressure supply line wall in order to reduce wall friction at the position of the pressure supply line (patent) Reference 1). This is usually done continuously and in a metered quantity proportional to the feed flow, resulting in the formation of a boundary layer between the inner wall of the pipe and the dense material strand. With the boundary layer, the supply pressure can be reduced. As the lubricant layer gradually disappears along the supply section, additional lubricant must be injected into the pressure supply line at some interval. In order to increase the filling degree of the supply cylinder, a preloading device (prepressing device) is usually provided in the region of the material filling container. Using the preload device, the filling pressure can be increased to at least 1 bar. In many cases, however, this is not sufficient.

ＥＰ‐Ｂ‐６３３８６３EP-B-633863

本願発明の課題は、既知の濃厚物質用ピストンポンプを、濃厚物質内の固形物の割合が多い場合でも、供給シリンダ内の充填度を著しく高められるように改良する点を基礎としている。 The object of the present invention is based on the improvement of a known piston pump for concentrated substances so that the filling degree in the supply cylinder can be significantly increased even when the proportion of solids in the concentrated substance is high.

上記課題を解決するために、請求項１、２及び１０で挙げられる特徴構成の組み合わせが提案される。本発明の有利な実施形態及び更なる展開は従属請求項から明らかである。
本発明に従う解決策は主として、オリフィス開口部の領域内に、供給シリンダへ開口するリングノズルが配されるという着想に基づいており、上記リングノズルは外部のプレッシャラインと接続されており、それによって上記プレッシャラインは高圧ポンプを介して潤滑剤をリングノズルに充填させることができる。プレッシャラインが、供給シリンダのオリフィス領域に配された孔を介してリングノズルへ開口するリング流路と接続されていれば、有利である。 In order to solve the above-mentioned problems, combinations of characteristic configurations mentioned in claims 1 , 2 and 10 are proposed. Advantageous embodiments and further developments of the invention are evident from the dependent claims.
The solution according to the invention is mainly based on the idea that a ring nozzle opening into the supply cylinder is arranged in the region of the orifice opening, said ring nozzle being connected to an external pressure line, thereby The pressure line can fill the ring nozzle with lubricant through a high-pressure pump. It is advantageous if the pressure line is connected to a ring flow path which opens to the ring nozzle via a hole arranged in the orifice area of the supply cylinder.

本発明の好ましい構成上の実施形態では、外側でプレッシャラインと接続する少なくとも１つの孔を有する外側リングを供給シリンダが担持しており、リングノズルへ至るリング流路を有し、それによってリング流路は、内側で、供給シリンダの外表面又はそれに軸方向に続く内側リングの外表面によって、また外側で、外側リングの内表面によって、境界を画定されている。上述の内側リングが、内側に向かって開口する外側リングの凹みに係合し、このリングと共にリングノズルとリング流路の範囲を定めているならば、有用である。これに関連して、半径方向に張り出したリア頚部を備えた内側リングが互いに向き合う供給シリンダと外側リング体の２つのリング表面の間に挟み込まれて支えられていれば、有利である。 In a preferred structural embodiment of the invention, the supply cylinder carries an outer ring having at least one hole connected to the pressure line on the outside, and has a ring flow path to the ring nozzle, whereby the ring flow. The path is bounded on the inside by the outer surface of the supply cylinder or on the outer surface of the inner ring following it in the axial direction and on the outside by the inner surface of the outer ring. It is useful if the inner ring described above engages a recess in the outer ring that opens inward and defines a ring nozzle and ring flow path with this ring. In this connection, it is advantageous if an inner ring with a radially projecting rear neck is sandwiched and supported between two ring surfaces of the supply cylinder and the outer ring body facing each other.

周辺にわたって濃厚物質の均一な分布を保証するため、リング流路が少なくとも１つのリング形状横断面拡張部を有するのが有用である。互いに間隔をおいて配される２つのリング形状の横断面拡張部を設けていれば、有利である。 It is useful for the ring channel to have at least one ring-shaped cross-sectional extension in order to ensure a uniform distribution of the concentrated material over the periphery. It is advantageous if there are two ring-shaped cross-section extensions that are spaced apart from one another.

本発明の好ましい実施形態によれば、供給シリンダにおいて供給ピストンの位置及び／又はストローク方向に応じる制御装置と、当該制御装置の出力信号に応答しプレッシャラインに配された制御弁とが設けられている。制御弁は供給ピストンの吸引ストローク（工程）の間は開き、その押圧ストロークの前に閉じる。これに関連して、制御弁が好ましくは磁気的に、供給ピストンを介して制御可能である方向弁のように形成されているならば、有用である。 According to a preferred embodiment of the present invention, the supply cylinder is provided with a control device that responds to the position and / or stroke direction of the supply piston, and a control valve arranged in the pressure line in response to an output signal of the control device. Yes. The control valve opens during the suction stroke (process) of the supply piston and closes before the pressing stroke. In this connection, it is useful if the control valve is shaped like a directional valve that is preferably magnetically controllable via a supply piston.

本発明の好ましい実施形態では、そのオリフィス領域内に各々リングノズルを有する２つの供給シリンダが設けられ、そのリングノズルは、プッシュプル式あるいは逆向きサイクルで制御される供給ピストンの吸引ストロークの各々の間、制御弁を介して潤滑剤を充填することができる。 In a preferred embodiment of the invention, two supply cylinders, each having a ring nozzle in its orifice area, are provided, each ring nozzle having a suction stroke of each of the supply pistons controlled in a push-pull or reverse cycle. Meanwhile, the lubricant can be filled through the control valve.

本発明は更に、濃厚物質用のピストンポンプを駆動するための方法に関している。その場合、濃厚物質材料は、吸引ストロークの間一方の側で開いており引き続いての押圧ストロークの間供給シリンダから出てプレッシャ供給ラインに押し込まれる供給シリンダに、交互に引き込まれる。供給シリンダの充填度を著しく高めるために、本発明によれば、各々の吸引ストロークで潤滑剤を供給シリンダへ注入することが提案される。これに関連して、潤滑剤が濃厚物質材料と供給シリンダの内表面との間の分離領域へ注入されるならば、有利である。そのうちでもとりわけ、その全周にわたって注入されるのが有利である。潤滑剤のための引込みラインの意図しない空状態を避けるために、潤滑剤の注入は押圧ストロークの間中断されるならば、有用である。潤滑剤は、供給シリンダに配された濃厚物質の圧力よりも高圧で注入される。注入圧力が５０ｂａｒより大きく、特に約１００ｂａｒであるならば有用である一方、吸引ストロークの間の濃厚物質材料での予圧（プレプレッシング）圧力がおおよそ２ｂａｒであるならば有用である。 The invention further relates to a method for driving a piston pump for concentrated material. In that case, the concentrate material is alternately drawn into the supply cylinder which is open on one side during the suction stroke and exits the supply cylinder and is pushed into the pressure supply line during the subsequent pressing stroke. In order to significantly increase the filling degree of the supply cylinder, it is proposed according to the invention to inject lubricant into the supply cylinder at each suction stroke. In this connection, it is advantageous if the lubricant is injected into the separation region between the concentrate material and the inner surface of the supply cylinder. Among them, it is advantageous to inject all around. In order to avoid unintentional emptying of the pull-in line for the lubricant, it is useful if the lubricant injection is interrupted during the pressing stroke. The lubricant is injected at a pressure higher than the pressure of the concentrated material disposed in the supply cylinder. It is useful if the injection pressure is greater than 50 bar, in particular about 100 bar, while it is useful if the pre-pressing pressure on the concentrate material during the suction stroke is approximately 2 bar.

本発明の好ましい形態は以下のことを想定する。つまり、２シリンダ式ピストンポンプの場合、第１及び第２の供給シリンダにおけるピストンがプッシュプル方式で吸引ストロークと押圧ストロークを実行しながら駆動され、その際、それぞれ各吸引ストローク中は潤滑油が供給シリンダ内へ注入され、各押圧ストローク中は潤滑剤の注入が中断される。 The preferred embodiments of the present invention assume the following. That is, in the case of a two-cylinder type piston pump, the pistons in the first and second supply cylinders are driven while performing the suction stroke and the pressing stroke by the push-pull method, and at that time, lubricating oil is supplied during each suction stroke. It is injected into the cylinder and the injection of lubricant is interrupted during each pressing stroke.

本発明に係る措置を用いて、とりわけ固形分を多く含む濃厚物質の場合に、供給シリンダ内の充填度（充填程度）の際立った改善が達成される。更に、供給シリンダに生じる潤滑剤の膜（潤滑剤層）は、プレッシャ供給ラインへ取り込まれるので、濃厚物質ポンプに続く第１のライン部分において、追加的な潤滑剤の注入がもはや不要となる。５０〜１００ｍ、あるいはそれ以上の長さを有した長いプレッシャ供給ラインの場合にだけ、追加的な潤滑剤が濃厚物質ポンプから離れたところでプレッシャ供給ラインに注入され得る。潤滑剤が吸引ストロークの間のみ供給シリンダに注入される一方、プレッシャ供給ラインへの潤滑剤注入は連続して行われなければならない。 With the measures according to the invention, a marked improvement in the filling degree (filling degree) in the supply cylinder is achieved, in particular in the case of concentrated substances with a high solid content. In addition, the lubricant film (lubricant layer) generated in the supply cylinder is taken into the pressure supply line, so that no additional lubricant injection is required anymore in the first line part following the concentrate pump. Only in the case of a long pressure supply line having a length of 50-100 m or more, additional lubricant can be injected into the pressure supply line away from the concentrate pump. Lubricant is injected into the supply cylinder only during the suction stroke, while lubricant injection into the pressure supply line must be performed continuously.

以下において、本発明を、図面に概略的に示された例示的な実施形態を用いて、より詳細に説明する。
図１に概略的に示された２シリンダ濃厚物質ポンプは、例えば部分的に脱水された汚水処理スラッジ、コールダストスラッジ、又はコンクリートの様な固形物を多く含む濃厚物質を搬送することを予定している。 In the following, the present invention will be described in more detail using exemplary embodiments schematically illustrated in the drawings.
The two-cylinder rich material pump schematically shown in FIG. 1 is intended to carry rich materials that are rich in solids such as partially dewatered sewage treatment sludge, coal dust sludge, or concrete. ing.

上記ピストンポンプは基本的に、材料充填容器１０、２つの供給シリンダ１６、２つの供給ピストン２０、水室（冷却缶）２２から構成されている。上記２つの供給シリンダは供給シリンダ端側のオリフィス開口部１２と壁開口部１４を介して材料充填容器１０に接続されている。上記２つの供給ピストンはプッシュプル式（逆向きサイクル）にて液圧駆動シリンダ１８を介して駆動可能である。上記水室は駆動シリンダ１８と供給シリンダ１６の間に配されている。材料充填容器１０の内部には、パイプスライド２４が配設されており、当該パイプスライドは、その入口開口部２６で、ピストンが押圧ストロークを実施する供給シリンダのオリフィス開口部１２に交互に接続可能であり、ピストンが吸引ストロークを実施する他方の供給シリンダのオリフィス開口部１２を開放し、その出口開口部２８は、材料充填容器１０に配されたプレッシャコネクタ３０を介して不図示のプレッシャ供給ラインと接続している。図１に示された実施例の場合、パイプスライド２４は材料充填容器１０内で旋回可能でＳ字形状に曲げられた旋回パイプを有する。それに応じて、濃厚物質は、それぞれの吸引ストロークの間、材料充填容器１０の内部から、場合によっては予圧圧力の作用下に、開いたオリフィス開口部１２を介して関連の供給シリンダ１６内へ達する。その一方で、他の供給シリンダ１６内にある濃厚物質は、パイプスライド２４の旋回パイプとプレッシャコネクタ３０を介して、押圧ストロークを行う供給ピストン２０によって、次のプレッシャ供給パイプに押し込まれる。 The piston pump basically includes a material filling container 10, two supply cylinders 16, two supply pistons 20, and a water chamber (cooling can) 22. The two supply cylinders are connected to the material filling container 10 through an orifice opening 12 and a wall opening 14 on the supply cylinder end side. The two supply pistons can be driven via a hydraulic drive cylinder 18 in a push-pull manner (reverse cycle). The water chamber is disposed between the drive cylinder 18 and the supply cylinder 16. A pipe slide 24 is arranged inside the material filling container 10, and the pipe slide can be alternately connected to the orifice opening 12 of the supply cylinder where the piston performs the pressing stroke at the inlet opening 26. The piston opens the orifice opening 12 of the other supply cylinder that performs the suction stroke, and the outlet opening 28 is connected to a pressure supply line (not shown) via a pressure connector 30 arranged in the material filling container 10. Connected. In the case of the embodiment shown in FIG. 1, the pipe slide 24 has a swivel pipe that can be swiveled in the material filling container 10 and bent into an S shape. Correspondingly, the concentrated material reaches from the inside of the material-filled container 10 during the respective suction stroke, possibly under the action of preload pressure, into the associated supply cylinder 16 via the open orifice opening 12. . On the other hand, the concentrated substance in the other supply cylinder 16 is pushed into the next pressure supply pipe by the supply piston 20 performing a pressing stroke via the turning pipe of the pipe slide 24 and the pressure connector 30.

本発明固有の特徴は、オリフィス開口部１２の領域にリングノズル３２が配設され、当該リングノズルがプレッシャパイプ３４、孔３６、リング流路３８を経て、約５０〜１００ｂａｒの圧で潤滑剤を適用させることができる点にある。リング流路３８及びリングノズル３２を形成するために、オリフィス開口部１２の領域内の供給シリンダ１６に、内側パイプ４０が軸方向に続いている。当該内側パイプは供給シリンダ１６に螺合された外側パイプ４２によって覆われている。このために、内側リング４０は半径方向に張り出した頚部（カラー）４４を有する。当該頚部は外側パイプ４２のリング面４６と供給シリンダ１６の端側リング面４８の間に取り付けられて、リングノズル３２とリング流路３８が内側パイプと外側パイプの間で開いた状態を保障されている。潤滑剤供給のための孔３６は、外側パイプ４２内に配されている。内側パイプ４０は、リング流路の境界を画定するその内面に２つのリング溝を有する。当該溝は横断面拡張部５０を形成し、リングノズル３２から流れ出る潤滑剤を周囲に渡って均一に分布することを保障する。 A unique feature of the present invention is that a ring nozzle 32 is disposed in the region of the orifice opening 12, and the ring nozzle passes through the pressure pipe 34, the hole 36, and the ring flow path 38, and supplies the lubricant at a pressure of about 50 to 100 bar. The point is that it can be applied. An inner pipe 40 continues in the axial direction to the supply cylinder 16 in the region of the orifice opening 12 in order to form the ring channel 38 and the ring nozzle 32. The inner pipe is covered with an outer pipe 42 screwed into the supply cylinder 16. For this purpose, the inner ring 40 has a radially projecting neck (collar) 44. The neck is attached between the ring surface 46 of the outer pipe 42 and the end side ring surface 48 of the supply cylinder 16 to ensure that the ring nozzle 32 and the ring flow path 38 are open between the inner pipe and the outer pipe. ing. A hole 36 for supplying the lubricant is arranged in the outer pipe 42. The inner pipe 40 has two ring grooves on its inner surface that define the boundary of the ring flow path. The groove forms a cross-sectional extension 50 and ensures that the lubricant flowing out of the ring nozzle 32 is evenly distributed over the periphery.

個々の供給シリンダ１６へ潤滑剤を供給するため、不図示の外部制御装置が制御されて、吸引ストロークの間のみ潤滑剤が供給シリンダへ注入される。そこで潤滑剤は濃厚物質と供給シリンダの内表面の間の分離領域に入り込むので、充填の度合いは滑り摩擦の減少のために改善される。本発明に係る方策を用いて、固形物を多く含む下水汚泥の場合、少なくとも２５％の充填度における改善を達成することが可能であることが実験によって示された。引き続いての押圧ストロークの間、潤滑剤は濃厚物質と共にプレッシャラインへ達し、そこでまた滑り摩擦を減少する。押圧ストロークの間、潤滑剤の注入はその都度、中断される。このようにして、通過して流れる濃厚物質のために潤滑剤誘導の空吸引（Leersaugen）のリスクが回避される。 In order to supply the lubricant to the individual supply cylinders 16, an external control device (not shown) is controlled so that the lubricant is injected into the supply cylinders only during the suction stroke. The lubricant then enters the separation region between the dense substance and the inner surface of the supply cylinder, so that the degree of filling is improved for reducing sliding friction. Experiments have shown that with the measures according to the invention, it is possible to achieve an improvement in the filling degree of at least 25% in the case of sewage sludge rich in solids. During the subsequent pressing stroke, the lubricant reaches the pressure line with the concentrated material, where it also reduces sliding friction. During the pressing stroke, the injection of lubricant is interrupted each time. In this way, the risk of lubricant-induced empty suction due to the dense material flowing through is avoided.

要約すると、以下のことが確認される：本発明は、濃厚物質のための、特に固形物を多く含む下水汚泥、石炭スラリー及びコンクリートのためのピストンポンプに関する。当該ピストンポンプは、モータ駆動又は液圧駆動の供給ピストン２０を含む少なくとも１つの供給シリンダ１６を有する。当該シリンダは、供給ピストン２０の動きに応じてスライド制御され、材料充填容器１０の内部とプレッシャ供給ライン３０とに交互に連通するオリフィス開口部１２を有する。少なくとも１つの供給シリンダ１６の充填度を著しく大きくするために、供給シリンダ１６に開口するリングノズル３２が、オリフィス開口部１２の領域に設けられている。上記リングノズルは、潤滑剤が供給される外部のプレッシャライン３４と接続されている。 In summary, the following is confirmed: The present invention relates to piston pumps for dense materials, in particular for solids-rich sewage sludge, coal slurries and concrete. The piston pump has at least one supply cylinder 16 including a motor-driven or hydraulically driven supply piston 20. The cylinder has an orifice opening 12 which is slide-controlled according to the movement of the supply piston 20 and communicates alternately with the inside of the material filling container 10 and the pressure supply line 30. In order to significantly increase the degree of filling of the at least one supply cylinder 16, a ring nozzle 32 that opens into the supply cylinder 16 is provided in the region of the orifice opening 12. The ring nozzle is connected to an external pressure line 34 to which a lubricant is supplied.

供給ラインに接続するための、濃厚物質用２シリンダピストンポンプの平面図である。It is a top view of the 2 cylinder piston pump for rich substances for connecting to a supply line. 材料充填容器を備えずに拡大描写で示す、図１に係る２シリンダピストンポンプの平面図である。FIG. 2 is a plan view of the two-cylinder piston pump according to FIG. 1 shown in an enlarged depiction without a material filling container. 材料充填容器を備えずに拡大描写で示す、図１に係る２シリンダピストンポンプの断面図である。FIG. 2 is a cross-sectional view of the two-cylinder piston pump according to FIG. 1 shown in enlarged depiction without a material filling container. 図２ｂに係る断面図の拡大詳細図である。2b is an enlarged detail view of the cross-sectional view according to FIG. 2b. 図３に比して拡大描写した、供給シリンダの１つのオリフィス領域を通る断面図である。FIG. 4 is a cross-sectional view through one orifice region of a supply cylinder, enlarged as compared to FIG. 3.

Explanation of symbols

１０材料充填容器
１２オリフィス開口部
１６供給シリンダ
２０供給ピストン
３０プレッシャコネクタ
３２リングノズル
３４プレッシャライン 10 Material Filling Container 12 Orifice Opening 16 Supply Cylinder 20 Supply Piston 30 Pressure Connector 32 Ring Nozzle 34 Pressure Line

Claims

The concentrated material piston pump has at least one supply cylinder (16) including a motor-driven or hydraulically-driven supply piston, the supply cylinder being connected to the interior of the material-filled container (10) and the pressure supply line (pressure connector 30). In the rich piston pump, which has orifice openings (12) alternately communicating with each other), the orifice openings are slide-controlled according to the movement of the supply piston (20).
A ring nozzle (32) opening in the supply cylinder (16) is disposed in the region of the orifice opening (12), and the ring nozzle is connected to at least one external pressure line (34). ,
The pressure line (34) can be filled with a lubricant by a high-pressure pump, and is connected to a ring flow path (38) that opens to the ring nozzle (32).
The supply cylinder (16) has an outer ring body (42), and the outer ring body has at least one hole (36) connected to the pressure line (34) on the outside, and the ring nozzle (32) It possesses the ring channel (38) leading,
The supply cylinder (16) has a control device corresponding to the stroke direction and / or position of the supply piston (20), and a control valve arranged in the pressure line (34) according to the output signal of the control device. A piston pump characterized by the following.

The concentrated material piston pump has at least one supply cylinder (16) including a motor-driven or hydraulically-driven supply piston, the supply cylinder being connected to the interior of the material-filled container (10) and the pressure supply line (pressure connector 30). In the rich piston pump, which has orifice openings (12) alternately communicating with each other), the orifice openings are slide-controlled according to the movement of the supply piston (20).
A ring nozzle (32) opening in the supply cylinder (16) is disposed in the region of the orifice opening (12), and the ring nozzle is connected to at least one external pressure line (34). ,
The pressure line (34) can be filled with a lubricant by a high-pressure pump, and is connected to a ring flow path (38) that opens to the ring nozzle (32).
The supply cylinder (16) has an outer ring body (42), and the outer ring body has at least one hole (36) connected to the pressure line (34) on the outside, and the ring nozzle (32) It possesses the ring channel (38) leading,
Two supply cylinders (16), each having a ring nozzle (32) in its orifice region (12), are provided, and these ring nozzles (32) actuate the control valve during the suction stroke of the supply piston (20). A piston pump, characterized in that each lubricant can be filled into a supply cylinder which can be controlled in a reverse cycle .

Said ring channel (38) is bounded on the inside by the outer surface of the supply cylinder or on the outer surface of the inner pipe (40) which extends axially to the supply cylinder and on the outside by the inner surface of the outer ring body (42) characterized in that it is bounded, piston pump according to claim 1 or 2.

At the end face, the supply cylinder (16) is followed by an inner pipe (40), which engages a recess in the outer ring body (42) that opens inward, together with the ring nozzle (32) and the ring. Piston pump according to any one of claims 1 to 3 , characterized in that the limit of the flow path (38) is defined.

The piston pump according to any one of claims 1 to 4 , characterized in that the ring channel (38) has at least one ring-shaped cross section extension (50).

6. Piston pump according to claim 5 , characterized in that the ring channel (38) has two ring-shaped cross-section extensions spaced from each other.

The control valve disposed in the pressure line (34) is open during the suction stroke of the feed piston (20), characterized in that the closed before the pressing stroke, according to any one of claims 1 to 6 Piston pump.

8. Piston pump according to any one of the preceding claims, characterized in that the control valve is formed as a directional valve, preferably magnetically controllable via a supply piston (20). .

The inner pipe (40) comprises a neck (44) projecting radially in the rear and is supported between the two ring surfaces (46, 48) of the supply cylinder (16) and the outer ring body (42). The piston pump according to any one of claims 1 to 8 , wherein the piston pump is characterized.

Operation of the piston pump for the concentrated material, in which the concentrated material is alternately sucked into the supply cylinder (16) opened on one side during the suction stroke and then exits the supply cylinder and is pushed out to the pressure supply line during the next pressing stroke. In the method
Lubricant is injected into the supply cylinder (16) for each suction stroke, with the lubricant being injected into the separation region between the concentrated material and the inner surface of the supply cylinder over the entire circumference of the inner surface of the supply cylinder. it, and,
A method characterized in that the injection of lubricant is interrupted during the pressing stroke .