Methods and apparatus for improving multi-plate scraped heat exchangers

Patent metadata

Field	Value
Publication number	US-11215410-B2
Application number	US-201916660206-A
Country	US
Kind code	B2
Filing date	Oct 22, 2019
Priority date	Nov 20, 2018
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A scraped heat exchanger apparatus, including a vessel and a plurality of internally cooled plates disposed parallel to each other within the vessel. A rotating shaft is disposed at a central axis of the vessel. A rotating scraper arm, connected to the rotating shaft, moves between adjacent plates. The rotating scraper arm includes a scraper positioned to scrape solids from the outer surfaces of adjacent plates. A cooling fluid flows through an interior of each plate. The cooling fluid cools a gaseous process fluid flowing between adjacent plates. An opening in each of the plates permits the process fluid, and solids removed from the process fluid and scraped by the rotating scraper arm, to pass through the plates.

First claim

What is claimed is:

1. A scraped heat exchanger apparatus for cooling a gaseous process fluid which can freeze-out solids, the apparatus comprising:
a vessel;
a plurality of internally cooled plates disposed parallel to each other within the vessel, wherein a spacing between adjacent ones of the plurality of internally cooled plates is varied within the vessel;
a rotating shaft disposed at a central axis of the vessel;
a rotating scraper arm, connected to the rotating shaft, and disposed to move between adjacent ones of the plurality of internally cooled plates, wherein the rotating scraper arm includes a scraper positioned to scrape solids from an outer surface of said adjacent ones of the plurality of internally cooled plates;
a cooling fluid configured to flow through an interior of each of the plurality of internally cooled plates and cool a gaseous process fluid flowing between adjacent ones of the plurality of internally cooled plates; and
an opening in each of one or more of the plurality of internally cooled plates, each opening configured to permit the gaseous process fluid and solids removed from the gaseous process fluid and scraped by the rotating scraper arm to pass through the one or more of the plurality of internally cooled plates.

2. The apparatus of claim 1 , wherein the plurality of internally cooled plates are disposed in a vertical orientation.

3. The apparatus of claim 1 , wherein the plurality of internally cooled plates are disposed in a horizontal orientation such that said plates comprise a vertical stack, and wherein the scraped solids fall through the opening in the one or more of the plurality of internally cooled plates.

4. The apparatus of claim 1 , wherein the opening in each of the one or more of the plurality of internally cooled plates comprises a notch extending outwardly from the central axis.

5. The apparatus of claim 4 , wherein each of the one or more of the plurality of internally cooled plates are arranged in a consecutive sequence, and wherein the notches in adjacent ones of the consecutively sequenced plates are angularly offset from one another, to thereby provide a tortuous path for the gaseous process fluid to flow through the vessel while being cooled by the plates.

6. The apparatus of claim 1 , wherein each of the plurality of internally cooled plates are sealed to an inner wall of the vessel to eliminate bypass of the process fluid around the plates.

7. The apparatus of claim 1 , further comprising a surface feature on an outer surface of one of the plurality of internally cooled plates, wherein the scraper is shaped to rotate past the surface feature.

8. The apparatus of claim 7 , wherein the surface feature comprises a set of concentric circular-path fins, the concentric circular-path fins being centered on the central axis, wherein a shape of the scraper is configured to remove solids from in between adjacent fins in the set of concentric circular-path fins, and wherein the circular-path fins are configured to increase heat transfer between the cooling fluid and gaseous process fluid.

9. The apparatus of claim 1 , wherein the apparatus is configured to supply the cooling fluid sequentially to the plurality of internally cooled plates.

10. The apparatus of claim 1 , wherein the apparatus is configured to supply the cooling fluid sequentially to the plurality of internally cooled plates in a direction that is counter-current to a direction of flow of the gaseous process fluid.

11. The apparatus of claim 1 , wherein the cooling fluid is a first cooling fluid, and wherein at least one of the plurality of internally cooled plates includes first and second segregated layers therein, the first segregated layer configured to permit the first cooling fluid to flow through an interior thereof, and the second segregated layer configured to permit a second cooling fluid to flow through an interior thereof;
wherein the first cooling fluid is different in composition and/or temperature from the second cooling fluid.

12. The apparatus of claim 11 , wherein each of the first and second cooling fluids have a composition comprising primarily ethane, primarily propane, primarily methane, or primarily nitrogen.

13. The apparatus of claim 1 , wherein the cooling fluid is a first cooling fluid, and wherein at least one of the plurality of internally cooled plates includes first and second segregated passages therein, the first passage configured to permit the first cooling fluid to flow through an interior thereof, and the second passage configured to permit a second cooling fluid to flow through an interior thereof;
wherein the first cooling fluid is different in composition and/or temperature from the second cooling fluid, and
wherein the first and second passages are within a single layer of each of the internally cooled plates.

14. The apparatus of claim 1 , wherein the cooling fluid is a first cooling fluid, wherein the plurality of internally cooled plates are divided into first and second sets, each of the first and second sets comprising one or more consecutively or sequentially arranged internally cooled plates; and
wherein the first cooling fluid is configured to flow through interiors of internally cooled plates in the first set and a second cooling fluid is configured to flow through interiors of internally cooled plates in the second set.

15. The apparatus of claim 14 , wherein the first cooling fluid enters the first set at a temperature higher than a temperature at which the second cooling fluid enters the second set.

16. The apparatus of claim 1 , further comprising:
a separator configured to receive the gaseous process fluid and the solids from the vessel after being cooled in the vessel, the separator configured to separate the solids from the gaseous process fluid, the separator having an opening through which the process gas exits therefrom; and
an auger having a first end located in a bottom portion of the separator, the auger configured to transport the solids from the separator such that the gaseous process fluid is prevented from exiting the separator through the auger.

17. A scraped heat exchanger apparatus for cooling a gaseous process fluid which can freeze-out solids, the apparatus comprising:
a vessel;
a plurality of internally cooled plates disposed parallel to each other within the vessel;
a rotating shaft disposed at a central axis of the vessel;
a rotating scraper arm, connected to the rotating shaft, and disposed to move between adjacent ones of the plurality of internally cooled plates, wherein the rotating scraper arm includes a scraper positioned to scrape solids from an outer surface of said adjacent ones of the plurality of internally cooled plates;
a cooling fluid configured to flow through an interior of each of the plurality of internally cooled plates and cool a gaseous process fluid flowing between adjacent ones of the plurality of internally cooled plates; and
an opening in each of one or more of the plurality of internally cooled plates, each opening configured to permit the gaseous process fluid and solids removed from the gaseous process fluid and scraped by the rotating scraper arm to pass through the one or more of the plurality of internally cooled plates,
wherein the opening in each of the one or more of the plurality of internally cooled plates comprises a notch extending outwardly from the central axis, and
wherein at least one of a notch size, a notch shape, or a position of the notch is varied from plate to plate within the vessel to match a variation in an amount of solids gen

Assignees

• Exxonmobil Upstream Res Co

Inventors

• Kaminsky Robert D
• Staedter Marcel

Classifications

• F28F19/008 Primary

  by using scrapers · CPC title

• F25J2220/66

  Separating acid gases, e.g. CO2, SO2, H2S or RSH · CPC title

• B01D5/0015

  Plates · CPC title

• F25J2205/24

  using regenerators, cold accumulators or reversible heat exchangers · CPC title

• B01D2257/7027

  Aromatic hydrocarbons · CPC title