Closed drying and fresh air fermentation combined type cow dung treatment system

Abstract

The invention discloses a closed drying and fresh air fermentation combined type cow dung treatment system, the cow dung treatment system comprises cow dung drying equipment and cow dung fermentation equipment, the cow dung drying equipment dries cow dung through hot air drying, and wet and hot air in the cow dung drying equipment circulates through a closed drying system; the closed drying system comprises a dust removal device, a heat exchange device and a heat pump device; the heat exchange device is further connected with a fresh air circulation system. The fresh air circulation system comprises a fresh air supply device, a return air adjusting device and an exhaust air adjusting device. The cow dung fermentation equipment is used for fermenting cow dung by using the fresh air treated by the fresh air circulation system. According to the cow dung treatment system, energy of all parts is fully utilized, and energy input and consumption are reduced to the maximum extent. The cow dung treated by the system is used as bedding for the cow in bed, so that the mastitis morbidity of the cow can be effectively reduced, and the milk yield of the cow is improved.

Description

Technical Field

[0001] The invention relates to a closed drying and fresh air fermentation composite cow dung treatment system, belonging to the field of livestock dung recycling. Background Art

[0002] In today's large-scale dairy farming, the discharge of cow dung is increasing, which has brought great negative impacts on the ecological environment and human health. If cow dung can be reused, this problem can be alleviated. At present, there are three main directions for the reuse of cattle dung, namely biogas raw materials, organic fertilizers and cow bedding. However, to be used as bedding for cattle, the cow dung needs to be dried. The existing drying process still has the following problems. For example, patent application CN201710402253.5 discloses a process for drying cow dung for cow bedding. It uses combustion to dry cow dung, which consumes a lot of fuel. There are waste gas emissions during the combustion process and the drying process of cow dung; patent application CN202120445878.1 discloses a device suitable for drying cow dung, which fails to recycle air and consumes a lot of energy. Therefore, it is urgent to develop a system with low energy consumption and large-scale drying of cow dung. Summary of the invention

[0003] Purpose of the invention: The purpose of the invention is to provide a closed drying and fresh air fermentation composite cow dung treatment system.

[0004] Technical solution: The closed drying and fresh air fermentation composite cow dung treatment system of the present invention comprises cow dung drying equipment and cow dung fermentation equipment.

[0005] The cow dung drying equipment dries the cow dung by hot air drying, and the hot and humid air therein is circulated through a closed drying system;

[0006] The closed drying system includes a dust removal device, a heat exchange device and a heat pump device;

[0007] The heat exchange device is also connected to a fresh air circulation system, which includes a fresh air supply device, a return air regulating device and an exhaust air regulating device;

[0008] The cow dung fermentation equipment utilizes the fresh air processed by the fresh air circulation system to ferment the cow dung.

[0009] Furthermore, the circulation route of the hot and humid air in the cow dung drying equipment is: first enter the dust removal device for dust removal, then enter the heat exchange device for heat exchange with the fresh air delivered from the fresh air supply device, and enter the heat pump device after cooling and dehydration, and become dry hot air after dehydration and heating, and then enter the cow dung drying equipment again.

[0010] Furthermore, the air temperature after cooling is 40-80° C., and the relative humidity is 100%-80%.

[0011] Furthermore, the air temperature after dehydration and heating is 70-100° C., and the relative humidity is 10%-1%.

[0012] Furthermore, the air flow route in the fresh air circulation system is: fresh air is transported into the heat exchange device through the fresh air supply device, and after the fresh air completes heat exchange with the humid and hot air after dust removal, part of it enters the cow dung fermentation equipment, part of it is discharged through the exhaust regulating device, and part of it returns to the fresh air supply device through the return air regulating device.

[0013] The present invention also provides a method for using the above system, comprising the following steps:

[0014] (1) pre-treating the cow dung, wherein the moisture content of the pre-treated cow dung is 55% to 65%;

[0015] (2) putting the cow dung into the cow dung drying equipment 1 for drying, and after the moisture content is lower than 48%, entering the cow dung fermentation equipment 8;

[0016] (3) The cow dung is subjected to fresh air fermentation treatment for 5 to 7 days to obtain qualified cow dung.

[0017] Furthermore, the pretreatment of the cow dung in step (1) includes removing impurities and water from the cow dung.

[0018] Furthermore, the specific steps of pre-treatment of cow dung are: removing impurities and other waste materials from cow dung with an initial solid content of 5% to 10%, filtering the cow dung mixture, retaining the solid materials in the cow dung, and finally squeezing and dehydrating the solid materials.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following outstanding advantages: The present invention discloses a cow dung treatment system, which uses closed drying to dry air and cow dung, and then ferments the cow dung with fresh air, making full use of the energy of each part, reducing energy input and consumption to the maximum extent, and no harmful gas emissions. The moisture content of the cow dung treated by the system is below 45%, and the content of harmful bacteria such as Escherichia coli is below 100MPN / g. The use of cow dung as bedding can effectively reduce the incidence of mastitis in dairy cows and increase the milk production of dairy cows. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a system schematic diagram of the present invention. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0022] Example 1

[0023] The present invention comprises a cow dung drying device 1 and a cow dung fermentation device 8.

[0024] The cow dung drying equipment 1 dries the cow dung by hot air drying, and the hot and humid air therein circulates through a closed drying system;

[0025] The closed drying system includes a dust removal device 2, a heat exchange device 3 and a heat pump device 4;

[0026] The hot and humid air in the cow dung drying equipment 1 first enters the dust removal device 2 for dust removal, and then enters the heat exchange device 3 to exchange heat with the fresh air delivered from the fresh air supply device 5 (the hot and humid air and the fresh air are in two independent spaces in the heat exchange device and do not contact each other). After cooling and dehydration, it enters the heat pump device 4 (the air temperature after cooling is 40-80°C and the relative humidity is 100%-80%). After dehydration and heating, it becomes dry hot air (the air temperature after dehydration and heating is 70-100°C and the relative humidity is 10%-1%), and then it can enter the cow dung drying equipment 1 again, and the cycle continues.

[0027] The heat exchange device 3 is also connected to a fresh air circulation system, which includes a fresh air supply device 5, a return air adjustment device 6 and an exhaust air adjustment device 7;

[0028] Fresh air is transported into the heat exchange device 3 through the fresh air supply device 5. After the fresh air completes heat exchange with the humid hot air after dust removal, part of it enters the cow dung fermentation equipment 8, part of it is discharged through the exhaust adjustment device 7, and part of it returns to the fresh air supply device 5 through the return air adjustment device 6 for circulation.

[0029] The cow dung fermentation equipment 8 ferments the cow dung using the fresh air processed by the fresh air circulation system, and the excess fresh air is discharged from the cow dung fermentation equipment 8 .

[0030] Compared with a system without fresh air heat exchange (excluding 3, 6 and 7), the energy consumption of the system of the present application is reduced by about 9%.

[0031] Example 2

[0032] The cow dung with a solid content of 5% to 10% in the initial cow dung pool is pretreated: impurities and other organic waste are removed from the cow dung, and the cow dung mixture is filtered. Most of the water is removed, and the solid materials in the cow dung are retained. The water content of the solid materials is 70% to 80%. Finally, the cow dung is squeezed and dehydrated. The water content of the solid materials after pretreatment is 55% to 65%.

[0033] The pretreated cow dung is placed in the cow dung drying equipment 1 for mass and heat transfer with the dry hot air delivered by the heat pump device 4. After the moisture content is lower than 48%, it enters the cow dung fermentation equipment 8, and the cow dung is subjected to fresh air fermentation treatment for 5 to 7 days. The fermented cow dung solid material temperature is 70°C-90°C, and the solid material moisture content is 40%-45%.

[0034] The E. coli content of the cow dung before and after fermentation was greater than 1000 MPN / g, and less than 100 MPN / g after fermentation. The cow dung treated by the process of the present application is used as bedding for cows, which can reduce the incidence of mastitis in dairy cows by at least 0.5%.

Claims

1. A closed drying and fresh air fermentation composite cow dung treatment system, characterized in that: The cow dung treatment system comprises a cow dung drying device (1) and a cow dung fermentation device (8). The cow dung drying equipment (1) dries the cow dung by hot air drying, and the hot and humid air therein is circulated through a closed drying system; The closed drying system comprises a dust removal device (2), a heat exchange device (3) and a heat pump device (4); The heat exchange device (3) is also connected to a fresh air circulation system, and the fresh air circulation system includes a fresh air supply device (5), a return air adjustment device (6) and an exhaust air adjustment device (7); The cow dung fermentation equipment 8 ferments the cow dung using the fresh air processed by the fresh air circulation system.

2. The closed drying and fresh air fermentation composite cow dung treatment system according to claim 1 is characterized in that: The circulation route of the moist hot air in the cow dung drying equipment (1) is: first entering the dust removal device (2) for dust removal, then entering the heat exchange device (3) for heat exchange with the fresh air delivered from the fresh air supply device (5), and after cooling and dehydration, entering the heat pump device (4), dehydration and temperature increase to become dry hot air, and then entering the cow dung drying equipment (1) again.

3. The closed drying and fresh air fermentation composite cow dung treatment system according to claim 2 is characterized in that: After cooling, the air temperature is 40-80°C, and the relative humidity is 100%-80%.

4. The closed drying and fresh air fermentation composite cow dung treatment system according to claim 2 is characterized in that: After dehydration and heating, the air temperature is 70-100°C, and the relative humidity is 10%-1%.

5. The closed drying and fresh air fermentation composite cow dung treatment system according to claim 1 is characterized in that: The air flow route in the fresh air circulation system is as follows: fresh air is transported into the heat exchange device (3) through the fresh air supply device (5); after the fresh air completes heat exchange with the humid hot air after dust removal, part of the fresh air enters the cow dung fermentation equipment (8); part of the fresh air is discharged through the exhaust air regulating device (7); and part of the fresh air returns to the fresh air supply device (5) through the return air regulating device (6).

6. The method for using the closed drying and fresh air fermentation composite cow dung treatment system according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) pre-treating the cow dung, wherein the moisture content of the pre-treated cow dung is 55% to 65%; (2) placing the cow dung into the cow dung drying equipment (1) for drying, and entering the cow dung fermentation equipment (8) after the moisture content is lower than 48%; (3) The cow dung is subjected to fresh air fermentation treatment for 5 to 7 days to obtain qualified cow dung.

7. The method for using the closed drying and fresh air fermentation composite cow dung treatment system according to claim 6, characterized in that: The pretreatment of the cow dung in step (1) includes removing impurities and water from the cow dung.

8. The method for using the closed drying and fresh air fermentation composite cow dung treatment system according to claim 6, characterized in that: The specific steps of pretreatment of cow dung are: removing impurities and other waste materials from cow dung with an initial solid content of 5% to 10%, filtering the cow dung mixture, retaining the solid materials in the cow dung, and finally squeezing and dehydrating the solid materials.

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