Preparation method of solid waste composite fuel

Abstract

The invention discloses a preparation method of a solid waste composite fuel, which comprises the following steps: step 1, sorting incoming materials: primarily sorting collected solid wastes into an inner core raw material and an outer layer raw material; 2, crushing and drying the raw materials: respectively crushing the inner core raw material and the outer layer raw material, and then respectively heating and drying to evaporate moisture; 3, inner core pressing, wherein the high-calorific-value raw materials are subjected to hot pressing to form inner core fuel; 4, outer layer pressing: wrapping the inner core fuel with the low-calorific-value outer layer raw material, and performing hot pressing to form the composite fuel; 5, steam softening is conducted, and the surface is softened and flattened through steam; according to the invention, the high-calorific-value raw material is crushed and dried to be used as the inner core for hot press molding, and the combustion calorific value and the combustion time of the composite material are ensured by utilizing the characteristics of high calorific value and slow combustion of the high-calorific-value raw material; the characteristics of small particles and fast combustion are utilized to facilitate fast ignition, and firepower of initial combustion is utilized to ignite a high-calorific-value raw material serving as an inner core.

Description

Technical Field

[0001] The invention relates to the technical field of solid waste treatment, and in particular to a method for preparing a solid waste composite fuel. Background Art

[0002] Solid waste composite fuel is a fuel made by treating and processing different types of solid waste. It mainly utilizes various industrial wastes, commercial wastes and some domestic wastes, etc., through certain pre-treatment processes such as crushing, sorting, drying, mixing and other operations, to make them reach certain quality standards, so that they can be used as fuel for energy recovery systems. By converting solid waste into fuel, the pressure on landfills can be reduced. If a large amount of solid waste is directly landfilled, it will occupy land resources and may cause pollution to the soil and groundwater. At the same time, the use of composite fuels to replace some traditional fossil fuels will help reduce the emission of greenhouse gases such as carbon dioxide, and will also have a certain positive effect on mitigating climate change.

[0003] The invention patent with application number 202311700413.6 discloses a composite fuel based on residual solid waste and its preparation method. The combustibles in the residual solid waste generated by the metal recovery production line are used as raw materials to process them into composite fuels suitable for high-temperature heating devices in the thermal power industry. The fuel has a high calorific value, low processing cost, and is easy to produce, thereby realizing the market space for the energy utilization of the residual solid waste. The whole process is simple to operate and has low difficulty.

[0004] However, in the above-mentioned composite fuel based on residual solid waste and its preparation method, combustible solid waste and fine particle mixture are mixed and then hot-pressed, which makes the interior of the composite fuel relatively tight, which is not conducive to the rapid spread of combustion after ignition. In the above-mentioned composite fuel based on residual solid waste and its preparation method, the combustible solid waste is crushed and then directly dried and hot-pressed. Over-drying before pressing can easily cause debris to form on the surface of the composite fuel after hot-pressing, affecting the normal use of the composite material. Therefore, the present invention proposes a preparation method of solid waste composite fuel to solve the problems existing in the prior art. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to propose a method for preparing a solid waste composite fuel, which comprises the following steps: crushing and drying high calorific value raw materials and hot-pressing them as an inner core, utilizing the characteristics of high calorific value and slow combustion to ensure the combustion calorific value and combustion time of the composite material; crushing and drying low calorific value raw materials and hot-pressing them as an outer layer of a composite fuel to wrap an inner core fuel, utilizing the characteristics of small particles and fast combustion to facilitate rapid ignition, and utilizing the firepower of the initial combustion to ignite the high calorific value raw materials as the inner core.

[0006] To achieve the purpose of the present invention, the present invention is implemented by the following technical scheme: a method for preparing solid waste composite fuel, comprising the following steps:

[0007] Step 1: Incoming material sorting: preliminarily sort the collected solid waste to remove obvious non-combustible components, and further classify them according to the type of raw materials into inner core raw materials and outer layer raw materials;

[0008] Step 2: crushing and drying the raw materials, pouring the inner core raw materials and the outer layer raw materials into the crusher for separate crushing, and then heating and drying them to evaporate the water;

[0009] Step 3: Inner core pressing, the high calorific value raw materials are first introduced into the hot press to form the inner core fuel by hot pressing;

[0010] Step 4: Pressing the outer layer, after the inner core is hot-pressed in step 3, pouring low calorific value raw materials into it and hot-pressing it again to form an outer layer of fuel, so that the low calorific value outer layer raw materials wrap the inner core fuel to form a composite fuel;

[0011] Step 5: Steam softening: Use steam to soften the surface of the composite fuel pressed in step 4, so as to soften and smooth the surface while avoiding the increase of moisture inside the composite fuel.

[0012] A further improvement is that the non-combustible components in step one include glass, stone and metal waste, the components of the inner core raw material and their weight ratio are: coal powder 50% to 60%, coke powder 30% to 40%, adhesive 10%, and the outer layer raw material includes wood chips and paper.

[0013] A further improvement is that in the step 2, a ball mill is used to crush the inner core raw material. After the inner core raw material is poured into the ball mill, the ball mill starts to rotate, and the inner core raw material is crushed by the impact and grinding of the falling steel balls. The rotation speed of the ball mill is 15 to 30 r / min, the filling rate of the steel balls in the ball mill is 30% to 40%, and the crushed particle size of the inner core raw material is 75 to 100 μm.

[0014] A further improvement is that: in the step 2, a pulverizer is used to pulverize the outer layer raw material, and the pulverizer starts to rotate after the outer layer raw material is put into the pulverizer, and the blade is used to rotate to cut and pulverize the outer layer raw material.

[0015] A further improvement is that after drying in step 2, the water content of the inner core raw material is 10% to 15%, and the water content of the outer layer raw material is 6% to 10%.

[0016] A further improvement is that the pressure of the hot pressing molding in step three is 10-15 MPa and the temperature of the hot pressing molding is 200°C.

[0017] A further improvement is that the pressure of the hot pressing molding in step 4 is 5-10 MPa and the hot pressing molding temperature is 140°C.

[0018] A further improvement is that the steam temperature in step five is 120-180°C.

[0019] The beneficial effects of the present invention are as follows: the present invention crushes and dries high calorific value raw materials and uses them as the inner core for hot pressing, and utilizes the characteristics of high calorific value and slow combustion to ensure the combustion calorific value and combustion time of the composite material; crushes and dries low calorific value raw materials and uses them as the outer layer of the composite fuel to wrap the inner core fuel for hot pressing, and utilizes the characteristics of small particles and fast combustion to facilitate rapid ignition, and utilizes the firepower of the initial combustion to ignite the high calorific value raw materials used as the inner core. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a process flow chart of the present invention; DETAILED DESCRIPTION

[0021] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0022] The process of preparing composite fuel is a process of resource recycling. The preparation of composite fuel from solid waste can also drive the coordinated development of related industries. It involves multiple links such as waste collection, transportation, pretreatment, fuel production and energy utilization, and can promote cooperation among multiple industries such as environmental protection industry, energy industry and manufacturing industry. From the perspective of overall waste treatment costs, compared with traditional landfill or simple waste treatment methods, preparing composite fuel and recovering energy can reduce costs. Traditional solid waste with low calorific value burns faster and produces less calorific value, which is not conducive to continuous combustion. Traditional solid waste with high calorific value burns slower and requires continuous input of firepower in the early stage for ignition.

[0023] Example 1

[0024] Based on this, according to Figure 1 As shown, this embodiment provides a method for preparing solid waste composite fuel, comprising the following steps:

[0025] Step 1: Incoming material sorting: preliminarily sort the collected solid waste to remove obvious non-combustible components, and further classify them according to the type of raw materials into inner core raw materials and outer layer raw materials;

[0026] Non-combustible components include glass, stone and metal waste, to prevent non-combustible waste from mixing in and affecting the combustion calorific value of the composite fuel. The components and their weight ratios of the inner core raw materials are: coal powder 50%, coke powder 40%, adhesive 10%, and the outer layer raw materials include wood chips and paper.

[0027] Step 2: crushing and drying the raw materials, pouring the inner core raw materials and the outer layer raw materials into the crusher for separate crushing, and then heating and drying them to evaporate the water;

[0028] The inner core raw material is crushed by a ball mill. After the inner core raw material is poured into the ball mill, the ball mill is started to rotate, and the inner core raw material is crushed by the impact and grinding of the falling steel balls. The speed of the ball mill is 15r / min, the filling rate of the steel balls in the ball mill is 30%, and the particle size of the inner core raw material is 100μm;

[0029] The outer layer raw materials are crushed by a crusher. After the outer layer raw materials are put into the crusher, the crusher starts to rotate and the outer layer raw materials are cut and crushed by the rotation of the blade.

[0030] Step 3: Inner core pressing, the high calorific value raw materials are first introduced into the hot press to form the inner core fuel by hot pressing;

[0031] After drying, the moisture content of the inner core raw material is 15%, the moisture content of the outer layer raw material is 10%, the hot pressing pressure is 10MPa, and the hot pressing temperature is 200°C. The high calorific value raw material is hot pressed as the inner core, and its compact structure and slow burning speed are utilized to achieve continuous and stable heat release and extend the burning time.

[0032] Step 4: Pressing the outer layer, after the inner core is hot-pressed in step 3, pouring the low calorific value raw material into the outer layer fuel and hot-pressing it again to form the outer layer fuel, so that the low calorific value outer layer raw material wraps the inner core fuel to form a composite fuel;

[0033] The hot pressing pressure is 5MPa, and the hot pressing temperature is 140℃. The low calorific value raw material is wrapped around the inner core and then hot pressed to form the outer layer of the composite fuel. The small particles and fast combustion speed make it convenient for the composite to be ignited quickly, and the outer layer is burned to ignite the high calorific value raw material of the inner core, so that the low calorific value raw material can be fully utilized.

[0034] Step 5: Steam softening: Use steam to soften the surface of the composite fuel pressed in step 4, so as to prevent the internal moisture of the composite fuel from increasing and soften the surface to make it smooth, and prevent the surface of the composite fuel from being too dry and causing debris to fall off.

[0035] The steam temperature is 120°C during steam softening.

[0036] Example 2

[0037] Based on this, according to Figure 1 As shown, this embodiment provides a method for preparing solid waste composite fuel, comprising the following steps:

[0038] Step 1: Incoming material sorting: preliminarily sort the collected solid waste to remove obvious non-combustible components, and further classify them according to the type of raw materials into inner core raw materials and outer layer raw materials;

[0039] Non-combustible components include glass, stone and metal waste, to prevent non-combustible waste from mixing in and affecting the combustion calorific value of the composite fuel. The components and their weight ratios of the inner core raw materials are: coal powder 55%, coke powder 35%, adhesive 10%, and the outer layer raw materials include wood chips and paper.

[0040] Step 2: crushing and drying the raw materials, pouring the inner core raw materials and the outer layer raw materials into the crusher for separate crushing, and then heating and drying them to evaporate the water;

[0041] The inner core raw material is crushed by a ball mill. After the inner core raw material is poured into the ball mill, the ball mill is started to rotate, and the inner core raw material is crushed by the impact and grinding of the falling steel balls. The speed of the ball mill is 20r / min, the filling rate of the steel balls in the ball mill is 35%, and the particle size of the inner core raw material is 80μm;

[0042] The outer layer raw materials are crushed by a crusher. After the outer layer raw materials are put into the crusher, the crusher starts to rotate and the outer layer raw materials are cut and crushed by the rotation of the blade.

[0043] Step 3: Inner core pressing, the high calorific value raw materials are first introduced into the hot press to form the inner core fuel by hot pressing;

[0044] After drying, the moisture content of the inner core raw material is 13%, and the moisture content of the outer layer raw material is 8%. The hot pressing pressure is 13MPa, and the hot pressing temperature is 200°C. The high calorific value raw material is hot pressed as the inner core, and its compact structure and slow combustion speed are utilized to achieve continuous and stable heat release and extend the burning time.

[0045] Step 4: Pressing the outer layer, after the inner core is hot-pressed in step 3, pouring low calorific value raw materials into it and hot-pressing it again to form an outer layer of fuel, so that the low calorific value outer layer raw materials wrap the inner core fuel to form a composite fuel;

[0046] The hot pressing pressure is 8MPa, and the hot pressing temperature is 140℃. The low calorific value raw material is wrapped around the inner core and then hot pressed to form the outer layer of the composite fuel. The small particles and fast combustion speed make it convenient for the composite to be ignited quickly, and the outer layer is burned to ignite the high calorific value raw material of the inner core, so that the low calorific value raw material can be fully utilized.

[0047] Step 5: Steam softening: Use steam to soften the surface of the composite fuel pressed in step 4, so as to prevent the internal moisture of the composite fuel from increasing and soften the surface to make it smooth, and prevent the surface of the composite fuel from being too dry and causing debris to fall off.

[0048] The steam temperature is 150°C during steam softening.

[0049] Example 3

[0050] Based on this, according to Figure 1 As shown, this embodiment provides a method for preparing solid waste composite fuel, comprising the following steps:

[0051] Step 1: Incoming material sorting: preliminarily sort the collected solid waste to remove obvious non-combustible components, and further classify them according to the type of raw materials into inner core raw materials and outer layer raw materials;

[0052] Non-combustible components include glass, stone and metal waste, to prevent non-combustible waste from mixing in and affecting the combustion calorific value of the composite fuel. The components and their weight ratios of the inner core raw materials are: coal powder 60%, coke powder 40%, adhesive 10%, and the outer layer raw materials include wood chips and paper.

[0053] Step 2: crushing and drying the raw materials, pouring the inner core raw materials and the outer layer raw materials into the crusher for separate crushing, and then heating and drying them to evaporate the water;

[0054] The inner core raw material is crushed by a ball mill. After the inner core raw material is poured into the ball mill, the ball mill is started to rotate, and the inner core raw material is crushed by the impact and grinding of the falling steel balls. The speed of the ball mill is 30r / min, the filling rate of the steel balls in the ball mill is 40%, and the particle size of the inner core raw material is 75μm;

[0055] The outer layer raw materials are crushed by a crusher. After the outer layer raw materials are put into the crusher, the crusher starts to rotate and the outer layer raw materials are cut and crushed by the rotation of the blade.

[0056] Step 3: Inner core pressing, the high calorific value raw materials are first introduced into the hot press to form the inner core fuel by hot pressing;

[0057] After drying, the moisture content of the inner core raw material is 10%, and the moisture content of the outer layer raw material is 6% to 10%. The pressure of hot pressing is 15MPa, and the temperature of hot pressing is 200°C. The high calorific value raw material is hot pressed as the inner core, and its compact structure and slow burning speed are utilized to realize continuous and stable heat release and extend the burning time.

[0058] Step 4: Pressing the outer layer, after the inner core is hot-pressed in step 3, pouring the low calorific value raw material into the outer layer fuel and hot-pressing it again to form the outer layer fuel, so that the low calorific value outer layer raw material wraps the inner core fuel to form a composite fuel;

[0059] The hot pressing pressure is 10MPa, and the hot pressing temperature is 140℃. The low calorific value raw material is wrapped around the inner core and then hot pressed to form the outer layer of the composite fuel. The small particles and fast combustion speed make it convenient for the composite to be ignited quickly, and the outer layer is burned to ignite the high calorific value raw material of the inner core, so that the low calorific value raw material can be fully utilized.

[0060] Step 5: Steam softening: Use steam to soften the surface of the composite fuel pressed in step 4, so as to prevent the internal moisture of the composite fuel from increasing and soften the surface to make it smooth, and prevent the surface of the composite fuel from being too dry and causing debris to fall off.

[0061] The steam temperature is 180°C during steam softening.

[0062] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing solid waste composite fuel, characterized in that The following steps are involved: Step 1: Incoming material sorting: preliminarily sort the collected solid waste to remove obvious non-combustible components, and further classify them according to the type of raw materials into inner core raw materials and outer layer raw materials; Step 2: crushing and drying the raw materials, pouring the inner core raw materials and the outer layer raw materials into the crusher for separate crushing, and then heating and drying them to evaporate the water; Step 3: Inner core pressing, the high calorific value raw materials are first introduced into the hot press to form the inner core fuel by hot pressing; Step 4: Pressing the outer layer, after the inner core is hot-pressed in step 3, pouring the low calorific value raw material into the outer layer fuel and hot-pressing it again to form the outer layer fuel, so that the low calorific value outer layer raw material wraps the inner core fuel to form a composite fuel; Step 5: Steam softening: Use steam to soften the surface of the composite fuel pressed in step 4, so as to soften and smooth the surface while avoiding the increase of moisture inside the composite fuel.

2. The method for preparing a solid waste composite fuel according to claim 1, characterized in that: The non-combustible components in step one include glass, stone and metal waste. The components and their weight ratios of the inner core raw materials are: 50% to 60% coal powder, 30% to 40% coke powder, and 10% adhesive. The outer layer raw materials include wood chips and paper.

3. The method for preparing a solid waste composite fuel according to claim 1, characterized in that: In the step 2, a ball mill is used to crush the inner core raw material. After the inner core raw material is poured into the ball mill, it starts to rotate, and the inner core raw material is crushed by the impact and grinding of the falling steel balls. The rotation speed of the ball mill is 15 to 30 r / min, the filling rate of the steel balls in the ball mill is 30% to 40%, and the crushed particle size of the inner core raw material is 75 to 100 μm.

4. The method for preparing a solid waste composite fuel according to claim 1, characterized in that: In the step 2, a pulverizer is used to pulverize the outer layer raw material. After the outer layer raw material is put into the pulverizer, it starts to rotate and the blade is used to rotate to cut and pulverize the outer layer raw material.

5. The method for preparing a solid waste composite fuel according to claim 1, characterized in that: After drying in step 2, the water content of the inner core raw material is 10% to 15%, and the water content of the outer layer raw material is 6% to 10%.

6. The method for preparing a solid waste composite fuel according to claim 1, characterized in that: The pressure of the hot pressing molding in the step 3 is 10-15 MPa, and the temperature of the hot pressing molding is 200°C.

7. The method for preparing a solid waste composite fuel according to claim 1, characterized in that: The pressure of the hot pressing molding in the step 4 is 5-10 MPa, and the hot pressing molding temperature is 140°C.

8. The method for preparing a solid waste composite fuel according to claim 1, characterized in that: The steam temperature in step 5 is 120-180°C.

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