A method for utilizing heat balance of bamboo charcoal

Abstract

The invention discloses a method for utilizing heat balance of bamboo charcoal, comprising S1, splitting and roughly planing raw bamboo to obtain bamboo slices and bamboo scraps; S2, placing the bamboo slices in a drying room, drying them by blasting air to obtain dried bamboo slices; S3, extruding and molding the bamboo scraps through a rod making machine to obtain bamboo sticks; S4, placing the bamboo sticks in a retort, and obtaining machine-made charcoal and combustible gas after thermal decomposition; S5, sending the combustible gas into a combustion chamber for combustion to obtain high-temperature gas; S6, using the high-temperature gas to heat the retort. The invention provides a method for utilizing heat balance of bamboo charcoal, which organically integrates bamboo decomposition, bamboo strip carbonization and machine-made charcoal production, realizes the nearby digestion and utilization of waste heat from a charcoal plant, fully improves the utilization efficiency of bamboo, and reduces the production cost of bamboo boards and bamboo charcoal.

Description

Technical Field

[0001] The invention belongs to the technical field of bamboo production, and in particular relates to a method for utilizing heat balance of bamboo charcoal. Background Art

[0002] my country's bamboo industry has developed rapidly in recent years, maintaining a compound growth rate of about 30% per year. However, due to the thin-walled hollow, thick-bottomed and thin-topped cylindrical structure of bamboo, and the presence of yellow and green bamboo on the inner and outer surfaces that are difficult to glue, most bamboo processing techniques can only use the "bamboo flesh" without the green and yellow bamboo. More than half of the bamboo exists in the form of "logging residues, lumbering residues, and processing residues", which is the so-called "three bamboo residues". The actual bamboo utilization rate of bamboo products is less than 50%. The "three bamboo residues" are mainly used for burning and heating, and for antiseptic treatment and drying of bamboo strips. This has low added value, resulting in high costs for bamboo board products.

[0003] Machine-made bamboo charcoal is made from "three leftover bamboo products" and is produced through "forming first and then carbonizing". It has high calorific value, is resistant to burning and smokeless. It can be used as barbecue charcoal, smoking charcoal, etc. and has high added value.

[0004] In the prior art, for example, Chinese patent CN112063402A discloses a carbonization combustible gas heating technology for machine-made charcoal production. This technology can recycle and reuse combustible gas, and use the gas to heat and dry the raw materials after ignition, thereby reducing the production cost of machine-made charcoal. However, in practice, machine-made charcoal plants rarely recover waste heat. This is because the commonly used self-heating carbonization kiln mainly relies on partial combustion of itself to maintain the carbonization temperature, and does not require additional energy supplementation. The recovered heat energy is useless, and the production of bamboo boards and bamboo charcoal has not formed a benign linkage between the upper and lower parts, resulting in a low utilization rate of bamboo materials. Summary of the invention

[0005] The purpose of the present invention is to provide a method for heat balance utilization of bamboo charcoal, so as to achieve heat energy complementarity in the production process of bamboo board and bamboo charcoal and improve the utilization rate of bamboo.

[0006] To this end, the present invention provides a method for utilizing heat balance of bamboo charcoal, comprising the following steps:

[0007] S1, breaking and roughly planing the original bamboo to obtain bamboo slices and bamboo chips;

[0008] S2, placing the bamboo chips in a drying room and drying them by blasting air to obtain dried bamboo chips;

[0009] S3, the bamboo chips are extruded and formed by a stick making machine to obtain bamboo sticks;

[0010] S4, the bamboo stick is placed in a dry distillation reactor, and after thermal decomposition, machine-made charcoal and combustible gas are obtained;

[0011] S5, the combustible gas is sent into the combustion chamber for combustion to obtain high-temperature gas;

[0012] S6. Use high temperature gas to heat the retort.

[0013] Preferably, the retort is an externally heated retort, which comprises an outer shell and an inner shell, a heating chamber is provided between the outer shell and the inner shell, and a condensation recovery device is provided above the heating chamber.

[0014] Further preferably, there are a plurality of retorts, which are connected in series and operated alternately to provide a stable supply of combustible gas.

[0015] Preferably, the inner tank is connected to a combustible gas outlet, and the combustible gas outlet is connected to a combustion chamber through a pipeline. The combustion chamber is separated from the retort, and the combustible gas is introduced into the combustion chamber for combustion under high temperature to form high-temperature gas, which heats the retort, thereby avoiding direct heating of the retort body by an open flame, thereby increasing the service life of the equipment, and preventing the precipitation of byproducts such as tar and vinegar liquid, and facilitating the temperature control of the retort.

[0016] Preferably, a base is provided at the bottom of the shell, a reaction chamber is provided in the base, a retort jacket is provided above the reaction chamber, a high-temperature gas inlet is provided at one end of the reaction chamber, a flue is provided at the other end of the reaction chamber, and the high-temperature gas inlet is connected to the combustion chamber through a pipeline. The high-temperature gas transfers heat from the retort jacket in the reaction chamber and discharges the exhaust gas from the flue.

[0017] Preferably, a water coil is provided above the retort jacket, a water coil water inlet is provided at one end of the water coil, and a water vapor outlet is provided above the water coil. Water in the water coil is heated to form water vapor, which heats the inner tank in the heating chamber and exchanges heat with the heat exchange coil, making full use of the heat, and the water vapor after heat exchange is condensed into liquid in the condensation recovery device and recovered.

[0018] Preferably, a heat exchange coil is provided in the heating chamber, and the heat exchange coil is above the water coil.

[0019] Preferably, the heat exchange coil is provided in multiple pieces and arranged in order from bottom to top. The bottom heat exchange coil is closer to the water vapor and has a higher temperature. Due to the heat loss of the water vapor during the rising process, the temperature of the heat exchange coil gradually decreases from bottom to top, thereby obtaining hot water of different temperatures. The hot water can be used for heating the drying room and domestic hot water.

[0020] Preferably, in step S6, high temperature gas is introduced into the reaction chamber from the high temperature gas inlet, and the heat of the high temperature gas is transferred to the water coil through the retort jacket, heating the water in the water coil into water vapor, and the water vapor heats the inner tank.

[0021] Preferably, in step S6, the water vapor exchanges heat with the heat of the heat exchange coil to heat the temperature of the water in the heat exchange coil.

[0022] Preferably, in step S6, the temperature of the water vapor gradually decreases from bottom to top, and the temperatures of the plurality of heat exchange coils gradually decrease from bottom to top, thereby obtaining hot water of different temperatures.

[0023] Beneficial effects:

[0024] 1. The present invention provides a method for thermal balance utilization of bamboo charcoal, which organically integrates bamboo decomposition, bamboo strip carbonization and machine-made charcoal production, realizes the local digestion and utilization of waste heat from the charcoal plant, fully improves the utilization efficiency of bamboo, and reduces the production cost of bamboo boards and bamboo charcoal.

[0025] 2. In the prior art, bamboo charcoal is generally produced using a self-heating carbonization kiln, which is heated by the heat of its own combustion, has a long carbonization time, and has a short service life. The present invention replaces the self-heating carbonization kiln with an externally heated retort, and the combustion chamber is separated from the retort. The combustible gas is introduced into the combustion chamber under a high temperature state to burn, forming a high-temperature gas, and the retort is heated by the high-temperature gas, avoiding direct heating of the retort body by an open flame, thereby increasing the service life of the equipment, and no by-products such as tar and vinegar liquid are precipitated. At the same time, it is easy to control the temperature of the retort, and the carbonization time can be shortened.

[0026] 3. Since the temperature of the high-temperature gas obtained by combustion in the combustion chamber is much higher than the temperature of the bamboo stick decomposition by heat, if it is directly used for heating the inner tank, the temperature will be too high and the charcoal yield will be reduced. If the temperature of the high-temperature gas is reduced, the heat will be wasted. Therefore, in this embodiment, the high-temperature gas is passed into the reaction chamber from the high-temperature gas inlet, and the heat of the high-temperature gas is transferred to the water coil through the retort jacket, and the water in the water coil is heated to become water vapor, and the water vapor heats the inner tank; the water vapor exchanges heat with the heat of the heat exchange coil to heat the temperature of the water in the heat exchange coil; the temperature of the water vapor gradually decreases from bottom to top, and the temperature of multiple heat exchange coils gradually decreases from bottom to top, thereby obtaining hot water of different temperatures. Hot water can be used for heating the drying room, making full use of the heat, and facilitating the drying of the bamboo sticks. After the heat is recovered by the heat exchange coil, the temperature of the rising water vapor is reduced, which is used to heat the inner tank, so that the temperature of the inner tank remains stable within an appropriate heating range, thereby ensuring the charcoal yield of the mechanism.

[0027] 4. There are multiple retorts, which are connected in series and operated alternately to provide a stable supply of combustible gas and ensure a balanced production of dried bamboo chips and machine-made charcoal. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 The present invention provides a method flow chart of an embodiment of a method for utilizing heat balance of bamboo charcoal.

[0030] Figure 2 The present invention provides a schematic structural diagram of an embodiment of a method for utilizing heat balance of bamboo charcoal.

[0031] Figure 3 The present invention provides a schematic structural diagram of an externally heated retort according to an embodiment of a method for utilizing heat balance of bamboo charcoal.

[0032] Among them, 1-external heating retort, 2-outer shell, 3-inner liner, 31-combustible gas outlet, 4-heating chamber, 5-condensation recovery device, 6-base, 61-reaction chamber, 62-retort jacket, 63-high-temperature gas inlet, 7-flue, 8-water coil, 81-water coil water inlet, 82-water vapor outlet, 9-heat exchange coil, 10-combustion chamber. DETAILED DESCRIPTION

[0033] The content of the present invention can be more easily understood by selecting the following detailed description of the preferred implementation method of the present invention and the embodiments included. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art to which the present invention belongs. When there is a conflict, the definition in this specification shall prevail.

[0034] Embodiment 1:

[0035] The present invention provides a method for heat balance utilization of bamboo charcoal, which organically integrates bamboo decomposition, bamboo strip carbonization and machine-made charcoal production, realizes the local digestion and utilization of waste heat from a charcoal plant, fully improves the utilization efficiency of bamboo, and reduces the production cost of bamboo boards and bamboo charcoal.

[0036] like Figure 1-3 A method for utilizing heat balance of bamboo charcoal is shown, comprising the following steps:

[0037] S1, breaking and roughly planing the original bamboo to obtain bamboo slices and bamboo chips;

[0038] S2, the bamboo chips are placed in a drying room and dried by blasting to obtain dried bamboo chips;

[0039] S3, bamboo chips are extruded into bamboo sticks by a stick making machine;

[0040] S4, the bamboo stick is placed in a dry distillation reactor, and after thermal decomposition, machine-made charcoal and combustible gas are obtained;

[0041] S5, the combustible gas is sent into the combustion chamber 10 for combustion to obtain high-temperature gas;

[0042] S6. Use high temperature gas to heat the retort and recover the heat for heating the drying room.

[0043] The retort is an external heating retort, and there are multiple retorts, which are connected in series and operated alternately to provide a stable supply of combustible gas. The external heating retort 1 includes an outer shell 2 and an inner liner 3, a heating chamber 4 is provided between the outer shell 2 and the inner liner 3, and a condensation recovery device 5 is provided above the heating chamber 4. The inner liner 3 is connected to a combustible gas outlet 31, and the combustible gas outlet 31 is connected to a combustion chamber 10 through a pipeline. The combustion chamber 10 is separated from the retort, and the combustible gas is introduced into the combustion chamber 10 under high temperature to form high-temperature gas, and the retort is heated by the high-temperature gas, so that the open flame is avoided from directly heating the kettle body of the retort, and the service life of the equipment is improved, and no by-products such as tar and vinegar liquid are precipitated. At the same time, the excess heat is recovered by the heat exchange coil 9, and the temperature of the retort is controlled while reducing the waste of heat.

[0044] The bottom of the housing 2 is provided with a base 6, a reaction chamber 61 is provided in the base 6, a retort jacket 62 is provided above the reaction chamber 61, a high-temperature gas inlet 63 is provided at one end of the reaction chamber 61, a flue 7 is provided at the other end of the reaction chamber 61, and the high-temperature gas inlet 63 is connected to the combustion chamber 10 through a pipeline. The high-temperature gas transfers heat from the retort jacket 62 in the reaction chamber 61, and exhausts the exhaust gas from the flue 7.

[0045] A water coil 8 is provided above the retort jacket 62, a water coil water inlet 81 is provided at one end of the water coil 8, and a water vapor outlet 82 is provided above the water coil 8. Water in the water coil 8 is heated to form water vapor, which enters the heating chamber 4 from the water vapor outlet 82. The water vapor heats the inner tank 3 in the heating chamber 4 and exchanges heat with the heat exchange coil 9, making full use of the heat. After the heat exchange, the water vapor continues to rise and enters the condensation recovery device 5, where it is condensed into liquid and recovered.

[0046] A heat exchange coil 9 is arranged in the heating chamber 4, and the heat exchange coil 9 is above the water coil 8. There are two heat exchange coils 9, which are arranged from bottom to top. The bottom heat exchange coil 9 is closer to the water vapor and has a higher temperature. Due to the heat loss of the water vapor during the rising process, the temperature of the heat exchange coil 9 gradually decreases from bottom to top, thereby obtaining hot water of different temperatures. The hot water at the bottom has a higher temperature and is used for the heating cycle of the drying room, and the hot water at the top is used for domestic hot water.

[0047] Since the temperature of the high-temperature gas obtained by combustion in the combustion chamber is much higher than the temperature of the bamboo stick decomposition by heat, if it is directly used for heating the inner tank, the temperature will be too high and the charcoal yield will be reduced. If the temperature of the high-temperature gas is reduced, the heat will be wasted. Therefore, in this embodiment, the high-temperature gas is passed into the reaction chamber 61 from the high-temperature gas inlet 63, and the heat of the high-temperature gas is transferred to the water coil 8 through the retort jacket 62, and the water in the water coil 8 is heated to become water vapor, and the water vapor heats the inner tank 3; the water vapor exchanges heat with the heat of the heat exchange coil 9 to heat the temperature of the water in the heat exchange coil 9; the temperature of the water vapor gradually decreases from bottom to top, and the temperature of multiple heat exchange coils 9 gradually decreases from bottom to top, thereby obtaining hot water of different temperatures. After the heat is recovered by the heat exchange coil 9, the temperature of the rising water vapor is reduced, and it is used to heat the inner tank 3, so that the temperature of the inner tank 3 remains stable within a suitable heating range, thereby ensuring the charcoal yield of the mechanism.

[0048] In this embodiment, assuming that one ton of raw bamboo is consumed per hour, the calorific value of the raw bamboo is about 430w kcal, and about 1,600 cubic meters of combustible gas is generated. The calorific value of each cubic meter of gas is 5.5MJ, corresponding to a calorific value of 210w kcal. 1 / 3 is used to heat the retort, and 2 / 3 is used to heat the water phase change in the heating coil. This part has a calorific value of 140w kcal, which can produce 3 tons of low-temperature steam, and the drying capacity can reach 3t / h. At the same time, the calorific value of the co-production mechanism charcoal is 160w kcal. The energy utilization rate of the traditional internal heating carbonization kiln production method is 34%, and the energy utilization rate in this embodiment is (140+160) / 430=70%, which greatly improves the energy utilization rate compared with the traditional method.

[0049] In a traditional internally heated carbonization kiln, 1 ton of bamboo powder can produce 180 kg of machine-made charcoal. By using the externally heated retort 1 shown in the present method, the temperature can be controlled more accurately to be maintained between 550°C and 650°C. Thus, 1 ton of bamboo powder can produce 200 kg of machine-made charcoal, and the charcoal yield is increased by 11%.

Claims

1. A method for utilizing heat balance of bamboo charcoal, characterized in that: The following steps are involved: S1, breaking and roughly planing the original bamboo to obtain bamboo slices and bamboo chips; S2, placing the bamboo chips in a drying room and drying them by blasting air to obtain dried bamboo chips; S3, the bamboo chips are extruded and formed by a stick making machine to obtain bamboo sticks; S4, the bamboo stick is placed in a dry distillation reactor, and after thermal decomposition, machine-made charcoal and combustible gas are obtained; S5, the combustible gas is sent into the combustion chamber for combustion to obtain high-temperature gas; S6, using high temperature gas to heat the retort; The retort is an externally heated retort, comprising an outer shell and an inner liner, a heating chamber is provided between the outer shell and the inner liner, and a condensation recovery device is provided above the heating chamber; The inner tank is connected to a combustible gas outlet, and the combustible gas outlet is connected to the combustion chamber through a pipeline; The bottom of the shell is provided with a base, a reaction chamber is provided in the base, a retort jacket is provided above the reaction chamber, a high-temperature gas inlet is provided at one end of the reaction chamber, a flue is provided at the other end of the reaction chamber, and the high-temperature gas inlet is connected to the combustion chamber through a pipeline; A water coil is arranged above the retort jacket, a water coil water inlet is arranged at one end of the water coil, and a water vapor outlet is arranged above the water coil; A heat exchange coil is arranged in the heating chamber, and the heat exchange coil is above the water coil; The heat exchange coil is provided in plurality and arranged in sequence from bottom to top; In step S6, high temperature gas is introduced into the reaction chamber from the high temperature gas inlet, and the heat of the high temperature gas is transferred to the water coil through the retort jacket, heating the water in the water coil into water vapor, and the water vapor heats the inner tank; In step S6, the water vapor exchanges heat with the heat of the heat exchange coil to heat the temperature of the water in the heat exchange coil; In step S6, the temperature of the water vapor gradually decreases from bottom to top, and the temperatures of the plurality of heat exchange coils gradually decrease from bottom to top, thereby obtaining hot water of different temperatures.

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