CDP - The Confuser-Diffuser Pump

 The new concept of construction of centrifugal pumps is developed, the flowing part of a wheel in which instead of the bent blades is executed as the accelerating muzzle. It has a straight-line characteristic. Well works with liquids with the high gas contents without gas separator. The centrifugal pump of a type CDP by productivity of less than 10 m³/day can replace unreliable sucker-rod pumps.  

  The invention concerns to hydro-mechanical engineering, and is more exact with submersible multistage electro-pump units of a modular type for an oil-extracting industry with which it helps to lift petroleum or water from oil-well, draw-well, tanks and open reservoirs.

The basic question, which arises, probably, at any expert of hydro machine-building, reading this information: "Why invent a wheel?" To answer briefly: because the traditional impeller of modern pumps is designed not on a science and contains some mistakes.

Let's consider some scientific rules of centrifugal pumps. The pumps were invented very long time ago. It is known, that the Egyptians, in times of Pharaoh, already used pumps giving water in pendant gardens located above the level of the river, from which water was taken for a half-willow.

 After thousands of years, in ancient Greece in IV century B.C., Aristotle formulates an axiom regarding the characteristic of the pump,: "The Greatest work is made by force, which action coincides with a direction of movement of a liquid, relocated by it ".

The force F a moving liquid in the flowing channel of impeller of a pump is directed strictly from the centre to circumference on radius. The bent blades of a traditional impeller lock centrifugal motion on direction of action of force, reducing its potential.

Each stage of the multi-modular pump for a liquid decides two, in some sort of opposite physical process: acceleration of a liquid up to the greatest possible speed what to receive the greatest meaning of kinetic energy of volume of a liquid and braking of this liquid to receive a maximum level of potential energy (pressure), measure in meters of lift:

Let's consider the left part of this equation, with reference to the traditional centrifugal pump. Now in an oil-extracting industry the multistage electropump units of a modular type are widely used, in which modules of driving impeller are executed closed or open and have flowing channels extending from the centre to periphery.

Let's prove, that in such channels the law ���������� of a flow " is broken hydrodynamical ":  

The area of cross section on an input in the flowing channel of a traditional centrifugal wheel of the pump always is less, than its area on an output:

Radius of a wheel on an input in the channel always is less, than radius on an output:

, but

Hence, at identical angular of speed :

It means, that a flow of a working liquid having discontinuity flaw. It causes occurrence vortical of separation currents, cavitation and failure of submission. At regulation of submission, the power EFFICIENCY of the pump, its pressure and productivity is essentially reduced.

Let's consider now the right part of equation: transforming of kinetic energy into potential energy (in a pressure). In traditional type of multistage of an electro-pump, the liquid from an output from a wheel of one stage up to an input in a wheel of the following stage percussion is braked about a wall of the frame with turn on 180 degree, that is the reason of decrease of speed twice.

After that, the liquid in addition is braked about the blade of the directing device placed usually between the next steps, therefore the transformation of kinetic energy of flow of a liquid in potential (pressure) is carried out with large losses.

In strict conformity with the marked hydro-dynamical laws, we create a new type of the centrifugal pump named the confuser-diffuser pump. In the new driving impeller, the law of continuousness of a flow "is observed". The driving impeller of the pump does not have traditional blades, and the flowing part is executed as accelerating of muzzle, that increases a pressure, the power EFFICIENCY and allows them to work well in liquids with the large gas contents and contents of firm particles.

The design of the driving impeller of the CDP allows the projecting of the pump on small productivity of the order 5 m³/day � 8 m³/day. Thus the rather large through passage apertures of driving impeller of CDP allow to create a constructive number (line) of reliable centrifugal of rodless pumps capable of high efficiency to replace existing of sucker-rod pumps. 

The opportunity has appeared to develop a "niche". The traditional centrifugal pumps, as is known, have the bottom limit of productivity of about 20 m³/day and can not make it.