Layered punch-formed quick-burning grilled charcoal and preparation process thereof

Abstract

The layered punch-formed quick-burning grilled charcoal comprises a quick-burning layer and a burning layer which are combined through punching, the quick-burning layer is composed of low-temperature biomass carbon residue powder, auxiliary carbon powder and a complexing agent I; the combustion layer is composed of high-temperature carbon powder, high-temperature biomass carbon residue powder and a second complexing agent. The layered design of rapid combustion and continuous combustion is adopted, and according to the rapid combustion layer, the low ignition point of low-temperature biomass charcoal residue powder is utilized, ignition is rapidly responded, and the combustion rate is adjusted through assistance of the charcoal powder; the combustion layer realizes continuous high-temperature heat release by virtue of high-temperature carbon powder (high calorific value) and high-temperature biomass carbon residue powder (flame resistance); stamping combination ensures close contact of the two layers, a quick-burning layer is formed to ignite a high-temperature burning layer, and therefore burning is stable and sufficient.

Description

Technical Field

[0001] The invention relates to the field of solid fuels, and in particular to a layered stamping-formed fast-burning charcoal and a preparation process thereof. Background Art

[0002] As the core fuel for outdoor dining and home barbecues, the technological development of barbecue charcoal has always evolved around the three core needs of "easy to ignite, flame-resistant, and low pollution." Early traditional charcoal relied on natural wood burning. Although it has excellent combustion characteristics, it has problems such as resource waste, long ignition time, and poor combustion stability. It has gradually been replaced by machine-made charcoal. Machine-made charcoal achieves raw material diversification through powder molding technology, but its single homogeneous structure still makes it difficult to balance the contradiction between fast burning and flame resistance. However, improving ignition performance requires reducing density, which shortens the burning time. If flame resistance is enhanced, the density needs to be increased, which increases the difficulty of ignition. Pain points: Difficulty in ignition and loss of charcoal. Slow fire and troubled by smoke.

[0003] To resolve this contradiction, layered structural design has become a technological breakthrough. The prior art disclosed in CN113355144A proposes a two-layer structure of a fast-burning layer and a flame-resistant layer. The fast-burning layer uses low-temperature fruit wood charcoal powder combined with a strong oxidant to achieve rapid ignition, while the flame-resistant layer uses high-temperature fruit wood charcoal powder to extend the burning time and reduce heat loss through a non-mesoporous block design. Although this technology has improved the ignition efficiency and burning time to a certain extent, the fast-burning layer and the flame-resistant layer of this technology both use fruit wood charcoal powder as the core raw material, and do not utilize waste charcoal resources (such as the charcoal residue left after barbecue), resulting in high raw material costs. More importantly, the uniformity of the composition of single fruit wood charcoal powder limits the space for performance regulation. The fast-burning layer only lowers the ignition point through low-temperature carbonization, and lacks the oxygen-conducting effect of porous structure raw materials (such as corn cob charcoal), resulting in the problem of rapid decay after initial combustion. The flame-resistant layer relies on high-temperature carbonization to increase the calorific value, but does not introduce high-calorific value mineral carbon (such as lignite, with a calorific value of 32MJ / kg, higher than the 26MJ / kg of fruit wood charcoal), resulting in insufficient upper limit of the overall combustion temperature, which makes it difficult to meet the needs of high-temperature barbecue.

[0004] Secondly, the flame-resistant layer blank is formed first, and then the fast-burning layer slurry is coated on the surface and baked together. This process causes the interface of the two layers to be bonded only by physical adhesion, and the shear strength between the layers is insufficient. Delamination and falling off are likely to occur during transportation or use, resulting in significant local temperature differences during combustion, which not only affects the barbecue effect, but also causes the charcoal blocks to break prematurely due to local overheating.

[0005] In summary, there is an urgent need for a new type of fast-burning charcoal with multiple raw materials and layered stamping to meet daily use needs. Summary of the Invention

[0006] The present invention aims to provide a layered stamping-formed fast-burning charcoal and a preparation process thereof, and a novel fast-burning charcoal is produced by combining multiple raw materials and performing layered stamping.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A layered stamping-formed fast-burning charcoal comprises a fast-burning layer and a combustion layer bonded by stamping; The fast burning layer is composed of low-temperature biomass carbon slag powder, auxiliary carbon powder and composite agent; The combustion layer is composed of high-temperature carbon powder, high-temperature biomass carbon slag powder and a composite agent.

[0008] Working principle and beneficial effects of the present invention: It adopts a layered functional design with rapid combustion and continuous combustion. The rapid combustion layer uses the low ignition point of low-temperature biomass charcoal slag powder to quickly respond to ignition, and assists the charcoal powder to adjust the combustion rate; the combustion layer relies on high-temperature charcoal powder (high calorific value) and high-temperature biomass charcoal slag powder (flame resistant) to achieve continuous heat release; the stamping combination ensures that the two layers are in close contact, forming a rapid combustion layer to ignite the high-temperature combustion layer, thereby achieving stable and full combustion.

[0009] To solve the contradiction between the rapid combustion and flame retardancy of traditional single-layer charcoal, the rapid combustion layer and the combustion layer are combined by stamping. The stamping combination makes the shear strength between the layers high, far exceeding the coating combination of existing technologies, and there is no risk of delamination during transportation and use.

[0010] Preferably, the low-temperature biomass charcoal residue powder includes low-temperature apple charcoal residue powder and low-temperature litchi charcoal residue powder, the auxiliary charcoal powder includes high-temperature fir charcoal powder and low-temperature corn cob charcoal powder; the combustion layer includes high-temperature lignite powder and high-temperature fruit wood charcoal residue powder.

[0011] In the fast-burning layer: low-temperature apple and litchi charcoal powders serve as the fast-burning matrix. They are sourced from waste charcoal and have a low ignition point. High-temperature fir charcoal powder has a high calorific value of over 4,000 kcal / kg, which can increase the initial combustion temperature. Low-temperature corncob charcoal powder has a porous structure with a porosity of ≥30%, which can conduct oxygen and avoid "post-deflagration decay" caused by local hypoxia. In the combustion layer, high-temperature semi-coke has a calorific value of 32MJ / kg, far exceeding the 26MJ / kg of fruit wood charcoal, providing core heat. High-temperature fruit wood charcoal slag powder, derived from waste charcoal slag, undergoes dry distillation at 800-1000°C, resulting in a fixed carbon content of ≥80%, which regulates the combustion rate and prevents the semi-coke from burning too quickly.

[0012] Apple and lychee charcoal residues ensure the basis for rapid combustion, fir charcoal powder increases the ignition temperature, which is a greater increase than that of single fruit wood charcoal powder, and corn cob charcoal powder makes the combustion more uniform, with temperature fluctuations ≤±50℃; lignite is combined with high-temperature fruit wood charcoal residues, and the burning time is longer than the pure fruit wood charcoal refractory layer in the existing technology, and the maximum temperature is higher, which is ≤600℃ in the existing technology.

[0013] Preferably, the components of the fast-burning layer are in the following proportions by mass: 35-45% of low-temperature apple charcoal residue powder, 35-45% of low-temperature litchi charcoal residue powder, 8-12% of high-temperature fir charcoal powder, and 8-12% of low-temperature corn cob charcoal powder; the composite agent, based on the total mass of the above components, includes: 14-18% of sodium chlorate, 2-4% of sodium humate, 2-4% of corn starch, 0.3-0.5% of PAM, and 0.3-0.5% of HPMC.

[0014] Apple / lychee charcoal residue accounts for 70-90%, ensuring the dominance of rapid combustion; 8-12% of fir charcoal supplements calorific value, and 8-12% of corn cob charcoal supplements air permeability. The three proportions work together to avoid "excessive rapid combustion, i.e., deflagration" or "insufficient rapid combustion, i.e., ignition failure"; sodium chlorate is an oxidant, releasing oxygen, which matches the ignition point of the rapid combustion layer and can accelerate the combustion of charcoal powder; sodium humate enhances thermal strength, i.e., resistance to cracking at high temperatures; corn starch, PAM, and HPMC form a structure to enhance strength and avoid damage during transportation.

[0015] Preferably, the components of the fast-burning layer are as follows: 40% by mass of low-temperature apple charcoal residue powder, 40% by mass of low-temperature litchi charcoal residue powder, 10% by mass of high-temperature fir charcoal powder, and 10% by mass of low-temperature corn cob charcoal powder; the composite agent comprises: 18% by mass of sodium chlorate, 2% by mass of sodium humate, 4% by mass of corn starch, 0.5% by mass of PAM, and 0.5% by mass of HPMC, based on the total mass of the above components.

[0016] Preferably, the mass proportions of the components in the combustion layer are: 75-85% of high-temperature blue charcoal powder, 15-25% of high-temperature fruit wood charcoal residue, and the second composite agent accounts for the total mass of the above components and includes: 1.5-2.5% of sodium humate, 3-5% of corn starch, 0.4-0.6% of PAM, and 0.4-0.6% of HPMC.

[0017] Semi-coke has high calorific value and low sulfur, accounting for a dominant 75-85%, ensuring continuous high temperature; fruit wood charcoal residue contains a small amount of volatile matter 5-8%, which regulates the combustion rate and avoids the shortening of the combustion time caused by the "fast burning" of semi-coke; 1.5-2.5% of sodium humate in the second composite agent enhances thermal strength, i.e., resistance to deformation at high temperature; 3-5% of corn starch forms a dense bond with 0.4-0.6% of PAM and HPMC, ensuring that the combustion layer is structurally stable at high temperatures above 700°C, i.e., there is no fragmentation.

[0018] Preferably, the mass proportions of the components in the combustion layer are: 80% high-temperature blue charcoal powder, 20% high-temperature fruit wood charcoal residue; the second composite agent accounts for the total mass of the above components and includes: 2% sodium humate, 4% corn starch, 0.5% PAM, and 0.5% HPMC.

[0019] A rapid combustion charcoal preparation process, comprising: S1. Preparation of combustion layer materials: crush high-temperature blue charcoal powder and high-temperature fruit wood charcoal slag powder and add them to a stirring device, add a compounding agent and stir for a preset time, then add a preset proportion of water and continue stirring until a uniform combustion layer material is obtained; S2. Preparation of fast-burning layer material: crush all raw materials and feed them into a mixing device. Add sodium humate, corn starch, PAM, and HPMC from the compound agent 1 and stir for a preset time. Then, dissolve sodium chlorate in a certain proportion of water and pour it into the mixing device and stir until uniform to obtain the fast-burning layer material. S3, layered conveying and stamping: the combustion layer material and the fast burning layer material are respectively fed into the corresponding hoppers of the stamping equipment, and the combustion layer is pre-pressed and formed, the fast burning layer is mainly pressed and composited, and the carbon blocks are demoulded by the secondary pressure. S4. Drying: Arrange the formed carbon blocks on the carrier at preset intervals, send them into the temperature-controlled drying equipment, dry them at the preset temperature for the preset time, and then cool and package them.

[0020] Preferably, S1 adds water in a proportion of 45% of the total mass of high-temperature blue charcoal powder, high-temperature fruit wood charcoal residue powder, and the composite agent; S2 dissolves sodium chlorate in water in a proportion of 40% of the total mass of each of the low-temperature apple charcoal residue powder, low-temperature litchi charcoal residue powder, high-temperature fir charcoal powder, low-temperature corn cob charcoal powder, and the composite agent.

[0021] The 45% water in the combustion layer forms a colloid with the compounding agent starch, which enhances the plasticity of the material, facilitates stamping and molding, and has uniform density; the 40% water in the fast-burning layer dissolves sodium chlorate to improve dispersibility, and cooperates with the binder to prevent the fast-burning layer material from being too dry and agglomerated, or too wet and collapsing after molding or becoming difficult to ignite.

[0022] Preferably, the thickness of the fast-burning layer after punching is 5 to 8 mm.

[0023] The main components of the combustion layer have a high ignition point, and the heat released during the combustion of the fast-burning layer is required to make the surface temperature of the combustion layer reach this threshold before it can be ignited.

[0024] When the fast-burning layer is 5-8mm thick, the combustion of its low-temperature biomass charcoal slag powder (40% apple + 40% lychee), high-temperature fir charcoal powder (10%), corncob charcoal powder (10%), and oxidizer (14-18%) releases sufficient heat (local temperatures reaching 560-600°C) to just meet the ignition requirements of the combustion layer. At this thickness, the fast-burning layer's combustion cycle completely covers the ignition and stabilization transition phases of the combustion layer, ensuring that the combustion layer can continue to burn independently after ignition, preventing premature exhaustion of the fast-burning layer and combustion interruption.

[0025] Preferably, the preset temperature of the temperature-controlled drying equipment is 60-90° C., and the preset drying time is 16-18 hours. DETAILED DESCRIPTION

[0026] The following is further described in detail through specific implementation methods: Low-temperature charcoal: The carbonization temperature is usually 200-400°C, which is considered "low-temperature anaerobic carbonization." At this temperature, the volatile matter (such as water, oil, and volatile organic matter) in the raw materials is not completely expelled, and the fixed carbon content is low (usually 50-70%). (For example: low-temperature apple charcoal residue powder, low-temperature lychee charcoal residue powder, low-temperature corn cob charcoal powder, carbonization temperature ≤ 400°C) Low-temperature apple and lychee charcoal residue powders are made from the residue left after burning apple and lychee wood to create charcoal. These residues are pre-treated (screened to remove impurities such as sand and rocks) and crushed to 100-150 mesh. This process recycles "waste charcoal resources" rather than using freshly burned fruit charcoal, reducing raw material costs and waste.

[0027] High-temperature fir charcoal powder: Made from fir wood through high-temperature carbonization (typically ≥600°C), this charcoal is then crushed and screened to a particle size that matches the other raw materials in the fast-burning layer. Fir wood is dense and has a high calorific value after high-temperature carbonization, supplementing the heat output of the fast-burning layer.

[0028] Low-temperature corncob charcoal powder is derived from the carbonization of corncobs at low temperatures. It is made from agricultural waste corncobs, which are carbonized at low temperatures (temperature ≤ 400°C) and then crushed. Corncobs have a porous structure, and after carbonization, they retain a large number of pores, which act as "oxygen channels" to regulate combustion rhythm.

[0029] High-temperature semi-coke powder: This product is derived from the dry distillation and pyrolysis of semi-coke. Semi-coke (also known as semi-coke) is produced from Jurassic non-caking and slightly caking coal through a dry distillation and pyrolysis process, followed by a cooling and purification process (the key is to control the pyrolysis temperature and atmosphere), and then crushed to 80-100 mesh. It has low sulfur, low ash, and high calorific value, and is the core heat source for the combustion layer.

[0030] High-temperature fruit wood charcoal residue powder: Abandoned fruit wood is carbonized using high-temperature dry distillation technology (carbonization temperature above 800-1000°C). After cooling for 24-72 hours, the remaining charcoal residue is separated by sieving. Abandoned fruit wood, such as apple wood, is used to produce high-temperature apple charcoal residue powder.

[0031] The specific implementation process is as follows: Example 1: The raw materials for the fast-burning layer include, by weight, 40% low-temperature apple charcoal residue powder, 40% low-temperature litchi charcoal residue powder, 10% high-temperature fir charcoal powder, and 10% low-temperature corncob charcoal powder. Also included are, in the following weight ratios, 18% sodium chlorate, 2% sodium humate, 4% corn starch, 0.5% PAM (polyacrylamide), and 0.5% HPMC (hydroxypropyl methylcellulose).

[0032] The raw materials for the combustion layer include: 80% high-temperature blue charcoal powder, 20% high-temperature fruit wood charcoal residue, and 2% sodium humate, 4% corn starch, 0.5% PAM, and 0.5% HPMC in the total weight ratio of the above raw materials.

[0033] According to the preparation process of the present application, a carbon block is prepared with a combustion layer having a specification of 130*40*40mm, and the overall specification of the carbon block is 130*40*45mm, that is, a fast-burning layer with a thickness of 5mm.

[0034] Blank control group: existing ordinary charcoal Prior art control group: fast-burning layer: 90% low-temperature fruit wood charcoal powder, 2% food-grade adhesive, 8% strong oxidant; flame-resistant layer: 98% high-temperature fruit wood charcoal powder, 2% food-grade adhesive; coating molding, no mesoporous blocks.

[0035] The following experiments were conducted: (1) Combustion performance test: Ignition time: Use a lighter to ignite the sample surface and record the time until complete ignition (50% of the surface is red hot); Burning time: The total time from complete ignition to the absence of red hot area; Maximum temperature: Use a thermocouple (accuracy ±5°C) to measure the maximum temperature during the combustion process; Temperature stability: Record the duration of temperatures above 500°C (rapid combustion stage) and above 700°C (combustion stage).

[0036] (2) Mechanical strength test: Cold compressive strength: Use a universal testing machine (range 0-50MPa) to test the compressive strength of the unburned sample; interlaminar shear strength: Use a shear testing machine to test the interface shear force between the fast-burning layer and the burning layer.

[0037] The following data in Table 1 are obtained:

[0038] Analysis shows that the present invention adopts a fast-burning layer combination of low-temperature apple / lychee charcoal residue (fast burning) + high-temperature fir charcoal (heat supplement) + corn cob charcoal (oxygen supply), combined with a combustion layer of blue charcoal (high calorific value) + high-temperature fruit wood charcoal residue (flame resistant), to form a gradient energy release with rapid ignition and continuous heat release, solving the problem of imbalance between fast burning and flame resistant of single fruit wood charcoal in the existing technology.

[0039] 2. Single Factor Influence Experiment Refer to Table 2 below:

[0040] According to the above experimental method, the data in Table 3 are obtained: Table 3

[0041] Result analysis: Low-temperature apple charcoal residue and litchi charcoal residue (80% combined) serve as the rapid-burning matrix. Their complementary properties (apple charcoal residue has a slightly lower ignition point, while litchi charcoal residue burns more stably) enable rapid and sustained initial ignition. High-temperature fir charcoal powder (10%) supplements calorific value, preventing a sudden temperature drop during the rapid-burning phase. Low-temperature corncob charcoal powder (10%) provides an oxygen channel, addressing the oxygen deficiency associated with dense charcoal combustion. An imbalance in the four components (as in Comparative Examples 1-5) disrupts the synergistic chain of rapid combustion, supplementing heat, and supplying oxygen, leading to reduced performance. The balance mechanism of the combustion layer components: High-temperature semi-coke powder (80%) serves as the core with a high calorific value (32MJ / kg), ensuring a consistently high temperature in the combustion layer. High-temperature fruitwood charcoal residue (20%) regulates the combustion rate (its fixed carbon content is ≥80%, resulting in slower combustion), preventing the semi-coke from burning too quickly. In Comparative Example 6, the insufficient proportion of semi-coke disrupts the balance between calorific value and flame resistance, confirming that 80% semi-coke + 20% fruitwood charcoal residue is the optimal ratio. The above is only an embodiment of the present invention, and the common knowledge such as the specific technical solutions and / or characteristics in the solution are not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several variations and improvements can be made, which should also be regarded as the scope of protection of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the description can be used to interpret the content of the claims.

Claims

1. A layered stamping fast-burning charcoal, characterized in that: It includes a fast burning layer and a burning layer bonded by stamping; The fast burning layer is composed of low-temperature biomass carbon slag powder, auxiliary carbon powder and composite agent; The combustion layer is composed of high-temperature carbon powder, high-temperature biomass carbon slag powder and a composite agent.

2. The layered stamping-formed rapid-burning charcoal according to claim 1, characterized in that: The low-temperature biomass charcoal residue powder includes low-temperature apple charcoal residue powder and low-temperature litchi charcoal residue powder, the auxiliary charcoal powder includes high-temperature fir charcoal powder and low-temperature corn cob charcoal powder; the combustion layer includes high-temperature blue charcoal powder and high-temperature fruit wood charcoal residue powder.

3. The layered stamping-formed rapid-burning charcoal according to claim 2, characterized in that: The components of the fast-burning layer are as follows: 35-45% by weight of low-temperature apple charcoal residue powder, 35-45% by weight of low-temperature litchi charcoal residue powder, 8-12% by weight of high-temperature fir charcoal powder, and 8-12% by weight of low-temperature corn cob charcoal powder; and the composite agent, based on the total weight of the above components, includes: 14-18% by weight of sodium chlorate, 2-4% by weight of sodium humate, 2-4% by weight of corn starch, 0.3-0.5% by weight of PAM, and 0.3-0.5% by weight of HPMC.

4. The layered stamping-formed rapid-burning charcoal according to claim 3, characterized in that: The components of the fast-burning layer are composed of 40% low-temperature apple charcoal residue powder, 40% low-temperature litchi charcoal residue powder, 10% high-temperature fir charcoal powder, and 10% low-temperature corn cob charcoal powder in terms of mass. The composite agent comprises 18% sodium chlorate, 2% sodium humate, 4% corn starch, 0.5% PAM, and 0.5% HPMC in terms of the total mass of the above components.

5. The layered stamping-formed rapid-burning charcoal according to claim 4, characterized in that: The components in the combustion layer are as follows by mass: 75-85% of high-temperature blue carbon powder, 15-25% of high-temperature fruit wood charcoal residue, and the second composite agent, based on the total mass of the above components, includes: 1.5-2.5% of sodium humate, 3-5% of corn starch, 0.4-0.6% of PAM, and 0.4-0.6% of HPMC.

6. The layered stamping-formed rapid-burning charcoal according to claim 5, characterized in that: The components in the combustion layer are as follows by mass: 80% high-temperature blue carbon powder and 20% high-temperature fruit wood charcoal residue; the second composite agent accounts for the total mass of the above components and includes: 2% sodium humate, 4% corn starch, 0.5% PAM, and 0.5% HPMC.

7. The process for preparing rapid combustion charcoal according to any one of claims 1 to 6, characterized in that: include: S1. Preparation of combustion layer materials: crush high-temperature blue charcoal powder and high-temperature fruit wood charcoal slag powder and add them to a stirring device, add a compounding agent and stir for a preset time, then add a preset proportion of water and continue stirring until a uniform combustion layer material is obtained; S2. Preparation of fast-burning layer material: crush all raw materials and feed them into a mixing device. Add sodium humate, corn starch, PAM, and HPMC from the compound agent 1 and stir for a preset time. Then, dissolve sodium chlorate in a certain proportion of water and pour it into the mixing device and stir until uniform to obtain the fast-burning layer material. S3, layered conveying and stamping: the combustion layer material and the fast burning layer material are respectively fed into the corresponding hoppers of the stamping equipment, and the combustion layer is pre-pressed and formed, the fast burning layer is mainly pressed and composited, and the carbon blocks are demoulded by the secondary pressure. S4. Drying: Arrange the formed carbon blocks on the carrier at preset intervals, send them into the temperature-controlled drying equipment, dry them at the preset temperature for the preset time, and then cool and package them.

8. The rapid combustion charcoal preparation process according to claim 7, characterized in that: S1 adds water in a proportion of 45% of the total mass of high-temperature blue charcoal powder, high-temperature fruit wood charcoal residue powder, and composite agent one; S2 dissolves sodium chlorate in water in a proportion of 40% of the total mass of low-temperature apple charcoal residue powder, low-temperature litchi charcoal residue powder, high-temperature fir charcoal powder, low-temperature corn cob charcoal powder, and composite agent one.

9. The rapid combustion charcoal preparation process according to claim 8, characterized in that: The thickness of the fast-burning layer after punching is 5 to 8 mm.

10. The rapid combustion charcoal preparation process according to claim 9, characterized in that: The preset temperature of the temperature-controlled drying equipment is 60-90° C., and the preset drying time is 16-18 hours.

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