The invention concerns the combined pressure milling pump which consists of a pump and a mill.

Hitherto known milling pumps are composed of a milling part only and therefore they do not make sure any continuous suction of the medium to be milled. They operate on brought in solution the overpressure of which is approximately 0.2 MPa. If this is not the case, they get filled with air and make difficult a continous operation of the milling pump. Foregoing disadvantages occur with pumps which make use of the segmental principle or of the endless screw principle, or with other simi 1ar pumps.

Filling with air aggravates the milling pump operation and therefore a pressure pump is needed to provide a steady supply of liquid with mixture at a pressure of 0.2 MPa. A combination of a pump with a milling device is fastidious from the economical point of view.

Due to positive inclination of holes of stator and rotor holes or segments only, the hitherto known milling pumps do not provide any perfect dispersion of milled particles. As by the way of another imperfec ion, they do not have exactly defined distance ratios between stators and rotors and therefore they do not provide the accurate milled particles size. Equally because of their not exactly defined ratios of passage hole areas of stators and rotors, they do not make provide perfect hydraulic flow passage of the medium to be mi 1 led.

To a considerable extent, the above mentioned disadvantages are suppressed with the combined pressure milling pump according to the invention, said milling pump being composed of a pump and a mill which are situated in a housing. The mill consists of at least one stator and at least two rotors, said stator and said rotor being fitted with passage holes and said rotor being mounted on the shaft passing through the entire arrangement.

Substance of the invention is rooted therein that the longitudinal axes of the retarding stator holes of the mill are inclined in a negative angle of O minutes up to 75 degrees with respect to the shaft and the longitudinal axes of the accelerating rotor holes of the mill are inclined in a positive angle of 0 minutes up tu 75 degrees with respect to the shaft. The area of the stator retarding hole and, subsequently in the discontinuous streaming direction, the area of the accelerating rotor hole or the area of the rotor accelerating hole and, subsequently in the discontinuous streaming direction, the area of retarding stator hole always decreases in accordance with the ratio 1 - 2. At the same time, the sum of hole areas increases from 0 up to 100 percent in the discontinuous streaming direction and the distances between stator and rotor always change in the decreasing ratio one to one tenth.

Advantageously, the solution according to the invention results in an arrangement which provides a necessary as well as steady pressure. The device does not get filled with air but disperges and mills the particles in the liquid in order to reach the demanded size.

The arrangement operates in such a way that the polluted liquid enters the pump where its passage is accelerated with simultaneous pressure increasing. In this state the liquid passes through individual stators as well as through rotors of the mill. Here it is retarded and accelerated during simultaneous milling which is performed by means of the movement of rotors with regard to stator. In the liquid the particle size is determined by means of the distance between stator and rotor. In the liguid the final particle size is determined by the distance between the last rotor and the last stator. The liquid with the particles of final and demanded size is driven out on one hand by means of a pump pressure and on the other hand by means of increasing pressure of the proper mill through the output opening out of the arrangement.

The pumping part generates a steady pressure of the conveyed liquid which lies within the interval 0.1 up to 0.3 MPa. The device according to the inven ion is simple and cheaper than hitherto used pump types.

In Fig.1 the layout according to the invention is explained in more detail by means of drawings where the stator and rotor of the mill are illustrated with holes and discontinuous streaming direction is indicated. In Fig.2 the layout of the pump and the mill inside the device is illustrated and the discontinuous streaming direction is indicated.

EXAMPLE

According to the invention, the combined pressure mill pump has been fabricated which included the pump 4 and the mill in one unit. Both of them are situated in the housing 7. The mill consists of one stator 2 and two rotors 3. These are located on the shaft 8 which passes through the entire arrangement. Both stator 2 and rotor 3 are fitted with passage holes i_, 6. The longitudinal axes of the retarding holes JL. of the mill stator 2 are inclined in a negative angle of lO minutes with respect to the shaft 8. The longitudinal axes of the accelerating holes 6 of the rotor 3 of the mill are inclined in a positive angle of lO minutes with respect to the shaft 8 as can be seen in Fig.i. Each area of the retarding hole i_ of the mill stator 2, the first one in the discontinuous streaming direction of the liquid, equalled 100 mm ² , and the area of each accelerating hole 6 of the mill rotor 3 equalled 50 mm ² , and finally the area of each retarding hole i, in the discontinuous streaming direction of the liquid, equalled 25 mm ³ in the second stator 2.

The sum of areas of the retarding holes 1_ of the first stator 2 equalled 1 000 mm ² , the sum of areas of the accelerating holes 6 of the rotor 3 equalled 1 100 mm ² , and the sum of areas of the retarding holes 1_, in the discontinuous streaming direction of the liquid, of the second stator 2 equalled 1 200 mm ² .

The distance 5 between the first rotor 3 and the stator 2 equalled 1 mm and the distance 5 between the stator 2 and the second rotor 3 equalled 0.1 mm.

The arrangement operates in such a way that a liquid contaminated with oil and with functional medium is retarded in the arrangement part with stators 2, further it is milled in the gap between the rotor 3 and the stator 2, and finally it is accelerated again in the rotors 3. In this way the milling of course bentonite and its dispersion in water, contaminated with oil, was accomplished.