RU2360740C1 - High gradient magnetic filter - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: facility is designed for purifying water and gas flows from containing in them particles possessing magnetic properties and can be implemented in heat power and nuclear power engineering, in metallurgy, in chemical and food industries, in radio-electronics, in medicine and other branches. The high gradient magnetic filter consists of a case, cover and an inlet and outlet branches. There are holes in the cover of the case, wherein one or several cassettes are secured. Axially magnetised constant magnets and pole pieces are assembled inside each cassette. The pole pieces are made in form of disks of equal with magnets diametre and are located between magnets facing each other with like poles. The pole pieces are made out of magnet soft material. The magnets and the pole pieces are united with a rigid non-magnetic mechanical constraint and are designed to travel relative to the cassette and to be extracted from the cassette through the hole in the cover. A matrix corresponds to a coil placed directly on the cassette. Winding of the coil is made by multi-layer winding of magnet soft corrosion resistant wire. Each following layer of matrix winding is made at angle of 30°-60° to a preceding layer.

EFFECT: simplification of filter design, increased efficiency of power utilisation of magnetic field and increased efficiency of process mediums purification, also simplified procedure of filter regeneration and reduced doze loads to personnel.

4 cl, 1 dwg

Description

The invention relates to devices for cleaning water and gas streams from particles contained in them having magnetic properties, and can be used in objects of thermal and nuclear energy, metallurgy, chemical and food industries, radio electronics, medicine and other industries.

A known magnetic filter containing a housing of non-magnetic material with input and output fittings, a ferromagnetic matrix and a ring-shaped magnetic system with axial magnetization, mounted outside the housing [RF Patent No. 2203124, Bull. No. 12, 2003].

The disadvantage of this filter is its low efficiency, due to the irrational design of the magnetic system, which does not allow to effectively realize the energy of the magnetic field. In addition, the use of a magnetic powder as a matrix complicates the process of cleaning the filter from impurities during its regeneration.

Known high-gradient magnetic filter (VGMF) [A. S. USSR No. 1785104, Bull. No. 16 (part II), 1998]. VGMF contains a housing in which a magnetic system is placed, consisting of permanent magnets installed in cassettes, and a matrix. Since the magnetic system is located directly in the filter housing, for regeneration it can be removed from the filter only when it is disassembled, which complicates the maintenance of the filter when cleaning radioactively contaminated water streams due to high dose loads on personnel. This device is closest to the claimed by most essential features and is selected as a prototype.

An object of the invention is the creation of a high-gradient magnetic filter of a simpler design, which allows to increase the efficiency of use of magnetic field energy and, as a result, to increase the efficiency of cleaning process media, simplify the filter regeneration procedure and, thereby, reduce the dose load on personnel.

To solve this problem and achieve the specified technical result in a known device, including a cylindrical housing made of non-magnetic corrosion-resistant material with inlet and outlet pipes, a magnetic system located inside the housing based on highly coercive axially magnetized permanent magnets made in the form of disks and installed in sealed cassettes directly in the filter housing, and the matrix, the feature is that the housing is equipped with a cover with holes in which cassettes are fixed, and the magnetic system additionally contains pole lugs in the form of disks of equal diameter with magnets made of magnetically soft material. Pole lugs are located between magnets facing each other with the same poles, while magnets and pole lugs are connected by rigid non-magnetic mechanical coupling with the possibility of axial reciprocating movement relative to the cartridge and with the possibility of extraction from the cartridge through the holes in the lid. The matrix is a coil placed directly on the cassette, while the coil winding is made of multilayer winding. The coil winding is made of a magnetically soft corrosion-resistant wire element with a diameter of (0.03-0.1) mm, for example, of stainless steel grade X17H9T or 00X13 with a pitch of (0.03-0.1) mm. Each subsequent winding layer is made at an angle of 30 ° -60 ° to the previous one.

The features of the invention are associated with the achieved technical result as follows.

In the claimed technical solution, the entire magnetic assembly, consisting of permanent magnets and pole pieces located between them, is placed in one cartridge, which greatly simplifies the design of the magnetic system and the filter as a whole. In addition, this design creates a sufficiently strong radial field around the magnetic assembly, which leads to a high efficiency of trapping particles of corrosion products having ferromagnetic, paramagnetic and diamagnetic properties and having sizes from hundredths of a micron to several tens of microns.

To achieve a high magnetic field induction inside the matrix, highly coercive magnets, for example Co ₅ Sm, NdBFe, are used as magnets. It is advisable to choose the diameter of the magnets within 30–50 mm, and the thickness 10–15 mm. To achieve a strong radial field, the thickness of the pole pieces must not exceed the thickness of the magnets. Experience has shown that the induction of the radial field on the surface of the pole pieces is almost equal to the induction on the surface of the poles of the magnets used. As you move away from the magnetic assemblies, the radial field induction decreases rather quickly, but at a distance of 30-40 mm, in the presence of a magnetized matrix, it is about 0.2 T, which is sufficient for the effective operation of the filter. This design of the magnetic system in the proposed technical solution allows many times to reduce the number of permanent magnets used.

The combination of magnets and pole pieces with a rigid mechanical connection makes it simple and easy to remove the magnetic assembly from the filter housing, which greatly simplifies the process of demagnetization of the matrix during its regeneration and, thereby, reduces the dose burden on personnel.

The matrix is placed directly on the cartridge, which makes it possible to concentrate the magnetic field over the volume of the matrix, minimizing the loss of magnetic energy. In addition, the matrix winding is multilayer, each subsequent layer of the matrix wire winding is made at an angle of 30 ° -60 ° to the previous layer. The wire winding has a diameter of 0.03-0.1 mm and is made in increments of 0.03-0.1 mm. This matrix formation allows you to create the maximum working surface of the matrix with a minimum fill factor of the filter volume, this leads to a decrease in the hydraulic resistance of the filter, which, in turn, increases the efficiency of cleaning process media.

A sketch of the proposed device is presented in the drawing.

The device comprises a housing 1 with a cover 2 and an input 3 and output 4 nozzles. One or several cassettes 5 are fixed in the cover 2 of the housing 1, inside of which powerful permanent magnets 6 and pole pieces 7 are placed. The matrix 8 is located directly on the cassette.

The device operates as follows. The flow of the medium to be cleaned is supplied through the inlet pipe 3, passes through a matrix 8 formed on a cylindrical cartridge 5 and located in the magnetic field of the axially magnetized disk highly coercive permanent magnets 6 and pole tips 7. In this case, the ferro-, para- and diamagnetic particles of impurities are held by the filter matrix . To regenerate the filter matrix after accumulating a sufficient amount of corrosion products, the flow of coolant into the filter is stopped, the magnetic assemblies are removed from the filter. Cleaning is carried out by direct or reverse increased consumption of flushing water with discharge into a special sewer.

Claims (4)

1. High-gradient magnetic filter containing a housing with inlet and outlet nozzles, a magnetic system based on axially magnetized permanent magnets made in the form of disks and installed in sealed cassettes directly in the filter housing, and a matrix, characterized in that the housing is equipped with a cover with holes, in which cassettes are fixed; the magnetic system further comprises pole tips in the form of disks of equal diameter with magnets, which are located between magnets facing the same poles, and the magnets and pole tips are connected by a rigid non-magnetic mechanical connection with the possibility of movement relative to the cartridge and removal from the cartridge through the hole in the lid; the matrix is a coil placed directly on the cassette, while the coil winding is made of multilayer winding. 2. High gradient magnetic filter according to claim 1, characterized in that the pole pieces are made of soft magnetic material. 3. High gradient magnetic filter according to claim 1, characterized in that each subsequent layer of the matrix winding is made at an angle of 30-60 ° to the previous layer. 4. High gradient magnetic filter according to claim 1 or 3, characterized in that the winding of the matrix is made of soft magnetic corrosion-resistant wire.