FAST PYROLYSIS REACTOR

Abstract

The invention relates to shipbuilding and can be used in reconditioning in order to economize fuel and to increase speed. The technical problem is solved by the shipboard installation of air compressors, air receiver tanks, pass valves, air conduits, air separating conduits, air intakes and air injectors, which are interconnected by air ducts. An air separating conduit is mechanically secured in the bow of the ship and has air injectors secured along the centre thereof up to the stern. The injectors direct a jet of air backwards so that the jet of air thrusts the ship forwards, then the air rises along the sides of the ship, maintaining a layer of air between the ship and the water, thus reducing water resistance. The injectors in the bow direct a jet of air such that the ship is constantly sailing into an air space.

Description

FIELD OF INVENTION

The claimed invention relates to a device for thermal processing of raw materials, e.g., peat, sawdust, agricultural waste, and more specifically relates to the design of a fast pyrolysis reactor for producing different kinds of end products, namely, liquid oil products, heavy and light gases, coke, activated carbon, etc.

BACKGROUND

Analysis of prior art has enabled to identify Russian and foreign patents, the closest of which are the following.

An analog, SOLID FUEL GASIFIER, which comprises a vertical shaft furnace, inside which there are successively downwards located drying, pyrolysis and solid fuel combustion zones. In the upper part of the furnace, there is a charging device and a branch pipe for feeding the gasifying agent and a device for accumulation and discharge of solid processing products, i.e., ash. Between the upper and the lower parts of the gasifier, there is one or more sections being the gasifier components having internal through cavities in the center, located in the direction of the vertical axis of the gasifier and communicating with internal cavities of other components of the gasifier. The sections have a jacket with lining inside, in which the ends of thermal storage elements arranged in the internal cavity of the section are fixed. Here, one or more sections of the furnace are configured to enable rotation relative to the upper and the lower parts of the gasifier around its vertical axis. The technical result lies in: simplification, increased reliability and productivity (Russian Federation invention patent No. 2232347, date of publication: Jul. 10, 2004, patentee: Meshchankin Andrey Ivanovich (RU)).

Decomposition of organic feedstock in this reactor is performed by gases forming from combustion of a fuel. Here, the effect is exercised by means of blowing the feedstock with hot flue gases. As a result, the gases newly generated due to decomposition of the feedstock are diluted with combustion products and become extremely lean. A considerable part of the carbon contained in the feedstock is oxidized to CO2 and becomes a ballast. The calorific value of hydrocarbons obtained is less than 3,000 kcal/kg. The efficiency factor of the feedstock processing plant would not exceed 20% due to the above reasons. The product obtained may only be used as a low grade fuel in heating systems, which are objective and primary shortcomings of the presented analog.

A prototype, PEAT FAST PYROLYSIS REACTOR, comprises three-section working chamber 1 with outlets for delivery of dry peat, coke discharge 4 and diversion 3 of the gas released as a result of peat pyrolysis. Inside chamber 1, there are horizontally installed two cylinder-shaped gas burners 5. Each of them is mechanically coupled with one inclined metal plate 6. Annular chambers 7 are filled with a cooling fluid and comprise inlet 8 and outlet 9 pipes, one arranged in each of three sections of chamber 1. Dry peat delivery outlet 2 and outlet 3 for diversion of the gas released as a result of peat pyrolysis are made in the upper part of the upper section of chamber 1, whereas coke outlet 4 is located in the lower part of the lower section. One of burners 5 and plate 6 coupled therewith is located in the upper section, the second one, in the medium section. Plates 6 of the reactor are arranged one below the other and inclined in the opposite directions. The invention excludes release of substances poorly suitable for further use (Russian Federation invention patent No. 2293104, date of publication: Feb. 10, 2007, patentees: Kotelnikov Vladimir Aleksandrovich (RU), Kotelnikov Andrey Vladimirovich (RU), Zamurayev Dmitriy Vladimirovich (RU), Podzorov Aleksandr Ivanovich (RU)).

Gasification of organic matter occurs in the mode of free fall of particles under gravity. Here, the particles flow through the heated zone, and fall onto steeply inclined heated steel plates arranged one below the other. For avoidance of stoppage of motion of particles along the plates, the plate inclination angle must be at least 60 degrees. The free fall acceleration is 9/8 m/sec, assuming air drag K=1.28. The speed of fall will be 7.6 m/sec. It is specified in the patent that the duration of time, when particles are in the free fall is 6 sec. This means that the reactor must be 45.6 meters high. Operability of such a plant in the working mode is questionable. Assuming the duration of stay of delivered feedstock in this reactor is 1 sec, the height of the reactor must be at least 7.6 m (or the height of a two-storeyed building). As a result of hypothetic reduction, the duration of stay of delivered organic matter in the reactor, the efficiency of utilization of feedstock will decrease sharply.

The productivity will decrease several times, which is the first significant shortcoming.

The second objective shortcoming of this reactor is a low combustible agent (gas) utilization factor for warming and keeping it operable. Its efficiency factor is as low as 30%. Such a low efficiency is determined by the fact that the gas combustion products are blown through the gas ducts passing through the reactor at a high speed, and a considerable part of heat leaves the reactor without being utilized.

The technical result of the claimed invention lies in elimination of the aforesaid shortcomings: high combustible agent (gas) utilization factor (up to 95%) for warming and keeping it operable.

SUMMARY

The stated technical result is achieved with a fast pyrolysis reactor installed on a steel framework, which is a steel housing accommodating a hollow steel cylinder comprising a charging hopper, a branch pipe for evacuation of organic destruction products and an outlet branch pipe for diversion of the product released in the course of pyrolysis, a heating element.

Here, the housing is made up of two parts interconnected with bolts on flanges. The lower part of the housing terminates with a pyramidal collector of solid pyrolysis products, through the upper plant of the housing, into which a feedstock delivery tray extends. The cylinder ends are limited on two sides with rings having through apertures in the center. Blades are welded along the horizontal axis of the cylinder, throughout its length. Hollow semi-axles are welded to the end rings of the cylinder, the inner diameter of the above semi-axles matching the diameter of the apertures made in the end rings. The semi-axles extend through annular apertures in the reactor side walls beyond the housing limits, rest on rotating supports. A driven sprocket of chain transmission is fixed with a screw joint on one of the semi-axles. An electric motor with a drive connected to a gearbox, on the shaft of which the driven sprocket is keyed, serves as an actuator for rotation of the cylinder. The cylinder assembly has a through cavity, inside which electric heating elements are accommodated along the rotation axis. A rod runs through the cavity center, on which electric heating elements are mounted on insulators with collars. The reactor housing is lined inside and outside with heat insulating materials.

Here, electric heating elements are constituted by silicon carbide electrodes.

Here, the outer and inner lining of the housing is implemented by means of kaolin heat insulating plates.

BRIEF DESCRIPTION OF THE DRAWINGS

The essence of the invention is further explained with drawings.

FIG. 1 presents a longitudinal section of the device.

FIG. 2 presents a transversal section of the device, where 1 is charging hopper; 2 is tray; 3 is branch pipe; 4 is upper part of housing; 5 is flange; 6 is rod; 7 is lower part of housing; 8 is pyramidal collector; 9 is outlet branch pipe; 10 is steel cylinder; 11 is ring; 12 is blade; 13 is through aperture; 14 is electric heating element; 15 is support; 16 is steel framework; 17 is driven sprocket; 18 is hollow semi-axle; 19 is annular aperture.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The steel housing of the reactor is made up of two parts 4, 7 interconnected with bolts on flanges 5. The lower part of the housing terminates with a pyramidal collector of solid pyrolysis products 8. A tray 2, along which feedstock is delivered onto the heated surface of the cylinder 10 extends through the upper plane of the housing of the fast pyrolysis reactor.

In the upper part of the side plane of the reactor, there is a branch pipe 3 for evacuation of organic destruction products (mixture of gases). The cylinder ends are limited on two sides with rings 11 having through apertures in the center 13. Blades 12 are welded along the horizontal axis of the cylinder, throughout its length, which are intended for efficient mixing and increasing the reaction surface of the cylinder 10. Hollow semi-axles 18 are welded to the end rings of the cylinder, the inner diameter of the above semi-axles matching the diameter of the apertures made in the end rings. The semi-axles extend through annular apertures 19 in the reactor side walls beyond the housing limits. The semi-axles rest on rotating supports 15. A driven sprocket 17 of chain transmission, by means of which rotation of the cylinder inside the housing is exercised, is fixed with a screw joint on one of the semi-axles, the above driven sprocket. An electric motor with a drive connected to a gearbox, on the shaft of which the driven sprocket is keyed, serves as an actuator for rotation of the cylinder 10 (not shown in FIGS. 1-2).

The cylinder 10 assembly has a through cavity, inside which electric heating elements 14 are accommodated along the rotation axis. A rod 6 runs through the cavity center, on which electric heating elements 14 are mounted on insulators with collars (not shown in FIGS. 1-2). The reactor housing is lined inside and outside with heat insulating materials. The reactor is installed on a steel framework 16.

The electric heating elements are constituted by silicon carbide electrodes.

Here, the outer and inner lining of the housing is implemented by means of kaolin heat insulating plates.

The device functions as follows.

The feedstock is delivered from charging hopper 1 by means of tray 2 on the pre-heated surface of steel cylinder 10 to point A. While rotating, the cylinder relocates the material from point A to point B, with the organic feedstock being continuously agitated (poured) along the heated surface. At point B, the solid residue of pyrolysis is dumped into the lower part of housing 7 and is evacuated out of the reactor through lower outlet pipe branch 9. The generated gas is evacuated through branch pipe 3.

At operation of the reactor, the cylinder has two zones:

• • working zone (position A-B), the temperature +800-+900° C., where decomposition of organic matter takes place;
  • idling zone (position B-A), the temperature +700-+800° C., where heating of the cylinder surface takes place.

Fast pyrolysis process control: Delivery of the feedstock (prepared organic mass) onto the cylinder is exercised downwards normal to the horizontal cylinder rotation axis.

Various organic compounds and materials are subjected to pyrolysis processes. Peat, sawdust, agricultural waste may serve as feedstock. Here, for each kind of feedstock, specific parameters of organic thermal decomposition process are to be met. For these processes to be controlled, the design is configured to enable regulation of material delivery volume in time by adjusting the current loads, variation of the reaction duration (the cylinder rotation period is variable within the range of 1 to 12 seconds), setting the decomposition temperature within the range of 450-1200° C. in the automatic and/or semi-automatic and/or manual modes.

Therefore, the claimed invention has the following additional advantages relative to the analog and the prototype.

• • 1. Compact overall dimensions of the device: height (including the receiving hopper)—4 m, width—2.5 m, length—3 m.
  • 2. The organic matter is not decomposed at the free fall period;

instead, it comes onto the heated metal surface of the cylinder and stays there for a specified time period.

Due to the fact that the reactor is heated with electric elements in closed space, with no air circulation occurring, up to 95% of thermal energy is spent on its designated purpose, namely, for warming the reactor and maintaining the operating temperature therein. The calorific value of the obtained mixture of gases is 9,000 kW*hr/m³ and may be used both as a fuel for heat generation and as a motor fuel for generation of electric energy in piston type gas generator plants.

Therefore,

• • The energy consumption per unit of processed products in the presented reactor is 3 times lower than in the prototype.
  • The economic efficiency in terms of generation of the end product per unit of raw materials is higher owing to complete decomposition of organic matter.

Therefore, both the analysis performed and the development model test confirm the stated technical result of the claimed invention: high combustible agent (gas) utilization factor (up to 95%) for warming and keeping it operable.

The suggested invention is novel as the entire totality of features is not known from prior art as presented in the relevant section of the specification.

Besides, it meets the criterion of inventive step as it cannot be clearly deduced from the prior art by a person skilled in the art.

Finally, it is industrially applicable as the model tests have proved that it can be used for thermal processing of raw materials.

Claims

1. A fast pyrolysis reactor characterized in that the reactor is installed on a steel framework, which is a steel housing accommodating a hollow steel cylinder, comprising a charging hopper, a branch pipe for evacuation of organic destruction products and an outlet branch pipe for diversion of a product released in a course of pyrolysis, a heating element, where the housing is made up of two parts, a lower part and an upper part, interconnected with bolts on flanges, a lower part of the housing terminates with a pyramidal collector of solid pyrolysis products, through an upper plant of the housing, into which a feedstock delivery tray extends, cylinder ends are limited on two sides with rings having through apertures in a center, blades are welded along a horizontal axis of the cylinder, throughout its length, hollow semi-axles are welded to the end rings of the cylinder, an inner diameter of the above semi-axles matching a diameter of the apertures made in the end rings, the semi-axles extend through annular apertures in reactor side walls beyond housing limits, rest on rotating supports, a driven sprocket of a chain transmission is fixed with a screw joint on one of the semi-axles, an electric motor with a drive connected to a gearbox, on a shaft of which the driven sprocket is keyed, serves as an actuator for rotation of the cylinder, a cylinder assembly has a through cavity, inside which electric heating elements are accommodated along rotation axis, a rod runs through a cavity center, on which electric heating elements are mounted on insulators with collars, the reactor housing is lined inside and outside with heat insulating materials.

2. The fast pyrolysis reactor according to claim 1 characterized in that the electric heating elements are constituted by working silicon carbide electrodes.

3. The fast pyrolysis reactor according to claim 1 characterized in that the outer and inner lining of the housing is implemented by means of kaolin heat insulating plates.