Guangzhou C&H Medical Technology Co., Ltd.

Oxygen, the chemical formula O₂, is a gas found in the air we breathe. Oxygen gas is necessary for human life. For some people with breating disorders can not get enough oxygen naturally, to supply oxygen gas is a effective treatment. Also, Oxygen gas is also used to be mixed with anesthetic for anesthsia.

In a hospital / clinic, the Oxygen gas is so widely used that it is the most consumed medical gas. To produce or to store high purity Oxygen gas or Oxygen liquid is important for a hospital / clinic.
Decades ago, for hospital / clinic users, the common way to get high purity Oxygen gas is to buy from professional Oxygen manufacturers. In these factories, high purity Oxygen gas or liquid was produced by many ways, filled into special cylinders after pressure boosting, and delivered to hospital users. And hospitals deliver it to patients or medical Oxygen equipment directly from individual Oxygen cylinders.
With developing of medical technologies, for a hospital, they need more and more Oxygen for medical purpose. Oxygen gas in individual cylinders were not safe nor convinient for them to us. So, they constructed Medical Oxygen Pipeline System in buidlings, to produce or store high purity Oxygen gas / liquid by Oxygen source equipment, and supply Oxygen gas to different function rooms by copper pipelines.
By this way, the Oxygen Source Equipment becomes the most important equipment of a Medical Gas Pipeline System.

There are two kinds of Medical Oxygen Source Equipment commonly used in hospitals. One kind stores Oxygen gas or Oxygen liquid, another kind produce Oxygen gas.
Here, we introduce both these two kinds of equipment in a hospital.

1. Oxygen Storing Equipment
As we mentioned in above, there are many different ways to produce high purity Oxygen. Now, the most widely used ways are to separate Oxygen from air. However, by different air separating technologies, we can separate high purity Oxygen gas or Oxygen liquid. 

1.1 Medical Oxygen Cylinders Manifold System

Traditionally, hospital uses Oxygen gas, and the Oxygen gas is stored in cylinders. Gaseous Oxygen is easy to use, and storing cost is low. However, with Medical Oxygen Pipeline System, the individual Oxygen cylinders were not used to supply Oxygen gas directly. They were connected together and were managed by Medical Oxygen Cylinders Manifold equipment.
A typical Automatic Change-Over Medical Oxygen Cylinders Manifold is as follow picture shows:


And a typical Manual Change-Over Medical Oxygen Cylinders Manifold is as follow picture shows:


No matter automatic change-over model or manual change-over model, the Medical Oxygen Manifold’s core function is to connect and to manage several Oxygen cylinders together. The managed Oxygen cylinders are divided into two groups, and are connected with Oxygen pipeline by the change-over controller unit. In common conditions, only one group of Oxygen cylinders are opend to supply Oxygen gas to pipeline. After the group empty, manifold changes over to another group (shut off the empty group cylinders pipe, and turn on another group pipe). And the empty cylinders can be unfixed to refill or to be replaced by full ones. Byt this way, the manifold system ensure continuous Oxygen gas supply to Oxygen pipelines.
The Medical Oxygen Manifold System, is the most widely used medical Oxygen source equipment in all different scales hospitals.
In medium and small scales hopistals, they are used as the main Oxygen source equipment. Even in a big scale hospital who use other kind of Oxygen source equipment, the Oxygen Cylinders Manifold is used as a back-up Oxygen source for the Medical Oxygen Pipeline System.

1.2 Medical Liquid Oxygen Tank System

For some big scale hospitals, they consume big quantity of Oxygen gas every day. For example, one hospital’ Oxygen consumption quantity was 600 normal cubic meters each day. For this Oxygen gas, it should be installed in more than 100 pcs of 40L capacity cylinders (suppose storing pressure is 15.0MPa / 150Bar). To store and to replace so many Oxygen cylinders should not be convinient for the hospital to do.
In such a situation, a better option is to store Oxygen liquid by Liquid Oxygen Tanks.
Small Liquid Oxygen Tanks (its’ more widely known name is Dewar Cylinder) were popular years ago.
But now, big capacity liquid Oxygen Tanks are available, and they are more widely adopted by big scale hospitals.
A typical Liquid Oxygen Tank is as follow picture shows:

It is a thermoal isulated metal tank, stores cryogenic Oxygen liquid, and delivers Oxygen liquid to liquid Oxygen vaporizer. After passing vaporizer, the Oxygen liquid comes Oxygen gas, and is supplied to Medical Oxygen Pipeline.
The biggest advantage of Liquid Oxygen Tank is to store big quantity of high purity Oxygen in a limited space. For example, one 1.0m³ (1000 Liters) capacity Liquid Oxygen Tanks stores about 800Nm³ (Normal Cubic Meters) Oxygen gas.
However, in all countries, there are strict requirements of Liquid Oxygen Tank installing place. And in many cities, it is not easy to get Liquid Oxygen by a reasonable cost. Installing space and Liquid Oxygen cost are most important limiting factos for hospitals to use liquid Oxygen tank as Medical Oxygen Source equipment for their Medical Gas Pipeline System. 

2. On-Site Oxygen Producing Equipment: Medical PSA Oxygen Generator
With developing of PSA Technologies, now medium and small PSA Oxygen Generating equipment has been realized. And in many countries, these PSA Oxygen Generating equipment are used by hospitals as on-site oxygen producing equipment.
A typical PSA Oxygen Generator is as follow picture shows:

It separates high purity (≥93%) Oxygen gas from air by PSA Technology (regarding the PSA Technology, please read our another article in this FAQ). The produced Oxygen gas can be supplied (passing Oxygen Buffer Tank / Tanks) to Medical Oxygen Pipeline directly.
By PSA Technolgy, the PSA Oxygen Generator produces Oxygen gas without any other consumption except electricity power. For most hospital users, they can get Oxygen gas by the cost which is near, even less than purchased one.
However, the PSA Technology determines produced Oxygen purity as no more than 96%. Though in many countries, the no less than 93% purifity Oxygen gas is permitted for medical using, it is not permitted in some countries (in these countries, required purifity of Medical Oxygen is no less than 99% or even more).

3. How to choose Medical Oxygen Source Equipment for hospital Medical Gas Pipeline System
To choose suitable medical Oxygen source equipment for a hospital Medical Gas Pipeline System, user shall consider multiple factories comprehensively.

3.1 Oxygen Consumption

Oxygen consumption is the most important factor for hospital users.
According our experence, a hospital user, whose average Oxygen consumption is no less than 100Nm³/day (it equals to about 16 pcs of 40L filling pressure 15.0MPa / 150Bar Oxygen cylinders each day), shall consider to adopt the on-site PSA Oxygen Generator system.
A hospital user, whose average Oxygen consumption is not less than 200Nm³/day (it equals to about 32 pcs of 40L filling pressure 15.0MPa / 150Bar Oxygen cylinders each day), can consider to adpot the Liquid Oxygen Tank and Vaporizer System.

3.2 Available or not to get Oxygen Gas / Oxygen Liquid by reasonable cost

In most cities, even for Medical Oxygen Gas and Liquid, the price is not high. For hospital users in such cities, to choose Oxygen Cylinders Manifold equipment or Liquid Oxygen Tank and Vaporizer equipment is economical.
However, in some cities, it is difficult for hospital users to get Oxygen gas or liquid by reasonable cost. In such cities, to choose On-Site PSA Oxygen Generator equipment is the only option.

3.3 Requirements of Medical Oxygen Purity

As we menstioned above, in some countries, only high purity as no less than 99% Oxygen is permitted for medical using.
And now, only available way to produce high purity Oxygen (both gas and liquid) is by cryogenic technology. But small cryogenic Oxygen Generator is not available. The available smallest commercial purpose Cryogenic Oxygen Generator’s Oxygen producing capability is 40Nm³/hour. And its’ economic output is 960Nm³/day (to continuous work 24 hours each day).
So, for hospital users in these countries, to purchase high purity Oxygen (gas or liquid) and to adpot Oxygen Cylinder Manifodl System (for Oxygen gas) or to adopt Liquid Oxygen Tanks and Vaporizer System is the only available option.