CA1296869C - System to reduce energy consumptions in heterogeneous reactors and relevant reactors - Google Patents
System to reduce energy consumptions in heterogeneous reactors and relevant reactorsInfo
- Publication number
- CA1296869C CA1296869C CA000551076A CA551076A CA1296869C CA 1296869 C CA1296869 C CA 1296869C CA 000551076 A CA000551076 A CA 000551076A CA 551076 A CA551076 A CA 551076A CA 1296869 C CA1296869 C CA 1296869C
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- Prior art keywords
- height
- diameter
- internal
- gas
- bed
- Prior art date
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- A—HUMAN NECESSITIES
- A44—HABERDASHERY; JEWELLERY
- A44C—PERSONAL ADORNMENTS, e.g. JEWELLERY; COINS
- A44C5/00—Bracelets; Wrist-watch straps; Fastenings for bracelets or wrist-watch straps
Landscapes
- Electric Clocks (AREA)
- Emergency Lowering Means (AREA)
- Devices And Processes Conducted In The Presence Of Fluids And Solid Particles (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
ABSTRACT
The system to reduce the energy consumption of heterogeneous synthesis reactors, particularly of ammonia reactors, f.i. the "Chemico"-type reactor, foresees the insertion of two cylindrical walls at least partially perforated in order to annularly delimit the catalytic beds; the first outer wall (Fe) having a diameter (Di) slightly smaller than diameter (Dc) of the cartridge (C), has a height (Hi) higher than (H'i) of the internal cylindrical wall (Fi) which has a diameter inferior to the above mentioned (Di), but superior to the external diameter (Dt) of the central feed pipe (T) of the quench gas (QG). The top (SO) of the internal cylindrical wall (Fi) is closed by a cover (CO) that has a distance from the bottom (FO) of the basket equal to the mentioned height (H'i) of the internal cylindrical wall. The catalytic bed is therefore annular in diameter (Di-D'i) on all of the said height (H'i), but is substantially cylindrical (of diameter Di) on the height (Hi-H'i).
In the substantially annular zone (Q) between the cylindrical internal perforated wall (Fi) and the external face of the pipe (T), which is also at least partially perforated, the reacted and quench gases are collected.
The system to reduce the energy consumption of heterogeneous synthesis reactors, particularly of ammonia reactors, f.i. the "Chemico"-type reactor, foresees the insertion of two cylindrical walls at least partially perforated in order to annularly delimit the catalytic beds; the first outer wall (Fe) having a diameter (Di) slightly smaller than diameter (Dc) of the cartridge (C), has a height (Hi) higher than (H'i) of the internal cylindrical wall (Fi) which has a diameter inferior to the above mentioned (Di), but superior to the external diameter (Dt) of the central feed pipe (T) of the quench gas (QG). The top (SO) of the internal cylindrical wall (Fi) is closed by a cover (CO) that has a distance from the bottom (FO) of the basket equal to the mentioned height (H'i) of the internal cylindrical wall. The catalytic bed is therefore annular in diameter (Di-D'i) on all of the said height (H'i), but is substantially cylindrical (of diameter Di) on the height (Hi-H'i).
In the substantially annular zone (Q) between the cylindrical internal perforated wall (Fi) and the external face of the pipe (T), which is also at least partially perforated, the reacted and quench gases are collected.
Description
~æs~
DESCRIPTION
___________ BACRGROUND QF THE INVENTEON
F1eld of the inventl-n This invention refers to a system to increase the conversion yield and the reduce the energy consumptions in the reactors of heterogeneous synthesis reactors, in particular ammonia reactor~, consisting of an external shell (P), usually in one piece, and of an internal cartridge ~C~ having a diameter ~Dc) and containing granular catalyst arranged in one or more catalytic beds tK) that have an axial height (Hi) and that are closed between one external cylindrical wall made up of sections of sald cartridge tC) having an internal diameter (Dc) and a height (Hi), an internal cylindrical wall made up Or sections of an internal feed pipe for the quench gas (T) having a diameter (Dt) (small with respect to Dc) and a height (Hii, the upper transversal face of each bed being open and invested axially by synthesis gas.
As already known, the reactors for catalytic synthesis under pressure, particularly for the catalytic synthesis of ammonia, methanol, higher alcohols, etc., consist of an external shell, generally in one piece and an inner cartrdige shell containing :~ ~
a granular catalyst arranged in one or more layers (catalytic beds) The synthesis gas that crosses the various catalytic beds is generally cooled between one bed and the other, with the aim of obtaining optimal temperature conditions in the various beds by means of the injection of fresh gas (quench reactor) or by means of a direct interchange with cold inlet gas.
.
D _cri~ti_n f _h_ Pr_or A__ Recently reactors have been proposed with gas radial flow in the catalytic beds (Lummus, Topsoe, Kellogg, Patents U.S.A.
No. 3918918 and no. 4181701, --------- ~ ~
or with axial-radial flow (Ammonia Casale Patent U.S.A. no. 4372920 and 4405562) that represent an important progress in comparision to reactors with axial flow, particularly when a large volume of catalyst must be exploited, permitting the reduction of the charge loss reduced across the catalytic beds, and therefore, of the energY
consumptions. The axial flow of the gas in these cases means , ~ .
, !
i8Ç~9 the adoption of reactors developed in width (low length-diameter ratio of the equipment) with high costs of the machinery and high energy consumption.
The Ammonia Casale patents U.S.A. no. 4372920 and U.S.A. no.
44D5562 have allowed a considerable simplification of the reactor's cartridge design favouring the obtainment of an internal reactor structure, with easy access for the maintenance and the loading and the substitution of the catalyst, and at the same time with low charge losses.
According to the above patents, each catalytic bed is made up of a perforated external cylindrical wall, of a perforated internal cylindrical wall and of only one closed bottom ~the upper wall Or the basket is in fact completely open); an unperforated UppQr portion of the above internal cylindrical wall (or Or both the cylindrical walls), in continuation with the open cross section between the upper edges of the two cylindrical walls arranged on a plane approximately perpendicular to the longitudinal axis of said perforated walls, forms a passage where A minor portion Or the gas crosses the bed with a prevailingly axial flow, whereas the remaining major portion of the gas crosses with radial flow the major cross section of the catalytic bed arranged in the perforated zone of the two cylindrical bed walls.
According to the patented inventlon, the gas portion that crosses the bed with prevailingIy axial flow is controled by the ~ height of the portion of the unperforated internal (or internal or external) cylindrical wall, that is in all cases, .
S
36~ -a minor portion of the total height of the said wall.
Reactors with dimensions corresponding to a height-diameter ratio higher than 10 (f.i. with diameter-height ratio lower than 0.1) are preferablely realized according to the said patented invention.
In the present world-wide economic situation, the market for the modernization of existing plants is very important, the major part of which especially, in the case of synthesis processes (f.i. ammonia synthesis) use reactors with axial gas flow in the catalytic beds taxial reactors~, characterized by a lo;Y height-diameter ratio of the equipment, due to the ahove mentioned necqssity to reduce the charge loss within the machinery.
;
The aPPlicants have already described a system to reduce energy consumptions of heterogeneous catalytic synthesis reactors under pressure, in particular a~ reactors with dimensions~corresponding to low height-diameter ratios tlower than 10); in particular a system is described wh~ch is a~ ideal system to be utilized in the modernization of existing reactors with axial gas flow, in particular in Rellogg-type.reactors which are used in numerous large-scale plants t800-1500 MTD) mostlg built towards the end of the 1970's. The main characteristics of the said plants, (besides the high capacity already cited), is the use of .~
., centrifugal machinery for the compression Or gas operated with vapour produced in the plant itself, according to an integrated cycle between the process vapour and the vapour used to operate the machinery, and the use of the said axial Kellogg-type reactors.
The said plants are also characterized by the uncritically high energy consumptions of those years in which energy was availa~le at a low cost, the axial-type reactor being the cause of said high consumptions.
In the continuation of their researches the Applicants have found a naw system that is now also easily applied for the modernization of "Chemico"-type reactors.
~-mQa~y- Q_ t h_ ~y_~t_Qn The invRntion, concerns therefore a system specified in the introduction of the description and of the main claim, which i~ now characterized by the fact that in order to delimit each catalytic bed the following is inserted therein (see fig. 2):
a) inside and near said external wall which forms the cartridge (C), an external c~ylindrical wall (Fe) that is ; at least partially perforated on its height tHi~ and has a diameter (Di) slightly smaller than that of the cartridge ( C);
~: .
~ 7 : : :
b) an internal cylindrical wall (Fi) showing, on at least one major portion (H'i) of the height (Hi) of the catalytic bed, a diameter (D'i) higher than that (Dt) of the internal transfer pipe (T) and perforations, and c) a cover (CO) on the top of the internal wall (Fi) whereby the catalytic bed has an annular a structure Or diameter (Di-D'i) on the said height (H'i) and structure substantially cylindrical, more precisely o~ annular : diameter (Di-Dt) on the minor height (Hi-H'i).
__talled _eSQEl~tl_n _f the Pref____d Emb dme_t_ In one Or the preferred embodiments Or the invention, the flow of the synthesis gas that axially invests the said upper open face of each bed i~ so divided into a radial flow along the ; perrorated haight (H'i) of (Fi) and, eventually, into an axial flow along the height (Hi-H'i). The flow that crosses (axially and radially) the catalytic bed is collected in the annular zone between the said transfer pipe (T) of diameter (Dt) and the portion of the internal wall (Fi) having height (H'i) and diameter (Di). In this zone it is mixed with quench gas exiting from holes in the pipes (T, T').
~:
: ~ ~ Th- external face of the perforated wall (Fe) forms a conduct :~ 8 : \
for the gas with the internal cartridge face tC~. Since the height (Hi) varies in the various catalytic beds, the height (H'i) can be regulated in order to have the optimal ratios on each bed between the radial flow and the axial flow (the latter which can be negligible and even null).
The ratio between the portions of gas (with prevailingly axial flow and radial flow) will result differently in the various catalytic beds Or the cartridge in the case that the same are of a variable height (ratio height-diameter of variable baskets), as in the application Or this invention for the transformation of the above mentioned "Chemico" reactors, in which the height (Hi) of the catalytic beds of the internal cartridge increases in the various beds arranged in series (3 to 4 beds), and even in the case that the described hereafter should be applied which forsees the use of a diaphram that reduces the cross section arranged on the upper edges of the external cylindrical wall of the bed, lying directly upon the upper surface of the catalytic bed itself.
As said above according to another embodiment Or the invention, the portion of gas that crosses the beds with axial flow in the upper beds of minor height can be reduced, at least equal to that of the following beds of major height, by means of a diaphram red~ucing the open cross section, contained between the upper edges of the external cylindrical wall of the beds, provided with suitable openings tholes, grooves or other) for the reduced passage of the gas, said diaphram lying directl~ on top of the upper surface of the catalytic bed it~elf, and showing accordlng to a prererred e-bodiment, an :
, opening, the total cross section of which increases r~dially from the inside to the outside of the bed (see European patent application no. 86104911.2). - ~ -According to another embodiment of the invention, especiallyin the case that the ~atio between the height of the catalytic bed and the radial distance Or the cylindrical walls of the same is much lower ~lower than 3), the diaphram reducing the open cross section mentioned above can be a solid wall ~without openings), alwa~s lying on the upper surface Or the bed.
` According to this modified embodiment the cylindrical walls may result perforated along their entire height tlacking the upper zone of the unperforated walls).
Other characteristics of the invention are specified in the claim~ from 2 to 6.
DQs_ri~tiQ~ of _he erawing_ The different aspects and advantages Or the invention better appear from the following description of the embodiment represented in Fig. ~ 2, as compared to the Prior A~t represented in Fig. 1, these two figures being schematic, longltudinal cross-sections. In particular the following exemplifying description of a preferred embodiment (modification of the Chemico re~actor with axial Plow) should better illustrate the characteristics of the invention.
`~ : 10 .
.~ .
~g~ ;9 -The embodiment described is referring to the modification of a Chemico ammonia reactor with several catalytic beds (f.i. rour beds) crossed by gas with axial flow, and cooling of the gas in the various beds by means Or an injection of fresh gas (quench reactor represented in fig. 1 of the English patent no. 11281244 to which it is referred).
The reaction gas enters from the top of the reactor in 1 and axially penetrates on a first catalytic bed (K1) open at the top and delimited by a portion o~ the internal wall (Ci~ of the cartridge ~C), by the corresponding portion of the internal face o~ the feed pipe (T) of the quench gas (GQ) and by a closed bottom (FO).
The raacted gases that have crossed the catalytic layer (K1) are mixed by various systems, with the quench gas (GA) exiting rrom the holes (F~ in the pipe ~T) and, cooled in this manner they pass through the next catalytic bed ~K2). Even on the lower part of this bed, the reacted~gases are mixed and the quench gases (GQ') fed by a pipe (T'). In fig. 1 the shell i5 '~
not represented.
In rig~ 2 the system according to the invention is represented, which forsees the insertion of an external cylindrical~wall ~Fe) at least partially perforated, having a height (Hi) and of diameter (Di) slightly lo~er than the 1'1 .
: - :
internal diameter (Dc) of the cartridge (Cj; the insertion of a second internal wall (Fi) of a height ~H~i < Hi) and of a diameter (D'i < Di), but higher than the external diameter (Dt) of the feed pipe (T) of the quench gas (G~); and the application of a cover (C0) on the upper end of (Fi) that creates in this waY a reversed cylinder closed at the top and open at the bottoM (A). As can be seen, on each basket the catalyst assumes a prevailingly annular structure in diameter (Di - D'i~ and in height (zone of radial flow ZR) and a minor structure substanially cylindrical in height (Hi - H'i) (zone of axial flow ZA). Actually the zone (ZA) is also annular in diameter (Di - Dt) and since (Dt) is small with respect to ~Di), it can be considered practically cylindrical. The reaction gases enter from the top into 1, the reacted gases exit from the bottom into UR, IGR, and UGR indicate the entrance and exit of the cooling gas respectively Or the internal wall of the shell (P) and of the external wall of the cartridge tC), f..i. of the airspace (I). T and T' indicate r. i. two feed pipes of the quench gas GQ and GQ', that can however be even more according to the number of catalytic baskets (K). Preferably, and in accordance with what described above in the preceding European patent application No. 86104911.2, the icatalytic beds now have heights (Hi) differing one from the other, even (H'i) shall be varible, r. i. increasing Erom the top to the:bottom, proportionally or no:t, to the incrementation of Hi.~: In other words, the ratio (Hi~H'i) can vary from one basket to another, which allows a better regulation of the valu~s of axial flows (and therefore, ., .
radial flows) on the slngle beds Hith respect to these and other aspects of the invention, it is ~orthwhile to refer to the above mentioned U.S. patents nos. 4372920 and 4405562.
, , , _ In accordance to what is foreseen in the said European patent application on at least some of the upper surfaces of the catalytic beds tK), as the reducinq ~or annullator~) diaphrams (DR1 - DRn) of axial flow are placed. They ars provided with adjustable ~penings (at the most, closable), preferably in sections varying from the inside to the outside.
.
Even i~ the invention has been described with reference to the preferred embodiment represented in Fig. 2 and 2A, it is susceptible to variations, modifications, substitutions and the like, that is iust because they are obvious to the technician skilled in this field, are to be considered automatically falling within the scope and the spirit of this invention.
"
:
: /~
~ :A7 ,. ~ . - . . . ~, .
DESCRIPTION
___________ BACRGROUND QF THE INVENTEON
F1eld of the inventl-n This invention refers to a system to increase the conversion yield and the reduce the energy consumptions in the reactors of heterogeneous synthesis reactors, in particular ammonia reactor~, consisting of an external shell (P), usually in one piece, and of an internal cartridge ~C~ having a diameter ~Dc) and containing granular catalyst arranged in one or more catalytic beds tK) that have an axial height (Hi) and that are closed between one external cylindrical wall made up of sections of sald cartridge tC) having an internal diameter (Dc) and a height (Hi), an internal cylindrical wall made up Or sections of an internal feed pipe for the quench gas (T) having a diameter (Dt) (small with respect to Dc) and a height (Hii, the upper transversal face of each bed being open and invested axially by synthesis gas.
As already known, the reactors for catalytic synthesis under pressure, particularly for the catalytic synthesis of ammonia, methanol, higher alcohols, etc., consist of an external shell, generally in one piece and an inner cartrdige shell containing :~ ~
a granular catalyst arranged in one or more layers (catalytic beds) The synthesis gas that crosses the various catalytic beds is generally cooled between one bed and the other, with the aim of obtaining optimal temperature conditions in the various beds by means of the injection of fresh gas (quench reactor) or by means of a direct interchange with cold inlet gas.
.
D _cri~ti_n f _h_ Pr_or A__ Recently reactors have been proposed with gas radial flow in the catalytic beds (Lummus, Topsoe, Kellogg, Patents U.S.A.
No. 3918918 and no. 4181701, --------- ~ ~
or with axial-radial flow (Ammonia Casale Patent U.S.A. no. 4372920 and 4405562) that represent an important progress in comparision to reactors with axial flow, particularly when a large volume of catalyst must be exploited, permitting the reduction of the charge loss reduced across the catalytic beds, and therefore, of the energY
consumptions. The axial flow of the gas in these cases means , ~ .
, !
i8Ç~9 the adoption of reactors developed in width (low length-diameter ratio of the equipment) with high costs of the machinery and high energy consumption.
The Ammonia Casale patents U.S.A. no. 4372920 and U.S.A. no.
44D5562 have allowed a considerable simplification of the reactor's cartridge design favouring the obtainment of an internal reactor structure, with easy access for the maintenance and the loading and the substitution of the catalyst, and at the same time with low charge losses.
According to the above patents, each catalytic bed is made up of a perforated external cylindrical wall, of a perforated internal cylindrical wall and of only one closed bottom ~the upper wall Or the basket is in fact completely open); an unperforated UppQr portion of the above internal cylindrical wall (or Or both the cylindrical walls), in continuation with the open cross section between the upper edges of the two cylindrical walls arranged on a plane approximately perpendicular to the longitudinal axis of said perforated walls, forms a passage where A minor portion Or the gas crosses the bed with a prevailingly axial flow, whereas the remaining major portion of the gas crosses with radial flow the major cross section of the catalytic bed arranged in the perforated zone of the two cylindrical bed walls.
According to the patented inventlon, the gas portion that crosses the bed with prevailingIy axial flow is controled by the ~ height of the portion of the unperforated internal (or internal or external) cylindrical wall, that is in all cases, .
S
36~ -a minor portion of the total height of the said wall.
Reactors with dimensions corresponding to a height-diameter ratio higher than 10 (f.i. with diameter-height ratio lower than 0.1) are preferablely realized according to the said patented invention.
In the present world-wide economic situation, the market for the modernization of existing plants is very important, the major part of which especially, in the case of synthesis processes (f.i. ammonia synthesis) use reactors with axial gas flow in the catalytic beds taxial reactors~, characterized by a lo;Y height-diameter ratio of the equipment, due to the ahove mentioned necqssity to reduce the charge loss within the machinery.
;
The aPPlicants have already described a system to reduce energy consumptions of heterogeneous catalytic synthesis reactors under pressure, in particular a~ reactors with dimensions~corresponding to low height-diameter ratios tlower than 10); in particular a system is described wh~ch is a~ ideal system to be utilized in the modernization of existing reactors with axial gas flow, in particular in Rellogg-type.reactors which are used in numerous large-scale plants t800-1500 MTD) mostlg built towards the end of the 1970's. The main characteristics of the said plants, (besides the high capacity already cited), is the use of .~
., centrifugal machinery for the compression Or gas operated with vapour produced in the plant itself, according to an integrated cycle between the process vapour and the vapour used to operate the machinery, and the use of the said axial Kellogg-type reactors.
The said plants are also characterized by the uncritically high energy consumptions of those years in which energy was availa~le at a low cost, the axial-type reactor being the cause of said high consumptions.
In the continuation of their researches the Applicants have found a naw system that is now also easily applied for the modernization of "Chemico"-type reactors.
~-mQa~y- Q_ t h_ ~y_~t_Qn The invRntion, concerns therefore a system specified in the introduction of the description and of the main claim, which i~ now characterized by the fact that in order to delimit each catalytic bed the following is inserted therein (see fig. 2):
a) inside and near said external wall which forms the cartridge (C), an external c~ylindrical wall (Fe) that is ; at least partially perforated on its height tHi~ and has a diameter (Di) slightly smaller than that of the cartridge ( C);
~: .
~ 7 : : :
b) an internal cylindrical wall (Fi) showing, on at least one major portion (H'i) of the height (Hi) of the catalytic bed, a diameter (D'i) higher than that (Dt) of the internal transfer pipe (T) and perforations, and c) a cover (CO) on the top of the internal wall (Fi) whereby the catalytic bed has an annular a structure Or diameter (Di-D'i) on the said height (H'i) and structure substantially cylindrical, more precisely o~ annular : diameter (Di-Dt) on the minor height (Hi-H'i).
__talled _eSQEl~tl_n _f the Pref____d Emb dme_t_ In one Or the preferred embodiments Or the invention, the flow of the synthesis gas that axially invests the said upper open face of each bed i~ so divided into a radial flow along the ; perrorated haight (H'i) of (Fi) and, eventually, into an axial flow along the height (Hi-H'i). The flow that crosses (axially and radially) the catalytic bed is collected in the annular zone between the said transfer pipe (T) of diameter (Dt) and the portion of the internal wall (Fi) having height (H'i) and diameter (Di). In this zone it is mixed with quench gas exiting from holes in the pipes (T, T').
~:
: ~ ~ Th- external face of the perforated wall (Fe) forms a conduct :~ 8 : \
for the gas with the internal cartridge face tC~. Since the height (Hi) varies in the various catalytic beds, the height (H'i) can be regulated in order to have the optimal ratios on each bed between the radial flow and the axial flow (the latter which can be negligible and even null).
The ratio between the portions of gas (with prevailingly axial flow and radial flow) will result differently in the various catalytic beds Or the cartridge in the case that the same are of a variable height (ratio height-diameter of variable baskets), as in the application Or this invention for the transformation of the above mentioned "Chemico" reactors, in which the height (Hi) of the catalytic beds of the internal cartridge increases in the various beds arranged in series (3 to 4 beds), and even in the case that the described hereafter should be applied which forsees the use of a diaphram that reduces the cross section arranged on the upper edges of the external cylindrical wall of the bed, lying directly upon the upper surface of the catalytic bed itself.
As said above according to another embodiment Or the invention, the portion of gas that crosses the beds with axial flow in the upper beds of minor height can be reduced, at least equal to that of the following beds of major height, by means of a diaphram red~ucing the open cross section, contained between the upper edges of the external cylindrical wall of the beds, provided with suitable openings tholes, grooves or other) for the reduced passage of the gas, said diaphram lying directl~ on top of the upper surface of the catalytic bed it~elf, and showing accordlng to a prererred e-bodiment, an :
, opening, the total cross section of which increases r~dially from the inside to the outside of the bed (see European patent application no. 86104911.2). - ~ -According to another embodiment of the invention, especiallyin the case that the ~atio between the height of the catalytic bed and the radial distance Or the cylindrical walls of the same is much lower ~lower than 3), the diaphram reducing the open cross section mentioned above can be a solid wall ~without openings), alwa~s lying on the upper surface Or the bed.
` According to this modified embodiment the cylindrical walls may result perforated along their entire height tlacking the upper zone of the unperforated walls).
Other characteristics of the invention are specified in the claim~ from 2 to 6.
DQs_ri~tiQ~ of _he erawing_ The different aspects and advantages Or the invention better appear from the following description of the embodiment represented in Fig. ~ 2, as compared to the Prior A~t represented in Fig. 1, these two figures being schematic, longltudinal cross-sections. In particular the following exemplifying description of a preferred embodiment (modification of the Chemico re~actor with axial Plow) should better illustrate the characteristics of the invention.
`~ : 10 .
.~ .
~g~ ;9 -The embodiment described is referring to the modification of a Chemico ammonia reactor with several catalytic beds (f.i. rour beds) crossed by gas with axial flow, and cooling of the gas in the various beds by means Or an injection of fresh gas (quench reactor represented in fig. 1 of the English patent no. 11281244 to which it is referred).
The reaction gas enters from the top of the reactor in 1 and axially penetrates on a first catalytic bed (K1) open at the top and delimited by a portion o~ the internal wall (Ci~ of the cartridge ~C), by the corresponding portion of the internal face o~ the feed pipe (T) of the quench gas (GQ) and by a closed bottom (FO).
The raacted gases that have crossed the catalytic layer (K1) are mixed by various systems, with the quench gas (GA) exiting rrom the holes (F~ in the pipe ~T) and, cooled in this manner they pass through the next catalytic bed ~K2). Even on the lower part of this bed, the reacted~gases are mixed and the quench gases (GQ') fed by a pipe (T'). In fig. 1 the shell i5 '~
not represented.
In rig~ 2 the system according to the invention is represented, which forsees the insertion of an external cylindrical~wall ~Fe) at least partially perforated, having a height (Hi) and of diameter (Di) slightly lo~er than the 1'1 .
: - :
internal diameter (Dc) of the cartridge (Cj; the insertion of a second internal wall (Fi) of a height ~H~i < Hi) and of a diameter (D'i < Di), but higher than the external diameter (Dt) of the feed pipe (T) of the quench gas (G~); and the application of a cover (C0) on the upper end of (Fi) that creates in this waY a reversed cylinder closed at the top and open at the bottoM (A). As can be seen, on each basket the catalyst assumes a prevailingly annular structure in diameter (Di - D'i~ and in height (zone of radial flow ZR) and a minor structure substanially cylindrical in height (Hi - H'i) (zone of axial flow ZA). Actually the zone (ZA) is also annular in diameter (Di - Dt) and since (Dt) is small with respect to ~Di), it can be considered practically cylindrical. The reaction gases enter from the top into 1, the reacted gases exit from the bottom into UR, IGR, and UGR indicate the entrance and exit of the cooling gas respectively Or the internal wall of the shell (P) and of the external wall of the cartridge tC), f..i. of the airspace (I). T and T' indicate r. i. two feed pipes of the quench gas GQ and GQ', that can however be even more according to the number of catalytic baskets (K). Preferably, and in accordance with what described above in the preceding European patent application No. 86104911.2, the icatalytic beds now have heights (Hi) differing one from the other, even (H'i) shall be varible, r. i. increasing Erom the top to the:bottom, proportionally or no:t, to the incrementation of Hi.~: In other words, the ratio (Hi~H'i) can vary from one basket to another, which allows a better regulation of the valu~s of axial flows (and therefore, ., .
radial flows) on the slngle beds Hith respect to these and other aspects of the invention, it is ~orthwhile to refer to the above mentioned U.S. patents nos. 4372920 and 4405562.
, , , _ In accordance to what is foreseen in the said European patent application on at least some of the upper surfaces of the catalytic beds tK), as the reducinq ~or annullator~) diaphrams (DR1 - DRn) of axial flow are placed. They ars provided with adjustable ~penings (at the most, closable), preferably in sections varying from the inside to the outside.
.
Even i~ the invention has been described with reference to the preferred embodiment represented in Fig. 2 and 2A, it is susceptible to variations, modifications, substitutions and the like, that is iust because they are obvious to the technician skilled in this field, are to be considered automatically falling within the scope and the spirit of this invention.
"
:
: /~
~ :A7 ,. ~ . - . . . ~, .
Claims (7)
1. A system to increase the conversion yields and to reduce the energy consumption in heterogeneous synthesis reactors, consisting of an external shell (P) generally in one piece, and of a cartridge (C) having a diameter (Dc) and containing granular catalyst arranged in a plurality of catalytic beds (K) that have an axial height (Hi) and are closed between an external cylindrical wall made up of sections of said cartridge (C) having internal diameter (Dc) and height (Hi), an internal cylindrical wall made up of sections of internal feed pipe for fresh quench gas (T), having diameter (Dt) which is small with respect to the internal diameter (Dc) and a bottom, the top face of each bed being oen and invested axially by synthesis gas, wherin there are provided:
(a) inside and near said external wall forming the cartridge (C), an external cylindrical wall (Fe) which is substantially perforated on its height (Hi) and has a diameter (Di) just slightly less than that (Dc) of the cartridge (C);
(b) an internal cylindrical wall (Fi)having, on at least one major portion (H'i) of the height (Hi) of the catalytic bed, a diameter (D'i) greater than that (Dt) of said internal feed pipe (T), and perforations; and, (c) a perforated cover (CO) at the top of the internal wall of height (H'i) whereby the catalytic bed has an annular structure of diameter (Di-D'i) on said height (H'i) and a substantially cylindrical, annular structure with diameter (Di-Dt) on the minor height (Hi-H'i), and wherein the ratio (Hi/H'i) varies from one catalyst basket to another.
(a) inside and near said external wall forming the cartridge (C), an external cylindrical wall (Fe) which is substantially perforated on its height (Hi) and has a diameter (Di) just slightly less than that (Dc) of the cartridge (C);
(b) an internal cylindrical wall (Fi)having, on at least one major portion (H'i) of the height (Hi) of the catalytic bed, a diameter (D'i) greater than that (Dt) of said internal feed pipe (T), and perforations; and, (c) a perforated cover (CO) at the top of the internal wall of height (H'i) whereby the catalytic bed has an annular structure of diameter (Di-D'i) on said height (H'i) and a substantially cylindrical, annular structure with diameter (Di-Dt) on the minor height (Hi-H'i), and wherein the ratio (Hi/H'i) varies from one catalyst basket to another.
2. The system as claimed in claim 1, wherein the gas flow path is axially and radially across at least one catalytic bed and into the annular zone between the internal feed pipe (T) at diameter (Dt)and the portion of internal wall (Fi) having height (H'i<Hi) and diameter (D'i<Di).
3. The system as claimed in claim 1, wherein cooling gas is circulated in the airspace between the internal wall of the shell and the external wall of the cartridge.
4. The system as claimed in claim 1, wherein the ratio between the rate of axial flow of the gas to radial flow of the gas in the various catalytic beds of variable height is regulated in at least one of said beds by the height (Hi-H'i) of the portion of the unperforated feed pipe of the quench has (T) in contact with the catalyst, and by a diaphram which reduces the quantity of gas that axially invests the upper open face of the catalytic bed.
5. The system as claimed in claim 4, wherein said diaphram is provided with adjustable opening of variable sections and increasing radially from the inside to the outside of the bed, and directly placed on the upper surface of the catlaytic bed, in such a way that the ratio; between the two gas flow rates in the various beds varies from zero to 0.6.
6. The system as claimed in claim 1, wherein the plurality of catalytic beds have different heights.
7. The system as claimed in claim 6, wherein the plurality of catalytic beds are arranged so that the height of each bed increases from the highest basket to the lowest.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH420486A CH669301GA3 (en) | 1986-10-22 | 1986-10-22 | |
| CH04204/86-2 | 1986-10-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1296869C true CA1296869C (en) | 1992-03-10 |
Family
ID=4271736
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000551076A Expired - Fee Related CA1296869C (en) | 1986-10-22 | 1987-10-22 | System to reduce energy consumptions in heterogeneous reactors and relevant reactors |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0264874A1 (en) |
| JP (1) | JPS63192464A (en) |
| AU (1) | AU7999387A (en) |
| BR (1) | BR8705651A (en) |
| CA (1) | CA1296869C (en) |
| CH (1) | CH669301GA3 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ITMI20060067U1 (en) * | 2006-02-27 | 2007-08-28 | Villa & Villa S A S | DECORATIVE CUSTOMIZABLE BRACELET TILE |
| GB2460828A (en) * | 2008-06-09 | 2009-12-16 | Karen Gail Lambert | Timepiece with elasticised band |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2639067A (en) * | 1951-12-14 | 1953-05-19 | Hirsch Theodore | Watch wristband |
| CH329337A (en) * | 1956-04-07 | 1958-04-30 | Baron & Cie V | Connecting member and method of manufacturing this member |
| CH368650A (en) * | 1961-02-17 | 1963-04-15 | Mestral George De | Watch strap |
| FR1384816A (en) * | 1963-11-28 | 1965-01-08 | Laffargue & Fils S | Improvements to bracelets, belts and similar products |
| DE7635640U1 (en) * | 1976-11-11 | 1977-08-04 | Compur-Electronic Gmbh, 8000 Muenchen | MONITORING AND SIGNAL DEVICE |
-
1986
- 1986-10-22 CH CH420486A patent/CH669301GA3/fr unknown
-
1987
- 1987-10-19 EP EP87115245A patent/EP0264874A1/en not_active Withdrawn
- 1987-10-21 AU AU79993/87A patent/AU7999387A/en not_active Abandoned
- 1987-10-22 CA CA000551076A patent/CA1296869C/en not_active Expired - Fee Related
- 1987-10-22 JP JP62265517A patent/JPS63192464A/en active Pending
- 1987-10-22 BR BR8705651A patent/BR8705651A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AU7999387A (en) | 1988-04-28 |
| EP0264874A1 (en) | 1988-04-27 |
| JPS63192464A (en) | 1988-08-09 |
| BR8705651A (en) | 1988-05-31 |
| CH669301GA3 (en) | 1989-03-15 |
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| MKLA | Lapsed |