EA009584B1 - Non-magnetic screen of glandless pump - Google Patents

Abstract

The invention relates to pump engineering design and can be used in designing glandless pumps driving through a magnetic clutch for pumping aggressive, explosive and other liquids having particular properties.The glandless pump comprises a housing with an impeller mounted therein, rotatably driven by a cylindrical magnetic clutch, a driven half-coupling of which is connected to a driving shaft of an electric motor, wherein a driven shaft to the impeller, whilst the half-couplings are coaxially-mounted and sealed-separated by a cylindrical non-magnetic screen mounted in the housing and made as multi-pole units with poles rotation. Wherein the screen is comprised of sealed flange, wall and bottom, the screen wall is made from non-magnetic material and sealed connected over a generatrix.

Description

FIELD OF THE INVENTION

The invention relates to a pump engineering and can be used to create sealed pumps with a drive through a magnetic coupling for pumping aggressive, explosive and other liquids with special properties.

State of the art

Known sealed centrifugal pump containing a housing with an impeller placed therein, driven by a cylindrical magnetic coupling, the driving coupling of which is connected to the drive shaft of the electric motor, and the driven coupling with the impeller, the coupling half mounted coaxially, separated by a screen in the form of a hermetically sealed in the housing cylindrical cups and are made multi-pole with alternating poles. A gauge of wear of the cylindrical wall of the cup between the poles of the leading and driven half-couplings is introduced, and the cylindrical cup is made with a variable wall thickness along its generatrix, and the portion of the smallest wall thickness is located between the poles of the leading and driven half-couplings [1].

A disadvantage of the known device is the high cost of producing a cylindrical glass, associated with the high complexity of its manufacture and a large amount of metal waste. Also in the manufacturing process, there is a high probability of marriage due to possible defects and caverns in the glass blank. The minimum wall thickness of the glass is limited by technological capabilities.

The relatively large thickness of the side walls leads to the loss of net power transmitted from the electric motor to the impeller of the pump, since heat losses from Foucault currents in the sealed pump screen increase.

It was possible to reduce the thickness of the walls, the mass of the product and the amount of waste in the technical solution, where the hermetic pump screen was made by stamping [2].

The screens obtained by stamping have restrictions on the ratio of length to diameter, associated with the technological capabilities of the equipment and the viscosity of the material used. Also, the disadvantages of such devices are the high cost of the technological equipment necessary for the manufacture of a stamped sealed pump screen, since for the manufacture of each version of the screen dimensions you need your own set of expensive equipment.

The last technical solution is the closest in technical essence and therefore adopted as a prototype.

An object of the invention is to reduce the cost of manufacturing a thin-walled sealed pump screen, with high standardization of equipment for producing screens with any required overall dimensions, including for a single production.

Disclosure of the invention

The stated technical problem is achieved by the fact that the proposed design contains a housing with an impeller placed in it, driven by a cylindrical magnetic coupling, the driving coupling of which is connected to the drive shaft of the electric motor, and the driven coupling - to the impeller. Moreover, the coupling halves are installed coaxially, hermetically separated by a cylindrical non-magnetic screen fixed in the housing and are made multi-pole with alternating poles. In this case, the screen consists of hermetically connected flanges, walls and bottom, and the wall of the screen is made of sheet non-magnetic material and hermetically connected along a generatrix.

New in the present invention is that the screen consists of a hermetically connected flange, wall and bottom, and the wall of the screen is made of sheet non-magnetic material and hermetically connected along a generatrix.

This allows you to get a screen with a wall of the required thickness and the required overall dimensions without the use of additional equipment.

An embodiment of the invention is possible in which the screen wall is made of titanium or chromium-nickel non-magnetic alloys.

The execution of the screen wall of titanium or chromium-nickel non-magnetic alloys increases its thermal and chemical resistance, and also reduces the thermal heating of the screen.

A variant of the invention is also possible in which the screen wall is interconnected, as well as with the flange and the bottom of the electric arc welding.

Electric arc welding allows you to get joints, the electromagnetic properties of which correspond to the base material.

An embodiment of the invention is possible in which the bottom of the screen is made of two or more parts hermetically connected to each other.

The implementation of the bottom of the screen in two or more parts can reduce the cost of manufacturing the screen due to the use for the manufacture of the bottom of cheaper materials.

Given the distinctive features of the claimed invention in comparison with the prototype can reduce the cost of manufacturing a thin-walled hermetic pump screen and allow you to abandon the use of expensive equipment. In this case, it is possible to carry out piecewise versions of the screen, without limiting the ratio of length to diameter.

- 1 009584

The invention is illustrated in the drawing.

Brief Description of the Drawing

The drawing shows a longitudinal section of a sealed pump screen.

An embodiment of the invention

The cylindrical screen comprises a flange 1, a wall 2 and a bottom 3. The wall 2 of the screen of titanium sheet has a cylindrical shape and is hermetically connected along the joint along the axis of rotation by electric arc welding. One of the ends of the cylinder of the wall 2 of the screen is hermetically connected to the bottom 3, and the second end to the flange 1. The bottom 3 is hermetically connected to the liner 4 by any known method (for example, by pressing).

The given screen has a wall of the minimum required thickness, is cheap to manufacture, and can have any given geometric dimensions.

Industrial applicability

The invention can be carried out on known metalworking equipment.

Sources of information taken into account

1. Patent KI No. 208807, MKI E 04 Ό 13/02, priority 05.24.1995, publ. 08/27/1997.

2. EP patent No. 0814268, MKI E 04 Ό 13/02, priority 06/19/1997, publ. 12/29/1997 - a prototype.

Claims (4)

CLAIM 1. Sealed centrifugal pump, comprising a housing with an impeller placed in it, a cylindrical magnetic coupling rotated, the coupling half leading to which is connected to the drive motor of the electric motor, and driven to the impeller, with the coupling half mounted coaxially, sealed by a cylindrical nonmagnetic screen mounted in the housing and made multipole with alternating poles, characterized in that the screen consists of a hermetically connected flange, wall and bottom, and the wall of the screen is made sheet of non-magnetic material and sealingly connected along a generatrix. 2. Sealed centrifugal pump according to claim 1, characterized in that the wall of the screen is made of titanium or nickel-chromium nonmagnetic alloys. 3. Sealed centrifugal pump according to any one of claims 1, 2, characterized in that the screen wall is interconnected, as well as with the flange and the bottom of the arc welding. 4. Sealed centrifugal pump according to any one of claims 1 to 3, characterized in that the bottom of the screen consists of two or more parts, hermetically interconnected.