Gypsum powder calcination tail gas emission treatment system

Abstract

The utility model provides a gypsum powder calcination tail gas emission treatment system which is used for producing gypsum powder by taking high-temperature flue gas generated by combustion of fire coal or natural gas as a heat source so as to reduce the tail gas oxygen content in the gypsum powder calcination process and reduce the tail gas treatment difficulty and cost, and relates to the technical field of gypsum powder production. The gypsum powder calcination tail gas emission treatment system comprises an anti-hardening fan, a desulfurization absorption tower and a powder frying device, a purified gas outlet channel of the desulfurizing absorption tower is provided with a purified gas outlet branch, a tail gas inlet of the desulfurizing absorption tower is connected with an exhaust port of the powder frying device, and an air inlet of the hardening-preventing fan is connected with the purified gas outlet branch. And an air outlet of the anti-hardening fan is connected with a pressure air inlet of the rice noodle frying device.

Description

Technical Field

[0001] This utility model relates to the field of gypsum powder production technology, specifically a gypsum powder calcination tail gas emission treatment system. Background Technology

[0002] Gypsum is one of the three traditional cementing materials, but most natural gypsum and industrial by-products are dihydrate gypsum, which needs to be dehydrated before it can be utilized. One current process involves dehumidifying and drying natural gypsum or industrial by-products, then passing them through a roasting device for dehydration. Heating to 145-180℃ further dehydrates the gypsum to produce hemihydrate gypsum (CaSO4·1 / 2H2O), and then heating to above 180℃ produces anhydrous gypsum (CaSO4).

[0003] The heat source for heating gypsum powder is generally the high-temperature flue gas generated by burning coal or natural gas. The exhaust gas produced after fuel combustion contains SO2, and desulfurization and denitrification treatment are required before emission. According to emission standards, the measured concentration of the exhaust gas needs to be converted into a baseline oxygen emission concentration, which must be below the specified value. The conversion formula for the baseline oxygen emission concentration is as follows:

[0004]

[0005] In the formula:

[0006] ρ represents the baseline oxygen content emission concentration of air pollutants, in mg / m3;

[0007] ρ / The concentration of atmospheric pollutants emitted is the measured concentration, in mg / m³.

[0008] This represents the measured oxygen content.

[0009] This is the baseline oxygen content.

[0010] For the same fuel, the baseline oxygen content Fixed and unchanging.

[0011] If the measured concentration ρ / Similarly, the higher the oxygen content in the exhaust gas, the higher the converted emission concentration. Therefore, reducing the oxygen content in the exhaust gas is an effective measure to reduce the converted emission concentration of the exhaust gas.

[0012] During the calcination process of gypsum powder, to prevent the powder from accumulating and caking, the industry currently uses a Roots blower to introduce pressurized air into the frying device. This air agitates the gypsum powder, preventing caking. However, the air currently supplied by the Roots blower is fresh air. This fresh air enters the desulfurization system along with the calcination exhaust gas, increasing the oxygen content in the final exhaust gas and increasing the difficulty and cost of subsequent exhaust gas treatment. Utility Model Content

[0013] The technical problem to be solved by this utility model is to provide a treatment system for the exhaust gas of gypsum powder calcination produced by using high-temperature flue gas generated from the combustion of coal or natural gas as a heat source, so as to reduce the oxygen content of the exhaust gas during the calcination process of gypsum powder, and reduce the difficulty and cost of exhaust gas treatment.

[0014] The technical solution adopted by this utility model to solve its technical problem is: a gypsum powder calcination tail gas emission treatment system, including an anti-caking fan, a desulfurization absorption tower and a powder roasting device.

[0015] The desulfurization absorption tower has a purified gas outlet branch on its purified gas outlet channel. The tail gas inlet of the desulfurization absorption tower is connected to the exhaust port of the frying powder device. The air inlet of the anti-caking fan is connected to the purified gas outlet branch. The air outlet of the anti-caking fan is connected to the pressure gas inlet of the frying powder device.

[0016] Furthermore, the anti-caking fan is a Roots blower.

[0017] Furthermore, it also includes a cooler, which is disposed between the purified gas outlet branch and the air inlet of the anti-caking fan to cool the exhaust gas flowing out from the purified gas outlet branch.

[0018] Furthermore, it also includes an exhaust fan, the air inlet of which is connected to the purified gas outlet branch, and the air outlet of which is connected to the cooler, so as to introduce the purified gas in the purified gas outlet channel into the cooler through the purified gas outlet branch.

[0019] Furthermore, it also includes an air storage tank, through which the cooler is connected to the air inlet of the anti-caking fan.

[0020] Furthermore, the desulfurization absorption tower is a spray tower.

[0021] The beneficial effects of this utility model are as follows: The gypsum powder calcination tail gas emission treatment system of this utility model connects the exhaust port of the calcining device to the tail gas inlet of the desulfurization absorption tower, and provides a purified gas outlet branch on the purified gas outlet channel of the desulfurization absorption tower. The air inlet of the anti-caking fan is connected to the purified gas outlet branch, and the air outlet is connected to the pressure gas inlet of the calcining device. In this way, the tail gas with low oxygen content from gypsum production can be desulfurized and purified, and then a part of the purified gas is sent into the calcining device through the anti-caking fan. This avoids the introduction of fresh air from the outside, which would increase the oxygen content of the tail gas, and achieves the purpose of reducing the emission concentration of the baseline oxygen content of the tail gas. The tail gas treatment cost is also lower. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] The diagram shows: 1. Powder frying device; 2. Desulfurization absorption tower; 3. Anti-caking fan; 4. Exhaust fan; 5. Cooler; 6. Gas storage tank; 21. Purified gas outlet channel; 22. Purified gas outlet branch. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] like Figure 1 As shown, the gypsum powder calcination tail gas emission treatment system of this utility model includes an anti-caking fan 3, a desulfurization absorption tower 2, and a gypsum powder roasting device 1. The desulfurization absorption tower 2 has a purified gas outlet branch 22 on its purified gas outlet channel 21. The tail gas inlet of the desulfurization absorption tower 2 is connected to the exhaust port of the gypsum powder roasting device 1. The air inlet of the anti-caking fan 3 is connected to the purified gas outlet branch 22, and the air outlet of the anti-caking fan 3 is connected to the pressure gas inlet of the gypsum powder roasting device 1. The anti-caking fan 3 is generally a Roots blower.

[0026] For systems that use high-temperature flue gas from coal or natural gas combustion as a heat source to produce gypsum powder, the flue gas entering the frying device 1 is generated by the combustion of coal or natural gas. Since most of the oxygen in the air is consumed during combustion, the oxygen content in this flue gas is low, generally below 9%. The oxygen content of the exhaust gas discharged from the frying device is also lower than that of air. This invention connects the exhaust port of the frying device 1 to the exhaust gas inlet of the desulfurization absorption tower 2, and provides a purified gas outlet branch 22 on the purified gas outlet channel 21 of the desulfurization absorption tower 2. The inlet of the anti-caking fan 3 is connected to the purified gas outlet branch 22, and the outlet is connected to the pressure gas inlet of the frying device 1. In this way, the low-oxygen exhaust gas from gypsum production can be desulfurized and purified before a portion of the purified gas is sent into the frying device 1 via the anti-caking fan 3. That is, the airflow of the anti-caking fan 3 comes from the low oxygen content gypsum powder production tail gas purified by the desulfurization absorption tower 2, which avoids the introduction of fresh air from the outside and thus increases the oxygen content of the tail gas, thereby achieving the purpose of reducing the emission concentration of the baseline oxygen content of the tail gas.

[0027] Since the exhaust gas from the gypsum powder roasting device 1 contains moisture carried from the gypsum, this invention also includes a cooler 5. The cooler 5 is located between the purified gas outlet branch 22 and the inlet of the anti-caking fan 3 to cool and lower the temperature of the exhaust gas from the purified gas outlet branch 22, condense some of the moisture in the exhaust gas, and reduce its moisture content. This results in a lower moisture content in the gas entering the gypsum powder roasting device 1 via the anti-caking fan 3, which is beneficial for gypsum powder production. Furthermore, the cooler 5 also lowers the temperature of the airflow entering the anti-caking fan 3, especially when the anti-caking fan 3 uses a Roots blower, better protecting the blower and extending its lifespan. The cooler 5 can be a liquid-cooled or air-cooled structure cooler, etc.

[0028] This utility model also includes an exhaust fan 4, whose inlet is connected to the purified gas outlet branch 22 and whose outlet is connected to the cooler 5, so as to introduce the purified gas in the purified gas outlet channel 21 into the cooler 5 through the purified gas outlet branch 22. The exhaust fan 4 can reduce the load on the anti-caking fan 3. The exhaust fan 4 can be any existing fan. An exhaust fan 4 can also be installed between the desulfurization absorption tower 2 and the frying device 1 as needed, so as to draw the tail gas flowing out of the exhaust port of the frying device 1 into the desulfurization absorption tower 2.

[0029] In the gypsum production process, the anti-caking fan 3 needs to provide a stable airflow with pressure and flow rate. To make the airflow and pressure generated by the anti-caking fan 3 more stable, this invention provides an air storage tank 6 between the cooler 5 and the air inlet of the anti-caking fan 3. The cooler 5 is connected to the air inlet of the anti-caking fan 3 via the air storage tank 6. When the airflow flowing out of the purified gas outlet branch 22 fluctuates, the air storage tank 6 can store or replenish a certain amount of air to the anti-caking fan 3, thereby reducing the impact of the fluctuations in the exhaust gas flowing out of the purified gas outlet branch 22 on the airflow discharged from the anti-caking fan 3.

[0030] The desulfurization absorption tower 2 can be any existing type of desulfurization absorption tower, such as a spray tower, a packed tower, a dual-loop tower, or a jet bubbling tower. In this invention, the desulfurization absorption tower 2 is preferably a spray tower, which has high treatment efficiency and a good cooling effect on the exhaust gas.

Claims

1. A gypsum powder calcination tail gas emission treatment system, characterized in that: It includes an anti-caking fan (3), a desulfurization absorption tower (2), and a powder roasting device (1); The desulfurization absorption tower (2) has a purified gas outlet branch (22) on the purified gas outlet channel (21). The tail gas inlet of the desulfurization absorption tower (2) is connected to the exhaust port of the frying device (1). The air inlet of the anti-caking fan (3) is connected to the purified gas outlet branch (22). The air outlet of the anti-caking fan (3) is connected to the pressure gas inlet of the frying device (1).

2. The gypsum powder calcination tail gas emission treatment system as described in claim 1, characterized in that: The anti-caking fan (3) is a Roots blower.

3. The gypsum powder calcination tail gas emission treatment system as described in claim 1 or 2, characterized in that: It also includes a cooler (5), which is disposed between the purified gas outlet branch (22) and the air inlet of the anti-caking fan (3) to cool the exhaust gas flowing out from the purified gas outlet branch (22).

4. The gypsum powder calcination tail gas emission treatment system as described in claim 3, characterized in that: It also includes an exhaust fan (4), the air inlet of which is connected to the purified gas outlet branch (22), and the air outlet is connected to the cooler (5), so as to introduce the purified gas in the purified gas outlet channel (21) into the cooler (5) through the purified gas outlet branch (22).

5. The gypsum powder calcination tail gas emission treatment system as described in claim 4, characterized in that: It also includes an air storage tank (6), and the cooler (5) is connected to the air inlet of the anti-caking fan (3) via the air storage tank (6).

6. The gypsum powder calcination tail gas emission treatment system as described in claim 1, characterized in that: The desulfurization absorption tower (2) is a spray tower.

Images