JP4289517B2 - Rotating drum type magnetic separator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary drum type magnetic separation device that efficiently collects fine sludge from a coolant liquid and improves sludge drainage. Improves the occurrence of sludge separation and conveyance failure, and also provides a circumferential groove on the squeeze roller to reduce liquid wetting at both ends of the roller, and improves punching by using punching metal as a scraper. The present invention relates to a rotary drum type magnetic separation apparatus excellent in separation / conveying capacity and solid-liquid separation efficiency.
[0002]
[Prior art]
In cutting and grinding of a magnetic material such as a metal material, particularly a steel material, cutting waste and chips discharged together with the coolant liquid are usually separated and collected into a liquid component and cutting waste and chips. Various magnetic sorting apparatuses have been proposed according to the shape of cutting waste and chips. For example, chips called sludge are easily powdered and easily gathered to contain liquid components and are difficult to separate and collect. Therefore, an apparatus that has excellent ability to separate and recover fine sludge is required. That is, in a rotating drum type magnetic separation apparatus that has been put into practical use as a configuration suitable for ordinary sludge separation, it is difficult to separate and collect fine sludge, and an improvement thereof is required.
[0003]
In the rotary drum type magnetic separation apparatus shown in FIG. 1, a coolant reservoir 2 is provided in a box-shaped main body 1, and the rotary drum 3 is horizontally supported at the center as it is divided into two. ing. The rotating drum 3 is a cylindrical body made of a non-magnetic material such as stainless steel, and an inner cylinder 5 having a magnet 4 disposed on the outer peripheral surface thereof is coaxially fixed inside. The magnet 4 of the inner cylinder 5 is appropriately arranged with magnetic poles so that a required magnetic flux acts on the outer peripheral surface of the rotary drum 3.
[0004]
Various configurations can be adopted as the range in which the magnetic force is applied to the rotating drum 3 depending on the outer diameter of the drum, the arrangement position of the scraper 7, etc. In the illustrated configuration, the portion immersed in the liquid reservoir 2 of the rotating drum 3 The magnet 4 is arranged in the inner cylinder 5 so that the adsorbing force is applied to the outer periphery of the outer quarter from the top to the top, and the remaining quarter part has no magnet in the inner cylinder 5 and no magnetic force acts. The sludge adsorbed on the outer peripheral surface of the rotating drum 3 at the bottom of the liquid reservoir 2 is conveyed to the top of the rotating drum 3 by the rotation of the drum 3, and is released from the adsorbing force after passing the top. Sludge is scraped off and collected by a plate-like scraper 7 in contact with the surface of the rotating drum 3.
[0005]
A squeezing roller 6 is disposed near the top of the rotating drum 3 and is configured to squeeze liquid contained in sludge adsorbed on the surface of the rotating drum 3 by contacting the outer peripheral surface with a predetermined pressing force. is there.
[0006]
[Problems to be solved by the invention]
In the magnetic separation device having a structure in which the inner cylinder of the magnet is built in the rotating drum, the mechanism for transporting the sludge has a sludge because the friction force between the sludge and the outer cylinder surpasses the force by which the magnet attracts the sludge. Is considered to be transported. If the surface roughness of the surface of the rotating drum becomes too good, the sludge transport capacity will decrease, and if the surface roughness becomes poor, the liquid will tend to drop out. There is a predetermined range based on the correlation with the shape.
[0007]
In addition, in the case of poor conveyance, when the sludge has already gathered into a lump or fluff when flowing into the separation device, or when the sludge itself is too large, fine sludge has gathered into a lump or floc In order to eliminate such a conveyance failure, it is conceivable to increase the frictional force between the sludge and the outer cylinder surface or increase the adsorption force. However, the above-mentioned surface roughness has an optimum range, and the improvement of the attractive force can increase the amount of magnets or improve the performance, but a balance between both is required.
[0008]
On the other hand, the scraper is in full contact with the rotating drum, scraping off the sludge and scraping off the liquid on the drum surface, resulting in a sludge containing liquid. In addition, the squeezing roller has a low squeezing efficiency at both ends, and the surface tends to get wet, and the liquid in this part is sucked up by the sludge at the scraper part, which causes the problem that the liquid of the separated sludge becomes poor. there were.
[0009]
An object of the present invention is to solve the problems of the conventional rotary drum type magnetic separation device described above, and occurs when fine sludge is gathered into a lump or flocculent when flowing into the separation device or after flowing into the separation device. An object of the present invention is to provide a rotating drum type magnetic separation device that can eliminate a conveyance failure and has an excellent separation and collection ability of fine sludge, and also has a structure in which excellent drainage is sustainable.
[0010]
[Means for Solving the Problems]
Inventors, a result of various studies for construction of the rotating drum for the purpose of eliminating the conveyance failure, for example, the required depth of the rotary drum surface made of non-magnetic material only, ferrite of the tissue, by martensite of In addition to the attractive force due to the magnetic force of the magnet, the attractive force from the rotating drum surface that is temporarily magnetized by the magnet acts on the sludge, and the conveying force is improved against the frictional force on the rotating drum surface, that is, It has been found that the frictional force between the sludge and the surface of the rotating drum is increased by the amount of the attracting force generated on the surface of the rotating drum, which exceeds the force of attracting the sludge of the magnet and can reduce the conveyance failure.
[0011]
Further, as a result of various studies on the configuration of the scraper and the squeezing roller for the purpose of improving the liquid breakage, the inventor has found that the scraper is in full contact with the rotating drum. It has been found that liquid scraping can be improved by forming a scraper using a so-called punching plate and reducing the contact area to separate the liquid to be scraped off.
[0012]
Furthermore, as a result of various investigations aimed at improving the wet state of both ends of the squeeze roller, the inventor controls the width at which the liquid wetted part occurs by inserting grooves and slits at both ends of the squeeze roller. We have found that we can control the liquid wetting part width from the end face according to the pressing force and rotation speed of the roller, and the type of liquid by appropriately selecting the width, depth, number, and interval of the slit, and completed this invention. did.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, a magnetic material having a required depth on the surface of the rotating drum is made into a magnetic material, and an attractive force from the drum surface is applied to the sludge in addition to the magnetic attractive force from the magnet. It increases by the amount of attraction force from the surface, exceeds the attraction force from the magnet drum, and reduces conveyance defects.
[0014]
In the present invention, the means for forming a magnetic material only for the required depth of the surface of the rotating drum is a modification treatment for ferritization or martensite treatment, for example, nitriding heat treatment, and a magnetic material sheet such as ferrite is attached or sandwiched. It is possible to provide the entire surface of the rotating drum, only a required portion, or a required pattern. The thickness of the magnetic layer is 10 μm to 0.5 mm, preferably 20 μm to 80 μm.
[0015]
Among the above reforming treatments, the nitriding heat treatment conditions are appropriately selected according to the material to be treated, but a treatment of holding at 300 ° C. to 700 ° C. for 30 minutes to 24 hours in a nitrogen-containing atmosphere is preferable.
[0016]
In the present invention, at least one circumferential groove is provided at both ends of the squeeze roller, because of the structure of the squeeze roller, it is difficult for a pressing force to act on both ends, resulting in poor squeezing efficiency. , where the required width, the liquid fraction by the groove depth in the circumferential direction s provided is discharged also the rotation enters the groove, the liquid wetting is reduced. The liquid wetting part width from the end face can be controlled by appropriately selecting the width, depth, number, and interval of the slits according to the pressing force and rotation number of the roller, and the type of liquid. In the case of 130 mm, the slit width is about 0.1 mm, the depth is 5 to 15 mm, and it is preferable to arrange them at intervals of about 5 mm.
[0017]
In the present invention, by using a plate material in which a plurality of holes having a required inner diameter are arranged in the scraper, the liquid component is discharged from the holes arranged in the plate material so that the liquid component does not return to the scraped sludge. Hole shape and dimensions as well as the sequence method sludge dimensions, but appropriately selected depending on the liquid type, for example, a round hole with an inner diameter of 0.5mm several to several tens / cm ^2, is to staggered preferable.
[0018]
【Example】
Example 1
In the rotary drum type magnetic separation apparatus having the configuration shown in FIG. 1 described above, a ferrite structure having a surface layer thickness of 30 μm is formed on the surface of the rotary drum made of stainless steel by nitriding heat treatment under the condition of a temperature of 530 ° C., a nitrogen-containing atmosphere for 4 hours. Formed on the entire surface.
[0019]
In the separation apparatus according to the present invention described above, when the magnetic separation is carried out from only water containing sludge having a size of 20 μm to 1000 μm or from three kinds of water-soluble and oil-based coolant liquids, the rotating drum is used in any case. Compared with the conventional apparatus which does not form a ferrite structure on the surface, it can be seen that the conveyance failure of sludge aggregated in a lump or cotton shape is reduced by 70%, and the conveyance capability is greatly improved.
[0020]
Example 2
In the rotary drum type magnetic separation apparatus having the configuration shown in FIG. 1, the squeezing roller 6 shown in FIG. 2A has liquid wetting portions 6a and 6b at both ends. When two grooves 6c each having a width of 0.1 mm and a depth of 10 mm are provided in each of the parts 6a and 6b, the liquid wetting part is reduced only to the part outside the outermost groove part 6c, and the sludge scraped by the scraper 7 8 was drastically reduced.
[0021]
Example 3
As shown in FIG. 3A, when a punching metal having small holes 9a having an inner diameter of 0.5 mm drilled at intervals of 1 mm is used for the scraper 9 to be brought into contact with the rotating drum 3, the weight of the sludge 8 to be separated and recovered is not perforated. It can be seen that it is reduced by 8% compared to the conventional case, and the liquid running out is greatly improved. Moreover, the scraper by punching metal improved 71% compared with the conventional scraper regarding the liquid breakage at the time of no load.
[0022]
【The invention's effect】
The rotating drum type magnetic separation device according to the present invention has a surface layer of a required depth on the surface of the rotating drum that is modified , specifically ferritized into a magnetic material, so that the sludge has an attractive force other than the magnetic force of the magnet. The suction force from the surface of the rotating drum that is temporarily magnetized by the magnet acts, and the conveying force is improved against the frictional force on the surface of the rotating drum to reduce the occurrence of sludge conveyance failure, or the squeezing roller A circumferential groove is provided to reduce liquid wetting at both ends of the roller, and a punching metal with a selected bore diameter can be used as a scraper to improve fluid breakage. By doing so, the conveyance capacity and the solid-liquid separation efficiency are further improved by a synergistic effect.
[Brief description of the drawings]
FIG. 1 is a longitudinal explanatory view showing the entire configuration of a rotary drum type magnetic separation device according to the present invention.
FIG. 2A is an explanatory diagram showing details of the positional relationship between the rotary drum and the squeezing roller of the rotary drum type magnetic separation device, and FIG. 2B is an explanatory diagram of the squeezing roller according to the present invention.
FIG. 3A is an explanatory view showing details of a positional relationship among a rotary drum, a squeezing roller and a scraper of the rotary drum type magnetic separation device, and FIG. 3B is an explanatory view showing details of the scraper according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body 2 Liquid storage part 3 Rotating drum 4 Magnet 5 Inner cylinder 6 Drawing roller 6a, 6b Liquid wetting part 6c Groove part 7, 9 Scraper 8 Sludge 9a Small hole

Claims (3)

In a magnetic separation apparatus comprising a rotary drum made of a non-magnetic material and having a built-in inner cylinder with magnets arranged at required positions on the outer peripheral surface and comprising a squeezing roller and a scraper in contact with the rotary drum, the entire surface of the rotary drum Alternatively, a rotating drum type magnetic separation device provided with a magnetic layer in which a required portion is made into a magnetic material at a required depth and the structure of the surface of the rotating drum made of stainless steel is ferritized .   2. The rotary drum type magnetic separation device according to claim 1, wherein at least one circumferential groove is provided at both ends of the squeeze roller. According to claim 1 or 2, scraper is required dimension, rotary drum-type magnetic separator comprising a plate material arranging a large number of holes of shapes.

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