Gas cooling apparatus and process

Claim 2

A heat exchanger as in claim 2 further comprising a purge baffle adapted to extend upstream from the upstream terminus of the first annular passage into the first steam chamber and around the outer surface of the inlet tube.

Claim 3

A heat exchanger comprising: an outer housing having a cylindrical passage for the flow of hot fluid therethrough which passage extends from the heat exchanger inlet to the heat exchanger outlet; a coolant chamber in the outer housing; an inlet tube fixed only to said heat exchanger inlet and extending therefrom to an intermediate location within the heat exchanger passage, whereby the surface of the passage and the outer surface of the inlet tube define a first annular passage; a first diffuser nozzle having an angle of divergence of 4*to 10* at the end of the inlet tube inside the hot fluid passage; a second diffuser nozzle located at the outlet of the hot fluid passage, which diffuser nozzle has a total angle of divergence of 4* to 10*; and an outlet line extending from the heat exchanger; the second diffuser nozzle extending into the outlet line, whereby the outer surface of the second diffuser nozzle and the inner Surface of the outlet line define a second annular passage.

Claim 4

A heat exchanger as in claim 4 further comprising an array of guides attached to the outer surface of the inlet tube adapted to maintain the inlet tube and heat exchanger passage in spaced relationship and an array of guides attached to the outer surface of the second nozzle to maintain the second nozzle and the outlet line in spaced relationship.

Claim 5

A heat exchanger as in claim 1 wherein the inlet tube is formed of INCOLOY 800 and the outer housing is formed of carbon steel.

Claim 6

A heat exchanger comprising: an outer housing having a cylindrical passage for the flow of hot fluid therethrough which passage extends from the heat exchanger inlet to the heat exchanger outlet; a coolant chamber in the outer housing; an inlet tube fixed only to said heat exchanger inlet and extending therefrom to an intermediate location within the heat exchanger passage, whereby the surface of the passage and the outer surface of the inlet tube define a first annular passage; a first diffuser nozzle having an angle of divergence of 4* to 10* at the end of the inlet tube inside the hot fluid passage; a second diffuser nozzle located at the outlet of the hot fluid passage, which diffuser nozzle has a total angle of divergence of 4* to 10*; an outlet line extending from the heat exchanger; the second diffuser nozzle extending into the outlet line, whereby the outer surface of the second diffuser nozzle and the inner surface of the outlet line define a second annular passage; and means to seal the first and second annular passages from the hot fluid passing through the hot fluid passage and allowing differential thermal expansion of both said inlet tube and said second diffuser nozzle.

Claim 7

A heat exchanger as in claim 7 wherein the inlet tube is rigidly attached to the heat exchanger outer housing at the inlet to the hot fluid passage in the outer housing.

Claim 8

A heat exchanger as in claim 8 further comprising an expansion joint adapted to connect the hot fluid passage to the outlet line and whereby the outer surface of the second diffuser nozzle and the inner surface of the expansion joint define the second annular passage.

Claim 9

A heat exchanger as in claim 1 wherein the means to seal the first annular passage is a steam seal comprised of a source of steam at a pressure higher than the pressure in the hot fluid passage; a first steam chamber in communication with the source of steam and communication means between the first steam chamber and the first annular passage, and the means to seal the second annular passage is a steam seal comprised of a source of steam at a pressure higher than the pressure in the hot fluid passage; a second steam chamber in communication with the source of steam and communication means between the second steam chamber and the second annular passage.

Claim 10

A heat exchanger as in claim 9 wherein the means to seal the first annular passage is a steam seal comprised of a source of steam at a pressure higher than the pressure in the hot fluid passage; a first steam chamber in communication with the source of steam and communication means between the first steam chamber and the first annular passage, and the means to seal the second annular passage is a steam seal comprised of a source of steam at a pressure higher than the pressure in the hot fluid passage; a second steam chamber in communication with the source of steam and communication means between the second steam chamber and the second annular passage.

Claim 11

A heat exchanger as in claim 10 further comprising a purge baffle adapted to extend upstream from the upstream terminus of the first annular passage into the first steam chamber and around the outer surface of the inlet tube.

Claim 12

A heat exchanger as in claim 11 further comprising a purge baffle adapted to extend upstream from the upstream terminus of the first annular passage into the firsT steam chamber and around the outer surface of the inlet tube.

Claim 13

A heat exchanger as in claim 13 further comprising an array of guides attached to the outer surface of the inlet tube adapted to maintain the inlet tube and heat exchanger passage in spaced relationship and an array of guides attached to the outer surface of the second nozzle to maintain the second nozzle and expansion joint in spaced relationship.

Claim 14

A heat exchanger as in claim 14 wherein the inlet tube is formed of INCOLOY 800 and the outer housing is formed of carbon steel.

Claim 15

A heat exchanger as in claim 15 wherein the purge baffle has a drainage opening formed therein.

Claim 16

A process for cooling hot fluid and generating high pressure steam comprising the steps of: introducing hot furnace effluent from a hydrocarbon cracking process into a heat exchanger passage; expanding the flow of hot fluid at an angle from 4* to 10* in the heat exchanger; passing water through the heat exchanger in indirect heat exchange relationship with the hot fluid flowing therethrough; and expanding the flow of hot fluid a second time at an angle of from 4* to 10* prior to discharge from the heat exchanger.