Vacuum negative pressure filter is one of the effective filtration equipment for filtering machine tool coolant. It generally uses recyclable filter belts or disposable filter paper, with a filtration accuracy of 5-15 microns. Stainless steel wedge-shaped filter screen is used for filtration, with an accuracy of about 50 microns. Small vacuum negative pressure filter generally refers to a flow rate less than 200L/min, suitable for filtering the coolant of a single machine tool. The vacuum negative pressure filter uses a water pump to suction and force the liquid through the filter layer. The dirty liquid enters the dirty liquid tank first, and there is a mesh plate at the bottom. The vacuum chamber is located below the dirty liquid tank. Lay recyclable filter belts or disposable filter paper between the sewage tank and the vacuum chamber to filter solid particles. Centrifugal pumps pump liquid from the vacuum chamber for use in machine tools, providing filtration and liquid supply functions. Vacuum negative pressure paper tape filters can generate higher pressure than gravity paper tape filters, allowing liquids to penetrate into the filter medium. The working pressure of a vacuum negative pressure paper tape filter water pump is generally at least 3-5 bar. In contrast, the liquid flow rate of a vacuum negative pressure paper tape filter with the same flow rate can reach 4-6 times that of a gravity paper tape filter, and one advantage is that it can save a lot of space.　　

With the increase of impurities in the filter medium, the passing speed of the liquid decreases, thereby changing the vacuum degree inside the vacuum chamber. When the vacuum degree reaches the preset value, the PLC control automatically starts the regeneration cycle. During this process, the water pump will not be affected, new filter media will be input through the conveyor belt, and dirty filter media will be discharged. Due to the short update cycle, only a small portion of the filter material is discharged, while a large amount of filter cake that can improve filtration efficiency is retained to ensure filtration quality.

The seal between the sewage tank and the vacuum chamber is a simple and reliable hydraulic seal that does not require maintenance. The transmission mechanism is only used for transmitting used filter media and impurities. The sturdy design can meet the requirements of heavy-duty transmission. Meanwhile, the vacuum negative pressure paper tape filter can save liquid consumption because the regeneration stroke time of the filter medium is short, allowing enough time for the liquid to return. The characteristics, permeability, cleanliness required for liquids, and cost considerations of solid impurities are crucial for choosing a vacuum negative pressure paper tape filter or a gravity paper tape filter.

The purpose and characteristics of vacuum negative pressure filter:

1. Application of vacuum negative pressure filter: mainly used to filter water and impurities in transformer oil, lubricating oil, turbine oil, engine oil, diesel, fire oil, aviation hydraulic oil and other oils. It can also be made of stainless steel for long-term use.

2. Structure of vacuum negative pressure filter:

The vacuum negative pressure filter is composed of a filter bed, a combination of multiple filter chambers, an oil pump, a coarse filter, and other components. Filter paper or filter cloth is lined between the filter plate and the filter frame as the filtering medium. Using the pressure of the clamping device, fix the filter plate and filter frame to form a separate filtering chamber. The filter paper or filter cloth pressed between the filter plate and the filter frame plays a filtering role.

3. Characteristics of vacuum negative pressure filter:

The vacuum negative pressure filter has the advantages of simple structure, easy operation, low operating cost, and not limited by site. The purification of lubrication and cooling systems for large equipment should carefully use plate and frame oil filters to ensure the normal operation of the equipment, extend the oil change cycle, not only save production costs and energy, but also protect the environment. Therefore, vacuum negative pressure filters are widely used in the power, petrochemical, and machinery industries.