US2897983A

US2897983A - Discharge means for containers or vertical retorts

Info

Publication number: US2897983A
Application number: US559339A
Authority: US
Inventors: Stewart Daniel
Original assignee: Scottish Oils Ltd
Current assignee: Scottish Oils Ltd
Priority date: 1955-01-17
Filing date: 1956-01-16
Publication date: 1959-08-04
Anticipated expiration: 1976-08-04

Description

D. STEWART Aug. 4, 1959 DISCHARGE MEANS FOR CONTAINERS OR 'VERTICAI. RETORTS Filed Jan. 16, 1956 3 Sheets-Sheet 1 HTTaENEYS.

Aug. 4, 1959 D. STEWART 2,397,983

DISCHARGE MEANS FOR CONTAINERS 0R VERTICAL RETORTS Filed Jan. 16, 1956 s Sheets-Shet 2 //v VE'A/TOE DEN/EL J TEWB/ET Aug. 4, 1959 D. STEWART 2,897,983

DISCHARGE MEANS FOR CONTAINERS OR VERTICAL RETORTS Filed Jan. 16, 1956 5 Sheets-Sheet 3 /A/ vz/vraz DEN/EL .5 TE WEB? 630/14 4, 4

A True/wry 5.-

United States Patent cc Application January 16, 1956, Serial No. 559,339

Claims priority,application Great Britain January '17, 1955 3 Claims. (Cl. 214-18) This invention relates to an improved discharge means for containers or vertical retorts and to containers or vertical retorts, of rectangular cross-section, equipped with improved discharge means.

Continuously operatedretorts-in which the flow of the contents thereof is vertically downward are usually provided at their lower ends. with continuously operating discharge gear whereby steady downward movement is maintained within the retort. A conventional form of continuously operating discharge gear employed in vertical retorts of rectangular cross-section comprises a pair of rollers mounted with their axes parallel and in a horizontal plane, said rollers havingsurface irregularities, usually in the formof ribs or radial teeth, said rollers being driven in opposite rotational directions'such that discharge takes place between the rollers.

In application to free moving materials or materials which tend to bond orform clinker to ajimited degree only, it is apparent that the materials contained. in a retort are capable not only of downward movement but also of a degree of'lateral shift? It has been found that by the use of conventionally driven discharge rollers, as hereinbefore described, :the. rate of downward progress of materials in acontainer or retort is non-uniform at intermediate'levelsmerein.

With a view to regularising the flow it has previously been proposed to insert baffles in retorts of rectangular cross-section but while some improvement is obtained in this manner, the flow is, in general, still substantially non-uniform in character.

According to the present invention there is provided improved discharge means, for a container or vertical retort of rectangular horizontal cross-section, which comprises at least one pair of rollers, having surface irregularities to assist movement of the material to be discharged, said rollers being mounted with axes parallel to the side walls and in a horizontal plane and being pro vided with driving means adapted to drive said rollers in such manner that the surfaces of the rollers in adjacency move upwards, said discharge means being adapted to discharge materials over the outwardly and/or downwardly moving surfaces of said rollers.

Preferably the rollers are mounted with only a small clearance between the upwardly moving surfaces. Preferably the rollers are mounted without the inter-position of a fixed component, for example a baflle, between the upwardly moving surfaces.-

According to a further feature of this invention there is provided a container such as a vertical retort or storage hopper comprising the improved discharge means hereinbefore described. Preferably said container is provided with a bafile therein, said bafifle comprising a pair of surfaces, each of said surfaces extending over part of the Width of the container or retort, that is in a direction parallel to the axes of the rollers, and being inclined to the horizontal, whereby the two surfaces in combination provide a ridge over the line of symmetry of the pair of Patented Aug. 4, 1959 rollers. Preferably said surfaces do not meet at their upper edges, whereby a narrow gap is provided in the ridge of the baflle, extending over substantially the full length of said ridge, to permit the passage of a poker inserted between the-rollers. Preferably a gap is left between said bafile and each end wall of the retort. Preferably the baflle is secured to the side walls by extensions offering relatively small resistance to or deflection of the flow of the materials.

Preferably the battle is provided with sloping end plates, essentially of triangular form, the baffle thus having the overall form of a bevel ended triangular prism.

- The flow of materials through the retort is further improved by the provision of deflectors in the vertical edges of said retort to minimise the retarding efiect of corners formed by the adjacent walls.

Preferably the side walls (that is the longer side walls as distinct from the end walls) of the retort are sloped inwardly at their lower ends, preferably by an arrangement of louvres or baffle plates, a suitable clearance being provided between the lower end of each wall and a roller to provide controlled discharge therebetween on rotation of the rollers.

Containers, including vertical. retorts, according to the present invention'are suitable for containing or treating any material in the form of separate lumps or particles 4 terials which require a constant residence time..- The invention is of particular value in retorting crushed minerals, such as shale, wherein a relatively long residence time leads to undesirable sintering with blockage of the retort 'and 'a relatively short residence time results in only partial re'inoval of the required volatile products. Furthermore, by. the .use. of dischargemeans of the presentinvention, crushing of the material being discharged is.reducd a'r'idilesspower isrequired for the operation ;of said discharge means.

The invention is further illustrated but in no way limited with reference to Figures 1-5 accompanying the specification.

Figure l is an end view, half in section along the line A-A', of a vertical shale retort of rectangular horizontal cross-section.

Figure 2 is a plan of the baffle 12 of Figure 1.

Figures 3, 4 and 5 are isometric views of the gas inlet section, discharge section and top section respectively, which make up the retort base and discharge gear of the retort shown in Figure 1.

With reference to said figures:

The framework 1 of the discharge (or bottom) section (shown in Figure 4) supports and is bolted to the framework 2 of the gas inlet (or middleysection (shown in Figure 3) which in turn is welded to the top section 26 (shown in Figure 5) forming the base of the retort. The main body 4 of the retort resting in the topmost section 26 is supported by external girders 3. Fire brick and insulation packing 28 are supported by external wall 29.

Serrated cylindrical rollers 5 and 6 are supported in laterally adjustable external bearings (not shown) the ends of the rollers passing through the end plates 7 and 8 by slot shaped openings 9. The clearance between rollers 5 and 6 is selected to prevent the discharge of shale, other than fines, therebetween, the bulk of the shale being discharged between the roller 5 and side wall 10 and between roller 6 and side wall 11.

Regularity 0f downward movement of the shale over the cross-section of the retort is provided by bafile 12, shown in detail in Figure 2. The baffle provides two sloping surfaces 13 and 14 secured to sloping triangular length of the ridge of the bafiie. The baffle 12 is supported by transverse horizontal bars 18, having chamfered upper surfaces whereby lodging of shale thereon is minimised, said bars 18- being carried bythe sloping'sid walls 19 and attached to the baflie by-vertical plates. 20 and strengthening pieces 21. Below the level of 'the baffle 12 are provided side louvre plates 22 of T crosssection supported by the end walls of the section shown in Figure 3. Behind louvre plates 22 are provided gas inlet ports 23 having deflectors 24 protecting-their inner extremities. Below the louvre plates 22" are provided smaller louvre plates 25 supported by' the end walls of the section shown in Figure 4.

Side walls 19 and louvre plates 22 and 25- constitute converging guide plates having openings to admit gas introduced to the retort base by ports 23.

Side walls 19 and louvre plates 22 constitute components of the gas inlet section, shownin Figure 3-. Louvre plates 25 constitute components of the discharge section, shown in Figure 4.

The rollers 5 and 6. are driven by any suitable, source of rotary power whereby, from the viewpoint of Figure 1, roller 5 rotates anti-clockwise and roller 6 rotates clockwise and whereby spent shale is passed between said rollers and louvre plates 25 and discharged between the rollers and side walls and 11. v 7

Within the main body of a retort having discharge gear as hereinbefore described with reference to Figures 1'-5, the downward movement of the shale is maintained very uniform, within an improvement in retorting efl'iciency.

With further reference to Figures 1-4', the following dimensions represent preferred features of a shale retort having a main body internal horizontal cross-section measuring 4 ft. x 8 ft.: 1 I

Length of members 13 and. 14:

Distance between member 13 and sidewall--. 1 ft. 2 in. Member 14 and side wall 1 ft. 2 in. Height of base of baffie 20 above top of I claim: 1. A vertical retort of rectangular cross-section having, at the bottom thereof, a gas inlet section and, below said gas inlet section, a discharge section, said discharge section comprising a pair of rollers, said rollers having surface irregularities. to assist movement of the material to be discharged, being..mounted with, axes parallel to the retort side walls and i'n'a horizontal plane and being provided with driving means adapted to drive said rollers in such manner that the surfaces of the rollers in adja- 'cency move upwards, said gas section having gas inlet ports and comprising side walls-and louvre plates together constituting converging guide plates having openings for admitting gas to the retort introduced by said gas inlet ports; and, a baflle, disposed in said gas inlet section, said baffle comprising surfaces inclined to the horizontal providing a ridge over the line of symmetry of the pair of rollers.

t 2. A retort as specified in claim 1 in which said baflle has a narrow gap between the surfaces constituting said bafiie and extending over substantially the full length of the ridge of said baffle. g

3. A retort as specified in claim 2 in which the baflle has the overall form of a bevel ended triangular prism.

References Cited in the file of this patent V UNITED STATES PATENTS 353,727 Woodbury Dec. 7, 1886 1,032,132 Gormley July 9, 1912 2,753,085 Plummer July 3,, 1956 FOREIGN PATENTS 471,410 Germany Feb. 12, 1929