DE10203323C1 - Material exchanger apparatus, for separating gas-liquid mixtures by absorption and rectification, has plate types in pairs and connected together as tubes and run-off shafts - Google Patents

Abstract

Material exchanger apparatus comprises a vertical cylindrical body with an inlet support and an outlet support for gas and liquid with co-current high speed plates with foot and counter current plates. The plate types are arranged in pairs to increase the load boundaries. The co-current high speed plate is in each plate pair above the counter current plate, and the liquid run-offs terminate in the column sump in a gas-tight manner using a siphon closure. Material exchanger apparatus comprises a vertical cylindrical body with an inlet support (2) and an outlet support (3) for gas and liquid with co-current high speed plates with perforated contact and removal elements (10) at the foot and counter current plates. The plate types are arranged in pairs to increase the load boundaries, i.e. for a flexibility factor of at least 12 with simultaneous reduction of the liquid sweep, and only the same type of plates are connected together in the form of tubes and run-off shafts (11) by liquid run-offs. The co-current high speed plate is in each plate pair above the counter current plate and the liquid run-offs terminate in the column sump (15) in a gas-tight manner using a siphon closure (16).

Description

The invention relates to the apparatus design of mass transfer equipment for chemical and related apparatus construction for the separation of gas-liquid mixed by absorption and rectification, especially in gas, petroleum and petrochemicals and the chemical and related industries.

When designing and operating such mass transfer devices, high demands must be made such as high performance and reliability, high effectiveness of the material and heat exchanges and phase separation, minimal equipment costs and a high Fle flexibility (turndown) in the operation of the fabric separators, d. H. the property of an equipment safe and function-fulfilling operation with large load fluctuations (Partial load 10% and less of the nominal power) with regard to both gas and liquid to ensure throughput.

Since mass transfer devices are the main equipment in gas processing and distillation Separation of materials are, meeting these requirements is compact with the creation of mi niaturized and flexible systems connected, both in chemical companies and in Underground natural gas storage facilities, on gas production fields on the mainland (onshore) as well as on the continental shelf (offshore) can be used, where reduced apparatus dimensions solutions, low apparatus weights and high specific performance of the systems of the greatest Meaning are.

There are known constructions of mass transfer apparatus which work with in cocurrent tendency contact and separation elements (KAE) with a fixed axial whirl + at the inlet end and a centrifugal separator at the outlet end to separate the liquid phase after the exchange of materials has taken place (German Patent 198 28 884 C1). The liquid phase is fed into the contact zone through circumferential bores in the Area of the inclined blades of the axial swirler below the swirler.  

It is also the application of a high speed floor (HGB) in cloth separation appa advise to dry natural gas with glycols known (German patent 199 29 408 C1). On Such mass transfer apparatus ensures a very high gas throughput, so that gas loads tion factors (F factors) from 6.5 to 10 based on the total column cross-section are realizable, d. H. the performance of such an apparatus is 4 to 5 times higher than that of one conventional fabric separation column with bubble cap trays.

A disadvantage of this mass transfer apparatus, however, is the limited flexibility, i. H. on stable operation of this column is only up to a lower limit in the partial load range of 30% of nominal power possible. This limitation limits the use of this device for some important areas of application, such as B. for natural gas storage facilities with high loads fluctuations.

Constructions of mass transfer apparatus have been proposed that use a station wagon represent nation of different soils B. sieve trays and high-speed trays with direct current contact elements, the sieve plate in this combination as the upper one Bottom and the high-speed bottom is arranged under the sieve bottom. The rivers Fluid flows from the sieve plate and from the high-speed plate are Mass transfer fed to a common downcomer (US Patent 5,885,488). A such construction has good technical-economic performance parameters, in particular regarding the mass transfer effectiveness and the prevention of foam formation the high-speed floor. However, this construction also has some disadvantages such as B.

• - the limitation of the permissible gas load factor due to the performance of the sieve plate arranged at the top, ie F _max = 2.5 m / s (kg / m ³ ) ^0.5
• - The liquid load is very limited and requires a relatively large one Area of the floor for the downcomers.
• - The flexibility limits (turndown) of such a combination of two differ soils is also limited and is a maximum of 3 (i.e. partial load modes up to 30% of the nominal load is possible).

The basis of the invention is to provide a high-speed apparatus construct that with high performance at the same time also a very high flexibility activity, d. H. through a special constructive design of the mass transfer elements to guarantee load driving procedures (turndown) with regard to the gas load of 1:12 and more, the liquid entrainment between the soils is largely suppressed.

The object of the invention is achieved by the mass transfer apparatus, which consists of a ver tical standing column column jacket and spigot for the supply and the Ab drove the gas as well as the liquid, with horizontally arranged floors inside is provided, with alternating two-phase mass transfer trays in countercurrent (e.g. valve trays) and high-speed trays with direct current - contact and Ab sheath elements that have circumferential holes on the foot are used to block as consist of a counter-current plate and a co-current plate, the similar floors with overflow pipes or drainage ducts for the liquid phase are connected and the drain shaft of the last lower counterflow floor with egg nem siphon ends in the column bottom and the liquid designed as a central tube flow of the last lower DC floor also by diving into the Ko is carried out.

Such a constructive design of a mass transfer apparatus ensures one Flexibility factor (turndown) of 12, d. H. the gas load can be related by a factor of 12 can be reduced to the nominal load resulting in a very great flexibility and great Stress limits of the mass transfer apparatus result.

In addition, such a constructive design ensures by alternating the two Soil types one after the other a strong reduction of the liquid entrainment from a Bo the other, because the KAE plays the role of liquid on the high-speed floors separators (demister) if only the valve heads are operated. In addition, it is useful to design the mass transfer apparatus so that the Hochge low-speed floors with each other through drain pipes with a small diameter  are passed through the valve bottoms in a liquid-tight manner, the being connected upper pipe ends also represent the drain weir, which are valve bottoms in turn connected to each other by downcomers, which are segment shafts with a larger cross cut. Such a design of the mass transfer apparatus allows one very efficient use of the column cross-section.

On the high-speed mass transfer trays there is one up to the height of the Drain pipe pent clear (vapor or gas-free) liquid through the circumferential bore at the foot of the KAE into the interior of the elements and there through the swirler tiny droplets split up with the gas enters into intensive mass transfer. The process of this clear liquid can easily be made through a small drain pipe, since the permissible Ab The running speed for the clear liquid is up to 1 m / s.

The liquid that is drained from the valve bottoms via the segment drainage ducts is a gas-liquid mixture and its rate of flow must not be 0.2 to 0.3 m / s exceed.

It is to increase the effectiveness of mass transfer and for economical process control appropriate for the chosen design solution, the liquid feed to regulate in the column via a liquid distributor, the liquid on the top th high-speed floor and / or the underlying first valve floor is given that at high and very high gas throughputs, the entire liquid on the top high-speed floor is abandoned and the valve floors remain dry, with smaller gas throughputs, however, the liquid will reach the top of the valve given and the upper high-speed floor remains without liquid feed, i. H. the Valve bottoms are fully loaded and the high-speed bottoms work as drops Scheider, with medium gas throughput both soil types are operated and the liquid The task is performed by a division control on the top high-speed booth the and the top valve bottom at the same time. Such a management allows the Transition from high gas throughputs to the lower the required amount of liquid opti  times to dose and with high liquid throughput both soil types with liquid supply in order to ensure a high mass transfer effectiveness.

Further details of the invention are described in detail on the basis of a concrete application example and a drawing. Drawing 1 shows:

Fig. 1 shows the basic scheme of the mass transfer apparatus with high flexibility according to the invention as a longitudinal section of the mass transfer column.

An embodiment of the invention is shown in the drawing and is in the following described in more detail.

The mass transfer apparatus with high flexibility ( Fig. 1) consists of the column jacket 1 with the nozzle 2 for the gas inlet and 3 for the gas outlet. The liquid feed takes place via the distributor 6 on the two nozzles 4 and 5 , the liquid is discharged via the nozzle 7 or in the case of an emptying of the column via the nozzle 8 .

Inside the column are the high-speed material exchange trays 9 with the high-speed elements 10 , these trays are connected to one another on the liquid side by the pipe drains 11 with a small cross-section, the drain pipe penetrates the valve trays 12 with the valves 13 thereon in a gas and liquid-tight manner. The valve bottoms 12 are interconnected by segment drain shafts 14 with a larger cross section. The processes of the last floor of the two floor types end in the floor swamp 15 , the drain pipe being guided through the valve floor 12 and being kept gas-tight by a siphon closure 16 . The segment shaft drain of the valve trays also ends in the bottom of column 15 and also has a gas-tight siphon seal 17 .

The mode of operation of the mass transfer apparatus with high flexibility is as follows:
With a gas load factor of

with w gas velocity [m / s] based on the full cross section of the column, ρ gas density under operating conditions [kg / m ³ ] only the high-speed trays are operated. The liquid task is carried out via the liquid divider such that only liquid is conveyed through the nozzle 4 to the high-speed floor. The high-speed floors operated in this way have a flexibility factor of 3, ie the gas load can be reduced to a third of the nominal load. The maximum throughput of such a high-speed column is limited by the permissible pressure drop, this pressure loss being 150 to 360 mm WS depending on the gas throughput. The valves 13 of the bottom 12 are open in this mode of operation and the bottom is dry. With a reduction of the gas throughput to less than a third of the nominal output, the operation of high-speed floors is unfavorable and the liquid is supplied via the liquid distributor 6 and the nozzle 5 to the uppermost valve plate 13 , the liquid feed via the nozzle 4 is closed and the Liquid located on the high-speed floors 10 rains down on the valve floors below through the holes at the foot of the KAE 10 . Valve trays in the simplest version have a flexibility factor of 4, so that the gas throughput during operation of the valve trays can be reduced by a factor of 4, ie the valve trays start with a gas load factor

and work stably up to a gas pollution factor

This results in a minimal flexibility factor for the sta bile operation of the mass transfer apparatus of 3 × 4 = 12, d. H. the gas load can vary from change the minimum to maximum load by a factor of 12. When using  For more complicated valves on the valve bottoms, the flexibility factor can be increased den, up to about 18.

At medium gas throughputs, both floor constructions are operated together, in this case the liquid is given via the liquid distributor 6 , both via the connection 4 to the upper high-speed floor and via the connection 5 to the upper Ven tilboden, which results in a high mass transfer efficiency at large L / G ratio (L-liquid flow, G-gas flow) means a doubling compared to operation with a soil type. The drain pipes of the high-speed floors can be designed with a small cross-section, which increases the active floor area, since the liquid that runs off is gas-free, ie clear and therefore allows a high running speed.

The liquid outlet of the valve bottoms is a gas-liquid mixture and is necessary for this agile drainage shaft requires a larger cross-section.

An important advantage of the proposed constructive solution is the strong reduction of the liquid miter between the soils, in particular the arrangement of the Hochge Velocity plates above the valve plates an effective separation of the gas entrained drops allowed at higher speeds in the KAE.

The present invention allows the creation of the highest mass transfer apparatus Flexibility with regard to the variation and fluctuations in gas and liquid loads and combines both the advantages of high-speed flooring, i.e. H. creating com Compact miniaturized, high-intensity separation columns with the advantages of the valve plates have a large stable working area.

The invention can be used in a wide variety of industries. she can are used in the natural gas industry in plants for the preparation and processing of Gases at medium and high pressures, including drying with glycol, with amine  washes for gas cleaning as well as for the absorption, desorption and rectification of coal hydrogen mixtures u. a., for the separation of crude oil, methanol, amines or gas condensate gases. In the chemical industry, this invention can be used in the various material separation tasks in combination with other material separation equipment for the separation of the gas-liquid systems.

The preferred area of application is gas drying systems with glycol in natural gas storage facilities very large seasonal or daily fluctuations in throughput. The weight (mass) this new mass transfer apparatus is 2 to 2.5 times smaller than the weight of the best con conventional mass transfer devices with structured packing, whose flexibility factor be in terms of gas throughput, it can reach 10 in terms of the flexibility of the rivers fluid throughput when the throughput increases by more than a factor of 2, the exchange of the Liquid distributor in the column required.

The present invention allows flexibility factors with regard to the gas load up to 12 (with special valve designs up to 18) and with regard to the liquid load in ranges from very small loads to the maximum load L _Max .

List of the reference numerals used

1

column jacket

2

Nozzle for gas entry

3

Nozzle for the gas outlet

4

.

5

Spigot for the liquid feed

6

liquid distributor

7

Nozzle for the liquid outlet

8th

Spigot for column emptying

9

DC high speed ground

10

Contact and separation elements (KAE)

11

Pipe downcomer

12

valve tray

13

valves

14

Segment downcomer

15

column bottom

16

Siphon closure of the pipe drain shaft

17

Siphon lock of the segment drain shaft

Claims (3)

1.Material exchange apparatus with high flexibility, consisting of a vertical cylindrical body with inlet and outlet connections for gas and liquid, inside equipped with high-speed direct current floors, which are equipped with perforated contact and separating elements on the foot and with counter current flows. characterized in that in order to increase the load limits, i.e. for a flexibility factor of at least 12 while simultaneously reducing the liquid level, the two floor types are arranged in pairs and only the similar floors are connected to one another on the liquid side by liquid drains in the form of pipes or drainage ducts, with a few in each floor the direct current high-speed tray is above the countercurrent tray and the liquid drains, which are liquid-tight with respect to the other type of tray, end in a gas-tight manner in the column sump, each with a separate siphon end n. 2. mass transfer apparatus with high flexibility as in claim 1, characterized there through that the DC high-speed floors with each other by Ab Running devices in the form of a tube with a small cross-section and the counter current floor through a drain device in the form of a segment-shaped drain shaft larger cross-section are interconnected. 3. mass transfer apparatus with high flexibility as in claim 1, characterized there through that to increase the mass transfer effectiveness of the liquid feed is regulated in the apparatus via a liquid distributor so that at high Gas throughputs the liquid supply only on the top DC High-speed floor is made so that the counterflow floors remain dry and with low gas flow rates, the liquid only on the upper counterflow floor is abandoned and the DC high-speed floors play the role droplet separators take over the matter in this mode of operation exchange only takes place on the counterflow floors and at medium gas throughputs Liquid distribution is regulated so that the liquid supply both on the top high-speed floor as well as the top counter-current floor he follows.