CN102795902B - Ventilation device applied to composting process - Google Patents

Abstract

The invention discloses a ventilation device applied to a composting process. The ventilation device consists of a hollow circular tube I and a hollow circular tube II, wherein the hollow circular tube I and the hollow circular tube II are in muff coupling with each other; enclosed circular rings are arranged at positions which are one fifth away from the lower end of the hollow circular tube I and three seventh away from the lower end of the hollow circular tube II; and the enclosed circular rings are used for partitioning a space between the hollow circular tube I and the hollow circular tube II into an upper ventilation space and a lower ventilation space. The ventilation device applied to the composting process related to the invention can have natural ventilation, forced ventilation and driven ventilation functions simultaneously, can be widely applied to composting treatment of rural and urban solid waste in China, and has the advantages of free change of the composting ventilation direction, elimination of the phenomenon of non-uniform local temperature generated in a ventilation process, free and convenient arrangement of ventilation positions in composts, control over ventilation uniformity, difficulty in blocking, convenience in flushing, low energy consumption, low needed pressure, uniform oxygen charging inside composts, short decomposition time, small ambient temperature influence and suitability for composting in four seasons.

Description

A kind of ventilation device used in composting process

technical field

The invention relates to the technical field of composting for treating sludge, livestock and poultry breeding waste, urban garbage, kitchen waste, garden waste, etc., and specifically relates to a ventilation device applied to the composting process.

Background technique

Composting is the process of using microorganisms and enzyme activity to accelerate the biodegradation and transformation of organic matter under controlled conditions, and finally make the organic matter decompose and stabilize. The composting process can not only reduce the volume, weight, and odor of organic solid waste, kill pathogenic bacteria, insect eggs, plant seeds, etc., but also produce a large amount of humus. The produced compost products can be used as soil conditioner and plant nutrient source, which can effectively improve soil structure and improve soil fertility. At present, composting technology has been widely used in the treatment of excess sludge, livestock and poultry farming waste, urban waste, kitchen waste, yard waste, etc. There are many parameters affecting the composting process. The main parameters affecting the composting raw materials are: C/N ratio, pH value, moisture content, particle size, organic matter content, C/P ratio, etc. The main control parameters in the composting process are: temperature, oxygen content etc. Aeration can be used to control the temperature and oxygen content of the composting process, so it is considered to be the most important factor in the composting system. Reasonable ventilation can not only improve the quality of composting products, but also save energy consumption. On the contrary, excessive ventilation rate will not only cause excessive ventilation loss, which is not conducive to maintaining the temperature of the compost, but also cause a large amount of nitrogen loss, reducing the composting product. Fertilizer efficiency increases composting energy consumption; but too low ventilation rate will reduce the oxygen concentration in the heap, which will cause local anaerobic (deficiency) oxygen in the heap, resulting in a large amount of odor and greenhouse gases such as NxO and methane, which will affect the surrounding area. The environment brings serious pollution and harm. Obviously, the optimization of compost ventilation system design, operation and management not only contributes to the vigorous promotion and wide application of composting technology, but also contributes to the reduction of greenhouse gas emissions. Ventilation during the composting process plays the role of oxygen supply, moisture removal and heat dissipation.

To sum up, the following main factors need to be considered in choosing the appropriate composting ventilation method: technical and economic conditions, material utilization, transportation and operation costs, equipment maintenance and management, staff training, site, etc. At present, due to the backward economic and technological conditions in rural areas of our country, natural ventilation and turning are mostly used for composting agricultural waste; for composting urban organic solid waste, forced ventilation fermentation bins are mostly used. Therefore, according to my country's national conditions, the composting of agricultural waste can choose the passive ventilation method with less equipment investment and less manual operation cost; considering the area occupied and the composting cycle, the forced ventilation reactor composting system is more suitable for urban organic waste composting .

At present, the existing compost ventilation methods can be divided into: natural ventilation, turning, passive ventilation, forced ventilation, etc. Natural ventilation, turning, and passive ventilation are often used in strip composting systems; forced ventilation is often used in forced ventilation static Heap and most reactor composting systems; natural ventilation mainly relies on the diffusion of air, which diffuses and transmits oxygen from the surface of the pile to the inside of the pile; passive ventilation uses perforated pipes arranged in the pile to promote air in the pile The principle of the transmission in the pile is that due to the temperature difference between the inside and outside of the pile, the outside air is sucked into the pile due to the rise of the heat inside the pile. Passive ventilation does not require turning over the pile and forced ventilation, so the investment and operating costs are greatly reduced; Forced ventilation is the use of fans to blow materials under positive pressure, negative pressure suction, and a combination of the two to exchange gases and promote material transfer and oxygen transfer to microorganisms. However, forced ventilation (positive pressure blowing or negative pressure Air extraction) will cause uneven distribution of temperature, moisture content, etc. during the composting process. For example, for positive pressure forced ventilation, the area near the ventilation pipe has an obvious cooling effect, and it is difficult to achieve the bactericidal effect of the pile in this area. Due to the introduction of dry air, the bottom layer of the heap becomes dry. On the contrary, the upper layer of the heap forms a large amount of condensed water due to the cooling of saturated air, which will affect the composting effect.

Existing "horizontal tube type ^* " ventilation device: refers to the "King"-shaped ventilation tube system buried in the bottom of the compost, and the ventilation holes are distributed on each branch tube, which has high energy consumption and high pressure required, and the compost is filled with air. Oxygen is not uniform, the decomposing time is long, it is greatly affected by the ambient temperature, and it is not suitable for composting in winter.

Contents of the invention

To sum up, the object of the present invention is to provide a ventilation device for composting process.

The purpose of the present invention is achieved by the following technologies:

A ventilation device used in the composting process, which is composed of a hollow circular tube I and a hollow circular tube II, and the hollow circular tube I and the hollow circular tube II are socketed; There is a closed ring at 3/7 of the center; the closed ring separates the space between the hollow tube I and the hollow tube II, and divides it into an upper ventilation space and a lower ventilation space; the two ends of the hollow tube I are open; the hollow The pipe wall of the round pipe II is provided with ventilation holes; the exposed end of the hollow round pipe I is connected to external equipment; the lower end of the hollow round pipe II is conical.

Advantage of the present invention and beneficial effect:

1. The composting process ventilation system involved in the present invention has the functions of natural ventilation, forced ventilation and passive ventilation at the same time, and can be generally applicable to the composting of solid waste in rural areas and cities in my country. ``

2. The invention is easy to use and fast in efficiency. The placement position in the compost can be adjusted by itself, the uniformity of ventilation can be controlled, and it is not easy to be blocked. It works safely and reliably, improves production efficiency, and saves working time.

3. The structure of the present invention is reasonable, and the composting ventilation direction can be changed freely, which can eliminate local temperature unevenness during the ventilation process, eliminate dead angles in the composting, reduce energy consumption, and achieve uniform composting effect at the same time.

4. The present invention is simple in structure, easy to manufacture, low in cost, convenient in maintenance and repair, easy to accept by the market and users, easy to popularize, and has great market potential.

5. The invention has a wide range of uses, and can also be applied in the ventilation process of other industries such as soil pollution restoration.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a schematic diagram of the passive ventilation airflow field of a single device of the present invention.

Fig. 3 is a schematic diagram of the airflow field of the forced ventilation blowing air of a single device of the present invention.

Fig. 4 is a schematic diagram of the airflow field of the forced ventilation and air extraction of a single device of the present invention.

Fig. 5 is a schematic diagram of the airflow field of the forced ventilation blowing air of the single/single, single/multiple, and multiple/multiple devices of the present invention.

Fig. 6 is a schematic diagram of the airflow field of the forced ventilation extraction of the single/single, single/multiple, and multiple/multiple devices of the present invention.

Fig. 7 is a schematic diagram of the combined airflow field of forced ventilation blowing and air extraction of the single/single, single/multiple, and multiple/multiple devices of the invention.

In the figure: 1-Hollow tube Ⅰ 2-Hollow tube Ⅱ 3-Closed ring

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing:

As shown in Figure 1, a ventilation device applied to the composting process is composed of a hollow circular tube I1 and a hollow circular tube II2. The hollow circular tube I1 and the hollow circular tube II2 are socketed; the lower end of the hollow circular tube I1 is 1 /5 and 3/7 of the lower end of the hollow tube Ⅱ2 are provided with a closed ring; the closed ring separates the space between the hollow tube Ⅰ1 and the hollow tube Ⅱ2 and divides it into an upper ventilation space and a lower ventilation space; the hollow Both ends of the round tube I1 are open; the wall of the hollow round tube II2 is provided with air holes; the exposed end of the hollow round tube I1 is connected to external equipment; the lower end of the hollow round tube II2 is conical.

Example 1

natural ventilation

The compost is piled in a rectangular parallelepiped fermentation box (length 50×width 50×height 100cm), when the volume of compost is 0.25m ³ , the total length of the ventilation device is set to 80cm, the diameter of the hollow circular tube Ⅱ2 is 4cm, and the diameter of the hollow circular tube Ⅰ1 is 2cm. A single ventilation device is inserted from the center of the upper section into the compost at a height of 20cm from the bottom. The upper opening is located outside the compost to increase the contact area between the interior of the compost and the outside world. Through air diffusion, oxygen is diffused and transmitted from the surface of the pile to the inside of the pile. .

When the heap size is 0.5m ³ , put the compost in a rectangular parallelepiped fermentation box (length 100×width 50×height 100cm), divide the upper section of the heap into two 0.25m ² areas on average, and separate the two ventilation devices from the above The centers of the two areas are inserted into the compost at a height of 20 cm from the bottom, and the upper opening is located outside the compost.

When the heap size is ^1m3 , put the compost in a cuboid fermentation box (length 100×width 100×height 100cm), insert 4 ventilators evenly into the compost at a height of 20cm from the bottom, and open the upper end outside the heap. Provide natural ventilation.

Example 2

passive ventilation

As shown in Figure 2, the compost is piled in a cuboid fermentation box (length 50×width 50×height 100cm), the total length of the ventilation device is set to 80cm, the diameter of the hollow circular tube II is 4cm, and the diameter of the hollow circular tube I is 2cm. 0.25m ³ , insert a single ventilation device from the center of the upper section into the compost at a height of 20cm from the bottom. The tubes flow to the interior of the compost for passive ventilation.

When the compost size is 0.5m ³ , put the compost in a cuboid fermentation box (length 100×width 50×height 100cm), divide the upper section of the compost into two 0.25m ² areas on average, and separate the two ventilation devices from the above two The center of the area is inserted into the compost at a height of 20 cm from the bottom surface, and the upper opening is located outside the compost.

When the heap size is 1m ³ , put the compost in a cuboid fermentation box (length 100×width 100×height 100cm), insert 4 ventilation devices evenly into the compost at a height of 20cm from the bottom, and open the upper end outside the heap so that the compost Provide passive ventilation.

Example 3

Forced ventilation (single unit)

As shown in Figures 3 and 4, the compost is piled in a cuboid fermentation box (length 50×width 50×height 100cm), the total length of the ventilation device is set to 80cm, the diameter of the hollow circular tube II is 4cm, and the diameter of the hollow circular tube I is 2cm. The volume of the compost is less than 0.25m ³ , and the center of the upper section of the single ventilation device is inserted into the compost at a height of ^20cm from the bottom. m ³ , at this time, the airflow in the compost forms a loop between the lower ventilation space at ventilation device 3/7 - the compost - the upper ventilation space at ventilation device 4/7, and the air extraction and air blowing are performed alternately during the composting process.

Example 4

Forced ventilation (single-single)

When the heap size is 0.25-0.5m ³ , put the compost in a cuboid fermentation box (length 100×width 50×height 100cm), set the total length of the ventilation device to 80cm, the diameter of the hollow circular tube II is 4cm, and the diameter of the hollow circular tube I Divide the upper section of the heap into two ^0.25m2 areas on average, use two ventilation devices to insert into the compost from the center of the above two areas respectively, at a height of 20cm from the bottom surface, according to the difference of the external equipment of the two ventilation devices, The ventilation rate of a single pipe is 0.1m ³ /min. m ³ , carry out the following three operation modes:

As shown in Figure 5, the upper end of the hollow circular tube I1 of the ventilation device a is connected to the blower, and the upper end of the ventilation device b is opened in the air, and the air flow passes through the hollow circular tube I1 of the ventilation device a and enters the lower ventilation space at 3/7 of the ventilation device , and then through the compost material, part of the gas goes upwards, enters the upper ventilation space at ventilation device a4/7 through the hollow circular tube II2 of the ventilation device a, and then enters the outside air; the other part of the gas flows to the ventilation device b, and passes through the ventilation device b. The air hole enters the ventilation device b, and then enters the outside air through the hollow circular tube of the ventilation device b.

As shown in Figure 7, the upper end of the hollow circular tube I1 of the ventilation device a is connected to the blower, the upper end of the hollow circular tube I1 of the ventilation device b is connected to the exhaust fan, and the air flow enters the ventilation device 3/7 through the hollow circular tube I1 of the ventilation device a part of the gas goes upward, and enters the upper ventilation space at ventilation device a4/7 through the hollow circular tube II2 of ventilation device a, and then enters the outside air; the other part of the gas flows to ventilation device b, Enter the lower ventilation space at ventilation device b3/7 through the vent hole on the hollow circular tube II2 of the ventilation device b, and then enter the exhaust fan through the hollow circular tube I1 to discharge.

As shown in Figure 6, the upper end of the hollow circular tube I1 of the ventilation device a is connected to the air extractor, and the upper end of the ventilation device b is opened in the air, and part of the external air enters the ventilation device b through the hollow circular tube of the ventilation device b, and then passes through The compost material enters the lower ventilation space at ventilation device a3/7, and is discharged into the outside air through ventilation device a hollow tube I1; the other part of the outside gas enters ventilation device a4/7 through the upper opening of ventilation device a outer tube II2 The upper ventilation space of the compost flows downward through the compost material, enters the lower ventilation space at the ventilation device a3/7 through the ventilation hole on the hollow circular tube II2 of the ventilation device a, and then enters the exhaust fan through the hollow circular tube I1 to be discharged.

Example 5

Forced ventilation (single-multiple)

When the heap size is 1.0m ³ , put the compost in a cuboid fermentation box (length 100×width 100×height 100cm), the total length of the ventilation device is set to 80cm, the diameter of the hollow circular tube II is 4cm, and the diameter of the hollow circular tube I is 2cm , divide the upper section of the compost body into four 0.25m ² areas on average, insert 4 ventilation devices from the center of each 0.25m ² area to the height of 20cm from the bottom inside the compost, and then insert one in the center of the overall section of the compost body Ventilation device, to the height of 20cm from the bottom inside the compost, according to the different external equipment of the ventilation device, the ventilation rate of a single pipe is 0.1m ³ /min. m ³ , carry out the following four operation modes:

As shown in Figure 5, the upper end of the inner tube I1 of the ventilation device a is connected to the blower, and the upper ends of the hollow circular tubes I1 of the other four ventilation devices b are opened in the air, and the air flow enters the ventilation device through the hollow circular tube I1 of the ventilation device a The lower ventilation space at a3/7 passes through the compost material, part of the gas goes upwards, enters the upper ventilation space at a4/7 of the ventilation device through the hollow circular tube II2 of the ventilation device a, and then enters the outside air; the other part of the gas flows to 4 A ventilation device b enters through the air hole on the hollow tube II2, and then enters the outside air through the hollow tube of the ventilation device b.

As shown in Figure 6, the upper end of the hollow circular tube I1 of the ventilation device a is connected to the air extractor, and the upper ends of the hollow circular tube I1 of the other four ventilation devices b are opened in the air, and a part of the external air passes through the hollow of the four ventilation devices b The round pipe enters the ventilation device b, and then passes through the compost material, enters the lower ventilation space at the ventilation device a3/7, and is discharged into the outside air through the hollow round pipe I1 of the ventilation device a; the other part of the outside air passes through the air pump connected with the air extractor. The upper opening of the hollow circular tube II2 of the ventilation device a enters the upper ventilation space at the ventilation device a4/7, flows downward through the compost material, and enters the lower ventilation space at the ventilation device a3/7 through the ventilation hole of the outer tube II2 of the ventilation device a. Then it enters the exhaust fan through the hollow tube I1 and discharges it.

As shown in Figure 7, connect the upper end nozzle of ventilation device a hollow round tube I1 to the air extractor, and the upper openings of the other four ventilation device b hollow round tubes I1 are respectively connected to an air blower, and the air blower will pass the air flow through the four ventilators. The hollow circular tube I1 of device b blows into the lower ventilation space of ventilation device b3/7, and then the air flows through the compost material directly into the lower ventilation space of ventilation device a3/7, through the hollow circular tube I1 of ventilation device a, Exhausted by exhaust fan. the

As shown in Figure 7, the upper end of the hollow circular tube I1 of the ventilation device a is connected to the air blower, and the upper openings of the four hollow circular tubes I1 of the ventilation device b are respectively connected to an air extractor, and the blower blows the air flow from the ventilation device a The hollow circular tube Ⅰ1 blows into the lower ventilation space at ventilation device a3/7, and then the airflow flows through the compost material and directly enters the lower ventilation space at the other 4 ventilation devices b3/7, and the hollow circular tube Ⅰ1 from these 4 ventilation devices b Exhaust via exhaust fan.

Example 6

Forced ventilation (multi-multi)

When the heap size is 1.0m ³ , put the compost in a cuboid fermentation box (length 100×width 100×height 100cm), set the total length of the ventilation device to 80cm, the diameter of the outer tube is 4cm, and the diameter of the inner tube is 2cm. The upper section is divided into 4 areas of 0.25m ² on average, and 4 ventilation devices are inserted from the center of each 0.25m ² area to the height of 20cm from the bottom inside the compost. According to the different equipment connected to the ventilation device, the ventilation rate of a single pipe is 0.1 m ³ /min． m ³ , carry out the following 3 operation modes:

As shown in Figure 5, the upper ends of the two ventilation devices a, the hollow circular tubes I1, are respectively connected to a blower, and the upper ends of the other two ventilation devices b, the hollow circular tubes I1, are opened in the air, and the air flows through the hollow circles of the ventilation device a respectively. Pipe Ⅰ1 enters the lower ventilation space at ventilation device a3/7, and then passes through the compost material; part of the gas goes upward, and enters the upper ventilation space at ventilation device a4/7 through the hollow round tube II2 of ventilation device a, and then enters the outside air; Another part of the gas flows to the two ventilation devices b, enters into the other two ventilation devices b through the air holes, and then enters the outside air through the hollow circular tubes of the two ventilation devices b.

As shown in Figure 6, the upper end of the hollow circular tube I1 of the ventilation device a is connected to the air extractor, the upper end of the hollow circular tube I1 of the ventilation device b is opened in the air, and a part of the external air enters the ventilation device b through the hollow circular tube of the ventilation device b , and then through the compost material, it enters the lower ventilation space at ventilation device a3/7, and is discharged into the outside air through the hollow tube I1 of ventilation device a; the other part of the outside air enters the ventilation through the upper opening of the hollow tube II2 of ventilation device a The upper ventilation space at 4/7 of the device a, then flows downward through the compost material, and enters the lower ventilation space at the 3/7 part of the ventilation device a through the ventilation hole of the hollow circular tube II2 of the ventilation device a, and then enters the exhaust air through the hollow circular tube Ⅰ1 of the ventilation device a machine discharge.

As shown in Figure 7, connect the upper end nozzles of the hollow circular tubes I1 of the ventilation device a to an air blower, and the upper openings of the hollow circular tubes I1 of the ventilation device b are connected to an air exhauster respectively, and the blower blows the air flow from the ventilation device a The hollow circular tube Ⅰ1 of the ventilation device blows into the lower ventilation space of the ventilation device a3/7, and then the air flows through the compost material and directly enters the lower ventilation space of the ventilation device b3/7, passes through the hollow circular tube Ⅰ1 of the ventilation device b, and passes through the exhaust fan discharge.

The compost in the above examples, according to the weight ratio of ingredients: wheat husk, sludge, return compost = 1:1:1; initial moisture content 55%; initial C/N = 30:1.

Table 1: is the forced ventilation comparison table of existing horizontal tube ventilation device and embodiment 3, 4, 5, 6

Claims (3)

1. be applied to a ventilation plant for composting process, formed by hollow circular-tube I (1) and hollow circular-tube II (2), it is characterized in that: described hollow circular-tube I (1) and hollow circular-tube II (2) socket; 3/7 place of 1/5 place, hollow circular-tube I (1) lower end and hollow circular-tube II (2) lower end is provided with closed circle (3); The both ends open of described hollow circular-tube I (1); The tube wall of hollow circular-tube II (2) is provided with ventilating pit.

2. a kind of ventilation plant that is applied to composting process as claimed in claim 1, it is characterized in that: described closed circle (3), by the space partition between hollow circular-tube I (1) and hollow circular-tube II (2), is divided into overdraught space and leg space ventilation space.

3. a kind of ventilation plant that is applied to composting process as claimed in claim 1 or 2, is characterized in that: the exposed junction of described hollow circular-tube I (1) connects external equipment; The lower end of hollow circular-tube II (2) is coniform.

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