Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
OPEN CONTACT REACTOR
Document Type and Number:
WIPO Patent Application WO/1998/033577
Kind Code:
A1
Abstract:
An open contact reactor is in the form of a tank (1), in which a plurality of spray nozzles (2) for spraying finely divided liquid are arranged and through which a gas is to be conducted in a main gas flow direction (P) in order to be contacted with the finely divided liquid, the spray nozzles (2) being arranged on different nozzle levels (L1, L2, L3), which are spaced apart in the main gas flow direction. The nozzles (2) on each level are substantially uniformly distributed over the cross-section of the tank. A nozzle assembly (4) for spraying finely divided liquid is arranged at the circumference of the tank (1) on at least one level along the main gas flow direction (P). Each nozzle assembly consists of an annular nozzle member (4), which extends along the circumference of the tank (1) on the respective levels and has a circumferential mouth gap (8) which is directed into the tank (1).

Inventors:
Halldin, Claes (PL 415 Gransholm, Gemla, S-360 32, SE)
�HMAN, Stefan (�lm�sv�gen 16, V�xj�, S-352 42, SE)
Johansson, Lars-erik (Puppram�la, �lmeboda, S-360 23, SE)
Collins, David J. (9012 Fox Lake Drive, Knoxville, TN, 37923, US)
Borio, Donald (1710 Chiswell Hill Lane, Knoxville, TN, 37922, US)
Doughty, Joseph V. (8664 Eagle Pointe Drive, Knoxville, TN, 37931, US)
Application Number:
PCT/SE1998/000186
Publication Date:
August 06, 1998
Filing Date:
February 03, 1998
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ABB FL�KT AB (Stockholm, S-120 86, SE)
Halldin, Claes (PL 415 Gransholm, Gemla, S-360 32, SE)
�HMAN, Stefan (�lm�sv�gen 16, V�xj�, S-352 42, SE)
Johansson, Lars-erik (Puppram�la, �lmeboda, S-360 23, SE)
Collins, David J. (9012 Fox Lake Drive, Knoxville, TN, 37923, US)
Borio, Donald (1710 Chiswell Hill Lane, Knoxville, TN, 37922, US)
Doughty, Joseph V. (8664 Eagle Pointe Drive, Knoxville, TN, 37931, US)
International Classes:
B01D47/06; B01D53/18; B01D53/79; F28C3/06; (IPC1-7): B01D47/06; F28C1/00
Domestic Patent References:
WO1993018842A1
Foreign References:
DE3341318A1
Attorney, Agent or Firm:
AWAPATENT AB (P.O. Box 5117, Malm�, S-200 71, SE)
Download PDF:
Claims:
CLAIMS
1. An open contact reactor being in the form of a tank (1), in which a plurality of spray nozzles (2) for spraying finely divided liquid are arranged and through which a gas is to be conducted in a main gas flow direc tion (P) in order to be contacted with the finely divided liquid, the spray nozzles (2) being arranged on different nozzle levels (L1, L2, L3), which are spaced apart in the main gas flow direction, the nozzles (2) on each level being substantially uniformly distributed over the cross section of the tank, and a nozzle assembly (4) for spray ing finely divided liquid being arranged at the circumfe rence of the tank (1) on at least one level along the main gas flow direction (P), c h a r a c t e r i s e d in that each nozzle assembly consists of an annular nozzle means (4), which extends along the circumference of the tank (1) on the respective levels and has a circumferen tial mouth gap (8) which is directed into the tank (1).
2. A contact reactor as claimed in claim 1, c h a r a c t e r i s e d in that the nozzle means (4) are arranged on a plurality of levels along the main gas flow direction (P).
3. A contact reactor as claimed in claim 2, c h a r a c t e r i s e d in that the levels on which the nozzle means (4) are arranged essentially coincide with the nozzle levels (L1, L2, L3).
4. A contact reactor as claimed in claim 3, c h a r a c t e r i s e d in that the spray nozzles (2) on one and the same nozzle level (L1, L2, L3) are iden tical and have a circumferential, conical spray action (3) with the same cone angle (2a), the axis of each cone extending in parallel with the main gas flow direction (P), and that the mouth gap (8) of the nozzle means (4) on the level corresponding to this nozzle level is directed such that it forms with the main gas flow direc tion (P) an angle (a) which is essentially equal to half the cone angle (2a).
Description:
OPEN CONTACT REACTOR The present invention relates to an open contact reactor being in the form of a tank, in which a plurali- ty of spray nozzles for spraying finely divided liquid are arranged and through which a gas is to be conduct- ed in a main gas flow direction in order to be contact- ed with the finely divided liquid, the spray nozzles being arranged on different nozzle levels which are spac- ed apart in the main gas flow direction, the nozzles on each level being substantially uniformly distributed over the cross-section of the tank, and a nozzle assembly for spraying finely divided liquid being arranged at the cir- cumference of the tank on at least one level along the main gas flow direction.

Reactors of this type are used for various purposes.

For instance, they may be used for cleaning of process gases containing gaseous pollutants, and for cooling/ heating of gases. In these two applications, it seems possible to improve the efficiency of the reactor, i.e.

increase the capacity of the reactor of respectively cleaning and cooling/heating the gases.

In a reactor as disclosed in WO 93/18842, in which the spray nozzles on the different levels are identical and have a circumferential, conical spray action, the capacity of the reactor of cleaning and cooling/heating the gases is increased by preventing the gas from flowing linearly through the reactor along the wall thereof. To this end, a nozzle assembly for spraying finely divided liquid is arranged at the circumference of the tank on each nozzle level. Each of these nozzle assemblies con- sists of a plurality of nozzles having a non-circumferen- tial, semi-conical spray action which is directed into the tank. As stated in WO 93/18842, the pattern of the nozzles will not be quite regular on any level, which implies that the distribution of nozzles on one level

must be followed by a compensating distribution on the next level. The reactor according to WO 93/18842 also suffers from the drawback that the impulse of the liquid sprayed by the nozzles arranged at the circumference is not fully utilised since a part of the liquid which is sprayed by a nozzle arranged at the circumference is sprayed towards the two neighbouring nozzles arranged at the circumference and, thus, towards a part of the liquid sprayed by these nozzles.

The object of the present invention therefore is to provide an open contact reactor, which has an improv- ed efficiency in relation to prior-art reactors, and in which the drawbacks described above are obviated.

According to the invention, this object is achieved by an open contact reactor, which is of the type describ- ed by way of introduction and which is characterised in that each nozzle assembly consists of an annular nozzle means which extends along the circumference of the tank on the respective levels and has a circumferential mouth gap directed into the tank.

Nozzle means are preferably arranged on a plurali- ty of levels, which suitably coincide with the nozzle levels.

Preferably, the spray nozzles on one and the same nozzle level are identical and have a circumferential, conical spray action with the same cone angle, the axis of each cone extending in parallel with the main gas flow direction, and the mouth gap of the nozzle means on the level corresponding to this nozzle level being directed such that it forms with the main gas flow direction an angle which is essentially equal to half the cone angle.

The invention will now be described in more detail with reference to the accompanying drawings, in which Fig. 1 is a schematic vertical sectional view and illustrates a portion of an open contact reactor accord- ing to the invention,

Fig. 2 is a schematic cross-sectional view along line II-II in Fig. 1, and Fig. 3 is an enlarged view and shows an annular nozzle means in cross-section.

The open contact reactor shown in the drawings is in the form of an upright, essentially circular-cylindrical tank 1, of which merely a portion is shown schematically in Fig. 1.

A plurality of spray nozzles 2 for spraying finely divided liquid are arranged in the tank 1. The spray nozzles 2 are arranged on a plurality of vertically spaced-apart levels L1, L2, L3, the nozzles on each level being substantially uniformly distributed over the cross- section of the tank 1. Each nozzle 2 has a circumferen- tial, conical spray action, by which is here meant that it sprays liquid essentially uniformly distributed over an intended cone or an intended truncated cone 3, the axis of which is parallel to the axis of the tank 1 and the cone angle of which is 2a.

In the embodiment shown, the spray action of the nozzles 2 is directed downwards. However, it will be appreciated that the spray action of the nozzles can also be directed upwards or directed both upwards and downwards.

An annular nozzle means 4 for spraying finely divided liquid extends along the circumference of the tank 1 on each of a plurality of different levels. In the embodiment shown, these levels coincide with the nozzle levels L1, L2, L3. The nozzle means 4 on each level is so designed as to produce, together with the spray nozzles 2 on the corresponding nozzle level L1, L2, L3, a liquid spray pattern which is essentially uniform over the entire cross-section of the tank 1.

As is especially shown in Fig. 3, the annular nozzle means 4 is mounted in a circumferential liquid supply duct 5, which in the embodiment shown is essentially square in cross-section. Perforated support elements 6,

which are distributed along the circumference, are ar- ranged inside the duct 5. The duct 5 has a liquid inlet 7, through which liquid is supplied to the duct to be sprayed, with the aid of the nozzle means 4, into the tank 1 in the manner indicated by arrows A in Fig. 2.

The nozzle means 4 has a circumferential mouth gap 8 which is directed into the tank 1. The mouth gap 8 is directed such that it forms, with the axis of the tank 1 and, thus, with the wall thereof, an angle a which is equal to half said cone angle 2a.

In the shown embodiment, the reactor is used for cleaning process gases containing gaseous pollutants.

The process gases are conducted essentially vertically through the tank 1 in the direction of the arrows P, i.e.

in parallel with the axis of the tank, in order to be contacted with the finely divided liquid. In other appli- cations, the process gases can be conducted through the tank 1 in the direction opposite to the direction of the arrows P. In this embodiment, the liquid consists of water and an absorbent dissolved or suspended therein, which reacts with the gaseous pollutants in the process gases.

The arrangement of the nozzle means 4 has been found to increase the efficiency of the reactor in a favourable manner, while at the same time the above drawbacks in the reactor according to WO 95/18842 have been obviated.