Home >> Industry Knowledge >> Large oxygen mechanism of nitrogen Operation Improvement
In recent years, with a 15 oxygen nitrogen KL vehicle production oxygen, nitrogen,
The oxygen station, the task of increasing production of nitrogen. According to KL 1 15
Nitrogen-based oxygen car operating instructions and related materials, oxygen owners
Period according to "first post-oxygen nitrogen" approach to complete production tasks. Analysis
The KL a 15 oxygen flow and the production of nitrogen car oxygen, nitrogen
The course of the air inside the distillation characteristics of the distillation column, the author found that
To take "after the first nitrogen oxygen," than "first post-oxygen nitrogen" more
Plus reasonable.
A "first post-nitrogen oxygen," the advantages of
The so-called "first after the oxygen nitrogen" means nitrogen in the oxygen cart Kai
Nitrogen directly after moving into the working conditions of nitrogen in the completion of the task, the sub -
Oxygen into the working conditions.
1.1 to reduce the loss of cooling capacity and shorten the time for start-up and conversion process
KL. 15 oxygen nitrogen trucks sieve plate distillation column, its process
Process shown in Figure 1.
Figure 1 KL-15-type oxygen flow diagram of nitrogen cart
Equipment in oxygen conditions, the exhaust gas from the distillation column the top row of
Pointed out that the total steam tower about the amount of air into the Taga workers 85%.
Steam bottom-up through the sieve plate with holes, through the liquid bubble and the
, The Tower board holding the liquid had been entrusted, according to a certain line from the tray
Upstream before, layer by layer through the overflow bucket flows down the tower to maintain a certain board
A high degree of liquid layer.
Equipment in nitrogen conditions, the exhaust gas from the distillation of the lower row of
Pointed out that the rising steam along the plate equal to the total heat recovery chiller liquid
Of the gas, does not exceed the amount of air into the work Taga 4o%. Raise
Reduction in the amount of steam, so that steam through the sieve larvae L plates 4,: fL, we can not
ADS holders Trays liquid, liquid from the tray of the sieve larvae L pouring down layer by layer
Drop tower board liquid layer thinning. Conversion of nitrogen in the oxygen condition condition gymnastics
Occurs when the evaporator to the rapid rise in the phenomenon of surface proved to
On the correctness of the analysis.
The foregoing analysis, "after the first nitrogen oxygen" can reduce the cooling capacity loss
Loss, reduce the equipment start-up and operating conditions the time required for the conversion process.
(1) As the liquid nitrogen when the Tower board oxygen when compared with thin-layer height
Much more, so that the appropriate equipment to shorten the time required to start. After more than
Than, KL-15-type oxygen nitrogen nitrogen needed to start vehicle when directly
Between oxygen shorter than direct 40min 1h.
(2) When the equipment in working condition to switch oxygen nitrogen condition, the tray
On the liquid layer gradually increased, the oxygen-rich liquid inside the evaporator evaporation,
Rapidly improve the purity of oxygen (equivalent to a short time and then after the temporary parking
Start). Therefore, the nitrogen conditions change does not require emission of oxygen condition
Evaporator liquid cooling tower capacity is not wasted, and simplifies the parade
To make the conversion process to shorten the time required accordingly.
1.2 Reduce the amount of demand for cold-repeated. Heat recovery chiller to improve transport
Transfer stability
Nitrogen from the oxygen equipment, cold needs analysis, equipment start -
Stage is the cooling process and maximum cooling capacity demand; while in the production of gaseous
Product phase is the cold fill process, reduced demand for cooling capacity. KL-15-type
Oxygen nitrogen car's main task is the production of gaseous nitrogen oxide gas, in the
Production of nitrogen, in order to improve the air in the tower of the distillation process and put
High-nitrogen output (nitrogen production in general can be achieved 25IrI3 / h), KLl5
Nitrogen-based oxygen car on the demand for cooling capacity than the production of oxygen
Great.
KL. 15 oxygen nitrogen vehicle used to provide cooling capacity of the machine is back
Thermal chiller to regulate the cooling capacity of the basic method is to increase or decrease
Working cavity of regenerative cryocooler average working pressure of the medium, namely, row
Release or supplementary hydrogen. If the device is in accordance with "Start a production of oxygen a
Production of nitrogen "in running condition, for the operation of regenerative cryocooler to
Demand is: Increase Cooling Capacity (nominal average working pressure) a decrease
Cooling Capacity (emission part of the hydrogen, reducing the average working pressure) an increase
Large cooling capacity (add hydrogen to the rated average working pressure);
If the device click "to start a production of nitrogen, oxygen produced a" process
Functioning of the regenerative cryocooler operating requirements are: Increase cooling
Amount (nominal average working pressure) to maintain a constant cooling capacity to reduce a
Cooling Capacity (emission part of the hydrogen, reducing the average working pressure). Can
See, the latter to reduce the production of nitrogen to the heat recovery chiller to add hydrogen
Gas, process, help to improve the functioning of regenerative cryocooler stability
Nature and reduce hydrogen consumption.
2 How
2.1 devices start the operation conditions of nitrogen conversion
(1) start-up phase in the device switches into the cooling heat exchanger
When opening a two-pass valve and bypass valve, proper off a small release valve, increase
Added to the air traffic tower (bubble pump liquid level rises due opening of a 11
Valves), and to maintain a stable level evaporator. Switch heat exchanger cooling
At the end of the evaporator liquid level should not be less than 10 15era.
(2) switch-type heat exchanger cooling is completed, turned into a normal work
, Press the nitrogen required to open or close the valve.
(3) In a 5-pass valve to open at the same time to open big blow a two valve, pass
A five-pass valve and two valves with a regulation, and maintain a level evaporator steady
Set.
(4) When the reservoir of liquid nitrogen level inside reaches a certain height,
Cooling liquid oxygen pumps, nitrogen purity after passing the Filling.
(5) to enter the normal operation of nitrogen condition.
2.2 Nitrogen-oxygen conditions to switch operating conditions
(1) to open a valve and a section of a one-pass valve, close the section of a two valve,
A 2-pass valve, a 5-pass valve and blowing a 2 valve.
(2) liquid oxygen pump to stop running, behind the net inside the liquid nitrogen reservoir.
(3) appropriate heat recovery chiller to reduce the average working pressure,
So that the purity of oxygen evaporator rapidly.
(4) to enter the normal operation of oxygen conditions.
3 Notes
In addition to the operation method described above, but also attention to the following This is
A few questions.
3.1 Evaporator Liquid Level Control
Good control of the evaporator water level of the liquid oxygen and to maintain stable
Determined to ensure that nitrogen production process, working conditions and nitrogen purity distillation column
The key to stability. Evaporator liquid level control should note the following two points; ①
Evaporator liquid level shall be determined in order to maintain the processing of air into the tower
Into the towers before and after the pressure stability (both before and after switching fluctuations small) for the former
Mention; ② evaporator liquid level regulator, should ensure that a 5-pass valves are
A certain degree of opening, the normal nitrogen evaporator when the regulator level, it should be
A 2-pass valve to regulate the main.
3.2 Processing of air traffic control
Nitrogen, the oxygen-rich liquid inside the evaporator air temperature is low, the air cold
Condensate to strengthen, it will affect the intake tower before and after the processing of air pressure, which
When, in addition to good control of the opening section of a two valve-givers, as well as control a good processing
Air volume (usually less than the amount of processing air-oxygen conditions) to ensure that
Switching valves and switches heat exchanger work correctly.
3.3 to prevent blowing a two valve was frozen to death
Blowing a valve in the two conditions, when nitrogen is the role of emissions from reservoir fluid inside
Evaporation of nitrogen, to ensure a stable pressure of liquid receiver, so that by-pass a
5 valve control device of the liquid nitrogen into the reservoir fluid flow and stability. Blowing a two valve is
※ ※
At room temperature cut-off valve, a long low-temperature gas emissions likely to stem cold
Death, when the device into the oxygen generator shut down operations difficult. Therefore, the system
Nitrogen should be taken to prevent blowing a two valves were frozen measures to strengthen the stem
Office of Protection and seal packing. The easiest way is to handle in the valve
And sealing packing some small plastic bags packed with a seal, conditional
When switching to low-temperature cut-off valve so blowing a 2 valve.
3.4 The correct cooling capacity control
Nitrogen-oxygen conditions change working conditions can not be opened when the liquid oxygen pump, lower back
The average thermal chillers working pressure should be based on the actual production refrigerator cold
Is based on the correct control of the amount of cooling capacity.