LDH GAS Systems Co., Ltd is a Chinese manufacturer specializing in on-site gas plants for nitrogen generation, oxygen generation, purification systems and so on.

With more than 100systems built worldwide since 2017 Systems win the respect of all with their reliability, cost-effectiveness, convenience and our excellent services.

A family of LDH Systems has been used in a wide range of industries: Chemical and Refining, Oil and gas production, Electronics, Aeronautics and aerospace, Pharmaceutical/Health care, Foods, Metallurgical, Glass, Coal-mine, and Aquaculture.

LDH Systems are the embodiment of the synthesis of the state-of-the-art technology and the perfect manufacturing techniques.

Our goal is to provide our customer with more reliable, more economical and more convenient

LDH  air separation systems and more professional services.
PSA Nitrogen Generator  full name: Pressure Swing Adsorption (PSA).PSA is a new gas separation technology, which has been developed rapidly in foreign countries since the late 1960s and early 1970s. Its principle is to separate the gas mixture by the difference of the "adsorption" performance of different gas molecules by molecular sieve. It takes air as raw material.The nitrogen and oxygen in the air are separated by the selective adsorption of nitrogen and oxygen with a high efficiency and high selection of solid adsorbent.

At present, carbon molecular sieves and zeolite molecular sieves are used more in the field of nitrogen and oxygen production.The separation of oxygen and nitrogen by molecular sieve is mainly based on the different diffusion rates of the two gases on the surface of molecular sieve. Carbon molecular sieve is a carbon-based adsorbent with some characteristics of activated carbon and molecular sieve.Carbon molecular sieves are composed of very small micropores with pore sizes ranging from 0.3nm to 1nm.The smaller diameter of the gas (oxygen) diffuses faster and more into the solid phase of the molecular sieve, so that nitrogen enrichment can be obtained in the gas phase.After a period of time, molecular sieve on oxygen adsorption balance, according to the carbon molecular sieve under different pressure on the adsorption of different gas adsorption characteristics, reduce the pressure to remove the carbon molecular sieve on oxygen adsorption, this process is called regeneration.PSA usually uses two towers in parallel, alternately pressurized adsorption and decompression regeneration to obtain a continuous flow of nitrogen.

With air as raw material, with carbon molecular sieve as adsorbent, the use of pressure change adsorption principle, the use of carbon molecular sieve on oxygen and nitrogen selective adsorption and separation of nitrogen and oxygen method, commonly known as PSA nitrogen.This method is a new technology of nitrogen production which developed rapidly in 1970s.Compared with the traditional method of nitrogen, it has simple process, high degree of automation, produce gas quickly (15 ~ 30 minutes), low energy consumption, product purity can be adjusted according to user needs in a wide range, convenient operation and maintenance, low operating cost, good adaptability device etc., in 1000 nm3 / h the following competitive in nitrogen making equipment,PSA is more and more popular among medium and small nitrogen users, and has become the choice method for medium and small nitrogen users.

1. Why choose PSA nitrogen generator ?
High nitrogen purity
PSA nitrogen generator plants allow production of high-purity nitrogen from air, which membrane systems are unable to provide - up to 99.9995% nitrogen.The nitrogen generators use CMS (carbon molecular sieve) technology to produce a continuous supply of ultra high purity nitrogen and are available with internal compressors or without.
Low operating costs
By substitution of out-of-date air separation plants nitrogen production savings largely exceed 50%. 
The net cost of nitrogen produced by nitrogen generators is significantly less than the cost of bottled or liquefied nitrogen.
Nitrogen Generators Create Less Impact on the Environment
Generating nitrogen gas is a sustainable, environmentally friendly and energy efficient approach to providing pure, clean, dry nitrogen gas. Compared to the energy needed for a cryogenic air separation plant and the energy needed to transport the liquid nitrogen from the plant to the facility, generated nitrogen consumes less energy and creates far fewer greenhouse gases.

Process flow and equipment introduction of PSA nitrogen making machine

1. Brief introduction to the technological processNitrogen Generator 

Air through the air filter to remove dust and mechanical impurities into the air compressor, compressed to the required pressure, after strict oil removal, water removal, dust removal and purification treatment, the output of clean compressed air, the purpose is to ensure the service life of the molecular sieve adsorption tower.There are two adsorption towers with carbon molecular sieve. One tower is operated while the other tower is decompressed and desorbed.Clean air into the working adsorption tower, through the molecular sieve oxygen, carbon dioxide and water are absorbed by it, flow to the outlet end of the gas is nitrogen and trace argon and oxygen.Another tower (desorption tower) allows adsorbed oxygen, carbon dioxide and water to escape from the pores of the molecular sieve and discharge into the atmosphere.In this way, the two towers take turns to complete nitrogen and oxygen separation and continuously output nitrogen, as shown in Fig. 2.The purity of nitrogen produced by pressure change  adsorption is 95%-99.9%. If higher purity nitrogen is needed, nitrogen purification equipment should be added.Psa nitrogen making machine output 95% 99.9% of the nitrogen into the nitrogen purification equipment, at the same time through the flowmeter to add just the right amount of hydrogen gas, hydrogen and nitrogen in the purification equipment of deoxidization tower of trace oxygen in catalytic reaction, and then by water to remove oxygen condenser cooling, in addition to water, water separator, and then through the depth of the dryer drying (two adsorption drying tower used interchangeably:One is adsorbed and dried for water removal, the other is heated for desorption and drainage) to obtain high purity nitrogen. At this time, the purity of nitrogen can reach 99.9995%. At present, the maximum production capacity of nitrogen production by pressure swapping adsorption in China is 3000M3N /h.

Which nitrogen generator should I choose?
Different parameters are essential for your choice of nitrogen generator 
• How big is your consumption?
• Is your consumption variable?
• Which pressure is required?
• What purity/capacity is required?
• Do you already have a compressed air system?

Why choose LDH GAS?
*Be your own supplier, customized.
*Mobile and flexible sloutions
*Produce gas when and where you want
*Save your installation cost
*minimum maintence .fully automatic operation
*Only quality compenents are used.

3) Spare Parts Service
Worldwide, quick and low-priced over the complete lifetime of your plant. The distinct tagging of all plant components delivered by us enables us to identify clearly the spare parts requested by you. We supply you with products designed for a long life and economic efficiency. 
For modifications and extensions we look for the most optimal and economic solution for your individual purpose. 
4) Maintenance/Revisions
Regular inspection and maintenance ensures permanent operation, avoids damage and prevents unexpected breakdowns. In the course of maintenance/revision works we check all relevant components for function and condition, exchange defect, used and worn parts and afterwards optimally eadjust your plant to the given operating conditions. Depending on the plant size and 
scope of work, our service range comprises also a detailed scheduling of revisions as well as coordination and supervision of contractors. As a matter of course we supply maintenance documentation in form of reports and spare part recommendations, and we coordinate our schedules according to your requirements. 


5) Training
Know-how for your personnel. 
Operation, maintenance and repair, electric measuring and control equipment or process engineering - we offer  you specific training by our experts. Whether on site working with theplant itself, or on our permises, we concentrate on your questions and problems. 

What is a Packaging Gas?
Air contains approximately 78% nitrogen, 21% oxygen and a variable amount of moisture. When exposed to air, foods such as potato chips absorb moisture and go stale and soggy quickly. Atmospheric oxygen also reacts with the unsaturated fatty acids present in foods, resulting in rancid off-flavours. Consequently, it is always a challenge faced by food manufacturers in preserving the desirable quality and prolonging the shelf life of food products.
The use of packaging gas is an effective solution. A packaging gas is a gas that is introduced into a package before, during or after filling with food to protect the food from oxidation or spoilage. Examples include nitrogen, carbon dioxide and nitrous oxide. Nitrogen has a long history of use as a packaging gas in various foods including snacks, breakfast cereals, candies, bakery products, dried fruits and vegetables, and processed meat products.
Nitrogen Does More than a Packaging Gas
Nitrogen has found its way to the brewery and coffee industries where nitrogen is infused in beer or cold brew coffee to make 'nitro beer' or 'nitro brew', giving the final product a richer and creamier mouthfeel.
How does Nitrogen Work as a Packaging Gas?
Unlike the air you breathe every second, nitrogen used in food packaging contains very little oxygen and moisture. Nitrogen is inert (i.e. not reacting with any food components), odourless and tasteless. When nitrogen is introduced into a package, it drives out oxygen and any moisture present. By modifying the atmosphere inside the package, food packaging with nitrogen preserves quality, slows down spoilage and extends the products' shelf life.
Nitrogen also cushions and protects delicate foods inside the package from being crushed during handling. Nonetheless, the amount of nitrogen used should provide enough protection but not too much to allow space for additional expansion due to pressure changes in transit and during storage.
The package, with low gas permeability, must be sealed tightly to prevent the nitrogen from escaping. Once you open the package, the food inside is exposed to atmospheric air containing oxygen and moisture. Without protection from an immediate, controlled environment, the contents are then prone to moisture pickup, spoilage and oxidation. Therefore, it is best to consume the food products as soon as possible once the package is opened.


Food suppliers are always seeking ways to extend shelf life. Improved shelf life allows manufacturers to extend their geographical reach and allows the product to remain in stores and consumer's homes longer.  Modified Atmosphere Packaging (MAP) is a technique commonly used in the food processing industry to extend shelf life. The MAP process involves displacing the air inside a package with a protective gas to keep oxygen at controlled levels (less than 2 percent). Too much oxygen and moisture in a package often leads to bacterial growth and oxidation resulting in spoilage, inconsistent flavors, poor product quality, and shortened shelf life. Nitrogen is frequently used as a protective gas because of its dry, inert qualities

Sources of nitrogen
Nitrogen can be obtained from outside suppliers in the form of high-pressure tanks, dewars, or bulk liquid supply. Nitrogen can also be produced on-site using standard compressed air with an in-house nitrogen generator.  An in-house generator separates nitrogen and oxygen from the air, and can often be the most efficient and economical method of supplying nitrogen for MAP applications.
Disadvantages of a delivered nitrogen supply
Relying on outside vendors can pose several challenges including uncontrollable price increases, contract negotiations, tank rental fees, adherence to OSHA requirements, hazardous material fees, delivery surcharges, and local and state taxes. Problems such as scheduling conflicts, delivery delays, and lengthy procurement processes can slow down operations.
This all adds up to extra administrative work and higher operational costs. The delivery approach also doesn't fit the trend toward lean production techniques and developing fewer, more efficient supply chains.  
Precautions must also be taken when handling and storing high pressure cylinders. A dangerous situation can be created if a cylinder is dropped and a valve is broken off, potentially causing the cylinder to become a projectile.
Operational benefits of generating nitrogen on-site
Generating your own supply of nitrogen in-house eliminates the challenges associated with outside vendors and ensures long-term cost stability. Generating nitrogen in-house is also good for the environment and represents a sustainable approach to supplying the gas. Producing nitrogen off site at fractional distillation plants and transporting it to end users is energy intensive and can result in large amounts of CO2 emissions.