Chemical reactor with a plate heat exchanger
View Patent ↗A steam cooled chemical reactor ( 1 ) comprising a vertical vessel ( 2 ), a plate heat exchanger embedded in a catalytic bed, to cool the catalytic bed by evaporation of a cooling water flow, wherein a water inlet and a steam outlet are located underneath the heat exchanger, and the plates and related piping are arranged so that the path of the cooling flow comprises a first ascending path from bottom to top of the catalytic bed, and a second descending path from top to the bottom of catalytic bed, and wherein internal evaporation channels of the plates provide the second descending or the first ascending path, and water upcomers or respectively steam downcomers provide the other of said first and second path.
1. A steam cooled chemical reactor comprising:
a vertical vessel containing a catalytic bed, and
a plate heat exchanger comprising a plurality of plated having internal passages or channels embedded in said catalytic bed,
said heat exchanger being arranged to cool the catalytic bed by evaporation of a cooling water flow, and comprising a water inlet and a steam outlet, and a piping to distribute the water and collect the steam flow to/from the internal passages or channels of the plates of the heat exchanger,
wherein said water inlet and steam outlet are located underneath the heat exchanger, and said piping and the heat exchange plates are arranged to provide a path for the cooling flow comprising a first ascending path from bottom to top of the catalytic bed, and a second descending path from top to the bottom of catalytic bed, a plurality of evaporation channels providing said second descending path, and one or more water upcomer(s) providing said first ascending path,
wherein the total cross section of the evaporation channels of each plate is greater than the total cross section of the one or more water upcomer(s) of the same plate, and
wherein the number of evaporation channels of each plate is greater than the number of the water upcomer(s) of the same plate.
2. The reactor according to claim 1 , wherein the plates of the heat exchanger are arranged with upper water inlets and lower steam outlets, and said internal piping comprises at least one upcomer arranged to deliver the cooling water feed from a main distributor to said inlets of the heat exchange plates.
3. The reactor according to claim 2 , comprising a plurality of upcomers for the water feed, each of said upcomers delivering water to a group of plates of the heat exchanger.
4. The reactor according to claim 2 , wherein at least one upcomer for the water feed is integrated in each plate of the heat exchanger.
5. The reactor according to claim 4 , wherein each plate of the plate heat exchanger comprises:
a bottom feeder associated to the lower side of the plate; a distributor associated to the upper side of the plate and an opposite bottom collector associated to the lower side of the plate;
said bottom feeder, said distributor and said bottom collector being formed with ducts or pipe elements structurally independent from the plate;
the plate having internal passages comprising a plurality of evaporation channels and at least one water feed passage, said internal passages being isolated from each other;
said water feed passage(s) providing a flow path between said bottom feeder and distributor, and said evaporation channels providing a flow path between the distributor and said bottom collector.
6. The reactor according to claim 5 , wherein each plate of the heat exchanger comprising two opposite metal sheets, said internal passages being longitudinal and parallel, said passages being isolated from each other by continuous spacer elements distancing the metal sheets or by continuous longitudinal seams between the metal sheets.
7. The reactor according to claim 1 , wherein the heat exchange plates are radially arranged around the vertical axis of the reactor.
8. The reactor according to claim 1 , wherein the reactor is a methanol converter.
9. A heat exchange plate for the manufacture of a plate heat exchanger for an isothermal chemical reactor, the plate comprising internal passages for a heat exchange fluid, a feeder and a collector for said fluid, wherein:
said feeder and said collector are both associated to a first side of the plate; the plate comprises a fluid distributor associated to a second side opposite to said first side;
said feeder, said distributor and said collector are formed with ducts or pipe elements structurally independent from the plate;
said internal passages of the plate comprise at least a first internal passage providing fluid communication between said feeder and said distributor, and a plurality of second internal passages providing fluid communication between said distributor and said collector, the second passages being separate from the first passage(s), wherein the total cross section of said second passages are greater than the total cross section of said first passage(s) and the number of said second passages are greater than the number of said first passage(s).
10. The heat exchange plate according to claim 9 , comprising two opposite metal sheets, and having a plurality of longitudinal and parallel internal passages between the metal sheets, the passages being isolated from each other by continuous spacer elements distancing said metal sheets or by continuous longitudinal seams.
11. The heat exchange plate according to claim 10 , wherein the first passage or each of the first passages has a cross section larger than the cross section of each of the second passages, taken alone.