based on vacuum hydrocirculating (VHC) units
for handling of flare, associated petroleum and other low-pressure gases
absorbtion gas cleaning units
for removal of hydrocarbons from breathing gases and recovery of oil gases and oil products gases
ejectors and injectors of various purpose
Russia, 105082, Moscow
B.Pochtovaya str., 26 "B", build.2, 5-th floor, office 1, room 11A
|1 – vacuum creating device
2 - separator
3 – cooler
4 - pump
I - gas-vapor mixture from vacuumized vessel
II – exhaust line for compressed gas
III – line of motive fluid excess withdrawal
IV – fresh motive fluid makeup line
Principle of operation
The pumpage from process apparatus, e.g. distillation column, is directed to the inlet of vacuum creating device 1. In vacuum creating device 1 there occurs the compression of vapor-gas at the caused by motive fluid energy delivered to device 1 by the pump 4. One of process flows can be used as an motive fluid, there is allowed to mix it with vapors pumped by the vacuum creating unit.
The diesel fraction or vacuum gas oil is used in petroleum refinery as motive fluid. The cyclohexanol-cyclohexanone mixture is the motive fluid in caprolactam production.
The process of vapors condensation on the jet of motive fluid occurs simultaneously with gas-vapor compression. Herewith the vapor condensation and gas cooling in the vacuum creating device occurs on isobar and their compression up to discharge pressure - on isotherm, what makes the device energy-efficient as compared with other vacuum pumps, particularly by pumping of gas-vapor mixtures with large vapor percentage.
The gas-vapor mixture generated goes from vacuum creating device 1 to the separator 2, where the separation of gas and fluid occurs. The gas compressed up to required pressure is directed for further recycling, for example, incineration. After the removal of heat excess in the cooler 3, the motive fluid is delivered to the vacuum creating device 1 by the pump 4. The makeup is carried out for refreshing of motive operating fluid, if necessary. The balance excess of motive fluid is let out of the system.
Main advantages of VHC units
The advantages of vacuum creating systems on basis of vacuum hydrocirculating unit as compared with
steam jet ejectors:
mechanical vacuum pumps:
liquid ring vacuum pumps:
The VHC unit can operate in compressor mode - compressing various gases
and gas-vapor mixtures including polluted and explosive ones by small
Other schemes for vacuum creation on basis of VHC unit in columns of refineries
Depending on required capacity and vacuum depth, compression degree, content of gas-vapor mixture pumped, operating conditions of column, layouts, Customer requirements and other factors, various scheme versions of vacuum hydrocirculating units are possible.
Experience of industrial application
First in the world practice, the VHC unit was introduced on distillation column VK-1 of atmospheric vacuum distillation unit-3 (AVT-3) of Moscow Refinery) in 1993.
Technovacuum Ltd. already performed over 50 implementations of vacuum creating systems on basis of VHC unit on vacuum columns of refineries, chemical and petrochemical plants of Russia and other countries.
The introduction of vacuum creating systems on basis of VHC unit at these plants resulted in considerable energy savings, reduction of costs for treatment of polluted wastewater and increase of product yield thanks to the maintenance of a stable vacuum level in the column.
Based on field experience of VHC units, the increase of yield reaches up to 1,5 %. The pay-back period of revamping of vacuum creating systems is therefore 4-18 months, depending on prices for energy resources and oil products.
In the oil-refining industry, the VHC units create vacuum in crude distillation units, in the chemical and petrochemical industry – in units for cyclohexanol-cyclohexanone production, alkylbenzene production, in plants for benzene-toluene-xylene cut production and other.
Operating characteristics of VHC units
Accepted notation of VHC units
Description of notation of VHC unit:
|2||minimum suction pressure, kPa|
|B||B – air-cooling (À - water-cooling)|
|1||number of constructive modification|
The capacity of industrial VHC units is 20 m3/min - 350 m3/min. The capacity of VHC units is indicated for dry air with temperature 290 Ê.
Technovacuum Ltd. constantly improves VHC units decreasing the power
consumption and increasing the vacuum depth.
VHC units are easily mounted both on new and existing columns.
If You are interested in vacuum creation technology on basis of VHC unit and You plan to apply it on Your enterprise, please, fill in the following