CA1184530A

CA1184530A - Discharging apparatus for a pyrolysis plant

Info

Publication number: CA1184530A
Application number: CA000370662A
Authority: CA
Inventors: Klaus Hillekamp
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-02-12
Filing date: 1981-02-11
Publication date: 1985-03-26
Also published as: WO1981002302A1; EP0033971A2; EP0045766A1; DE3005205A1; EP0033971A3; DE3005205C2; EP0045766B1; EP0033971B1

Abstract

ABSTRACT OF THE DISCLOSURE

The application discloses a discharge apparatus for a pyrolysis plant for treating of waste materials in a heatable furnace for discharging of the treated solid, lo-temperature carbonization materials. An erectly placed container is provided to which the solid, low-temperature carbonization materials are led on the upper side and which exhibits at its lower side a blocking apparatus preventing the sliding through of the solid, low-temperature carbon-ization materials. Due to the height of the container, the low-temperature carbonization materials found therein form a gas tight layer, and by an apparatus for maintaining a temperature of ? 250°C in the upper region of the low-temperature carbonization material support of a length over which practically no diffusion of the condensationable ingredients can occur anymore.

Description

A Discharging Apparatus for a Pyrolysis Plant The invention concerns a discharge apparatus for a pyrolysis plant for treating o~ waste materials iIl a heatable furnace for discharying of treated, solid,low-temperature carboni-zation materials.

Pyrolysis plants generally comprise a heatable furnace, perhaps a rotary pipe furnace, to which the waste materials to be treated are added at one end and which are decomposed to solid, low-temperature carbonization materials and low-temperature carbonization gas dur~ng their stay in the furnace. The low-temperature carbonization gas is used further, whereas the treated, solid,low-temperature carbonization materials are removed from the furnace by a di~charge apparatus, by which the discharge pipe extends into a water bath which acts as a barrier, through which the low-temperatUre carbonization gases cannot escape. This wet discharge has, however, the disadvantage that the residuals of the pyrolysis can become wet during passage throuyh the water bath. For a dry, subsequent treatment, for example for air sifting, the manufacture of fuel or active carbon production, the ~ater must be evaporated from the wet residuals with a considerable ex~penditure of energy.
Additionally, the fine residual particles agglomerate in the water bath, for example, carbon particles with ash particles. It can, therefoxe, become necessary to grind the residuals, perhaps for the sifting after drying.

It is the task of the invention to create a discharge apparatus of the type mentionned at the outset, which manayes without the use of water as a gas barrier and wh.ich is also gas-tight during impact ~ith the gas pressures found in the pyrolysis plant, that is, also during a certain l~w-pressure in the furnace. ~oreover, it should be attained that the residuals are free of hydrocarbon con-densates which considerably burden the infiltrated water durin~ a deposit.

The solution to this problem is given by an erectly placed container, to which the solid, low-temperature carbonization materials are :Led at the upper si.de and which has at its lower side a blocking apparatus preventing the slipping ~hxough of the solid, low-temperature carbonization materials, at such a hei~ht of the container, that the low-temperature carbon.ization materials found therein form a gas-tight layer, and by an apparatus for maintaining a tempera-ture of ~250~C
in the upper region of the low-temperature carbonization matexial support of a length over which practically no diffusion of the condensationable ingredients can occur anymore. By means of these precautions, it can be prevented that condensations and burnings occur in the discharged solid~ low~temperature carbonization materials. The solid, low-temperature carbonization materials can thus be dis-charged dry. A blockage of the discharge apparatus and a burdening of the low-temperature carbonization materials with higher hydrocarbons, such as; tar, etcO, does therefore not re.sult.

With a discharge apparatus for a pyrolysis plant with a dust separator for the dust contained in the low-temperature carbonization gas, the solid discharge of the dust separator can also be attached to a discharge apparatus in accordance with the characteristics of the main claim.

According to a particular execution, the blocking apparatus is formed by a rotary volute with which the solid, low temperature carbonization materials or the dust can be con~yed out of the container.

~lternatively, the blocking apparatus can be a tappet. The latter is preferably placed, reciprocally moveable, in a pipe running diagonally to the container, ~hose outlet is placed shifted opposite the container. It is thereby a~oided that wires can lead to a blockage, as perhaps with a rotating blocking apparatus.

3~

In accordance with another practical form, the blocking apparatus is formed by a lid which i5 attached to the lower opening of the contaIner undex prestress. A blocking apparatus of this ~ype opens the lower opening of the container automatically at a certain fill level of the containex and allo~s solid, low-temperature carbonization materials to escape.

q'he blocking appara-tus can also be steered or regulated by the fill level of the low-temperature carbonization materials in the container.

According to a particular performance, the apparatus for m~intaining the temperature is a heating apparatus. Al-ternatively or addltionally, the apparatus for maintaining the terrlpexatur~ can be an insulation of the wall of the container.

~n essential de~elopment IS seen therein that the container exhihi-ts a cooling apparatus in the lower reyion. Thereby, the solid, low-temperature carbonization materials can be cooled at a discharge temperature far below the condensation point of the gas and the spontaneous combustion point, so that the solid, low~temperature carbonization materials cannot begin to glimmer or burn durin~ contact with air and dust-laden discharge materials canno-t explode. The 3~

cooling apparatus further has the advantage that the blocking apparatus is thermally slightly burdened.

However, an apparatus can also be provided for inerti-zation of the chamber attached to the blocking apparatus, in order to prevPnt dust explosions.

Preferably, the container is developed as a tubular shaft.
~he latter can expand do~nward, lightly conical in a descending direction in order to avoid the occurrence of blockages.

In the following, the invention is supplementarily clc~cribed by way of several practical examples with the aid of schemat;cal drawinys.

igure 1 shows, in an axial section, a discharge apparatus which is fastened to the outlet of a rotary pipe furnace.
Fi~ure 2 shows another practical form of a discharge apparatus.
Figure 3 shows a further, automatically working discharge apparatus.

The discharge apparatus shown in Figure 1 encompasses a container 1, which is developed as a tubular shaft and which consists of a circularly cylindrical upper region 2, i3q~
a conically truncated region 3 attaching thereto and a circularly cylindrical lower region 4, connecting to the smaller opening thereof with a reduced diameter.
However t the conici-ty cannot be so large that a blockage results in this area. The tubular shaft is vertically placed and the o~erhead inlet 5 thereof is connected with the outlet of a rotary pipe furnace 7 by way of a feed pipe 6. I'he feed pipe 6 expands in the direction of fl~w in order to dim~nish therisk of a blockage.

In the inside of the cl'rcularly cyclindrical lower region 4, a rotatable volute 8, comprising several windings, is placed, whose spindle 9 is led at its top end into an upper bearing 10, braced to the container, and at its lower end in~o a lower bearing 11. rrhe lower bearing is held in a sl:ide which borders on the outlet 13 of the tubular shaft.
The upper hearing 10 can be advantageously omitted, since ~he volute can then deviate during transporting of hard mat~r:ials.

T~ circularly cylindrical upper area 2 of the container is surrounded by a coil 14, which is fastened to a fuel circulation at its inlet 15 and outlet 16 (not shown).
Hot gas can, for example, flow through the coil. The upper region 2 and the coil 14 are additionally surrounded by a casing 17 which, together with the wall of the container, leaves a space which is filled with an insulating agent 18.

3~

The length of this heating and insulating area shvuld be so great that the solid, low-temperature earbonization materials ean be kept in the respeeti~e area of the tubular shaft at a tempexature by whieh no eondensation of the condensationable ingredients ean yet oecur. In most cases, a temperature of more than 250~C is required herefor.

A cooling coil 19 is ~nstalled around the circularly cylindrical lower area 4 which is, at its inlet 20 and outlet 21, fastened to a coolant circulation, perhaps to xunning water. Thereby, the solid, low-temperatuxe earbonization ~.ater~als are eooled to a temperature which i5 below the spontaneous combustion temperature thereof~

At the wall of the conically truncated area 3 is a filling gauge 22 of a known construction, which is developed in such a way that it only responds when the tubular shaft is filled with solid~ low temperature carbonization m~terials to the le~el of the fLlling gauge.

The conically truncated area 3, which forms the transition zone ~etween the heated area and the cooled area, should of course be selected so large that the cooled area does not react to the heated area.

3~

The discharge apparatu6 is opera~ed in the following manner.

The solid, low-temperature carbonization materials flowing out of the rotary pip2 furnace 7 get to the tubular shaft by means of the feed pipe 6 and, at the beginning of the operation, fall until the volute 8, on which they remain ~ince the slope of the volute is chosen so small that the low-temperature carbonization materials cannot slide outwards on the co~l plate. During the further operation, the tubular shaft is increasingly filled until a certain fill le~el 23 is attained by which the filling gauge responds. As a result, the motor 24 which drives the ~olute 8 is switched on, 50 that the latter conveys low-temperature carbonization materials out of the tubular shaft~ The solid, low-temperature carboniza-tion materials passing out through the outlet 13 reach the slide 12 and are carried out from there ~nto the open, perhaps for fux-~her treatment for fuel production or production of active carbon and/or for deposit.

The upper area of the tubular shaft i5 heated by means of the coil 14 to such a temperature, usually to at least 250C, that condensationable products cannot separate, so that they do not also reach outside with the solid, low-temperature carbonization materials.

In the conically truncated area 3, the solid, low-temperature carbonization materials are compressed as a re.sult of the weight of the low-temperature carbonization support lying on top, so that the gas permeability is further diminished.
The coni.city of the conically truncated area 3 must not~
of course, be so large that it hinders the sliding through of the solid, low-tempe~ature carbonization materials.

As soon as the coil 8 has con~eyed a portion of -the content out o the tubular shaft and the fill level has sunk down to the lower f~ll level 25, the filling gauge 22 switches of so that the motor 24, which activates the coil 8, becomes dead. The conta~ner be~ins again to f.ill up to ~h~ fill level 23, with which the next discharging cycle is commenced.

By suitable choice of the fIll level, it can be attained that the discharge apparatus is gas-tight and that the gas-tiyhkness is also not reduced when a low-pressure pr~ails in the rotary pipe furnace 7, as the weight of the low-temperature carbonization ma-terial support is in the position in the tubular shaft to withstand a certain pre.ssure difference between the outlet and the inlet.

Figure 2 shows another practical form of a discharge apparatus, by which the container 31 comprises a double-walled, upper area 32, which turns into a cylindrical 3~

discharge pipe 33. The outlet end 34 of the rotary pipe of the rotary pipe furnace extends, fittiny tightly, into the double-walled region 32.

A conveyîng pipe 35, which runs dIagonally to the outlet pipe and in which a conveyiny coil 36 is rotatably placed and is coupled with a driving motor 37, borders at the lower end of the outlet pipe 33.

The discharge pipe 33 empties at an end area of the con-veying pipe 35, whereas an ou-tlet 38 is provided at the other end area thereof.

~lot gas flowsthrough the double-walled upper area 32 of the container 31 and can be removed at a suitable point o~ the pyrolysis plant (not shown), so that the container i.S heaked ~n this area.

Th~ ].ower axea of the discharge pipe 33 and the con~eying pipe 35 are surrounded by a cooling coil 39, which cools the solid, low-temperature car~onization materials to a temperatuxe below the spontaneous combustion temperature thereof.

In the upper area of the discharge pipe 33, a lower fill-level sensor 40 and an upper fill-level sensor 41 are 3q~

placed. These are developed in such a way ~hat they respond when the solid, low-temperature carbonization materials reach up to a fill-level sensor~

The fill-level sens~rs are connected with a control ~not shown) for the dri~ing motor 37, wh~ch is develop~d in such a way that the upper fill-le~el sensor 41, when it is covered by low-temperature carbonization materials, switches the driving motor on, whereas the lower fill-level sensor 40 al~ays switches the driving motor 37 off when it is no longer covered by low-temperature carboni-æation materials.

Such level controls are in themselves known and do not form a part of the ~nvention.

~he acti.on o the di5charge apparatus accoxding to Figure

2 is similar to the discharge apparatus according to Figure 1, so that a ~urther description is unnecessary.

Figure 3 shows a further, automatically working discharge apparatus. The container is constructed similarly as the one in accordance with the practical form according to Figure 2, whereby only the lower area of the container is developed as discharge pipe 44, conically expanding to the outlet. The upper area 43 is surrounded with an Lq~

insulator casing 45 which extends downward until perhaps more than half the length of the discharqe pipe 44. The heat curbing resistance of the insulator casing 4~ is measuredin such a way that the solid, low-temperature carbonization materials, ~hich are found in the area of the container surrounded by the insulator casing, do not cool below 250~C.

'rhe outlet end of the discharge pipe 44 is slanted against and protrudes into a collector 46. At a hinge 47, fastened to the discharge pipe 44, a closing lid 48 is hooked on, which forms a t~o-armed lever, whose one side is developed plate-like and can close the outlet of the discharye pipe 44, and whose other end carries a counter-weight 49, which ensures that the closing lid endeavours to close the lower opening of the discharge pipe 44.

When the solid, low-temperature oarbonization materials have attained a certain fill-le~el during the operation of the discharye apparatus, the pressure exerted on the closing lid i5 SO great that the counterweight 49 can no longer keep the opening of the discharge pipe closed and that, as a result, solid, low-temperature carbonization materials pass out of the opening until the closing lid o the solid material support can again keep the balance in the container. In this way, a simple control of the fill-gauge level, which is suscepticle to little interference, results~

With a low-pressure in the discharge system, the length of the low-temperature carbonization material support must, of course, be chosen so great that the solid, low-temperature carbonization mater~als are not raised and loosened by the greater pressure acting on the underside of the container, in order to guarantee the gas-tightness. This is attained with certainty if the weight of the low~
temperature carbonization material support in the container is greater, per unit of surface, than the pressure difference between the underside and uppersi.de of the low-temperature carbonization material support.

For inertization, the residual can be discharged, for example hot, in a receptacle, into which water is blasted in a quantity that the discharged substances, now as before, remain dry but are cooled~

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Discharge apparatus for a pyrolytic waste utilization plant for discharging of dried, solid, low-temperature carbonization materials, the discharge apparatus having the form of a vertically disposed, conically tapered container to which the carbonization materials are supplied from above and which has a blocking device preventing the carbonization materials from sliding through, and whose carbonization-material column is utilized to seal the reactor against the ingress of air, characterized by:
a discharge pipe (4) connected to the conical tapering (3) of the container (1), the pipe having a blocking device (8,36) preventing the solid carbonization material from sliding through, the device having the form of a rotary volute or a tappet;
the container (1) being of such height that the carbonization materials contained therein form a gas-tight layer;
a device (14-16,18) for maintaining a temperature of at least 250°C in the upper region of the carbonization-material column of a length over which practically no diffusion of the condensable constituents can occur any longer; and a cooling device (19-21; 39) in the lower region of the material column, the cooling device including the blocking device (8; 36).

2. Discharge apparatus according to claim 1, characterized by a dust separator for the dust contained in the low-temperature-carbonization gas, the solid matter outlet of the separator being also connected to a container to which the separated dust is led on the upper side and which has a blocking device at its bottom.

3. Discharge apparatus as claimed in claim 1, characterized in that the tappet (36) is disposed, reciprocally movable, in a pipe (35) situated diagonally to the container (1), the outlet of the pipe (38) being arranged offset in relation to the container (1).

4. Discharge apparatus as claimed in claims 1 to 3, characterized in that the blocking device is controlled or regulated by the filling level of the carbonization materials in the container (1).

5. Discharge apparatus as claimed in claim 1, characterized in that the temperature maintaining device is a heating device (14-16).

6. Discharge apparatus as defined in claim 5, characterized in that the temperature maintaining device forms a wall insulation (18) of the container (1).

7. Discharge apparatus as claimed in claim 1, characterized in that it has a device for inertization of the space connected with the blocking device.

8. Discharge apparatus according to claim 1, characterized in that the container (1) forms a tubular shaft.

9. Discharge apparatus according to claim 8, characterized in that the tubular shaft extends in down dip direction slightly conically toward the bottom.