A safe and stable gas supply system for waste tire pyrolysis furnace

Abstract

The present invention relates to a safe and stable gas supply system for a waste tire pyrolysis furnace, and belongs to the technical field of harmless treatment and resource utilization of solid waste. It includes a gas combustion module, which burns pyrolysis non-condensable gas to provide heat for waste tire pyrolysis, and is composed of a combustion furnace, a switch valve, a flame arrester and a flow meter; a pyrolysis non-condensable gas pipeline, which is composed of a switch valve and a one-way valve; a nitrogen pipeline, which provides nitrogen for the system; a supplementary gas source, which serves as a gas source when starting the furnace; a gas calorific value control module, which adjusts the calorific value of the gas to meet the requirement of complete combustion of the combustion furnace gas; a gas pressure stabilizing module, which provides the combustion furnace with stable pressure gas, and is composed of a tank body, an elastic airbag, a pyrolysis non-condensable gas inlet, a gas outlet, a supplementary gas inlet, a sewage outlet, an elastic airbag nitrogen inlet, an elastic airbag nitrogen outlet, a tank body side pressure gauge and an elastic airbag side pressure gauge. The system of the present invention is simple and compact, has a high degree of automation, and is easy to copy and promote.

Description

Technical Field

[0001] The present invention relates to the technical field of harmless treatment and resource utilization of solid waste, and in particular to a safe and stable gas supply system for a waste tire pyrolysis furnace. Background Art

[0002] Pyrolysis of waste tires offers high throughput, high efficiency, and minimal environmental pollution. This approach aligns with the concept of resource recycling and is considered one of the best methods for treating waste tires today. The primary products of waste tire pyrolysis are pyrolysis oil, pyrolysis carbon black, and non-condensable gas. The latter can be burned as fuel to provide or supplement the heat required for the pyrolysis process.

[0003] Existing waste tire pyrolysis technology can generate the required heat through the combustion of non-condensable gases, but the amount of pyrolysis gas fluctuates, leading to unstable combustion pressure in the incinerator. To ensure a stable gas supply pressure in the incinerator, a large floating roof tank is typically installed to increase the pressure within the tank, which is then reduced by a pressure reducing valve to meet the required combustion pressure. This floating roof tank is bulky and requires high safety standards, as well as additional auxiliary pressurization equipment. Summary of the Invention

[0004] The purpose of the present invention is to provide a safe and stable gas supply system for a waste tire pyrolysis furnace, which adopts an elastic airbag pressure-stabilizing tank, combined with a back-pressure nitrogen supply valve and a nitrogen release valve to achieve a safe and stable supply of gas to the combustion furnace.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a safe and stable gas supply system for a waste tire pyrolysis furnace, comprising:

[0006] The gas combustion module burns the pyrolysis non-condensable gas to provide heat for the pyrolysis of waste tires. It consists of a combustion furnace, a switch valve, a flame arrester and a flow meter.

[0007] The pyrolysis non-condensable gas pipeline consists of an on-off valve and a one-way valve;

[0008] Nitrogen pipeline, providing nitrogen to the system;

[0009] Supplement the gas source and serve as the gas source when starting the furnace;

[0010] Gas calorific value control module adjusts the calorific value of the gas to meet the requirements of complete combustion of the gas in the combustion furnace;

[0011] The gas pressure stabilizing module provides gas with stable pressure for the combustion furnace. It consists of a tank body, an elastic airbag, a pyrolysis non-condensable gas inlet, a gas outlet, a supplementary gas inlet, a sewage outlet, an elastic airbag nitrogen inlet, an elastic airbag nitrogen outlet, a tank side pressure gauge and an elastic airbag side pressure gauge.

[0012] For ease of transportation, preferably, the supplementary fuel gas source is liquefied petroleum gas, which is transported in gas cylinders.

[0013] The calorific value of non-condensable gas from waste tire pyrolysis is generally 40-50 MJ / Nm 3 , while the calorific value of liquefied petroleum gas is 90MJ / Nm 3 , the theoretical amount of air required for combustion of the two is different. Although the existing burners have a certain adjustment range for air distribution, they cannot achieve the goal of burning both non-condensable gas and liquefied petroleum gas. It is preferred to set up a gas calorific value control module, and by mixing nitrogen into the liquefied petroleum gas, its calorific value is reduced to be close to the calorific value of pyrolysis non-condensable gas. When starting the furnace, the diluted liquefied petroleum gas is used as fuel. In order to accurately control the calorific value of the fuel, the preferred gas calorific value control module includes a flow meter and a one-way valve with an adjustable flow on the supplementary gas side, and a flow meter and a one-way valve with an adjustable flow on the nitrogen side. The flow meter can be automatically adjusted according to the set value and can be remotely controlled.

[0014] In order to achieve pressure stability of the gas pressure stabilizing module, preferably, the nitrogen inlet of the elastic airbag in the gas pressure stabilizing module is composed of two parallel lines, one line is controlled by a ball valve, and the other line is controlled by a back pressure nitrogen supply valve; the nitrogen outlet of the elastic airbag in the gas pressure stabilizing module is connected in series with a ball valve and a back pressure nitrogen unloading valve.

[0015] In order to make the back pressure nitrogen supply valve and the back pressure nitrogen unloading valve work together to maintain the pressure of the gas pressure stabilizing module stable, preferably, the setting pressure of the back pressure nitrogen unloading valve is 100 to 200 Pa higher than that of the back pressure nitrogen supply valve, and both are one-way valves.

[0016] In order to reduce the complexity of the system and reduce the number of control loops, back-pressure nitrogen supply valves and back-pressure nitrogen discharge valves are both mechanical automatic valves. The back-pressure nitrogen supply valve opens when the downstream pressure is lower than the set value, and closes when it is higher than the set value; the back-pressure nitrogen discharge valve opens when the upstream pressure is higher than the set value, and closes when it is lower than the set value.

[0017] In order to stabilize the combustion furnace pressure, preferably, the pressure range of the gas pressure stabilizing module is 12 to 15 kPa.

[0018] In order to avoid the formation of a mixture of gas and air in the tank of the gas pressure stabilizing module, it is preferred that before starting the furnace, the elastic airbag nitrogen outlet ball valve is closed, the drain valve is opened to fill nitrogen into the elastic airbag, and the air in the tank is discharged; then the elastic airbag nitrogen outlet ball valve is opened, and the gas calorific value control module is used to inject gas into the tank, and the gas injection is stopped when the pressure gauge on the tank side reaches the set value.

[0019] In order to reduce operating costs, preferably, the nitrogen filled in the elastic airbag can be replaced by compressed air.

[0020] When the non-condensable gas from the pyrolysis of waste tires enters the tank body, the amount of the non-condensable gas fluctuates. Preferably, when the amount of the non-condensable gas decreases, the pressure in the tank body decreases. At this time, the pressure on the elastic airbag side also decreases. The back-pressure nitrogen supply valve opens to supply nitrogen into the elastic airbag to stabilize the pressure in the tank body. Conversely, when the amount of the non-condensable gas from the pyrolysis of waste tires increases, the pressure in the tank body increases. At this time, the pressure on the elastic airbag side also increases. The back-pressure nitrogen unloading valve opens to discharge the nitrogen in the elastic airbag to stabilize the pressure in the tank body.

[0021] When the furnace is shut down, in order to improve the safety of the gas pressure stabilizing module, preferably, when the furnace is shut down, the elastic airbag nitrogen outlet ball valve is closed, the elastic airbag nitrogen inlet valve is opened, nitrogen is filled into the airbag, and the gas in the tank is squeezed out.

[0022] Compared with the prior art, the present invention is beneficial in that:

[0023] The present invention can realize the safe and stable supply of gas for the waste tire pyrolysis furnace, and the system is simple and compact with a high degree of automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a safe and stable gas supply system for a waste tire pyrolysis furnace in an embodiment of the present invention.

[0025] Figure 2 The figure shows the change of the pressure of the gas pressure stabilizing module over time in the embodiment of the present invention.

[0026] Figure 3 The components and calorific value of the pyrolyzed non-condensable gas in the embodiment of the present invention. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention is further described below with reference to the embodiments and accompanying drawings. It should be understood that the described embodiments are only a portion of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the described embodiments without requiring creative effort are intended to fall within the scope of protection of the present invention.

[0028] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words “include” or “comprise” and the like used in the present invention mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as “connect” or “connected” and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. “Up”, “down”, “left”, “right” and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0029] Example

[0030] See also Figure 1 In this embodiment, a safe and stable gas supply system for a waste tire pyrolysis furnace includes: a gas combustion module 1, a pyrolysis non-condensable gas pipeline 2, a nitrogen pipeline 3, a supplementary gas source 4, a gas calorific value control module 5, and a gas pressure stabilization module 6.

[0031] Among them, the gas combustion module burns pyrolysis non-condensable gas to provide heat for the pyrolysis of waste tires, and is composed of a combustion furnace 101, a switch valve 102, a flame arrester 103 and a flow meter 104; the pyrolysis non-condensable gas pipeline is composed of a switch valve 201 and a one-way valve 202; the nitrogen pipeline provides nitrogen for the system; the supplementary gas source serves as the gas source when starting the furnace; the gas calorific value control module adjusts the calorific value of the gas to meet the requirements of complete combustion of the gas in the combustion furnace; the gas pressure stabilizing module provides the combustion furnace with stable pressure gas, and is composed of a tank body 601, an elastic airbag 602, a pyrolysis non-condensable gas inlet 603, a gas outlet 604, a supplementary gas inlet 605, a sewage outlet 606, an elastic airbag nitrogen inlet 607, an elastic airbag nitrogen outlet 608, a tank body side pressure gauge 609 and an elastic airbag side pressure gauge 610.

[0032] In order to facilitate transportation, the supplementary gas source is liquefied petroleum gas, which is transported in gas cylinders.

[0033] The components of non-condensable gas from waste tire pyrolysis are shown in Figure 3 Its calorific value is generally 40~50MJ / Nm 3 , while the calorific value of liquefied petroleum gas is 90MJ / Nm 3 The theoretical air volume required for combustion differs between the two. While existing burners have a certain degree of air distribution adjustment, they cannot burn both non-condensable gas and LPG. A gas calorific value control module is implemented to blend nitrogen into the LPG, lowering its calorific value to a value similar to that of pyrolyzed non-condensable gas. During furnace startup, diluted LPG is used as fuel.

[0034] To precisely control the calorific value of the fuel, the gas calorific value control module includes a flow meter 501 and a check valve 502 for the supplementary gas side, and a flow meter 503 and a check valve 504 for the nitrogen side. The flow meters can automatically adjust according to set values ​​and can be remotely controlled.

[0035] In order to achieve pressure stability in the gas pressure stabilizing module, the nitrogen inlet of the elastic airbag in the gas pressure stabilizing module consists of two parallel routes, one controlled by ball valve 6071 and the other controlled by back pressure nitrogen supply valve 6072; the nitrogen outlet of the elastic airbag in the gas pressure stabilizing module is connected in series with ball valve 6081 and back pressure nitrogen unloading valve 6082.

[0036] In order to make the back pressure nitrogen supply valve and the back pressure nitrogen unloading valve work together to maintain the pressure of the gas pressure stabilizing module stable, the setting pressure of the back pressure nitrogen unloading valve is 200Pa higher than that of the back pressure nitrogen supply valve. Both are one-way valves.

[0037] In order to reduce the complexity of the system and reduce the number of control loops, back-pressure nitrogen supply valves and back-pressure nitrogen discharge valves are both mechanical automatic valves. The back-pressure nitrogen supply valve opens when the downstream pressure is lower than the set value, and closes when it is higher than the set value; the back-pressure nitrogen discharge valve opens when the upstream pressure is higher than the set value, and closes when it is lower than the set value.

[0038] In order to stabilize the combustion furnace pressure, the gas pressure stabilizing module has a pressure range of 13kPa.

[0039] In order to avoid the formation of a mixture of gas and air in the tank of the gas pressure stabilizing module, before starting the furnace, close the elastic airbag nitrogen outlet ball valve, open the drain valve to fill the elastic airbag with nitrogen, and discharge the air in the tank; then open the elastic airbag nitrogen outlet ball valve, use the gas calorific value control module to inject gas into the tank, and stop gas injection when the tank side pressure gauge reaches the set value.

[0040] When the non-condensable gas from pyrolysis of waste tires enters the tank, the amount of non-condensable gas fluctuates. When the amount of non-condensable gas decreases, the pressure in the tank decreases. At this time, the pressure on the elastic airbag side also decreases. The back-pressure nitrogen supply valve opens to supply nitrogen to the elastic airbag to stabilize the pressure in the tank. Conversely, when the amount of non-condensable gas from pyrolysis increases, the pressure in the tank increases. At this time, the pressure on the elastic airbag side also increases. The back-pressure nitrogen discharge valve opens to discharge the nitrogen in the elastic airbag to stabilize the pressure in the tank. The change of the tank side pressure over time during operation is shown in Figure 2. Figure 2 .

[0041] When the furnace is shut down, in order to improve the safety of the gas pressure stabilizing module, close the elastic airbag nitrogen outlet ball valve, open the elastic airbag nitrogen inlet valve, fill the airbag with nitrogen, and squeeze out the gas in the tank.

Claims

1. A safe and stable gas supply system for waste tire pyrolysis furnace, characterized in that: include: The gas combustion module burns the non-condensable gas to provide heat for the pyrolysis of waste tires, and is composed of a combustion furnace, a switch valve, a flame arrester and a flow meter; The pyrolysis non-condensable gas pipeline is composed of a switch valve and a one-way valve; the nitrogen pipeline provides nitrogen for the system; Supplement the gas source and serve as the gas source when starting the furnace; Gas calorific value control module adjusts the calorific value of the gas to meet the requirements of complete combustion of the gas in the combustion furnace; The gas pressure stabilizing module provides the combustion furnace with gas of stable pressure, and is composed of a tank body, an elastic air bag, a pyrolysis non-condensable gas inlet, a gas outlet, a supplementary gas inlet, a sewage outlet, an elastic air bag nitrogen inlet, an elastic air bag nitrogen outlet, a tank body side pressure gauge and an elastic air bag side pressure gauge.

2. A safe and stable gas supply system for a waste tire pyrolysis furnace according to claim 1, characterized in that: The supplementary gas source is liquefied petroleum gas.

3. A safe and stable gas supply system for waste tire pyrolysis furnace according to claim 1, characterized in that: The gas calorific value control module uses nitrogen to adjust the gas calorific value, wherein the gas calorific value control module includes a flow meter and a one-way valve with adjustable flow on the supplementary gas side, and a flow meter and a one-way valve with adjustable flow on the nitrogen side.

4. A safe and stable gas supply system for waste tire pyrolysis furnace according to claim 1, characterized in that: The nitrogen inlet of the elastic airbag in the gas pressure stabilizing module consists of two parallel connections, one of which is controlled by a ball valve and the other is controlled by a back pressure nitrogen supply valve.

5. A safe and stable gas supply system for waste tire pyrolysis furnace according to claim 4, characterized in that: The nitrogen outlet of the elastic air bag in the gas pressure stabilizing module is connected in series with a ball valve and a back-pressure nitrogen unloading valve.

6. A safe and stable gas supply system for waste tire pyrolysis furnace according to claim 5, characterized in that: The setting pressure of the back pressure nitrogen unloading valve is 100~200Pa higher than that of the back pressure nitrogen supply valve.

7. A safe and stable gas supply system for waste tire pyrolysis furnace according to claim 5, characterized in that: Before starting the furnace, close the elastic airbag nitrogen outlet ball valve, open the drain valve to fill the elastic airbag with nitrogen, and discharge the air in the tank; then open the elastic airbag nitrogen outlet ball valve, and use the gas calorific value control module to inject gas into the tank, and stop gas injection when the pressure on the tank side reaches the set value.

8. The safe and stable gas supply system for waste tire pyrolysis furnace according to claim 5 is characterized in that: After starting the furnace, the pyrolysis non-condensable gas enters the tank body. When the amount of pyrolysis non-condensable gas fluctuates and the output decreases, the pressure in the tank body decreases. At this time, the pressure on the elastic airbag side also decreases. The back-pressure nitrogen supply valve opens to supply nitrogen to the elastic airbag to stabilize the pressure in the tank body. Conversely, when the amount of pyrolysis non-condensable gas increases, the pressure in the tank body increases. At this time, the pressure on the elastic airbag side also increases. The back-pressure nitrogen unloading valve opens to discharge the nitrogen in the elastic airbag to stabilize the pressure in the tank body.

9. The safe and stable gas supply system for waste tire pyrolysis furnace according to claim 5 is characterized in that: When the furnace is shut down, close the elastic airbag nitrogen outlet ball valve, open the elastic airbag nitrogen inlet valve, fill the airbag with nitrogen, and squeeze out the gas in the tank.

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