GB2193699A - Adjustable supply of solid particles to one or more receiving stations - Google Patents

Description

GB2193699A 1 SPECIFICATION particles to the slide are also possible, for

instance discharge means of another slide, or Adjustable supply of solid particles to one discharge means from a conveyor (for in or more receiving stations stance a screw, belt, bucket, vibrating or 70 other conveyor).

The invention relates to an apparatus and pro- The discharge means of the end of the slide cess for the adjustable supply of solid par- may be any known discharge means. It will be ticles to one or more receiving stations. appreciated that this discharge means needs a Apparatus and processes for the transport sufficient capacity to avoid congestion on the and distribution of smaller and larger amounts 75 slide. The solid particles discharged at the end of bulk solid particles are known. of the slide may be carried off, and/or may The present invention relates to an appara- be recirculated. The same discharge means as tus suitable for the adjustable supply of solid the discharge means described before, i.e. a particles to one or more receiving stations, discharge means comprising at least two adja comprising a slide arranged at a small angle to 80 cent, communicating vessels, each having a the horizontal plane in the longitudinal direc- bottom and fluidization means, may also be tion, said slide having a bottom and aeration used at the end of the slide.

or fluidization means in or close to the bottom A suitable discharge means to be used in and at least one or more discharge means the apparatus according to the present inven which are not located at the end of the slide, 85 tion is a solids syphon, consisting of two ves each of these discharge means comprising at sels interconnected by at least one orifice, the least two adjacent, communicating vessels, first vessel communicating with the slide each having a bottom and fluidization means (downcomer), the second vessel provided with in or close to the bottom, one vessel commu- outlet means for communication with the re nicating with the slide and one vessel having 90 ceiving station (riser). Both vessels are each outlet means for communication with a receiv-, provided with suitable fluidization means, for ing station. example a perforated or a porous bottom An advantage of the apparatus according to which is connected to a gas supply line. The the invention is that it does not comprise any porous bottom is for example made of a po moving parts. This is especially important un- 95 rous sintered metal or of a porous ceramic der operational conditions of high solid par- plate. It is also possible to use fluidization ticles throughputs and high temperatures, means built up of a plurality of tubes provided creating highly erosive conditions. with a large number of openings to obtain a The slide of the apparatus according to the good distribution of the fluidization gas. The invention is arranged at a small angle to the 100 flow of solids through the syphon is based on horizontal plane, for example at an angle of 1 the pressure difference between the fluidized to 15, especially 5 to 10'. The slide is pro- beds under operational conditions across the vided with suitable aeration or fluidization orifice, resulting from a difference in bed means, for example a perforated plate or a height and/or bulk density between the beds.

porous bottom which is connected to a gas 105 The first vessel is in open gas communication supply line. The porous plates are for example with the slide, the second vessel usually is made of a porous sintered metal or of a po- provided with a gas outlet at or near to the rous ceramic plate. It is however possible to top of the vessel.

4 use instead fluidization means built up of a At least one orifice of the solids syphon has plurality of tubes provided with a large number 110 to be situated below the bed height of the of openings to obtain a good distribution of first vessel under operational conditions, for the fluidization gas. example at one/third or at two/third of the The slide is preferably provided with two distance between the bottom of the vessel side walls and a top wall so that the slide is and the bed height in the vessel, but is prefer closed and dusting is prevented. Furthermore, 115 ably situated near the bottom of the first ves when the particles to be transported along the sel. The bottom of the second vessel has to slide are very hot, it is preferred to provide be situated below the orifices, and is prefera the slide and the walls with heat-insulating bly situated at the same height as the first material to reduce the loss of heat. vessel. The substantially vertical vessels may The slide may be connected to a distribu- 120 have the same or different shapes, for in- tion vessel at the upper end of the slide. stance completely or partly cylindrical or rec From this vessel, for instance a bunker or a tangular. Optionally a, for instance spherical or vessel provided with fluidization means suitrectangular, part may be cut out.

able to maintain a fluidized bed, solid particles A preferred shape of both vessels is a half- are supplied to the slide. The vessel is proround or a u-shaped longitudinal vessel vided with an inlet for the supply of solid whereby the two ends of the first vessel are particles. If desired two or more parallel slides connected with the two ends of the second can be used, for example three parallel slides, vessel, preferably each connection having at which are each connected to the distribution least one orifice. In this arrangement an en vessel. Other means for the supply of solid 130 closed cylindrical tube is formed which may 2 GB2193699A form part of the outlet means of the second means of second vessel of the solids syphon.

vessel. In that case the riser and downcomer The invention relates also to a method for are situated coaxially around the overflow the adjustable supply of solid particles to one tube, resulting in a compact construction or more receiving stations.

which reduces mechanical problems in high 70 The invention especially relates to an appa- temperature operations. ratus and process to be used in the extraction One or both vessels of each discharge of hydrocarbons from a hydrocarbon- contain- means may be placed in or beside the slide, ing substrate, such as oil shale, tar sand or a or partly in and partly beside the slide, The bituminous coal, by heating hydrocarbon-con communicating means of the first vessel and 75 taining substrate particles in the substantial the slide, for instance the upper end of the absence of oxygen at a temperature of at vessel or an orifice, will have to be placed in, least 400 'C to give a coke-bearing spent near or above -the bottom of the slide to substrate and liberated hydrocarbons and re make under operational conditions a solids covering the liberated hydrocarbons.

flow possibld from the slide to the vessel. It 80 In a known process of this kind, carried out is preferred to place both vessels directly be- in a retorting vessel, the hydrocarbon-contain side the slide. ing substrate particles are passed through a The outlet means of the second vessel may plurality of stages, wherein in at least some of be for example a simple orifice or a tube. A said stages the hydrocarbon- containing sub preferred outlet means is a tube formed by 85 strate particles are mixed with hot solid par the two vessels in the way as described ticles, preferably hot spent substrate particles, above. The outlet means is preferably situated in order to heat the hydrocarbon-containing at the same height as the bed height of the substrate particles, the mixture is maintained solid particles in the slide under operational in a'fluidized condition and the liberated hy conditions. 90 drocarbons are recovered.

During normal use solid particles are sup- The hot solid particles used are preferably plied to the slide, and aeration or fluidization hot spent substrate particles obtained by the gas is supplied to the aeration or fluidization separate combustion of the coke-bearing means of the slide, causing aeration or fluidi- spent substrate particles in a suitable combus zation of the bed of solid particles on the 95 tor.

slide. Solid particles are displaced along the In the above known process and apparatus, slide to the discharge means and a part of the which is described for example in US patent particles flows into the first vessel of the dis- specification No. 4,439, 306 published on 27th charge means (downcomer). March, 1984, the hot solid particles are sepa- Fluidization gas is supplied to the fluidization 100 rately supplied to some or all of the said means of this vessel causing fluidization of stages.

solid particles in the vessel. Via the communi- The present invention especially relates to cating means solid particles flow into the sec- the improved apparatus as described before ond vessel (riser). Fluidization gas is supplied for the supply of the hot solid particles, pre to the fluidization means of this vessel causing 105 ferably hot spent substrate particles, to a re fluidization of the solid particles in the vessel. torting vessel for extraction of hydrocarbons Via the outlet means the solid particles ulti- from a hydrocarbon- containing substrate.

mately leave the discharge means. Normally, the apparatus according to the in- The adjustable discharge of solid particles, vention comprises a plurality of discharge now, is achieved by regulating the amount of 110 means arranged near the slide, wherein each fluidization gas in the first and second vessel discharge means is in communication with the of the discharge means. For instance, a rela- slide and with a corresponding inlet for hot tively low velocity of the fluidization gas in the solid particles of the retorting vessel, and first vessel will result in a relatively high den- wherein the fluidization means of each dis sity of the material in this vessel, thus creat- 115 charge means are connected to the means for ing a relatively large particle flow into the sec- the supply of fluidization gas to the said fluidi ond vessel. A relatively high velocity of the zation means.

fluidization gas in the second vessel will tran- A particularly attractive embodiment of the sport the solid particles relatively fast to the apparatus according to the invention com outlet means. In this way a relatively large 120 prises a temperature measuring device ar discharge of solid particles is obtained. In- ranged in a compartment in the retorting ves creasing the gas velocity in the first vessel, as sel containing a fluidized bed of substrate par well as decreasing the gas velocity in the sec- ticles during normal operation and adapted to ond vessel will cause a decrease of the dis- produce a signal corresponding to the temper charge By choosing the right conditions the 125 ature measured in the said fluidized bed, discharge will even stop. means for transferring the signal obtained to a It will be appreciated that the solids syphon control device for controlling the quantity of discharge means functions as a gas-sealing fluidization gas supplied to the fluidization device, as the aeration or fluidization gas from means of a corresponding discharge means, the slide is prevented to leave the outlet 130 so as to control the quantity of hot solid par- 3 GB2193699A 3 ticles passing from the discharge means into each corresponding gas supply chamber 11, the corresponding inlet of the retorting vessel. 12, 13, 14 and 15 by respectively a corre- By means of this embodiment, the tempera- sponding perforated or porous plate 16, 17, ture of the hydrocarbon-containing substrate 18, 19 and 20. Furthermore each gas supply particles in the various compartments of the 70 chamber 11, 12, 13, 14 and 15 is provided retorting vessel can be regulated in an ex- respectively with a corresponding gas inlet 21, tremely simple and effective manner. 22, 23, 24 and 25.

The invention relates as well to a method Above each compartment 1, 2, 3, 4 and 5 for the adjustable supply of hot solid particles, cyclones 26, 27, 28, 29, 30 and 31 are pre preferably hot spent substrate particles, to a 75 sent. Furthermore each compartment 1, 2, 3, retorting vessel by means of the apparatus 4 and 5 is provided respectively with a corre according to the invention. sponding inlet 41, 42, 43, 44 and 45 for the The invention will now be described with supply of hot solid particles, preferably hot reference to the drawings, wherein: spent substrate particles, to the various com- Figures la and lb show schematically a 80 partments 1, 2, 3, 4 and S. These inlets 41, vertical and horizontal cross-section of a part 42, 43, 44 and 45 are each connected to the of an airslide together with a solids-syphon apparatus 50 for the supply of hot solid par discharge means. ticles to the retorting vessel 46.

Figures 2a and 2b show schematically a One side of the retorting vessel 46 is pro- vertical and horizontal cross section of a pre- 85 vided with an inlet 32 for the supply of fresh ferred embodiment of the discharge means. hydrocarbon-containing substrate particles to Figure 3 shows schematically a vertical be treated in the retorting vessel 46. The ref- cross-section of a retorting vessel together erence numberal 35 indicates a steam stripper with an apparatus according to the invention which is provided with an outlet 36.

for the supply of hot solid particles to the 90 The apparatus 50 for the supply of hot solid retorting vessel. particles, preferably hot spent substrate par- Figure 4 shows schematically a vertical ticles, to the retorting vessel 46, will now be cross-section on an enlarged scale of a frag- described with reference to figures 3 and 4.

ment of the apparatus for the supply of hot The apparatus 50 comprises a slide 52 solid particles to the retorting vessel. 95 which is connected to a distribution vessel The discharge means as shown in fig. 1 a 51. The slide 52 is preferably provided with and lb comprises a slide 52 which is con- two side walls 47 and top wall 48 so that the nected to two adjacent vessels 60 and 61, slide is closed and dusting is prevented. Fur communicating via orifice 65. The slide 52 is thermore, since the particles to be transported provided with suitable aeration or fluidization 100 along the slide 52 are very hot, it is preferred means, for example a perforated bottom or to provide the slide 52 and the walls 47 and porous bottom 59 which is connected to a 48 with heat-insulating material to reduce the gas supply line 58. Further, the slide is pro- loss of heat. The vessel 51 is provided with vided with two side walls 47 and a top wall an inlet A for the supply of hot solid particles.

48 so that the slide is closed and dusting 105 If desired two or more parallel slides 52 can prevented. The two adjacent vessels 60 and be used, for example three parallel slides 52, 61 are also provided with suitable fluidization which are each connected to the distribution means, for example perforated bottoms or po- vessel 51. The, or each, slide 52 is arranged rous bottoms 59, which are connected to gas above the retorting vessel 46 as shown in supply lines 58. Vessel 61 is connected at the 110 figure 3 and is provided with a number of upper end with slide 52 for the supply of discharge means 53, 54, 55, 56. Furthermore solid particles from the slide to the vessel. a discharge means 57 is arranged near the Vessel 60 has no communication means with distribution vessel 51. The discharge means slide 52, but may communicate with vessel 53, 54, 55 and 56 are basically of similar 61 via orifice 65, and is connected with dis115 construction. Discharge means 57 is also of charge pipe 41. similar construction, or is of another construc- Figures 2a and 2b show a preferred em- tion.

bodiment of the present invention. The riser The discharge means 53, 54, 55, 56 and vessel 60 together with the downcomer ves- 57 are respectively connected to the inlets for sel 61 are situated coaxially around the 120 the hot solid particles 41, 42, 43, 44 and 45.

overflow tube 41. The operation of the apparatus according to The retorting vessel 46 as shown in figure the invention will now be explained with refer- 3 comprises a number of compartments 1, 2, ence to figures 2 and 3.

3, 4 and 5 which are arranged in series and For the sake of simplicity, it will be as- which are separated from each other by weirs 125 surned that the hydrocarbon-containing sub 6, 7, 8, 9. Below compartments 1, 2, 3, 4, strate to be treated is oil shale and that the and 5, corresponding gas supply chambers are hot solid particles used for heating the oil present which are indicated by reference shale are hot spent oil shale particles supplied numerals 11, 12, 13, 14 and 15. Each com- from a suitable combustor for combusting partment 1, 2, 3, 4 and 5 is separated from 130 coke-bearing spent oil shale particles.

4 GB2193699A 4 During normal use of the retorting vessel 46 the slides connected to the distribution vessel as shown in figure 3, fresh preheated oil shale 5 1. The angle of the slide 52 (or slides 52) to particles (of a size preferably less than 3 mm) the horizontal plane need only be small, for are supplied to the retorting vessel 46 through example only 1' to 15', more especially 5' to inlet 32. At the same time hot spent oil shale 70 10', since fluidization gas, for example steam, particles are supplied via the supply apparatus is supplied to the slide 52 through the gas through inlets 41, 42, 43, 44 and 45 to supply line 58 and through the fluidization the respective compartments 1, 2, 3, 4 and means, viz. the perforated or the porous bot 5. An inert gas, for example steam, is suptom 59 of the slide 52. This fluidization gas plied to each gas supply chamber 11, 12, 13, 75 causes fluidization of the hot spent oil shale 14 and 15 through the respective gas inlets particles 62 present on the slide 52 and con 21, 22, 23, 24 and 25. From the various gas sequent displacement of these particles along supply chambers 11, 12, 13, 14, 15, the the slide 52.

steam passes through the respective perfo- The fluidized hot spent oil shale particles rated or porous plates 16, 17, 18, 19 and 20 80 flow into the various discharge means 53, 54, into the respective compartments 1, 2, 3, 4 55, 56 and furthermore hot spent oil shale and 5 so as to cause fluidization of the mass particles flow directly from distribution vessel of oil shale particles present in each compart- 51 into discharge means 57.

ment 1, 2, 3, 4 and 5. In order to obtain a desired flow of hot The fluidization of the mass of oil shale par- 85 spent oil shale particles from each discharge ticles in each compartment 1, 2, 3, 4 and 5 means 53, 54, 55, 56 and 57 into each cor causes an intensive mixing of the oil shale responding inlet 41, 42, 43, 44 and 45 gas, particles and an excellent transfer of heat from for example steam, is passed through supply the very hot spent oil shale particles to the line '58 and through the fluidization means, viz.

fresh oil shale particles. The heating of the 90 the perforated or porous bottoms 63 and 64 fresh oil shale particles causes the liberation of communicating vessels 60 and 61.

of hydrocarbons from the fresh oil shale par- Mass flow of the hot spent oil shale par- ticles. The liberated gaseous hydrocarbons, ticles from each draw-off vessel into the re which are the desired product, together with torting vessel 46 can be controlled by the steam, are passed via the cyclones 26, 27, 95 quantity of gas, for example steam, supplied 28, 29, 30, 31 to a product outlet 40 to be to the perforated bottoms 59 of the corre treated further, if necessary. In these cy- sponding discharge means. It is for example clones, oil shale particles entrained by the lipossible to install a temperature measuring berated gaseous hydrocarbons and the steam control loop in each compartment 1, 2, 3, 4 are separated and passed back to the com- 100 and 5, which will monitor the temperature of partments 1, 2, 3, 4 and 5. the fluidized bed in each compartment 1, 2, 3, The fluidized oil shale particles pass from 4 and 5. The temperature signals obtained compartment 1 over weir 6 (see arrow a) into can be used as input to control the amount of compartment 2, thence via weir 7 (see arrow gas, for example steam, to be supplied to the b) into compartment 3, thence via weir 8 (see 105 perforated bottoms 63 and 64 of each corre arrow c) into compartment 4, thence via weir sponding discharge means. In this manner the 9 (see arrow d) into compartment 5 and fin- flow of hot spent oil shale particles to each ally from compartment 5 over weir 10 (see compartment 1, 2, 3, 4 and 5 can be con arrow e) into steam stripper 35. 'In order to trolled in dependence of the temperature of enable the mass of fluidized oil shale particles 110 the fluidized bed in the corresponding corn to move smoothly from one compartment to partment 1, 2, 3, 4 and 5.

another, the successive weirs 6, 7, 8, 9 and Any hot spent oil shale particles remaining n are each lower than an adjacent preceding (see arrow B) are passed for example to a weir as shown in figure 2. In the steam strip- preheater for preheating fresh oil shale par per 35 final traces of product are removed 115 ticles before they are supplied to the inlet 32 from the oil shale particles, whereafter these of the retorting vessel 46, or are recirculated particles are passed to the outlet 36 of the to the distribution vessel 51.

steam stripper 35. The particles leaving the

Claims (8)

1. steam stripper 35, which comprise a large CLAIMS quantity of spent

   coke-bearing oil shale par- 120 1. Apparatus suitable for the adjustable sup- ticles, are supplied to a suitable combustor to ply of-solid particles to one or more receiving produce heat and hot spent oil shale particles. stations, comprising a slide arranged at a The apparatus 50 for the supply of the hot small angle to the horizontal plane in the longspent oil shale particles to the retorting vessel itudinal direction, said slide having a bottom 46 will now be discussed in detail with referand aeration or fluidization means in or close ence to figure 3. to the bottom and at least one or more dis- Hot spent oil shale particles from the corn- charge.means which are not located at the bustor enter into the distribution vessel 51 end of the slide, each of these discharge through inlet A and pass to the slide 52, or if means comprising at least two adjacent, corn there are a plurality of parallel slides 52 to all 130 municating vessels, each having a bottom and GB2193699A 5 fluidization means in or close to the bottom, gas to pass through the fluidization means of one vessel communicating with the slide and the discharge means and causing the hot solid one vessel having outlet means for communiparticles to flow into corresponding inlet(s) for cating with a receiving station. hot solid particles of the retorting vessel.
2. 2. Apparatus according to claim 1 in which 70 9. The method as claimed in claim 8, com- the communicating vessels form a solids sy- prising measuring the temperature of a fluid phon consisting of two vessels interconnected ized bed of substrate particles in a compart by at least one orifice, preferably situated near ment in the retorting vessel, so as to obtain a the bottom of the first vessel. signal corresponding to the temperature mea-
3. 3. Apparatus according to claim 2 in which 75 sured in the said fluidized bed, controlling the both vessels are half-round or u-shaped longi- quantity of fluidization gas supplied to the tudinal vessels whereby the two ends of the fluidization means of a corresponding dis first vessel are connected with the two ends charge means in dependence of the tempera of the second vessel, preferably each connecture measured so as to cause a quantity of tion having at least one orifice. 80 hot solid particles to pass from the discharge
4. 4. Apparatus for the supply of hot solid means into the corresponding inlet of the reparticles, preferably hot spent substrate par- torting vessel, which quantity of hot solid par ticles, to a retorting vessel for extraction of ticles is dependent of the temperature mea hydrocarbons from a hydrocarbon-containing sured.

   substrate as claimed in claims 1-3. 85 10. An apparatus for the supply of hot solid
5. 5. Apparatus as claimed in any one of the particles, preferably hot spent substrate par- claims 1-4, wherein the slide is connected to ticles, to a retorting vessel for the extraction a distribution vessel which is provided with an of hydrocarbons from a hydrocarbon-contain inlet for solid particles. ing substrate, substantially as described with
6. 6. Apparatus as claimed in claim 5, com- 90 particular reference to the accompanying prising a discharge means arranged near the drawings.

   distribution vessel, which discharge means is 11. A method for the supply of hot solid in communication with the interior of the dis- particles, preferably hot spent substrate par tribution vessel and with a corresponding inlet ticles, to a retorting apparatus, substantially as for hot solid particles of the retorting vessel, 95 described with particular reference to the ac- fluidization means in the said discharge means companying drawings.

   and means for the supply of fluidization gas to the fluidization means of the said discharge Published 1988 at The Patent Office, State House, 66/71 HighHolborn, London WC 1 R 4TP. Further copies may be obtained from means. The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD.

   Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87,
7. 7. The apparatus as claimed in any one of the claims 1 to 5, comprising a temperature measuring device arranged in a compartment in the retorting vessel containing a fluidized bed of substrate particles during normal oper ation and adapted to produce a signal corre sponding to the temperature measured in the said fluidized bed, means for transferring the signal obtained to a control device for control ling the quantity of fluidization gas supplied to the fluidization means of a corresponding dis charge means, so as to control the quantity of hot solid particles passing from the draw-off vessel into the corresponding inlet of the re torting vessel.
8. 8. A method for the supply of hot solid particles, preferably hot spent substrate par ticles, to a retorting vessel for the extraction of hydrocarbons from a hydrocarbon-contain ing substrate by means of the apparatus as claimed in any one of the claims 1 to 7, com prising supplying hot solid particles to the slide, supplying fluidization gas to the fluidiza tion means of the slide, allowing the fluidiza tion gas to pass through the fluidization means causing fluidization of the bed of hot solid particles on the slide, allowing the hot fluidized particles to be displaced along the slide and to fill the discharge means, supply ing fluidization gas to the fluidization means of the discharge means, allowing the fluidization