"Innovative filtration technology in the automotive industry

This article focuses on some innovative filtration and separation technologies used in the automotive industry. The article focuses on the application of these technologies in the field of engine manufacturing. First, it briefly reviews the technical trends of engine work and their impact on filtration requirements, and then introduces the progress of filtration and separation technologies used in engine manufacturing, mainly discussing oil mist Cleaning, magnetic filtration of coolant and cleaning of engine parts. The filtration and separation process involved in the production of motor vehicles: one is the need to filter during the production of molds for the manufacture of car body parts, and the other is the need to separate solids from the car body treatment solution, paint and paint. Finally, the article introduces an innovative technology used in automobile assembly and maintenance processes.

Engine manufacturing

In the internal combustion engine industry, liquid and air filters are currently using more efficient materials, using various innovative technologies, such as the introduction of nanomaterials in filters produced by Porvair Filtration. This filter uses P2i Ltd's patented nano coating technology. This technology uses a pulsed ionized gas (plasma) generated in a vacuum chamber to attach a nano-scale polymer film layer to the entire surface of the filter product through intermolecular adhesion.

Richard Canepa, a business development consultant at RTC Consulting, reported that with regard to filter housing design, the current trend is to develop compact filter systems, such as Z-pleated filters. Richard Canepa said: ""The more eco-friendly filter housing is also a design trend, which aims to minimize the waste materials in the recycling process, such as the filter element of the oil filter, whose housing has become a part of the engine.""

Richard Canepa added: “As cars develop from the era of internal combustion engines to the age of electronics, it is necessary to combine air and gas filtration, especially when using fuel cells. There are also many research and development work on new technologies. In progress, such as HCCI (Homogeneous Compression Ignition) engines, and more and more applications of direct injection technology. Because of the use of exhaust gas recirculation, high-temperature filtration systems are increasingly needed to filter the recirculated exhaust gas on direct injection engines. .""

The following focuses on the filtration process used in the manufacture of automobile engines, without considering the filtration issues involved in engine operation, so now we focus on three innovative technologies, which are used for oil mist removal, coolant magnetic filtration and engine Cleaning of parts.

The development of engine technology and manufacturing technology has obviously tightened the tolerances of machined parts. This has increased its need for filtration and separation technology to remove particles and debris from coolant, lubricating fluid and cutting fluid. Through the use of effective filtering, the problem of short tool life can be avoided, thereby reducing defects and reprocessing of machined parts.

Oil mist removal

For many automakers, oil mist filtration has now become one of the more and more concerns. Due to the high-speed operation of the machine tool, the coolant delivery pressure is higher. The traditional electrostatic and centrifugal oil mist recovery system will cause the coolant oil mist to escape into the atmosphere of the workshop along with other pollutants (such as tiny debris and bacteria, etc.). This has spurred relevant parties to conduct health and safety research aimed at investigating the potential link between oil mist and serious respiratory diseases such as occupational asthma and exogenous allergic alveolitis.

The Vokes Air Group company has developed a new method to remove oil mist. The company's ScandMist technology uses a three-stage filtration process. The first two stages of filtration eliminate the oil mist in the air, and the last stage of filter can clean the air so that it can return to the local atmosphere.

A high-performance fan blows the contaminated air out of the filters at all levels. The oil filter recovers oil mist or coolant and discharges it to the bottom of the ScandMist device. The contaminated air passes through the filter medium, and the oil mist particles are adsorbed on the oleophobic fibers; the oil droplets constantly touch the fibers and become larger. As the oil droplets become larger, they gradually become heavier and drip, and are blown down to the bottom of the ScandMist device by the airflow, where the oil mist can be recovered or directly drained back to the machine oil pool. The purified air then passes through a high-efficiency condenser, where the condensation process is repeated. According to Vokes-Air Group, after secondary filtration, the oil mist in the air has been removed on average by 95%-98%.

The third-stage filter is designed to thoroughly clean the remaining air to a standard that is much higher than the cleanliness of the surrounding atmosphere. The last level of filtration uses HEPA filters to trap ultrafine particles (such as traces of oil, smoke, bacteria, pollen and spores) and prevent them from returning to the workshop. The HEPA filter used here has a working efficiency of 99.95% and a filtration grade of 0.3 microns.

This means that in the workshop environment, all harmful particles are effectively collected, ensuring that only clean air returns to the workshop.

Many car manufacturers have installed oil mist filtration systems on their production equipment. Despite the economic downturn during this period, the Vokes-Air Group of Companies reported that they still received a large number of ScandMist system orders.

Coolant filtration

The Micromag magnetic filter produced by Eclipse Magnetics is currently widely used in reaming and boring processes to remove particles and debris. It can not only reduce processing costs, but also improve the quality, accuracy and surface quality of processed products.

Honda has applied Eclipse Magnetics' Micromag technology to a custom boring machine at its Swindon plant in the UK. This machine tool is designed and manufactured by Honda's Engineering Department to produce engine valve seats-an engine part that requires high product accuracy and surface quality.

Honda's engineers discovered that the fine metal particles carried in the coolant of the machine tool would adversely affect the surface quality of the processed valve seat, thereby reducing engine efficiency.

Peter Jones, the field engineer in charge of the process, believes that magnetic filtration is a feasible solution. Peter Jones said: ""Since the introduction of the Micromag magnetic filter in our process, we have found that it not only effectively removes potentially harmful metal particles, but the easy maintenance of the equipment also ensures that our machine tool maintenance downtime is minimized. .""

The magnetic core in the Micromag is composed of neodymium iron boron magnets, which can generate high-intensity magnetic fields. The coolant enters the shell and is evenly distributed around an aluminum cover along the tapered flow channel. The liquid stream flows downward through the outside of the magnetic core, where the magnetic particles are absorbed by the high-intensity magnetic field.

The magnetic core at the center utilizes a geometric magnetic circuit. The magnets are arranged around a central magnetic flux return cover to ensure that all magnetism is utilized. Even when the magnetic core is completely saturated due to contamination, the unaffected coolant can still flow.

Parts cleaning

The water washing or chemical cleaning process relies on fine filtration to ensure that there are no other particles on the engine parts. The aqueous solution needs to be configured with high-purity water, and the reverse osmosis membrane (RO) technology can meet the required specifications.

Electropositive reverse osmosis pretreatment technology has been widely used in high-purity water treatment systems to extend the service life of permeable membranes. In fact, all reverse osmosis membrane manufacturers have set a minimum standard for the water supply of their systems to maintain system integrity and return on investment. It is generally stipulated that the turbidity of feed water should be less than 1.0 NTU (turbidimetric turbidity), and the pollution density index (SDI) should be less than 3.0.

Argonide has compared its NanoCeram positive electric pleated filter element with several commercial reverse osmosis prefilters currently on the market. Argonide said that the NanoCeram filter element has more obvious advantages than these existing commercial filter elements in removing sub-particles. Under extreme load, the NTU value produced by NanoCeram is lower than the detectable limit value, and the SDI value is comparable to ultrafiltration membranes-assuming that the reverse osmosis membrane that is prone to premature contamination has been protected for a long time.

The NanoCeram filter has been installed in a reverse osmosis system at Toyota's manufacturing plant, which uses municipal water. Before these positive filters were installed, the average SDI of the system feedwater was 4.42. After installing the NanoCeram filter element, the average SDI is 1.19.

Before installing the NanoCeram filter, Toyota had to clean the reverse osmosis membrane every 1-2 weeks and replace the membranes every 2-3 months due to the early and irreversible contamination of the reverse osmosis membrane. After installing the NanoCeram filter cartridges, after an initial start-up period of 2 months, these reverse osmosis membranes have been in operation for a year without cleaning.

Production of vehicles

In this section, we focus on some innovative technologies used in the production, cleaning, surface treatment and subsequent multi-layer painting of car body parts. We introduced the removal of sulfur dioxide in the production of molds, the separation of solids in pretreated phosphate solutions, and another innovative application of magnetic filters in painting workshops, thereby extending the service life of existing cartridge and bag filter devices.

Casting

Special sand molds are required to produce body panels. In the sand mold curing process, sulfur dioxide gas needs to be removed. Gotaverken Miljo delivered a sulfur dioxide cleaning system to Volvo Powertrain's foundry in Skovde, Sweden. The air stream to be cleaned contains a large amount of sulfur dioxide with a concentration of approximately 70 g/Nm3. Because the sand mold used in the casting process needs to be solidified with sulfur dioxide, the demand for gas treatment is increasing.

The blower pumping system can be used to remove contaminated sulfur dioxide in the sand mold. In the reactor, the blower pressurizes the gas, and the gas and lime are mixed and reacted to form gypsum. A small amount of sulfur dioxide diffuses out of the sand mold and enters the surrounding cavity. These gases are collected and passed into a scrubber, where sulfur dioxide is converted to sulfuric acid. In another process, these sulfuric acid will be converted into gypsum.

The process does not discharge sulfates into the water, and the concentration of sulfur dioxide discharged into the air is very low. Gypsum is the only residual product formed, and it can be recycled for use in the cement industry.

Surface treatment

The car body assembly requires several steps, and each step of the work will produce waste particles, causing pollution and affecting the subsequent painting process. Welding car panels and side pillars to the frame will produce weld metal spatter, and fine grinding will also bring grinding particles and debris. Dust in the atmosphere of the workshop may also be contaminated on the panel. Therefore, these contaminants must be removed before the initial surface treatment to provide a smooth surface for the painting process.

Cartridge and bag filter systems are widely used in automobile manufacturing processes and many treatment processes to remove coarse and fine particles. In the automotive industry, they are mainly used for surface treatment and filtration of various paints and coatings in paint spray shops.

Phosphate paint is usually used for the first surface treatment. In the subsequent painting process, a variety of paints (usually 5 layers) are sprayed to achieve the final appearance. Contamination of the metal surface before the first coat of phosphate paint can cause obvious defects in the finished vehicle after the five coats of paint. Although the industry has established standards to allow a certain number of defects on each car body panel, if the number of defects exceeds the acceptable limit, manual inspection and manual polishing are required, which will increase the cost of automakers. The efficiency is reduced.

Pre-cleaning before phosphate coating

A large automobile manufacturer located in Detroit, USA, due to the insufficient processing capacity of the current bag filter system, resulted in unsatisfactory spraying defects and obvious flaws in its automotive products.

Although the bag filter method they used was once effective in removing fine fibers (about 150-400 μm), they could not remove other large-particle contaminants that caused defects, such as solder balls and grinding particles. The use of finer grade filter bags will bring maintenance and cost issues, while the use of coarser grade filter bags will cause many potential spray defects. Obviously, the bag filter is not effective in eliminating solder balls and grinding debris.

The car manufacturer realized that it was necessary to remove all solid impurities during the pre-cleaning operation of the car body before spraying the phosphate coating. They installed a Lakos separator as a pre-treatment system on the washing water circulation line before the bag filter to effectively perform pre-filtration to remove large particles such as solder balls, grinding fine particles and slag.

The use of a separator to remove these heavier solid particles enables the bag filter to bear a larger load composed of small particles, removes fibers and sealants, extends the service life of the bag filter, and improves the efficiency of the micron filter bag. Therefore, Lakos said that in some car factories, spray defects have been reduced by as much as 85%. The automaker has now adopted the process worldwide.

Paint and coating filtration

Amazon FerroStik’s magnetic pre-filter is another innovative application of magnetism, designed to extend the service life of bag filters and cartridge filters in paint and coating filtration applications. By applying magnetic pre-filtration technology upstream of these filters to protect them, their performance can be significantly improved, and the cleanable FerroStik system can extend the life of the filters and improve the quality of the filtrate.

Amazon's system consists of a standard bag filter housing and four high-strength magnetic rods suspended in it. Magnetic filters can remove large and small iron particles, otherwise they will block the final filter or pass through them and remain in the liquid. When the surface of the magnet is covered with iron particles, it can be cleaned online, and then continue to work.

The Amazon FerroStik system can be fixedly installed or connected to a hose for use as a portable device. The magnetic filtration system can be used in single-channel mode or in a circulatory system to remove impurities to the greatest extent. Amazon pointed out that the main advantages of the system include improved filtrate quality, enhanced protection of downstream equipment, extended filter life, and reduced operating costs.

Assembly

After the basic structure of the car is completed, countless parts are installed on the vehicle, and many filtration and separation processes are used in their manufacture, installation and operation. We are here to focus on an innovative technology that applies gas separation technology and can be used in production workshops and local auto repair plants.

Nitrogen for tire inflation

The TyreSaver system developed by Parker Hannifin is specifically designed to fill tires with nitrogen. The system can be installed on a production line or on a smaller scale for use by car repairers in the tire assembly and repair process. Parker Hannifin said that compared with ordinary compressed air commonly used for tire inflation, dry nitrogen leaks from tires 3-4 times slower than the former. This brings a variety of benefits, including long-term tire pressure stability and greater resistance. Small, less wear (25%), lower fuel consumption (8%), less carbon dioxide emissions, better performance, and higher safety.

Parker’s system uses hollow fiber-based gas separation membrane technology. Composed of thousands of hollow fibers"