How much does the outlet temperature of the atmospheric and vacuum device furnace decrease by 5 degr

The atmospheric and vacuum distillation device can control the distillation range, freezing point, flash point, etc. of light diesel oil. The temperature at the top of the tower is mainly the temperature at which water vapor and non-condensable gas leave the top of the tower. Reduction, related to on-site production operations, is the change in gas flow rate.

54 ext. Yongli Fushun Petrochemical Research Institute.

DCS has been used in refineries in China for 15 years, and more than 20 refining enterprises have installed and used different types.

It depends on what you control, air pressure or what?

The increase of the outlet temperature of the coke oven and the increase of the temperature of the coking reaction will be the more complete the coke reaction will be, the better the quality of the coke generated, the higher the yield of gasoline and diesel, and the yield of gas and coke will decrease, but it is necessary to consider whether the increase of the reaction temperature can cause the coking of the coking furnace tube.

The reaction temperature increases, the depth of the reaction increases, the coke yield decreases, the gasoline, diesel and gas yields increase, and the wax oil yield decreases.

There are many definitions of circulating oil at home and abroad: 1. Oil and gas condensation oil, quenching oil, washing oil; 2. Oil in addition to fresh raw materials in the feeding of the heating furnace; 3. Internal reflux oil at the bottom of the fractionation column; Basic principle: the circulation ratio is larger, and the processing volume is relatively reduced, which is equivalent to deep processing of the circulating oil, so that it can be further cracked and condensed, and develop to its two ends of the fraction.

In general, the light yield is increased, but the energy consumption is larger, and the coke production is larger, and the overall liquid yield is reduced. At present, except for the coking oriented by special products, most of them are developing towards a low cycle ratio trend, such as the derived tunable cycle ratio process, distillate cycle cycle process, etc. We apologize for any inappropriateness.

Upstairs said well, to add, after the increase in the circulation ratio, it is equivalent to the oil in the unit for multiple cracking and polymerization, which eventually leads to an increase in the light component and coke production, but we have done experiments, no matter what, the wax oil fraction is always there, and it is not possible to eliminate the wax oil fraction by increasing the cycle ratio.

Why does the top of the vacuum and vacuum distillation device produce non-condensable gas, atmospheric distillation and vacuum distillation are commonly referred to as atmospheric and vacuum distillation, and atmospheric and vacuum distillation is basically a physical process. The raw oil is divided into different boiling point range of oil (called fraction) in the distillation tower according to the evaporation capacity, and some of these oils are blended and added additives before leaving the factory in the form of products, and a considerable part is the raw material of the subsequent processing device. It consists of three processes:

** of desalination and dehydration; atmospheric distillation; Vacuum distillation.

Primary distillation. Desalination, dehydration of the ** heat exchange to 215-230 into the primary distillation column, distillation from the top of the column distillation of the primary distillation point -130 fraction condensation cooling, part of which for the top of the column reflux, the other part of the lead as reforming raw material or heavier gasoline, also known as primary top oil. 2. Atmospheric distillation The bottom of the primary distillation column is heated to 350-365 in a regular pressure heating furnace and enters the atmospheric fractionation column.

Cold reflux is injected into the top of the tower to control the temperature at 90-110. The temperature rises gradually from the top of the tower to the feed section, and the gasoline is evaporated from the top of the tower by using the different boiling point ranges of the fraction, and kerosene, light diesel oil and heavy diesel oil are steamed from the side line, side two line and side three line respectively. These lateral fractions are often compressed by the air stripper to extract the light components with superheated steam, and then after heat exchange, a part of the heat is exchanged, and then cooled to a certain temperature before being sent out of the device.

The bottom of the tower is about 350, and the unvaporized heavy oil at the bottom of the tower is used as the feed oil of the pressure reducing tower after the light component is put out by hot water steam. In order to make the steam and liquid load of each part along the tower height in the tower more uniform, and make full use of the reflux heat, generally between the pumping outlets of each side line in the tower, 2-3 middle sections of circulation reflux are entered. 3. Vacuum distillation The heavy oil at the bottom of the atmospheric column is pumped into the vacuum heating furnace and heated to 390-400 to enter the vacuum fractionation tower.

After the non-condensable gas is cooled by condensation, the non-condensable gas is usually pumped out by a two-stage steam ejector to maintain the residual pressure in the tower, so as to facilitate the full evaporation of the oil under reduced pressure. The tower side extracts different lubricating oil fractions or cracking raw materials from one or two side lines, and after they are respectively airstripped, heat exchanged, and cooled, part of them can be returned to the tower for circulation and reflux, and part of them are sent out of the device. The vacuum residue at the bottom of the tower is also blown into the superheated steam gas to put forward the light component, and after the extraction rate is improved, it is pumped out with a pump, and after heat exchange and cooling, it can be used as self-use fuel or commercial fuel oil, and can also be used as a raw material for asphalt raw materials or propane deasphalting units to further produce heavy lubricating oil and asphalt.

Reasons for punching the tower: the formation of the vapor-liquid term in the tower conforms to all factors that are too large, which can cause the tower, such as: the first processing capacity, the first water volume entering the tower, the amount of steam blowing at the bottom of the tower, and the excessive return flow at the top of the tower. In the case of salt build-up in the tower or clogged downcomer, uneven vapor-liquid phase loading can also cause the product to change color.

3. Punching tower phenomenon: when punching the tower occurs, due to the deterioration of the fractionation effect in the tower, the normal mass and heat transfer is destroyed, resulting in the top temperature, pressure, side line distillation outlet temperature, and reflux temperature all rising, the low liquid level of the tower drops suddenly, and the color of the distillate oil turns black.

4. Punch tower treatment: the treatment principle is to reduce the vapor-liquid load, that is, to reduce the treatment capacity, such as the punch tower caused by excessive water content, it is required to strengthen the dehydration of electric desalination, reduce the water content in the tower, when the treatment capacity is too large, it is necessary to pay attention to the blowing steam flow at the bottom of the tower should not be too large, and the return at the top of the tower should be appropriate. When the color of the oil deteriorates, it should be resent to the unqualified tank.

When punching the tower, the gas on the top of the product tank should be stopped as heating furnace fuel immediately to prevent gasoline from entering the heating furnace with the gas from combustion.