JPH032004B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for treating steel cold rolling coolant, and more specifically, the present invention provides a method for treating steel cold rolling coolant, and more specifically, a method for treating coolant used in cold rolling of steel materials by subjecting the coolant to an electromagnetic filter at a high flow rate. The present invention relates to a method for treating steel cold rolling coolant that efficiently removes iron, an impurity component, while suppressing as much as possible the removal of oil, which is an effective component of coolant.

Coolant is used in cold rolling of steel materials mainly to prevent seizure. This type of coolant is like an aqueous emulsion of oils such as various animal and vegetable oils and mineral oils, but as it is used, a large amount of iron, which is an impure component, becomes mixed into the coolant. Therefore, in preparation for circulating and reusing the coolant after use, it is necessary to remove the iron content from the coolant.In this case, it is necessary to remove the iron content efficiently, and at the same time remove the active ingredients in the coolant. Therefore, it is requested that the removal of oil content be suppressed as much as possible.

Conventionally, used steel cold rolling coolant has been treated with a magnetic separator using a permanent magnet such as a disk type or a drum type.

However, such conventional methods have the disadvantage that iron content is insufficiently removed and, in particular, a large amount of oil content is carried out along with the iron content.

The present invention solves the conventional drawbacks as described above.
An improved method for treating steel cold rolling coolant is provided.

Hereinafter, the configuration of the present invention will be explained in detail based on the drawings.

FIG. 1 is a schematic diagram illustrating a processing system according to the present invention. The coolant 2 used in the steel cold rolling equipment 1 is temporarily stored in a tank 3, and a part of it is returned to the steel cold rolling equipment 1 via a valve 5 from the tank 3 via a pump 4, while the rest is The coolant is supplied to an electromagnetic filter 7 via a valve 6, subjected to magnetic separation treatment by the electromagnetic filter 7, and the treated coolant is circulated and reused to the steel cold rolling equipment 1 via a valve 8. Of course, during processing, the valve 5 can be closed to process the entire amount, and when the electromagnetic filter 7 is backwashed, the valve 6 can be closed and the valve 5 can be opened for bypass.

FIG. 2 is an enlarged perspective view (partially cut away in section) illustrating the electromagnetic filter 7. FIG. Container 7 with an opening
Inside a, a laminated filter section 7d composed of magnetic thin wires 7c supported between upper and lower pole pieces 7b is loaded, and an excitation coil 7e is attached to the outside of the container 7a.

In the present invention, the electromagnetic filter 7 includes magnetic thin wires 7c filled in a magnetic field space, as shown in FIG.
It is a general term for magnetic separators that capture particles by generating a high magnetic field gradient around them, and continuously processes the coolant after use, so that the iron content in the coolant continues to be captured. The iron trapped and accumulated in the filter section 7d is transferred to the valve 9, the electromagnetic filter 7 and the valve 1 at regular intervals, for example.
It is backwashed by a separate system formed by 0 and discharged to the outside of the system.

According to the present invention, the degree of iron removal is improved, and in particular, the amount of oil carried out with the iron can be significantly suppressed. In the conventional method described above, iron content is usually removed by only about 50% (by weight), and about eight times the amount (by weight) of the removed iron content is removed. In contrast, in the present invention, more than 90% (weight) of iron can be removed depending on the processing conditions, and on the other hand, approximately 1.5 times the amount (weight) of iron removed
This makes it possible to suppress the oil content to a certain extent.

This result is due to the fact that in the conventional method using a magnetic separator using permanent magnets, it is difficult to obtain a high magnetic field gradient due to its configuration, and the flow of the coolant to be treated is static, laminar, and slow. In contrast, in the present invention, due to the structure of the electromagnetic filter, a high magnetic field gradient is formed around the magnetic wire, and when iron is captured by the magnetic wire, the flow of the coolant to be treated is moved. This is because the flow is precise, turbulent, and high-speed, so that the oil content itself is not entrained, and this state of entrapment continues for a certain period of time, so that the oil content that has been entrained and captured once again flows into the coolant.

Due to its configuration, electromagnetic filters can process used coolant at a higher flow rate than conventional magnetic separators that use permanent magnets. When treated with an electromagnetic filter, it was found that the flow rate affected the amount of oil taken out due to entrapment and capture. In other words, the flow velocity is 600m/
When the temperature exceeds 100 hrs, the amount of oil carried out per unit amount of iron removed becomes significantly smaller.

In the present invention, the flow velocity refers to the flow velocity at the opening portion when wire mesh structures made of magnetic thin wires are laminated. This situation is shown in FIG. FIG. 3 is an enlarged schematic view of the filter section shown in FIG. 2, illustrating the flow state of the coolant. For example, the porosity of laminated wire mesh made of magnetic fine wire 7c is 50%.
Then, the flow rate A is the flow rate divided by the cross-sectional area of the filter part 7d (generally referred to as LV), assuming that the porosity of the laminated wire mesh made by the filter section 7c is 50%. It will be twice as much. Usually, a wire mesh with a porosity of 40 to 80% is used, and wire meshes include those woven with magnetic fine wires and expanded metal.

Figure 4 shows that in order to make the effects of the present invention more concrete, a used steel cold rolling coolant (beef tallow-based) containing 1200 ppm of iron and 4.5% (by weight) of oil is applied to a filter with a filter diameter of 180 mmφ and a filter cross-sectional area of 0.025m ² , wire mesh porosity 50%, wire diameter 0.8mmφ, filter length 150mm
When treated with an electromagnetic filter (magnetic field 3KOe), iron removal rate (wt%, black solid line in the figure) and oil removal amount per unit amount of iron removed (both This is a graph illustrating the results of weight (white dotted line and dashed line in the figure). As is clear from Figure 2, the iron removal rate decreases in a nearly linear relationship as the flow velocity increases.
If the flow velocity is about 200 m/hour, more than 90% of it can be removed, and even if the flow velocity is as high as 1200 m/hour, more than 75% of it can be removed. It rapidly decreases to below 1.5 when the flow rate exceeds 200m/hour.
Even at times, we have been able to keep it below 4. A similar result is
For example, when the porosity of the wire mesh is varied from 40 to 80%, when the magnetic field is varied from 2 to 6 KOe, and even when these combinations are applied to mineral oil-based coolant, etc. obtained even in the case of

[Brief explanation of drawings]

FIG. 1 is a schematic diagram illustrating a processing system according to the present invention, FIG. 2 is an enlarged perspective view (partially cut away in cross section) illustrating the electromagnetic filter of FIG. 1, and FIG. 3 is a diagram showing the filter section of FIG. FIG. 4 is an enlarged schematic diagram illustrating the flow state of the coolant, and FIG. 4 is a graph illustrating the results of the iron removal rate and the amount of oil carried out per unit amount of removed iron with respect to the flow velocity in the case of the present invention. be. 1... Steel cold rolling equipment, 2... Coolant, 3...
... Tank, 4 ... Pump, 5, 6, 8, 9, 10
... Valve, 7 ... Electromagnetic filter, 7a ... Container, 7b ... Pole piece, 7c ... Magnetic thin wire,
7d... Filter section, 7e... Excitation coil.

Claims (1)

[Claims] 1 Coolant used in cold rolling of steel materials is subjected to an electromagnetic filter in preparation for circulating and reusing the coolant, and the flow velocity in the opening part of the wire mesh filter stacked in the container of the electromagnetic filter is determined. A method for processing steel cold rolling coolant, which is characterized by processing at a high flow rate of 600 m/hour or more.