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US4279295A Expired / Lapsed US ⏱️ 0.0 years remaining

Scraped-surface heat exchanger

Assignee: A Johnson and Co London Ltd
•
Filing: 1980-06-26
•
Granted: 1981-07-21
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Expires: 2000-06-26
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Abstract

Abstract A scraped-surface heat exchanger comprises a stator surrounding a rotor, the stator having annular projections extending inwardly towards the axis of rotation of the rotor. Scrapers on the rotor scrape both blanks of each projection as the rotor rotates. The two blanks of each projection could be planar, the planes being substantially perpendicular to the axis of rotation of the rotor. Instead, at least one of the flanks could be sloping with respect to the axis of rotation.

Inventors

  • 👤 Edward D. Duckworth

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 22:44
CPC Classifications
A; A23; A23G; A23G3/00; A23G3/02; A23G3/04; A23G1/00; A23G1/04; A23G1/18; F; F28; F28F; F28F19/00; F28F19/008; Y; Y10; Y10S; Y10S165/00; Y10S165/076; Y10S165/08

Claims Analysis

Total Claims: 33
Claim 1
Independent Claim 84 words
A scraped-surface heat exchanger comprising a stator surrounding a rotor, the stator having a plurality of annular projections extending inwardly towards the axis of rotation of the rotor, each projection having a first flank which is the upper flank when the heat exchanger is appropriately positioned, with the axis of rotation of the rotor vertical, and which then slopes downwardly, proceeding towards said axis, the rotor carrying scrapers which scrape the first flanks and the opposite flanks of the projections as the rotor rotates.
Claim 2
Dependent Claim 84 words
A scraped-surface heat exchanger comprising a stator surrounding a rotor, the stator having a plurality of annular projections extending inwardly towards the axis of rotation of the rotor, each projection having a first flank which is the upper flank when the heat exchanger is appropriately positioned, with the axis of rotation of the rotor vertical, and which then slopes downwardly, proceeding towards said axis, the rotor carrying scrapers which scrape the first flanks and the opposite flanks of the projections as the rotor rotates.
Claim 3
Dependent Claim 22 words
A heat exchanger according to claim 1 in which said opposite flanks of the projections slope downwardly, proceeding away from said axis.
Claim 4
Dependent Claim 19 words
A heat exchanger according to claim 1 in which the greater part of each upper flank is concavely rounded.
Claim 5
Dependent Claim 20 words
A heat exchanger according to claim 1 in which the greater part of each said opposite flank is concavely rounded.
Claim 6
Dependent Claim 20 words
A heat exchanger according to claim 3 in which the two flanks of each projection are provided by separate members.
Claim 7
Dependent Claim 17 words
A heat exchanger according to claim 1 in which the tips of the projections are convexly rounded.
Claim 8
Dependent Claim 19 words
A heat exchanger according to claim 1 in which there is concave rounding between the roots of adjacent projections.
Claim 9
Dependent Claim 39 words
A heat exchanger according to claim 1 in which in each annular space between two adjacent projections there is at least one scraper blade which scrapes one flank of one projection and the opposite flank of the other projection.
Claim 10
Dependent Claim 35 words
A heat exchanger according to claim 8 in which each scraper blade also scrapes the part of the stator between the roots of two adjacent projections and half of the tip of each of them.
Claim 11
Dependent Claim 21 words
A heat exchanger according to claim 1 in which the blades are held in slots in plates mounted on the rotor.
Claim 12
Dependent Claim 26 words
A heat exchanger according to claim 1 in which the stator comprises a stack of annular parts each of which provides only one of the projections.
Claim 13
Dependent Claim 19 words
A heat exchanger according to claim 1 in which the projections taper, proceeding towards the axis of the rotor.
Claim 14
Dependent Claim 29 words
A heat exchanger according to claim 1 in which the projections are hollow, the spaces within them being for one of the two fluids involved in the heat exchange.
Claim 15
Dependent Claim 15 words
A heat exchanger according to claim 13 in which the projections are of sheet material.
Claim 16
Dependent Claim 46 words
A heat exchanger according to claim 13 in which the spaces within the projections communicate with one another at their extremities remote from the rotor, so that said one of the fluids can flow into and out of them, from one to another along the stator.
Claim 17
Dependent Claim 64 words
A heat exchanger according to claim 15 in which the connections between the spaces within the adjacent projections are staggered circumferentially so that said one of the fluids entering the space within one projection has to flow part of the way around the axis of rotation of the rotor before it can leave that space and flow into the space within the next projection.
Claim 18
Dependent Claim 21 words
A heat exchanger according to claim 16 in which the space within each projection is divided into a plurality of parts.
Claim 19
Dependent Claim 33 words
A heat exchanger according to claim 17 in which the division is effected by each projection being made up of two or more segments distributed around the axis of rotation of the rotor.
Claim 20
Dependent Claim 23 words
A heat exchanger according to claim 18 in which the two flanks of each segment of each projection are provided by separate members.
Claim 21
Dependent Claim 143 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with one another at locations radially inwardly of the tips of the projections, said projections having convexly rounded tips, the rotor carrying scraping means comprising, in each annular space between two adjacent projections, at least one scraper blade which scrapes the whole of one flank of one projection and the whole of the opposite flank of the other projection, whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material.
Claim 22
Dependent Claim 143 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with one another at locations radially inwardly of the tips of the projections, said projections having convexly rounded tips, the rotor carrying scraping means comprising, in each annular space between two adjacent projections, at least one scraper blade which scrapes the whole of one flank of one projection and the whole of the opposite flank of the other projection, whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material.
Claim 23
Dependent Claim 148 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with one another at locations radially inwardly of the tips of the projections, the stator having concave rounding between the roots of adjacent projections, the rotor carrying scraping means comprising, in each annular space between two adjacent projections, at least one scraper blade which scrapes the whole of one flank of one projection and the whole of the opposite flank of the other projection, whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material.
Claim 24
Dependent Claim 148 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with one another at locations radially inwardly of the tips of the projections, the stator having concave rounding between the roots of adjacent projections, the rotor carrying scraping means comprising, in each annular space between two adjacent projections, at least one scraper blade which scrapes the whole of one flank of one projection and the whole of the opposite flank of the other projection, whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material.
Claim 25
Dependent Claim 158 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with one another at locations radially inwardly of the tips of the projections, the rotor carrying scraping means comprising, in each annular space between two adjacent projections, at least one scraper blade which scrapes the whole of one flank of one projection, the whole of the opposite flank of the other projection, the part of the stator between the roots of the two adjacent projections and half of the tip of each of them, whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material.
Claim 26
Dependent Claim 158 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with one another at locations radially inwardly of the tips of the projections, the rotor carrying scraping means comprising, in each annular space between two adjacent projections, at least one scraper blade which scrapes the whole of one flank of one projection, the whole of the opposite flank of the other projection, the part of the stator between the roots of the two adjacent projections and half of the tip of each of them, whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material.
Claim 27
Dependent Claim 140 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with each other, the rotor carrying scraper means comprising, in each annular space between two adjacent projections, scraping means which scrape the whole of one flank of one projection, the whole of the opposite flank of the other projection, the part of the stator between the roots of the projections and half of the tip of each of the projections whereby some of the material is scraped off the projections as the rotor rotates and is mixed with the remainder of the material.
Claim 28
Dependent Claim 140 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with each other, the rotor carrying scraper means comprising, in each annular space between two adjacent projections, scraping means which scrape the whole of one flank of one projection, the whole of the opposite flank of the other projection, the part of the stator between the roots of the projections and half of the tip of each of the projections whereby some of the material is scraped off the projections as the rotor rotates and is mixed with the remainder of the material.
Claim 29
Dependent Claim 43 words
A heat exchanger according to claim 23 in which each said scraping means comprises at least one scraper blade which scrapes the whole of the two flanks, said part of the stator and half of the tip of each of said two projections.
Claim 30
Dependent Claim 195 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with one another at locations radially inwardly of the tips of the projections, radial plate-like parts on the rotor, portions of the radial plate-like parts defining slots therein, the radial plate-like parts being imperforate except for said slots, and scraping means mounted in said slots and comprising, in each annular space between two adjacent projections, at least one scraper blade which has a width when free from stress which is greater than the spacing between the flanks which it scrapes and is flexed so that is cross-section is arcuate and it scrapes the whole of one flank of one projection and the whole of the opposite flank of the other projections, whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material.
Claim 31
Dependent Claim 195 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with one another at locations radially inwardly of the tips of the projections, radial plate-like parts on the rotor, portions of the radial plate-like parts defining slots therein, the radial plate-like parts being imperforate except for said slots, and scraping means mounted in said slots and comprising, in each annular space between two adjacent projections, at least one scraper blade which has a width when free from stress which is greater than the spacing between the flanks which it scrapes and is flexed so that is cross-section is arcuate and it scrapes the whole of one flank of one projection and the whole of the opposite flank of the other projections, whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material.
Claim 32
Dependent Claim 234 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with each other, radial plate-like parts on the rotor, portions of the radial plate-like parts defining slots therein, the radial plate-like parts being imperforate except for said slots, and scraper means mounted in said slots and comprising, in each annular space between two adjacent projections, scraping means which scrape the whole of one flank of one projection, the whole of the opposite flank of the other projection, the part of the stator between the roots of the projections and half of the tip of each of the projections whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material, said scraping means comprising at least one scraper blade which scrapes the whole of the two flanks, said part of the stator and half of the tip of each of said two projections, said scraper blade having a width when free from stress which is greater than the spacing between the two flanks and being flexed so that its cross-section is arcuate.
Claim 33
Dependent Claim 234 words
A scraped-surface heat exchanger for treating a fluid material comprising a stator surrounding a rotor, said heat exchanger including means for rotating said rotor, the stator comprising a plurality of annular projections extending inwardly towards the axis of rotation of the rotor and dividing the space within the stator into a plurality of annular spaces which communicate with each other, radial plate-like parts on the rotor, portions of the radial plate-like parts defining slots therein, the radial plate-like parts being imperforate except for said slots, and scraper means mounted in said slots and comprising, in each annular space between two adjacent projections, scraping means which scrape the whole of one flank of one projection, the whole of the opposite flank of the other projection, the part of the stator between the roots of the projections and half of the tip of each of the projections whereby some of the material is scraped off the projections as the rotor rotates and is mixed in said annular spaces with the remainder of the material, said scraping means comprising at least one scraper blade which scrapes the whole of the two flanks, said part of the stator and half of the tip of each of said two projections, said scraper blade having a width when free from stress which is greater than the spacing between the two flanks and being flexed so that its cross-section is arcuate.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-07-20 1985-01-19 1985-07-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-07-20 1989-01-19 1989-07-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-07-20 1993-01-19 1993-07-21 $7700.00 Window Closed / Lapsed

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