Searching for effective compressed air dehydration, oil removal, and filtration equipment

Two solutions are recommended for the original poster’s reference: 1. First, use mechanical methods (such as oil-water separators) to separate most of the oil and water, and then connect an alumina or silica gel dryer to remove any remaining oil and water； 2. Separate oil and water using mechanical methods combined with ultrafiltration. The first option is to simply design and purchase it ； In the second option, the person in charge of ultrafiltration can do some research – there are many people doing this these days. This post was last edited by mfjxg on 2009-2-3 10:15.]

Can automatic drainage be achieved using the first method you mentioned? Since the device is unattended, it cannot be drained manually. Also, there are some triple units with an automatic drainage function now; I wonder if they are reliable? Is mechanical or electronic drainage better? If a dryer is added, what is the replacement cycle for the dryer?

Based on the poster’s situation, it is recommended to use the three key pneumatic components. The three main components of pneumatic systems include: air separator and filter, pressure regulator, and oil mister. A component formed by the tubeless connection of three major parts is called a triad. The three key components are essential air supply devices in most pneumatic systems; installed near the equipment that uses air, they serve as the final guarantee for the quality of compressed air. The installation order of the three main components, in the direction of air intake, is the air separator and filter, the pressure regulator, and the oil mister. In use, one or two pieces can be employed according to actual requirements, or even more than three. There are many such products these days; you can find them by simply searching online. Its working principle can be found at http://www.chinajxgcs.cn/yeqi/yeqi-100-21.htm, where it is explained in detail with illustrations.

As mentioned above, it is not suitable for chemical production; the instrument air used in chemical production must be oil-free, so oil misters are not allowed. Moreover, if the air contains a high level of moisture, it can freeze easily in winter, and the air supply pipes for control valves are quite thin.

First, cooling with cooling water is carried out for primary separation; thereafter, further dehydration and deoiling are achieved using an adsorption unit with adiabatic regeneration or mild thermal regeneration; finally, a fine filter is used

Is there a simple way? We have very few devices – just a few control valves. It also occupies very little space, so it cannot accommodate large post-treatment systems.

The situation described by the poster is suitable for ultrafiltration, which allows for automatic drainage without the need for manual intervention.

Based on the gas flow rate mentioned by the poster, a system that combines adsorption, regeneration, drying, and precision filtration can be used; the specific equipment to be selected depends on the requirements of the product gas, such as dew point, oil content, and solid dust content. The requirements mentioned by the poster are still a bit vague; automatic drainage isn’t an issue, as current devices can handle that ； It doesn’t freeze in winter; you need to specify where you are located and what the lowest temperatures are there ； What are the operating conditions for the control valve you are using?

I’m sorry, I didn’t explain it clearly. The device is not meant to be used only in one place; it can be used in the north as well as in the south. But the project I’m working on at the moment is for Wuhan. It is only used to drive on-off valves and control valves. So, let’s not consider areas with very cold climates for now.

I recommend purchasing an oil-free small air compressor, which will save you the need for an oil removal system. The required air volume for wrapping is approximately 40 Nm3/h, and many manufacturers can provide this; it can be found easily by searching online. As for drying, one can follow the standard methods used for air compressor drying; it is sufficient to find a manufacturer to produce a smaller drying device. Moreover, the price of drying equipment is generally not too high; those with a capacity of over a thousand liters cost only a few tens of thousands of yuan. This post was last edited by aigo on 2009-2-4 10:21.]

Ultrafiltration is one of the membrane separation technologies driven by pressure. With the aim of separating macromolecules from small molecules, the membrane pore size ranges from 20 to 1000 Å. Hollow fiber ultrafilters (membranes) have advantages such as a high packing density within a single unit and a small footprint. 　　During the ultrafiltration process, the liquid is pushed by pressure to flow over the membrane surface. Solutes and water molecules that are smaller than the membrane pores pass through the membrane, becoming the purified fluid (filtrate), while solutes and molecular complexes that are larger than the membrane pores are retained and carried away with the flow of water, forming the concentrated fluid. The ultrafiltration process is a dynamic filtration process, with separation taking place while the fluid is in motion. The solute deposits only to a limited extent on the membrane surface; the ultrafiltration rate declines to a certain level and approaches equilibrium, and it can be restored through cleaning. 　　Ultrafiltration originated in 1748, when Schmidt used cotton gel membranes or cellulose membranes to separate solutions; under certain pressure, the solution (water) passed through the membrane while substances such as proteins and colloids were retained. Its filtering precision was far superior to that of filter paper, which led him to introduce the term \"ultrafiltration.\" In 1896, Martin created the first artificial ultrafiltration membrane. The introduction of the concept of molecular weight in the 1960s marked the beginning of modern ultrafiltration. The 1970s and 1980s saw rapid development, and after the 1990s, this technology began to mature. Our country started researching this technology relatively late; it was still in the research phase in the 1970s, and it was not until the late 1980s that it entered the stage of industrial production and application. 　　Like reverse osmosis devices, ultrafiltration devices come in various forms such as plate-type, tubular (internal pressure tube array type and external pressure tube bundle type), spiral-wound type, and hollow fiber type. Concentration polarization is a natural phenomenon in membrane separation processes, and minimizing this phenomenon is one of the key challenges in ultrafiltration technology. The measures currently taken include: ① increasing the water flow velocity over the membrane surface to reduce the thickness of the boundary layer and enable the trapped solutes to be carried away by the water promptly ； ②Apply physical or chemical cleaning methods.

Reply to hyt1973: I haven’t researched the specific aspects related to drying. In the past, for the air compression systems I designed, separate air compression rooms were created, which were not classified as explosion-proof areas. Are you planning to place the equipment in a blast protection zone, or is your entire plant designed according to Blast Protection Zone 2 standards?

If the original poster’s requirements are not high, buy an oil-free compressor as suggested in floor 11. The dryer can be a microheated or heat-free regenerative adsorption dryer.

Let’s think differently. Does your factory have nitrogen? Or a combustible gas with a low dew point? They can all be used more or less

The poster needs to make it Type 2 anti-riot; personally, I don’t think there should be too many problems. But I don’t work in equipment, so I can’t be sure. It is recommended to consult the relevant air compressor manufacturers. If there are no domestic options, inquire with foreign manufacturers such as Atlas, BOGE, and so on.

Based on what the poster described, it seems there is no nitrogen left. I have some doubts about using low-dew-point flammable gases as instrument air ? ? I don’t quite understand.

We use the oil and water removal device from Wuxi Youyuan – that’s what our factory uses. I have a question for Haiyou: What does the author mean by the function of the control valve? ? What we produce in our factory are compressors, oil removal, and drying devices

A control valve refers to the use of this compressed air system as a source of air for control valves. That is, it is used as instrument air to power the pneumatic actuators of control valves.

Thank you, the person on floor 19. Simply put, this compressed air is used as instrument air. I know what instrument air is; now it’s finally connected to the control valve. Thank you!