JP2015223692A - Floating oil collection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently collect a floating oil on a surface of a coolant liquid which is circulated in a coolant tank, and prevent the floating oil from returning to a processing point.SOLUTION: A V-shaped partition 5 for efficiently holding and accumulating the floating oil on a coolant tank channel, is installed for preventing the floating oil from returning to a processing point, a belt of an oil skimmer 1 is installed on a floating oil accumulation position so that the belt contacts the liquid, and on both surfaces of the belt of the oil skimmer 1, a scraper is provided respectively, or a groove and a projection are installed on a pulley, thereby a collection efficiency of the floating oil is improved. The partition can hold and accumulate the floating oil more efficiently, by adjusting an aperture of the partition (a sharp angle formed by two partitions, and a gap formed by a bottom part of the partition and a bottom part of the tank), and prevents the floating oil which is left without being collected by the oil skimmer from returning to the processing point, so that, floating oil collection efficiency in whole system can be improved.

Description

The present invention relates to improvements in parts that contribute to the efficiency of floating oil recovery of an oil skimmer installed in a coolant processing apparatus.

In advanced manufacturing technology such as aircraft parts and next-generation automobiles, a large amount of coolant is used to maintain machining accuracy. Especially when machining difficult-to-cut materials, a large amount of coolant must be continuously poured into the processing point to prevent product distortion due to processing heat, to prevent deformation of the processing jig and spindle, and to prevent rust.

The coolant is mixed with lubricating oil supplied during machining of the machine tool, and gradually becomes dirty and decays with time. As a result, the machine accuracy decreases, the machine tool stops, and the line stops. The deteriorated coolant must be discarded or purified and recycled.

When purifying the coolant liquid, mainly floating oil is manually removed or automatically removed by a device such as an oil skimmer. However, when a large amount of coolant is used, it is not easy to efficiently recover oil (floating oil) that floats on the surface of the coolant that flows in a large tank. On the other hand, if the tank is made smaller, the coolant liquid is agitated and hinders the floating of the oil, and therefore cannot be recovered efficiently.

An oil skimmer, which is one of the general methods for collecting floating oil, consists of a belt for absorbing and collecting floating oil as a basic structure, a drive unit that rotates the belt, and a scraper that scrapes off the oil collected and absorbed by the belt. Become. The belt sinks into the coolant liquid in the coolant tank by the drive unit, returns to the upper part while adsorbing the floating oil on the surface, and the floating oil is recovered by the scraper.

Various techniques and devices have been developed in order to increase the oil collection efficiency of oil skimmers, which is one of the common techniques for collecting floating oil. Without changing the basic structure of the oil skimmer, a method for improving the specifications such as the installation position (Japanese Patent Application No. 2011-036816), the material and width of the belt, or a rotating disk having a large area instead of the belt (Japanese Patent Application Laid-Open No. 07-024455) There are things that use.

For example, a method has been developed in which the installation position is devised in order to increase the collection efficiency, or the guidance and accumulation to the collection position of floating oil is attempted (Japanese Patent Application No. 2011-036816). However, such attempts are also supplied for each part, and there are few studies on floating oil recovery systems with the entire coolant tank in mind. Chip manufacturers that collect cutting waste mixed with coolant, oil skimmers that collect floating oil, and processing tanks that install them are provided by different manufacturers. This is the current situation. For this reason, the processing performance is not optimized, and the entire floating oil recovery system is not optimal in accordance with the current situation at the site.

JP 07-024455 JP2000-072084 JP 2000-079389 Japanese Patent Application No. 2011-036816 JP2012-183513 Utility model registration No. 3162303

Factors that limit the recovery efficiency of floating oil can be broadly divided into two factors: the factor in the specifications on the oil skimmer side and the factor in the method of guiding floating oil. The factors on the specifications on the oil skimmer side are the material, width, installation position, etc. of the belt that absorbs and collects floating oil. Factors in the method of guiding the floating oil include the shape of the coolant tank, the circulation method of the coolant, and the installation position and shape of the partition plate installed in the coolant tank.

As a device for improving the oil skimmer side specification to increase the collection efficiency of floating oil, there is a technique that employs a large area rotating disk (Japanese Patent Laid-Open No. 07-024455). However, there is a problem that the size of the apparatus is increased and it is not possible to meet the demands of the field that attempts to improve the working environment by reducing the size of the apparatus. Also, a method using a pump has been developed as a technique that does not use a belt and does not increase the size of the apparatus (Japanese Patent Laid-Open No. 2012-183513). However, in this method, it is essential that the floating oil is guided to the collection position, that is, the floating oil suction position by the pump. In addition, it is necessary to install a pipe in the tank for sending floating oil collected by the pump to the outside of the tank.

As a factor in the method of guiding the floating oil, a method has been proposed in which the floating oil is guided to the floating oil collection position of the oil skimmer while circulating the floating oil (Japanese Patent Application No. 2011-036816). However, this case has a drawback that the floating oil that could not be recovered by the oil skimmer is mixed again in the coolant and returned to the processing point together with the coolant. In addition, in the case of the floating oil guiding method using a partition for circulating the coolant liquid, depending on the flow path width, the floating oil does not necessarily pass near the belt of the oil skimmer, and the flow path is narrowed to the belt width. As a result, the passage speed of the coolant liquid is increased, leading to a result of lowering the floating oil recovery efficiency of the oil skimmer. There have been various proposals for floating oil guidance methods in other fields (JP 2000-072084, JP 2000-079389), both of which have been developed for the purpose of collecting floating oil that has flowed into the sea or lakes. It is not a technique optimized for the purpose of recovering floating oil floating on the surface of the so-called coolant with an oil skimmer, and is not applicable.

Patent Document 6 (Utility Model Registration No. 3162303) is a technique that combines a device that prevents the apparatus from becoming large and induces floating oil. A partition plate that circulates the coolant at a specified speed is installed in the coolant tank, and an oil recovery unit is installed at a position where the floating oil accumulates. The oil recovery unit always floats on the coolant surface by a weight, and sucks the floating oil. Can be recovered. The recovered floating oil is discharged through a pipe below the collector. However, this method is a device that requires installation work in the case of a work site where a coolant tank has already been installed and operated. In addition, it is difficult to control the installation position of the oil recovery unit due to the influence of the coolant liquid flow. In some cases, the oil recovery unit is separated from the accumulation position of the floating oil, and the recovery efficiency decreases.

The system that is mainly required at the work site is a device that has high recovery efficiency, is small, and is easy to install and maintain. In order to achieve such a problem, it is necessary to construct a system that can improve the collection efficiency by utilizing existing equipment, minimizing changes in specifications, and installing simple parts.

At our company, we have been engaged in the improvement of coolant treatment equipment in response to requests from customers for chip conveyors and magnet separators that have been provided in the past. For example, in order to improve the recovery accuracy of the chip conveyor, the specification and mounting position of the circulation pump installed in the processing tank are changed, the partition plate is installed in the tank to optimize the coolant flow, or the performance of the oil skimmer We have developed and provided our own partition plates for improvement. As a result of such systematic measures, we were able to achieve a significant improvement in the recovery efficiency of floating oil while maintaining the specifications and dimensions of the conventional oil skimmer.

However, there is a limit to improving each elemental technology individually, and the introduction of the entire system has been required from the field. In addition, we have also found that it is possible to achieve zero waste by examining all systems. Therefore, the development of coolant treatment system was examined. Specifically, we have newly designed a coolant treatment tank that maximizes the purification performance of the following equipment that has been individually examined so far, and devised various combinations of multiple coolant treatment equipment with multiple processes to develop Went.

As a result, it is found that the floating oil of the coolant liquid circulating in the tank has a property of locally accumulating according to the flow, and that a recovery method using the property can be realized at the lowest cost. Attention was focused on the installation of partitions to accumulate floating oil more efficiently. The basic structure of the partition is a partition for accumulating floating oil floating on the surface of the coolant liquid and retaining it in one place, and there is a gap for circulating the purified coolant liquid in the lower part. By installing the partition in the tank, even if the oil skimmer cannot collect the floating oil, the partition stays at the accumulation position, and only the coolant liquid circulates in the tank through the lower part of the partition, and as a result is purified. It was found that only the coolant liquid returned to the processing point and could be reused.

It was also discovered that the oil skimmer's floating oil recovery efficiency is greatly improved by installing an oil skimmer at the floating oil accumulation position formed by the partition. In order to further improve the recovery efficiency, prototypes of various shapes were prototyped, and as a result of investigating the method of flotation oil accumulation, the character shape was the simplest and most effective, and there was an appropriate opening for the character shape. Turned out to be. And it was found that the floating oil accumulated in the partition of the appropriate condition can achieve surprising recovery efficiency by installing an oil skimmer at the accumulation position.

Furthermore, while searching for improvement of the floating oil recovery efficiency based on the basic structure of the floating oil recovery system with the above partitions installed, the amount of floating oil adhering to the oil skimmer belt is large, but the belt is driven by the pulley inside the oil skimmer. The floating oil adhering to the back side of the steel was pushed out and sometimes dropped to the bottom. In studying various ideas to overcome this problem, it has been found that if grooves and protrusions are processed in the pulley, the falling of the floating oil adhering to the belt in a large amount can be greatly reduced. Grooves and protrusions machined on the pulley create a gap between the belt and pulley, preventing oil from being pushed out. Furthermore, in order to reliably collect a large amount of floating oil not only on the front side but also on the back side of the oil skimmer belt, it is possible to collect the floating oil more efficiently by installing scrapers on both sides of the belt. I found By combining the above partitions, and improved pulleys and scrapers, we found that they are synergistic and interlocked, and that the floating oil can be recovered significantly efficiently. As a result, the floating oil is processed. It was confirmed that it did not return to the point, and the present invention was reached.

By employing the present invention, the floating oil can be recovered more efficiently and while preventing the entire system from becoming large.

  Floating oil recovery system structure diagram   Oil skimmer and grooved pulley

The floating oil recovery system 6 includes an oil skimmer 1, a coolant tank 2, a pump 4, a partition 5, and other incidental equipment. The coolant tank 2 in which the oil skimmer 1 is installed is supplied with the coolant liquid used in the machine tool, purified, and then returned to the machine tool again. However, this figure is only an example, and the actual shape and structure of the coolant tank is not limited to this. The inventors first invented a method of circulating the coolant liquid in the coolant tank 2 and have intensively studied the circulation speed and the flow path for circulation. In the present invention, when the oil skimmer 1 is installed in the flow path, by providing the partition 5 at the installation position, the floating oil is retained, and the recovery rate of the floating oil is improved.

That is, by installing the V-shaped partition 5 in the flow path of the coolant tank 2, the floating oil moving on the water surface stays and accumulates in the V-shaped acute angle portion of the partition without being emulsified. Since the accumulation of floating oil stays and accumulates with the V-shaped sharp corner as the head, installing the oil skimmer recovery belt in contact with this accumulation position maximizes the floating oil recovery rate. be able to.

Only the coolant liquid purified from the gap between the bottom of the partition 5 and the bottom of the tank 2 circulates and can be reused. The floating oil that the oil skimmer 1 could not be collected temporarily stays at the sharp corner of the partition and is collected again by the oil skimmer to increase the collection efficiency and prevent the floating oil from returning to the processing point again.

As a result of the partition 5, although a large amount of floating oil adheres to the belt 8 of the oil skimmer 1, the belt 8 is rotated by a pulley inside the oil skimmer 1, and the pulley is in contact with the back side of the belt 8. The floating oil adhering to the back side of the oil may be pushed out by the pulley and fall to the lower part. In this case, if grooves and protrusions are processed in the pulley, it is possible to greatly reduce the falling of the floating oil that has adhered to the belt 8 in a large amount. The grooves and protrusions processed in the pulley create a gap between the belt 8 and the pulley 7 and prevent the oil from being pushed out. Further, in order to reliably collect a large amount of floating oil adhering not only to the front side but also to the back side of the belt 8 of the oil skimmer 1, the floating oil is more efficiently collected by installing scrapers on both sides of the belt 8. be able to. By combining the partition 5, the pulley 7, and the scraper as described above, the floating oil can be efficiently recovered, and a floating oil recovery system provided with an inexpensive partition and other parts that do not return to the processing point can be provided. .

The recovery rate of the floating oil in the coolant liquid was evaluated using the coolant tank 2 in which the oil skimmer 1 was installed. The recovery rate of the floating oil is improved and the return to the processing point of the floating oil is eliminated, so the defective rate of the product is improved. A V-shaped partition 5 was installed at the center of the coolant tank 2 (2000 × 400 × 400 mm), and an oil skimmer was installed at the V-shaped floating oil accumulation position. Two types of oil skimmers were used, manufactured by Company A (resin belt, belt width 50 mm, belt feed speed 5.3 m / min) and Company B (metal belt, belt width 30 mm, belt feed speed 2.8 m / min). ). 160 L of tap water was put into the coolant tank 2, and 1 kg of machine oil (Noritake cut) was gently poured onto the water surface 3. Tap water and oil in the coolant tank were circulated using a pump 4 (VKN115A manufactured by Teral Co.). Two types of oil skimmers were operated separately, and the amount of floating oil recovered with and without partitions was evaluated.

As a result, in the case of Company A, the amount of floating oil recovered was 0.35 kg per 10 minutes when partition 5 was not provided, but was 1.6 kg when partition 5 (opening 90 °) was provided. . When the partition 5 was not provided, not only the recovery amount was small, but also an emulsion phenomenon was observed. In comparison between Company A and Company B, it was found that the higher the belt width and the higher the belt feed speed, the better the recovery rate.

Simultaneously with the partition 5, a scraper for collecting floating oil adhering not only to the front side but also to the back side of the belt 8 of the oil skimmer 1 is installed, and a groove (pulley of the pulley) is further rotated to rotate the belt 8 of the oil skimmer 1. 12 grooves with a width of 1.27 mm and a depth of 1.4 mm were processed on the circumference. As a result, the grooved pulley 7 makes it difficult for the floating oil adhering to the back side of the belt 8 to fall, and the scraper can recover it more efficiently, and 1.6 kg of floating oil recovery takes 10 minutes. It became possible to collect in 7 minutes.

As mentioned above, Japan has an important direction as a technological nation to develop and export more advanced precision processing machines, but we will promote it as a waste liquid treatment device indispensable for such machine tools. The machine tool performance is also demonstrated correctly, and high trust from users can be obtained. In order to gain recognition from the world as a supplier of precision processing machines that work stably, the zero waste liquid combined floating oil recovery system of this project can gain a ripplely large market.

1, oil skimmer 2, coolant tank 3, water surface 4, pump 5, partition 6, floating oil recovery system 7, pulley 8, belt

Claims (4)

In a floating oil recovery system that is installed and used in a coolant tank with a partition plate that forms a flow path for circulating the coolant in one direction, the vertical partition is in the middle of the flow path with a gap at the bottom of the tank. The floating oil recovery system is characterized in that the floating oil stays and accumulates in one place and the oil skimmer is installed at the accumulation position. 2. The floating oil recovery system according to claim 1, wherein the opening of the U-shaped partition is 60 to 120 ° and the gap with the bottom is 10 to 200 mm. 3. The floating oil recovery system according to claim 2, further comprising a scraper for collecting floating oil adhering not only to the front side but also to the back side of the belt of the oil skimmer. 4. The floating oil recovery system according to claim 2 or 3, wherein a groove or a protrusion is provided in a pulley for rotating an oil skimmer belt.

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