A negative pressure gasification furnace capable of pre-drying materials

Abstract

The present invention discloses a negative pressure gasification furnace capable of pre-drying materials, comprising a furnace body, a feeding assembly, a feeding assembly, a water collecting assembly, a gas circulation assembly and an air entrainment assembly; the feeding assembly comprises a first shell having a feeding chamber, and a material guiding mechanism arranged in the feeding chamber; the water collecting assembly comprises a second shell having a gas collecting chamber and a water collecting chamber, one end of the feeding chamber is located outside the gas collecting chamber, and the other end passes through the gas collecting chamber and is connected with the furnace chamber; the first shell is provided with a connecting port connected with the gas collecting chamber, and a drainage channel connected with the water collecting chamber; the gas circulation assembly comprises an air guide pipe, one end of the air guide pipe is connected with the gas collecting chamber, and the other end is connected with the furnace chamber, and a gas circulation mechanism is arranged on the air guide pipe; the gas circulation mechanism is used to draw hot flue gas in the furnace chamber to the feeding chamber, and heat exchange is performed with the material to achieve pre-drying of the material; the air entrainment mechanism forms a negative pressure in the furnace chamber, effectively preventing dust and harmful odorous gases in the furnace chamber from leaking out, thereby improving the safety performance of the gasification operation.

Description

Technical Field

[0001] The invention relates to the technical field of gasifier equipment, in particular to a negative pressure gasifier capable of pre-drying materials. Background Art

[0002] Small gasifiers can convert garbage or biomass into fuel gas for combustion on site, avoiding large-scale centralized transportation of garbage or biomass, and are very suitable for small-scale centralized treatment of widely distributed garbage and biomass and their thermal energy utilization. In particular, they can avoid the accumulation of dioxins around the treatment furnace due to centralized treatment of large amounts of garbage, causing irreparable permanent pollution.

[0003] Small-scale gasifiers currently use fixed furnace bottoms, which have the advantages of low investment and simple structure. However, fixed furnace bottom gasifiers generally have the following problems: slagging makes it difficult to discharge slag, uneven distribution of incoming materials makes it easy to burn suspended materials and cause unstable furnace conditions, and burning through interrupts gasification, which limits the size of the furnace and prevents stable and continuous operation.

[0004] Whether the gasifier is processing biomass or garbage, the moisture content of the input material is a basic factor that determines whether the gasification process can be stable and continuous and the calorific value of the gas produced.

[0005] Using conventional methods, biomass dehumidification and drying requires space and costs, while garbage cannot be dried by sun drying or baking. Pressing will also cause pollution and cost. Dehumidification and drying of the materials entering the furnace is a major problem for gasification. This is also the reason why the garbage currently used for incineration for power generation is mixed with coal even though it has been drained for about a week.

[0006] Although the existing upward air-intake gasifier has a natural heat exchange process between the flue gas and the incoming materials, which almost does not incur any cost, all the water enters the gas production in the form of steam, reducing the calorific value of the gas production by about 40%, and further reducing the temperature of the subsequent combustion flame. Due to the high gas production temperature of the existing downward air-intake gasifier, all the water also exists in the gas production in the form of steam, which takes away a lot of physical heat, making the gasification process difficult to continue, and high calorific value fuels such as coal or oil need to be added to assist combustion. Summary of the invention

[0007] In view of one or more deficiencies in the above-mentioned prior art, the present invention provides a negative pressure gasification furnace capable of pre-drying materials, which utilizes a gas circulation mechanism to enable heat exchange between the hot flue gas in the furnace chamber and the material in the feeding chamber, thereby achieving pre-drying of the material, making the gasification process of the material stable and continuous, and improving the calorific value of the gas production.

[0008] To achieve the above-mentioned purpose, the present invention provides a negative pressure gasification furnace capable of pre-drying materials, comprising a furnace body, a material feeding assembly, a water collecting assembly, and a gas circulation assembly, wherein the material feeding assembly is used to feed materials, and the furnace body is used to perform combustion and gasification treatment on the materials;

[0009] The feeding assembly comprises a first shell having a feeding cavity and a material guiding mechanism arranged in the feeding cavity, wherein the feeding cavity is located at the lower side of the feeding assembly for receiving materials;

[0010] The water collecting assembly comprises a second shell having an air collecting chamber and a water collecting chamber, one end of the feeding chamber is located outside the air collecting chamber, and the other end passes through the air collecting chamber and communicates with the furnace chamber in the furnace body, so as to introduce the material into the furnace body after passing through the air collecting chamber, and separate the air collecting chamber and the water collecting chamber;

[0011] The upper wall surface of the first shell is provided with a communication port communicating with the air collecting chamber, and the lower wall surface of the first shell is provided with a drainage channel communicating with the water collecting chamber;

[0012] The gas circulation component includes an air duct, one end of which is connected to the gas collecting chamber, and the other end is connected to the material oxidation layer in the furnace body. The air duct is provided with a gas circulation mechanism for drawing the hot flue gas in the furnace chamber to the feeding chamber, pre-drying the material during the heat exchange process between the flue gas and the material, and sending the low-temperature flue gas after the heat exchange back to the material oxidation layer in the furnace body.

[0013] In one of the embodiments, an air bleed assembly is further included, wherein the air bleed assembly includes an air bleed pipe, one end of which is connected to the furnace cavity in the furnace body, and the air bleed pipe is provided with an air bleed mechanism for extracting the gas generated by the gasification furnace out of the furnace cavity and generating negative pressure in the furnace cavity.

[0014] In one embodiment, the material discharge assembly includes a loading pipe having a loading channel, and a third shell having a material discharge channel;

[0015] The top of the loading pipe is provided with a discharge port connected to the loading channel for feeding materials; the bottom end of the loading pipe is connected to the third shell so that the materials fall from the loading channel into the discharge channel;

[0016] The material discharge channel is connected with the gas collecting chamber, and the connecting position between the material discharge channel and the gas collecting chamber is located above the connecting port. A material guiding mechanism is provided in the material discharge channel to feed the material into the gas collecting chamber, so that the material falls into the material supply chamber from the connecting port.

[0017] In one of the embodiments, the air duct is further provided with a filtering device for filtering the gas drawn into the air duct; the filtering device is located on the air duct pipeline between the gas circulation mechanism and the water collecting chamber.

[0018] In one of the embodiments, the water collection assembly further includes a water receiving box with a top opening, and a water outlet communicating with the water collection chamber is provided at the bottom of the second shell, and the water outlet is located directly above the opening of the water receiving box.

[0019] In one embodiment, the gas circulation mechanism is a circulation fan.

[0020] In one embodiment, the material guiding mechanism is a shaftless screw conveyor.

[0021] The present invention provides a negative pressure gasification furnace capable of pre-drying materials. The gas circulation mechanism is used to draw the hot flue gas in the furnace cavity to the feeding cavity so as to perform heat exchange with the materials. The materials can be pre-dried during the heat exchange process, and the heat energy of the hot flue gas can be returned to the furnace body during the heat exchange process. This not only makes the gasification process more continuous, but also eliminates the need to add high calorific value fuels such as coal or oil to assist combustion. At the same time, the air entrainment mechanism forms a negative pressure in the furnace cavity, which can also effectively prevent dust and harmful odorous gases in the furnace cavity from leaking out, thereby improving the safety performance of the gasification operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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 the structures shown in these drawings without paying creative work.

[0023] Figure 1 Schematic diagram of the structure of a negative pressure gasifier capable of pre-drying materials in an embodiment of the present invention.

[0024] Figure numbers: furnace body 1, furnace cavity 11, grate mechanism 12, air inlet 13, first shell 21, loading cavity 22, material guiding mechanism 23, connecting port 24, drainage channel 25, second shell 31, water collecting cavity 32, water outlet 33, water receiving box 34, air collecting cavity 35, air guide pipe 41, gas circulation mechanism 42, filtering device 43, air duct 51, air duct mechanism 52, loading pipe 61, loading channel 62, third shell 63, unloading channel 64, material guiding mechanism 65.

[0025] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0028] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0031] like Figure 1 The negative pressure gasification furnace disclosed in this embodiment is capable of pre-drying materials, which specifically includes a furnace body 1, a material discharge assembly, a material loading assembly, a water collection assembly, and a gas circulation assembly. The material discharge assembly is used to feed materials, and the furnace body 1 is used to perform combustion and gasification treatment on the materials.

[0032] In this embodiment, the feeding assembly includes a first shell 21 having a feeding cavity 22, and a material guiding mechanism 23 arranged in the feeding cavity 22. The feeding cavity 22 is located at the lower side of the feeding assembly to receive the material transported by the feeding assembly. The water collecting assembly includes a second shell 31 having a water collecting cavity 32 and an air collecting cavity 35. One end of the feeding cavity 22 is located outside the air collecting cavity 35, and the other end passes through the air collecting cavity 35 and communicates with the furnace cavity 11 in the furnace body 1, so as to guide the material in the feeding cavity 22 into the furnace body 1 after passing through the air collecting cavity 35. The upper wall surface of the first shell 21 is provided with a connecting port 24 communicating with the air collecting cavity 35, and the lower wall surface of the first shell 21 is provided with a drainage channel 25 communicating with the water collecting cavity 32. The gas circulation assembly includes an air guide pipe 41, one end of which is connected to the gas collecting chamber 35, and the other end is connected to the material oxidation layer in the furnace body 1. The air guide pipe 41 is provided with a gas circulation mechanism 42, which is used to draw the hot flue gas in the furnace chamber 11 to the feeding chamber 22, and send the remaining gas and the gasification agent back to the material oxidation layer after the hot flue gas and the material are heat exchanged, and the material is pre-dried during the heat exchange process between the flue gas and the material, and the liquid generated by the pre-drying is introduced into the bottom of the water collecting chamber 32 through the drainage channel 25. Among them, the gas circulation mechanism 42 in this embodiment adopts a circulation fan.

[0033] In this embodiment, the first shell 21 includes a first shell wall, a second shell wall, a third shell wall, a fourth shell wall and a fifth shell wall which are connected in sequence, wherein the first shell wall is connected between the second shell wall and the furnace body, and the driving component of the material guiding mechanism 23 is arranged on the fifth shell wall. Preferably, the second shell wall and the fourth shell wall are arranged on the outer wall of the second shell 31 and are integrally formed with the second shell 31, the third shell wall is arranged inside the second shell 31 and divides the internal space of the second shell 31 into a water collecting chamber 32 and an air collecting chamber 35, and the drainage channel 25 is located on the third shell wall.

[0034] Further preferably, the feeding chamber 22 in this embodiment is a structure that is inclined downward from the furnace chamber 11 to the water collecting chamber 32, that is, the position of the feeding chamber 22 connected to the furnace chamber 11 is located at the highest point of the feeding chamber 22, and the height of the remaining part gradually decreases, and the length of the feeding chamber 22 is 3 to 8 meters; and the material guiding mechanism 23 correspondingly adopts a shaftless screw conveyor. This structure can effectively enrich the liquid generated during the heat exchange between the flue gas and the material under the action of gravity and flow it to the drainage channel 25 area, avoiding backflow to the furnace chamber 11, thereby achieving pre-drying.

[0035] Further preferably, the air duct 41 is further provided with a filter device 43 for filtering the gas drawn into the air duct 41; the filter device 43 is located on the air duct 41 between the gas circulation mechanism 42 and the water collecting chamber 32 to prevent dust and mucus in the air flow from clogging the gas circulation mechanism 42. The filter device 43 in this embodiment is an air filter.

[0036] Further preferably, the water collecting assembly in this embodiment also includes a water collecting box 34 with a top opening, and a water outlet 33 connected to the water collecting chamber 32 is provided at the bottom of the second shell 31. The water outlet 33 is located directly above the opening of the water collecting box 34 to receive the liquid flowing out of the water collecting chamber 32, thereby avoiding pollution.

[0037] Further preferably, the negative pressure gasification furnace disclosed in this embodiment also includes an air bleed assembly, which includes an air bleed pipe 51 connected to the furnace chamber 11, and an air bleed mechanism 52 is provided on the air bleed pipe 51 to extract the gas produced in the furnace chamber 11. The air bleed mechanism 52 adopts an induced draft fan. Of course, the air bleed mechanism 52 in this embodiment is not limited to an induced draft fan, and other induced draft equipment with the same function can also be used. The air bleed mechanism 52 is used to form a negative pressure in the furnace body 1, which can effectively prevent the dust and harmful odorous gases in the furnace chamber from leaking out, and improve the safety performance of the gasification operation.

[0038] In this embodiment, the unloading assembly includes a loading tube 61 having a loading channel 62, and a third shell 63 having a unloading channel 64; wherein, a unloading port connected to the loading channel 62 is provided at the top of the loading tube 61 for feeding materials; the bottom end of the loading tube 61 is connected to the third shell 63, so that the material falls from the loading channel 62 into the unloading channel 64; the unloading channel 64 is connected to the gas collecting chamber 35, and the connecting position between the unloading channel 64 and the gas collecting chamber 35 is located above the connecting port 24, and a material guiding mechanism 65 is provided in the unloading channel 64 for feeding the material and the gasifying agent into the gas collecting chamber 35, so that the material falls from the connecting port 24 into the loading chamber 22, wherein the material guiding mechanism 65 adopts a shaftless screw conveyor. It should be noted that the loading assembly in this embodiment may also not be provided with the third shell 63, but the discharge pipe 61 may be directly connected to the second shell 31, so that the material falls directly into the material guide cavity 22 from the discharge channel 62, and falls into the furnace cavity 11 driven by the material guide mechanism 23.

[0039] The working process of the negative pressure gasifier capable of pre-drying materials in this embodiment is as follows:

[0040] The crushed material enters the discharge channel 64 in the third shell 63 from the top opening of the charging pipe 61, enters the gas collecting chamber 35 driven by the downward shaftless screw conveyor, and falls into the guide chamber 22, and is then lifted by the upward shaftless screw conveyor and sent into the furnace chamber 11 from the furnace wall of the furnace body 1. The gasified slag falls through the grate mechanism 12.

[0041] The gasifying agent or air with an oxygen content equivalent to that of air enters the material oxidation layer from the air inlet 13 to gasify the material, and the air entraining mechanism 52 leads the produced gas out through the air entraining pipe 51.

[0042] In the above process, the hot flue gas enters the feeding chamber 22 from the furnace chamber 11 through the work of the circulating fan, and flows against the material to the gas collecting chamber 35. In the process of flowing against the material, the flue gas continuously transfers heat to the material, evaporates its free water and structured water and other liquids, and realizes the drying of the material. The evaporated water vapor continues to flow against the material with the flue gas. As the heat exchange proceeds, the temperature of the flue gas gradually decreases, and the water vapor contained in it condenses into water again, and releases the heat of vaporization to heat the material. The condensed water flows down along the second shell 31, flows to the water collecting chamber 32 through the drainage channel 25, and enters the water receiving box 34. After the flue gas heat exchange, it passes through the gas collecting chamber 35 and the air filter, and is sent to the material oxidation layer in the furnace body 1 by the gas circulation fan along the air duct 41 for reheating and enters the next cycle.

[0043] When the above working process operates normally, the air volume of the gas circulation fan is 2-5 times that of the gasifier, and it has three main functions: first, it provides sufficient heat for material drying; second, it fully decomposes toxic and odorous gases when flowing through the high-temperature zone for multiple times; third, it increases the thickness of the oxidation layer and reduction layer of the material in the furnace body 1, thereby improving the gasification processing capacity.

[0044] By adopting the negative pressure gasification furnace capable of pre-drying materials disclosed in this embodiment, not only can the gasification process be made more continuous without the need to add additional high calorific value fuels such as coal or oil to assist combustion, but it can also effectively prevent the leakage of dust and harmful odorous gases in the furnace chamber 11, thereby improving the safety performance of the gasification operation.

[0045] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A negative pressure gasifier capable of pre-drying materials, characterized in that: It includes a furnace body, a material feeding component, a material feeding component, a water collecting component, and a gas circulation component, wherein the material feeding component is used to feed materials, and the furnace body is used to perform combustion and gasification treatment on the materials; The feeding assembly comprises a first shell having a feeding cavity and a material guiding mechanism arranged in the feeding cavity, wherein the feeding cavity is located at the lower side of the feeding assembly for receiving materials; The water collecting assembly comprises a second shell having an air collecting chamber and a water collecting chamber, one end of the feeding chamber is located outside the air collecting chamber, and the other end passes through the air collecting chamber and communicates with the furnace chamber in the furnace body, so as to introduce the material into the furnace body after passing through the air collecting chamber, and separate the air collecting chamber and the water collecting chamber; The upper wall surface of the first shell is provided with a communication port communicating with the air collecting chamber, and the lower wall surface of the first shell is provided with a drainage channel communicating with the water collecting chamber; The gas circulation component includes an air duct, one end of which is connected to the gas collecting chamber, and the other end is connected to the material oxidation layer in the furnace body. The air duct is provided with a gas circulation mechanism for drawing the hot flue gas in the furnace chamber to the feeding chamber, pre-drying the material during the heat exchange process between the flue gas and the material, and sending the low-temperature flue gas after the heat exchange back to the material oxidation layer in the furnace body.

2. The negative pressure gasification furnace capable of pre-drying materials according to claim 1, characterized in that: It also includes an air bleed component, which includes an air bleed pipe, one end of which is connected to the furnace cavity in the furnace body, and an air bleed mechanism is provided on the air bleed pipe to extract the gas generated by the gasification furnace out of the furnace cavity and generate negative pressure in the furnace cavity.

3. The negative pressure gasification furnace capable of pre-drying materials according to claim 1 or 2, characterized in that: The material discharge assembly comprises a loading pipe having a loading channel, and a third shell having a material discharge channel; The top of the loading pipe is provided with a discharge port connected to the loading channel for feeding materials; the bottom end of the loading pipe is connected to the third shell so that the materials fall from the loading channel into the discharge channel; The material discharge channel is connected with the gas collecting chamber, and the connecting position between the material discharge channel and the gas collecting chamber is located above the connecting port. A material guiding mechanism is provided in the material discharge channel to feed the material into the gas collecting chamber, so that the material falls into the material supply chamber from the connecting port.

4. The negative pressure gasifier capable of pre-drying materials according to claim 1 or 2, characterized in that: The air duct is also provided with a filtering device for filtering the gas drawn into the air duct; the filtering device is located on the air duct pipeline between the gas circulation mechanism and the water collecting chamber.

5. The negative pressure gasifier capable of pre-drying materials according to claim 1 or 2, characterized in that: The water collection assembly also includes a water receiving box with an opening at the top, and a water outlet communicating with the water collection chamber is provided at the bottom of the second shell, and the water outlet is located directly above the opening of the water receiving box.

6. The negative pressure gasifier capable of pre-drying materials according to claim 1 or 2, characterized in that: The gas circulation mechanism is a circulation fan.

7. The negative pressure gasifier capable of pre-drying materials according to claim 1 or 2, characterized in that: The material guiding mechanism is a shaftless screw conveyor.

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