Efficient cooling method and cooling system for quartz ore

Abstract

The application discloses a high-efficiency cooling method and system for quartz ore, and specifically comprises the following steps: S1: in stage I, the quartz ore after roasting and water quenching is subjected to once positive pressure blowing from bottom to top; when the temperature of the blowing gas after dust removal is less than or equal to 300 DEG C, stage II is entered; otherwise, stage I is continuously performed; S2: in stage II, the quartz ore is subjected to twice positive pressure blowing from bottom to top; when the temperature of the blowing gas after dust removal is less than or equal to 200 DEG C, stage III is entered; otherwise, stage II is continuously performed; S3: in stage III, the quartz ore is subjected to thrice positive pressure blowing from bottom to top; the blowing is continuously performed until the temperature of the quartz ore is lower than 40 DEG C. The application realizes gradient cooling by adopting blowing air to perform positive pressure blowing on the quartz ore, and free water and heat in the crevice of the ore are taken away, so that the double goals of ore cooling and water removal are achieved.

Description

Technical Field

[0001] This invention belongs to the field of ore processing, and specifically relates to a high-efficiency cooling system and method for quartz ore. Background Technology

[0002] In the production of high-purity quartz sand, the quartz ore needs to be roasted to 1100-1400℃, followed by cooling. Existing methods for cooling quartz ore mainly include the following:

[0003] (1) Open-air room temperature natural cooling is adopted to enhance air convection. However, the quartz calcination cooling time is long with this cooling method, which leads to the production cycle being inconsistent with the downstream process. Moreover, as the number of products increases, the space occupied is large, which seriously affects production efficiency and unit investment cost. In addition, open-air cooling is prone to introducing impurities, which increases the difficulty of subsequent product purification;

[0004] (2) Patent document CN110145948A improves the cooling efficiency of quartz ore by increasing the cold source (condenser) and increasing the number of air convections (fan water vapor) to reduce the temperature of the cooling medium. However, although this cooling scheme can reduce the temperature, the cooling temperature gradient is too large, and condensation is easily generated during the cooling process, so the maximum cooling efficiency cannot be achieved and it will have a negative impact - residual moisture. This causes the crushed quartz powder to clump together, making screening difficult, resulting in screen damage, equipment downtime, and seriously affecting production efficiency.

[0005] (3) In patent document CN218155195U, the ore is vertically flipped while being dehumidified by a cold airflow, so that all parts of the outer surface of the ore can be fully dehumidified, achieving the effect of dehumidifying multiple outer surfaces of the ore simultaneously and improving the dehumidification effect of the ore. However, the rotation of the mechanism in this cooling scheme will cause friction between the ore and the metal surface, resulting in metal contamination of the ore. At the same time, the mechanism has a small loading capacity, low production efficiency, and is prone to material leakage and dust, reducing product yield. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention discloses a highly efficient cooling method and system for quartz ore. The method employs multi-stage positive pressure purging of the quartz ore with purging air to achieve gradient cooling, thereby removing free water and heat from the ore's fissures and achieving the dual goals of ore cooling and moisture removal.

[0007] The specific technical solution of the present invention is as follows:

[0008] A highly efficient cooling method for quartz ore, comprising the following steps:

[0009] S1: Stage I, the roasted and water-quenched quartz ore is purged from bottom to top with positive pressure. When the temperature of the purging gas after dust removal is ≤300℃, it enters Stage II; otherwise, it continues to carry out Stage I.

[0010] S2: Stage II, the quartz ore is purged under positive pressure from bottom to top. When the temperature of the purging gas after dust removal is ≤200℃, it enters Stage III; otherwise, it continues to carry out Stage II.

[0011] S3: Stage III, the quartz ore is purged three times from bottom to top under positive pressure, and the purging continues until the temperature of the quartz ore is below 40℃.

[0012] Preferably, in S1, the purge gas pressure for a single positive pressure purge is 0.3 MPa, and the flow rate is 10-15 m / s.

[0013] Preferably, in step S2, the purge gas pressure of the secondary positive pressure purging is 0.4 MPa, and the flow rate is 8-10 m / s.

[0014] Preferably, in step S3, the purging gas pressure for the three positive pressure purgings is 0.05-0.6 MPa, the flow rate is 5-8 m / s, and the purging continues until the ore temperature is below 40°C.

[0015] Preferably, in stages I and II, the purged gas is completely discharged through the exhaust valve after dust removal treatment. In stage III, the purged gas is partially recovered and recycled to stage III for three positive pressure purgings to achieve return air preheating.

[0016] Preferably, during the positive pressure purging process in stages I, II, and III, the gas collection channel of the purging gas is continuously and periodically closed to create purging pressure oscillations and improve the free water removal efficiency.

[0017] A cooling system, characterized in that it comprises: a cooling box, a gas collection device, a dust collector, and an air filter fan; the bottom of the cooling box is provided with a perforated plate, and the purge gas is diverted from the bottom of the cooling box through the perforated plate and then blown upwards evenly to sweep quartz ore; the gas collection device and the dust collector are connected by a pipe, the gas collection device is located above the cooling box and is used to collect the purge gas, and the collected purge gas is treated by the dust collector before being discharged or recycled; the outlet of the air filter fan is connected to the bottom of the cooling box through a pipe, and the inlet of the air filter fan is divided into two branches, one branch is connected to the outlet of the dust collector through a return air valve, and the other branch is used to connect to air.

[0018] Preferably, it also includes a high-point discharge pipe, which is connected to the air outlet of the dust collector via an exhaust valve.

[0019] Preferably, in stage III, during the utilization of waste heat from the return air, the opening degree of the exhaust valve is gradually adjusted from 100% to 10%.

[0020] Preferably, the dust collector is a pulse dust collector, and the valve plate of the pulse dust collector is periodically opened and closed during the purging and cooling process. The period is once every 5-30 minutes, and the valve plate is closed for 5-30 seconds.

[0021] Beneficial effects: This invention discloses a highly efficient cooling method and system for quartz ore, which has the following advantages:

[0022] (1) On the one hand, the present invention adopts a gradient cooling method to avoid condensation caused by excessive cooling temperature gradient, resulting in residual moisture inside the ore; on the other hand, it utilizes the residual heat of return air to evaporate the residual free water, thereby solving the problem of residual condensation in the ore and the problem of quartz sand agglomeration, reducing the downtime rate of crushing and screening processes, and improving production efficiency.

[0023] (2) The present invention utilizes a perforated plate to divert the purge air, so that it can be fully purged onto the quartz ore carrying free water and heat. The purge gas after being diverted by the perforated plate can pass through the gaps between the quartz ore, increasing the contact area of ​​the cooling medium, improving the cooling efficiency, and has a simple structure and is easy to operate, reducing the preparation time for maintenance and inspection.

[0024] (3) The present invention utilizes the periodically opening and closing of the dust collector valve plate to cause oscillation of the purging pressure, providing slight kinetic energy to cause the ore to vibrate slightly, thereby improving the free water removal efficiency. Attached Figure Description

[0025] Figure 1 This is a system structure diagram of Example 1;

[0026] In the diagram: 1. Cooling box; 2. Air collection device; 3. Pulse dust collector; 4. Air filter fan; 5. High-point discharge pipe; 6. Exhaust valve; 7. Return air valve; 8. Ventilation perforated plate; 9. Pipe. Detailed Implementation

[0027] The present invention will now be described with reference to the accompanying drawings, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0028] Example 1

[0029] A cooling system for efficient cooling of quartz ore, such as Figure 1 As shown, it includes a cooling box 1, an air collection device 2, a pulse dust collector 3, an air filter fan 4, and a high-point discharge pipe 5, wherein,

[0030] The bottom of the cooling box 1 is provided with a perforated plate 8. The purging gas is diverted from the bottom of the cooling box 1 through the perforated plate 8 and then blown upwards evenly to purify the quartz ore.

[0031] The gas collecting device 2 and the pulse dust collector 3 are connected by a pipe 9. The gas collecting device 2 is located above the opening of the cooling box 1 and is used to collect the purge gas. The collected purge gas is treated by the pulse dust collector 3 and then discharged or recycled. The valve plate of the pulse dust collector 3 opens and closes periodically throughout the purge cooling process. When the valve plate is closed, the pipe 9 is closed, causing the purge gas to be blocked, resulting in purge pressure oscillation and improving the free water removal efficiency. In this invention, there is a positional gap between the gas collecting device 2 and the opening of the cooling box 1. The specific gap distance can be adjusted by those skilled in the art according to actual needs.

[0032] The air outlet of the air filter fan 4 is connected to the bottom of the cooling box 1 through the pipe 9. The air inlet of the air filter fan 4 is divided into two branches. One branch is connected to the air outlet of the pulse dust collector 3 through the return air valve 7, and the other branch is used to connect the air. The high point discharge pipe 5 is connected to the air outlet of the pulse dust collector 3 through the exhaust valve 6.

[0033] A highly efficient cooling method for quartz ore, comprising the following steps:

[0034] S1: Stage I, a positive pressure purging is performed on the roasted and water-quenched quartz ore from bottom to top. If the temperature of the purging gas after dust removal is ≤200℃, Stage II begins; otherwise, Stage I continues. In Stage I, the freshly roasted and water-quenched quartz ore is at a high temperature and has a high water content. Therefore, it is necessary to quickly remove a large amount of free water and high-temperature water-containing gas from the surface of the quartz ore. The temperature of the purging gas is collected by a temperature sensor located at the return air valve 7.

[0035] In this embodiment, the purge gas pressure for a single positive pressure purge is 0.3 MPa, and the flow rate is 10-15 m / s. Since the purge gas contains a large amount of moisture and has a high temperature, it is not suitable for return air preheating and recovery. The purge gas, after dust removal, is directly discharged from the high-point discharge pipe 5 through the exhaust valve 6. The higher the internal pressure of a liquid, the greater the pressure that molecules on the liquid surface need to overcome to enter the gas phase. That is, the higher the internal pressure of the liquid, the slower the evaporation rate. Therefore, during stage I, the return air valve 7 of the cooling system is closed, and the exhaust valve is 100% open. By increasing the airflow power (flow rate), a large amount of water vapor is removed with the air and discharged entirely from the high-point discharge pipe 5.

[0036] S2: Stage II, the quartz ore is purged under positive pressure from bottom to top. When the temperature of the purging gas after dust removal is ≤100℃, it enters Stage III; otherwise, it continues with Stage II.

[0037] During Stage II, the purge air pressure for the secondary positive pressure purging is 0.4 MPa, and the flow velocity is 8-10 m / s. During Stage II, the return air still contains a large amount of moisture. Direct discharge can improve removal efficiency. If waste heat recovery from the return air is implemented at this stage, a certain proportion of this moisture will remain in the system and cannot be discharged, failing to achieve the desired effect. Therefore, waste heat recovery from the return air is not implemented in Stage II, and the purge gas, after dust removal, is directly discharged from the high-point discharge pipe 5 through exhaust valve 6. During Stage II, by changing the pressure, the moisture adhering to the quartz ore is made easier to enter the gas phase. Therefore, during Stage II, the return air valve 7 of the cooling system is closed, and the exhaust valve is 100% open.

[0038] S3: Stage III, the quartz ore is purged three times from bottom to top under positive pressure, and purging continues until the temperature of the quartz ore is below 40°C. In this embodiment, the purging gas pressure for the three positive pressure purgings is 0.05-0.6MPa, the flow rate is 5-8m / s, and purging continues until the ore temperature is below 40°C.

[0039] In Stage III, the moisture content of the purged gas is already very low. Therefore, the opening degree of the exhaust valve can be gradually adjusted from 100% to 10% to reduce the amount of purging gas discharged. The return air valve can then be opened to recycle the purging gas back into the air filter fan, allowing for three positive-pressure purgings of the quartz ore. This fully utilizes the residual heat of the return air to remove free water from the ore's fissures. In Stage III, by reducing the purging gas pressure, the low-temperature residual heat can be effectively used to evaporate moisture, thus achieving both waste heat utilization and moisture removal.

[0040] In this embodiment, during the positive pressure purging process of Stage I, Stage II and Stage III, the pulse dust collector valve plate is continuously and periodically closed, generally once every 5-30 minutes, and the valve plate closure duration is 5-30 seconds, forming a purging pressure oscillation to improve the free water removal efficiency.

[0041] The above description is merely an illustration of the present invention and represents a preferred embodiment. It should be noted that those skilled in the art can make various improvements and modifications without departing from the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A highly efficient cooling method for quartz ore, characterized in that, The specific steps include: S1: Stage I, the roasted and water-quenched quartz ore is purged from bottom to top with positive pressure. When the temperature of the purging gas after dust removal is ≤300℃, it enters Stage II; otherwise, it continues to carry out Stage I. S2: Stage II, the quartz ore is purged under positive pressure from bottom to top. When the temperature of the purging gas after dust removal is ≤200℃, it enters Stage III; otherwise, it continues to carry out Stage II. S3: Stage III, the quartz ore is purged three times from bottom to top under positive pressure, and the purging continues until the temperature of the quartz ore is below 40℃; In stages I and II, the purged gas is completely discharged through the exhaust valve after dust removal. In stage III, the purged gas is partially recovered and recycled to stage III for three positive pressure purgings to achieve return air preheating. During the positive pressure purging process in stages I, II and III, the gas collection channel of the purging gas is continuously and periodically closed to create purging pressure oscillations and improve the free water removal efficiency. The cooling system employed in the cooling method includes: a cooling box, a gas collection device, a dust collector, an air filter fan, and a high-point discharge pipe. The bottom of the cooling box is equipped with a perforated plate, allowing the purge gas to flow upwards from the bottom of the cooling box, be distributed through the perforated plate, and then evenly blown upwards onto the quartz ore. The gas collection device and the dust collector are connected by a pipe. The gas collection device, located above the cooling box, collects the purge gas, which is then treated by the dust collector before being discharged or recycled. The outlet of the air filter fan is connected to the bottom of the cooling box via a pipe. The inlet of the air filter fan is divided into two branches: one branch connects to the outlet of the dust collector via a return air valve, and the other branch is used to connect to the air supply. The high-point discharge pipe is connected to the outlet of the dust collector via an exhaust valve. The dust collector is a pulse jet dust collector, and its valve plate opens and closes periodically during the purging cooling process, closing once every 5-30 minutes, with the valve plate remaining closed for 5-30 seconds.

2. The efficient cooling method for quartz ore according to claim 1, characterized in that, In S1, the purge gas pressure for a single positive pressure purge is 0.3 MPa, and the flow rate is 10-15 m / s.

3. The efficient cooling method for quartz ore according to claim 1, characterized in that, In S2, the purge gas pressure for the secondary positive pressure purging is 0.4 MPa, and the flow rate is 8-10 m / s.

4. The efficient cooling method for quartz ore according to claim 1, characterized in that, In step S3, the purging gas pressure for the three positive pressure purgings is 0.05-0.6 MPa, the flow rate is 5-8 m / s, and the purging continues until the ore temperature is below 40°C.

5. The cooling system according to claim 1, characterized in that, In Phase III, during the process of utilizing waste heat from the return air, the opening degree of the exhaust valve is gradually adjusted from 100% to 10%.

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