Patent Application
20200140760
The object of the invention is a pyrolysis apparatus feed device and pyrolysis apparatus feed method according to the preamble to claim 1.
A pyrolysis apparatus is used for processing shredded waste material, such as plastic and/or rubber waste using pyrolysis. Pyrolysis, i.e. dry distillation, is a chemical reaction wherein organic solids are decomposed by heating without allowing oxygen to influence the process. Pyrolysis usually uses either a vacuum, as is the case in vacuum pyrolysis, or an inert atmosphere, such as nitrogen, to supplant atmospheric oxygen. As a general rule, industrial pyrolysis reactions take place at temperatures of 300 to 700° C. Known pyrolysis apparatuses have been presented in the publications DE102013003319 A1, U.S. Pat. No. 2,033,730 and US2007029184 A1.
In the pyrolysis apparatus, waste that contains hydrocarbons, for example plastic and/or rubber waste, is processed such that the process mainly produces oil, carbon and gas. According to a known method, plastic and/or rubber waste is shredded and the shredded material is placed in a pyrolysis chamber. The chamber is locked to make it air-tight with an air trap which is usually also the closing device for the feed opening for the material to be processed. This allows the feed material to be first fed into the feed chamber, which is equipped with closing members such as hatches or valves. When the material has been fed into the closed chamber, the feed hatch is closed. Then the hatch or valve leading to the reactor chamber is opened. This prevents outside air from freely entering the reactor chamber. In known pyrolysis apparatuses, however, air entering the closed chamber enters the reactor chamber along with the material fed into it, wherein the oxygen it contains can disrupt the reactor's production process. It is important in pyrolysis reactions that oxygen does not enter the reactor to induce combustion in the reactor because the carbon dioxide resulting from the combustion reduces the quality of the end product.
Pyrolysis apparatuses also use feed devices which have a scraper conveyor or a screw conveyor in an inclined position, whose bottom part is placed in a liquid, such as oil, contained in a liquid basin. Thereby the liquid forms an air trap to prevent air from entering into the reactor. The material to be fed into the pyrolysis apparatus is conveyed into a bin which simultaneously forms a liquid basin. The scraper conveyor placed in an inclined position lifts the material out of the liquid contained in the bin. From the top end of the scraper conveyor, the material falls into the pyrolysis reactor. The problem with an oil-filled screw conveyor is, however, that the oil in the feed device is conveyed into the pyrolysis apparatus together with the feed material. The transfer of oil can be reduced using the grooves in the inclined surface of the scraper conveyor, along which oil can flow back into the liquid basin. There can also be, attached to the scraper conveyor of the feed device, a timer which sequentially consecutively starts and stops the forward movement of the conveyor, such that the changes in the movement cause at least part of the liquid transported with the material to fall into the groove of the conveyor and flow back into the liquid contained in the feed bin.
A common problem in known feed devices is also that the particles fed into the pyrolysis apparatus must be crushed into small enough pieces. The size of the feed particles in commonly used feed devices must usually be less than 9 mm. If overly large particles accidentally remain among the feed particles, they can cause problems. First of all, large particles can block the feed device. An even greater disadvantage is, however, that the pores of the large particles retain air which contains oxygen that disrupts the production process of the pyrolysis reactor when it enters the reactor chamber.
In order to remove the air trapped in the particles' pores, attempts have been made to compress the particles. Normally, the particles are crushed as small as possible, however. Crushing the particles into small pieces can, however, be difficult, especially when the material in question is rubber. In any case, crushing consumes plenty of energy, which reduces the efficiency of the whole process.
The purpose of this invention is to create a new pyrolysis feed device that overcomes the above-mentioned drawbacks. The pyrolysis apparatus feed device according to the invention is characterised in what has been presented in the characterising section of claim 1.
According to the invention, the pyrolysis apparatus feed device includes a feed chamber equipped with closing members, through which the crushed material such as plastic and/or rubber waste is conveyed into the pyrolysis chamber. According to the invention, a vacuum pump is also located in conjunction with the pyrolysis apparatus's feed chamber, through which a vacuum or sufficiently large underpressure can be achieved in the feed chamber. Using the vacuum pump, air and the oxygen it contains, which is harmful to the pyrolysis process, can be removed from the feed chamber. At the same time as a vacuum or sufficient underpressure is achieved in the feed chamber, also the air and the oxygen it contains can be sucked out of the pores of the particles fed into the feed chamber. Due to the vacuum or sufficiently large underpressure, there is no longer oxygen in the feed chamber or the particles inside it, or at least there is so little oxygen that it does not have any significance for the pyrolysis reaction. After this, the feed chamber's closing member leading to the pyrolysis reactor is opened and the particles in the feed chamber are transferred to the pyrolysis reactor. Oxygen does not enter the pyrolysis reactor in connection with the transfer as there is none in the feed chamber or in the pores of the particles being transferred.
Because, as presented above, large particles of more than 9 mm can be fed into the pyrolysis reactor according to the invention, the feed device's feed chamber and the size of its closing members can be dimensioned such that the size of the feed material does not cause any problems. Thus, also the channel or conveyor leading from the feed chamber to the pyrolysis reactor can be dimensioned so that larger pieces than normal can be fed through them and the material moves without any problems to the pyrolysis device's pyrolysis chamber. As the feed particles do not need to be crushed as small as in known feed devices, i.e. no more than 9 mm in size, the energy-consuming crushing phase can be entirely omitted in the pyrolysis apparatus according to the invention.
As a vacuum or sufficient underpressure is achieved in the feed chamber according to the invention, also material that cannot be fed into known feed devices can be fed through the feed chamber into the pyrolysis reactor according to the invention. Materials such as this are floating and porous materials. These materials cannot be fed into the feed devices of known pyrolysis apparatuses but in a feed chamber according to the invention, the air and oxygen located in the pores of porous materials can be removed before the material is fed into the pyrolysis chamber.
The feed device according to the invention can be attached to any pyrolysis apparatus, in which case the efficient feed device makes the pyrolysis apparatus even more efficient. The feed device according to the invention can be located above the pyrolysis reactor, in which case the feed material falls directly from the feed device into the pyrolysis apparatus's pyrolysis chamber. The feed device can, however, also be below the pyrolysis reactor or at its side. In this case, the advantage is that the hot pyrolysis chamber does not heat the feed device. In a solution such as this, there is a gas-tight conveyor between the feed device and the pyrolysis reactor, which transfers the feed material from the feed device to the pyrolysis reactor. When the feed device is under the pyrolysis reactor, the hot steam from the pyrolysis chamber cannot rise into the feed device either.
According to the invention, the material to be processed in the pyrolysis apparatus, such as plastic and/or rubber waste, is fed into the pyrolysis apparatus's pyrolysis chamber using a feed device that has a feed opening for the material to be processed, a feed chamber, closing members in conjunction with the feed chamber, a vacuum pump for achieving a vacuum in the feed chamber and a discharge opening through which the material to be processed can be conveyed into the pyrolysis apparatus. There can also be, in conjunction with the pyrolysis apparatus's pyrolysis chamber, a vacuum pump for achieving a vacuum or sufficient underpressure in the pyrolysis chamber.
The feed device according to the invention can be made air-tight such that the feed chamber closing member in conjunction with the feed device's feed opening has a gate valve equipped with a seal. The second closing member may also include a closing plate that can be pressed tightly against the end of the feed chamber. In this case, when the closing plate of the feed device closing member is open, the feed chamber is connected to the feed device's discharge chamber. According to the invention, there can be a discharge member in conjunction with the feed device's feed chamber for transferring material from the feed chamber to the feed device's discharge chamber, from which the material is conveyed through the discharge chamber's discharge opening into the pyrolysis apparatus's pyrolysis chamber.
The feed device of the pyrolysis apparatus can be located above the pyrolysis apparatus's pyrolysis chamber, in which case the material to be processed can be dropped through the discharge opening into the pyrolysis chamber. When the pyrolysis apparatus's feed device is located below the pyrolysis apparatus's pyrolysis chamber or at the side of the pyrolysis chamber, a gas-tight conveyor has been attached to the feed device for transferring the feed material from the feed device to the pyrolysis chamber.
According to the invention, the pyrolysis apparatus has a feed device with which the material to be processed in the pyrolysis apparatus, such as plastic and/or rubber waste, can be fed into the pyrolysis apparatus, in which feed device there is, for the material to be processed, a feed opening, a feed chamber, closing members in conjunction with the feed chamber and a discharge opening through which the material to be processed can be conveyed into the pyrolysis apparatus's pyrolysis chamber.
A vacuum pump has been adjoined in conjunction with the feed device's feed chamber to achieve a vacuum or sufficient underpressure in the feed chamber after the material to be processed has been fed into the feed chamber and the feed chamber closing members 14, 50) have been closed.
The vacuum pump is attached to the feed chamber with a pipe which has a valve and that a vacuum of sufficient underpressure is achieved in the feed chamber by starting up the vacuum pump and opening the valve.
A sensor or a meter has been attached in conjunction with the feed chamber in order to measure the value of the vacuum or underpressure achieved by the vacuum pump in the feed chamber.
The feed chamber's closing member in conjunction with the feed device's feed opening comprises a gate valve equipped with a seal and the second closing member of the feed chamber contains a closing plate that can be pressed tightly against the end of the feed chamber and that when the material to be processed has been fed into the feed chamber and both the gate valve and the closing plate are closed, a vacuum or sufficient underpressure can be achieved in the feed chamber using the vacuum pump.
The feed chamber containing the material to be processed which has a vacuum or sufficient underpressure can be opened by opening the closing plate of the feed device's closing member, in which case the feed chamber connects with the feed device's discharge chamber and further with the pyrolysis apparatus's pyrolysis chamber.
A discharge member is in conjunction with the feed device's feed chamber for transferring material from the feed chamber to the feed device's discharge chamber, from which the material is conveyed through the discharge chamber's discharge opening into the pyrolysis apparatus's pyrolysis chamber.
The feed device of the pyrolysis apparatus is located above the pyrolysis apparatus's pyrolysis chamber, in which case the material to be processed can be dropped through the discharge opening into the pyrolysis chamber.
The pyrolysis apparatus's feed device is located below the pyrolysis apparatus's pyrolysis chamber or at the side of the pyrolysis chamber, wherein a gas-tight conveyor has been attached to the feed device for transferring the feed material from the feed device to the pyrolysis chamber.
The pyrolysis apparatus feed method is a method in which the material to be processed in the pyrolysis apparatus, such as plastic and/or rubber, is fed into the pyrolysis apparatus's feed device and onward into the pyrolysis chamber. According to the method, the material to be processed is first fed into the feed device's feed chamber, through the feed opening, after which the feed opening's closing member is closed, in which case both closing members of the feed chamber are closed. Thereafter, the closing member of the feed chamber's discharge opening is opened and the material to be processed is conveyed into the pyrolysis chamber.
In the pyrolysis apparatus feed method, a vacuum or sufficient underpressure is created using the vacuum pump in the feed chamber into which the material to be processed has been fed and both of whose closing members are closed, such that air and the oxygen it contains, which is harmful to the pyrolysis process, are removed from the feed chamber and the material to be processed. After the closing member of the feed chamber's discharge opening has been opened, the material to be processed, from which the oxygen harmful to the pyrolysis process has been removed, is conveyed into the pyrolysis chamber.
In the following, the invention is described using examples with reference to the appended drawings, in which
As presented in
According to the method according to the invention, when the feed chamber 20 is closed, the valve 23 of the pipe 22 leading to the vacuum pump 21 is opened in which case the vacuum pump 21 begins to suck. The creation of a vacuum in the feed chamber 20 is monitored using a sensor 24 or meter attached to the feed chamber 20. The creation of a vacuum can also be monitored using an automatic device.
When in the situation presented in
As before the opening of the closing plate 51 there is a vacuum or underpressure in the feed chamber 20 and there can be a different type of pressure in the discharge chamber 41 in conjunction with the pyrolysis chamber, this pressure differential can impede the opening of the closing plate 51. If a pressure differential such as this exists, the pressure differential can also be equalised such that, at the same time as the closing plate 51 is opened, the piston 33 of the discharge member's 30 cylinder 32 pushes the push plate 31 to the left in
After this, the feed chamber 20 can be opened entirely so that the closing plate 51 is moved to the position shown in
After this, the piston 33 of the discharge member's 30 cylinder 32 pushes the push plate 31 in the manner shown in
When the material 12 fed into the pyrolysis apparatus's feed device 10 has been transferred as presented above into the pyrolysis apparatus's pyrolysis chamber, the piston 33 of the discharge member's 30 cylinder 32 pulls the push plate 31 back to the right in
| Number | Date | Country | Kind |
|---|---|---|---|
| 20170097 | Jun 2017 | FI | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/FI2018/000016 | 6/28/2018 | WO | 00 |
