Waste acid concentration preheating device and method of using same

Abstract

The application discloses a waste acid concentration preheating device and a use method thereof, a rectangular cavity, a waste acid shunt plate, the waste acid shunt plate is adapted in the center of the rectangular cavity, a herringbone-shaped flow channel, the herringbone-shaped flow channel is arranged above the waste acid shunt plate, the top highest point of the herringbone-shaped flow channel is communicated with the outside to form a liquid inlet, an inverted herringbone-shaped flow channel, two flow channels of the inverted herringbone-shaped flow channel are respectively communicated with two flow channels of the herringbone-shaped flow channel, the lowest point of the inverted herringbone-shaped flow channel extends to the bottom of the rectangular cavity and is communicated with the outside to form a liquid outlet, a shunt channel, the shunt channel is communicated between two flow channels of the herringbone-shaped flow channel and two flow channels of the inverted herringbone-shaped flow channel, and a rotating shaft, the rotating shaft traverses the center of the waste acid shunt plate and is rotationally connected with two sides of the rectangular cavity at both ends. The application has the beneficial effects that the preheating temperature is adjusted by adjusting the distance between the heating plate and the waste acid shunt plate, the energy consumption is reduced, and the preheating time is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of titanium dioxide production, in particular to a waste acid concentration preheating device and a method thereof. BACKGROUND

[0002] Titanium dioxide production mainly adopts three methods of sulfuric acid method, chlorination method and hydrochloric acid method, and 95% of titanium dioxide in China is produced by the sulfuric acid method. Waste acid is generated in the production process of titanium dioxide, and 8-10 tons of waste acid are discharged per ton of titanium dioxide produced. The waste acid contains sulfuric acid, ferrous sulfate and other inorganic salts, and its treatment process is complex and difficult. At present, China has become the second largest titanium dioxide producing country in the world, and the total waste acid produced by the industry is about 8000 kt / a. How to treat and recycle these waste acids has attracted great attention from industry insiders. The recycling of waste acid not only effectively utilizes waste acid resources, but also saves a lot of waste acid treatment cost, and can achieve very significant economic and social benefits. At present, there are many waste acid concentration methods, such as submerged combustion method and vacuum concentration method. The vacuum concentration method is a concentration method widely used by titanium dioxide enterprises at home and abroad in recent years.

[0003] For example, the Chinese invention patent authorization announcement No. CN104555948B discloses a waste acid concentration process. The process first separates the waste acid through a solid-liquid separator, then adds a sulfidation agent to the separated waste acid, and then inputs the treated waste acid into a crystallization kettle, and then inputs the treated waste acid into a first-stage concentration heater and a second-stage concentration heater after preheating, so as to concentrate the waste acid to 75%-80%.

[0004] The Chinese utility model patent publication No. CN208018167U discloses a waste acid concentration device, which comprises a preheater (1) connected with a waste acid inlet pipeline, the pipeline outlet of the preheater (1) is connected with a first-stage heater (2); the outlet of the first-stage heater (2) is connected with a first evaporator (3) through a pump, the first evaporator (3) and a second-stage heater (4) are connected through a pipeline, a pressure reducing valve (5) is arranged on the pipeline; the outlet of the second-stage heater (4) is connected with a second evaporator (6), the outlet of the second evaporator (6) is arranged at the top thereof, a communication pipe (7) is arranged to connect the second evaporator (6) and an acid storage tank (8), and a graphite heat exchanger (9) is arranged at the inlet of the acid storage tank (8).

[0005] The above patents all focus on optimizing the concentration process, but no one pays attention to preheating before concentration. However, the effect of preheating determines the concentration effect in the later stage. The existing preheater is difficult to accurately control the temperature of the waste acid, has high energy consumption, and has a long preheating time, which prolongs the treatment process. SUMMARY

[0006] The technical problem to be solved by the present application is that the existing waste acid preheating before concentration is difficult to accurately control the temperature of the waste acid, consumes more energy, and takes a long time to preheat, thereby prolonging the treatment process.

[0007] The technical scheme of the present application is: a waste acid concentration preheating device, comprising: a rectangular cavity, the top of the rectangular cavity is open; a waste acid distribution plate, the waste acid distribution plate is adapted in the center of the rectangular cavity; a herringbone-shaped flow channel, the herringbone-shaped flow channel is opened above the inside of the waste acid distribution plate, the top highest point of the herringbone-shaped flow channel is communicated with the outside to form a liquid inlet; an inverted herringbone-shaped flow channel, the two flow channels of the inverted herringbone-shaped flow channel are respectively communicated with the two flow channels of the herringbone-shaped flow channel, the lowest point of the inverted herringbone-shaped flow channel extends to the bottom of the rectangular cavity and is communicated with the outside to form a liquid outlet; a distribution channel, the distribution channel is communicated between the two flow channels of the herringbone-shaped flow channel and the two flow channels of the inverted herringbone-shaped flow channel; a shaft, the shaft traverses the center of the waste acid distribution plate and is rotatably connected to the two sides of the rectangular cavity at both ends, the both ends of the shaft are provided with positive and negative threaded segments; two heating plates, the two heating plates are located in the rectangular cavity and are respectively located on both sides of the waste acid distribution plate, the two heating plates are slidably connected with the inner wall of the rectangular cavity, the center of the two heating plates is provided with a through hole for the shaft to pass through, the through hole is threadedly connected with the positive and negative threaded segments; a heating pipe, the heating pipe is distributed on the two heating plates and matches the shape of the herringbone-shaped flow channel, the inverted herringbone-shaped flow channel and the distribution channel.

[0008] In the above scheme, the two flow channels of the herringbone-shaped flow channel gradually contract from top to bottom.

[0009] In the above scheme, the two flow channels of the inverted herringbone-shaped flow channel gradually expand from top to bottom.

[0010] In the above scheme, one end of the shaft is provided with a driving mechanism.

[0011] In the above scheme, the rectangular cavity is filled with a heat preservation liquid.

[0012] The use method of the waste acid concentration preheating device comprises the following steps: injecting waste acid into the waste acid distribution plate from the liquid inlet, the waste acid is distributed through the herringbone-shaped flow channel, the inverted herringbone-shaped flow channel and the distribution channel, rotating the shaft to make the two heating plates close to the waste acid distribution plate, the heating pipe is close to the herringbone-shaped flow channel, the inverted herringbone-shaped flow channel and the distribution channel at a suitable distance to preheat the waste acid, and the preheated waste acid is discharged from the liquid outlet into the next process.

[0013] The present application has the beneficial effect of adjusting the preheating temperature by adjusting the distance between the heating plate and the waste acid distribution plate, reducing energy consumption and shortening the preheating time. BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1Figure is the waste acid shunt plate schematic diagram of the waste acid concentration preheating device of the present application;

[0015] Fig. 2 Figure is the waste acid concentration preheating device schematic diagram of the present application;

[0016] In the figure, 1, rectangular cavity, 2, waste acid shunt plate, 3, herringbone flow channel, 4, inverted herringbone flow channel, 5, shunt channel, 6, rotating shaft, 7, heating plate. Embodiment

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments within the scope of the present application without creative labor are within the protection scope of the present application.

[0018] As Figs. 1-2 shown, the waste acid concentration preheating device comprises: a rectangular cavity 1, the top of the rectangular cavity is open; a waste acid shunt plate 2, the waste acid shunt plate is adapted in the center of the rectangular cavity; a herringbone flow channel 3, the herringbone flow channel is opened above the inside of the waste acid shunt plate, the top highest point of the herringbone flow channel is communicated with the outside to form a liquid inlet; an inverted herringbone flow channel 4, the two flow channels of the inverted herringbone flow channel are respectively communicated with the two flow channels of the herringbone flow channel, the lowest point of the inverted herringbone flow channel extends to the bottom of the rectangular cavity and is communicated with the outside to form a liquid outlet; a shunt channel 5, the shunt channel is communicated between the two flow channels of the herringbone flow channel and the two flow channels of the inverted herringbone flow channel; a rotating shaft 6, the rotating shaft traverses the center of the waste acid shunt plate and is rotatably connected with the two sides of the rectangular cavity at both ends, the both ends of the rotating shaft are provided with positive and negative threaded segments; two heating plates 7, the two heating plates are located in the rectangular cavity and are respectively located on both sides of the waste acid shunt plate, the two heating plates are slidably matched with the inner wall of the rectangular cavity, the center of the two heating plates is provided with a through hole for the rotating shaft to pass through, the through hole is threadedly matched with the positive and negative threaded segments; a heating pipe, the heating pipe is distributed on the two heating plates and matches the shape of the herringbone flow channel, the inverted herringbone flow channel and the shunt channel.

[0019] As an embodiment of the present application, the waste acid shunt plate can be one, and the heating plate can be two. Of course, the waste acid shunt plate can be two, and the heating plate can be four. In short, the heating plate is in pairs and located on both sides of the waste acid shunt plate, providing heating from two sides to the herringbone flow channel, the inverted herringbone flow channel and the shunt channel on the waste acid shunt plate.

[0020] The shunt channel can have two, four or even more, so that the waste acid has more shunt paths.

[0021] As a preferred example of the present application, the two flow channels of the inverted chevron-shaped flow channel gradually contract in diameter from top to bottom, so that the waste acid can be accelerated when flowing, and the two flow channels of the inverted chevron-shaped flow channel gradually expand in diameter from top to bottom, so that the waste acid can slow down the flow rate, prolong the time of the waste acid in the waste acid distribution plate, and avoid the blockage of the drain port by impurities in the waste acid.

[0022] The driving mechanism is arranged outside one end of the rotating shaft and can drive the rotating shaft to rotate, and the rotating shaft drives the heating plate to move back and forth.

[0023] In order to avoid heat loss, the rectangular cavity is filled with a heat preservation liquid, which immerses the waste acid distribution plate and the heating plate.

[0024] The method for using the waste acid concentration preheating device includes the following steps: injecting waste acid from the liquid inlet into the waste acid distribution plate, distributing the waste acid through the chevron-shaped flow channel, the inverted chevron-shaped flow channel and the distribution channel, rotating the rotating shaft to make the two heating plates approach the waste acid distribution plate, and preheating the waste acid by the heating pipe at a suitable distance from the chevron-shaped flow channel, the inverted chevron-shaped flow channel and the distribution channel, and discharging the preheated waste acid from the liquid outlet to the next process.

[0025] The waste acid is preheated to about 50℃ for 20-40 minutes in the past, and the preheating time can be shortened to 10-15 minutes by using the preheating device of the present application.

Claims

1. A waste acid concentration preheating apparatus, characterized by: It comprises: a rectangular cavity (1) with an open top; a waste acid distribution plate (2) fitted in the center of the rectangular cavity; a herringbone-shaped flow channel (3) opened above the waste acid distribution plate inside, the top of which is connected with the outside to form a liquid inlet; an inverted herringbone-shaped flow channel (4) with two flow channels respectively connected with the two flow channels of the herringbone-shaped flow channel, the lowest point of which extends to the bottom of the rectangular cavity and is connected with the outside to form a liquid outlet; a distribution channel (5) connected between the two flow channels of the herringbone-shaped flow channel and the two flow channels of the inverted herringbone-shaped flow channel; a rotating shaft (6) crossing the center of the waste acid distribution plate and rotatingly connected with the two sides of the rectangular cavity at both ends, the two ends of which are provided with positive and negative threaded segments; two heating plates (7) located in the rectangular cavity and on both sides of the waste acid distribution plate, which are slidingly fitted with the inner wall of the rectangular cavity, and the center of each heating plate is provided with a through hole for the rotating shaft to pass through, which is threadedly fitted with the positive and negative threaded segments; and heating pipes distributed on the two heating plates and matched with the shape of the herringbone-shaped flow channel, the inverted herringbone-shaped flow channel and the distribution channel.

2. The waste acid concentration preheating apparatus according to claim 1, wherein: The two flow channels of the herringbone-shaped flow channel gradually contract in diameter from top to bottom.

3. The waste acid concentration preheating apparatus according to claim 1, wherein: The two flow channels of the inverted herringbone-shaped flow channel gradually expand in diameter from top to bottom.

4. The waste acid concentration preheating apparatus according to claim 1, wherein: One end of the rotating shaft is circumscribed with a driving mechanism.

5. The waste acid concentration preheating apparatus according to claim 1, wherein: The rectangular cavity is filled with a heat preservation liquid.

6. The method of using a waste acid concentration preheating device according to any one of claims 1-5, characterized in that: It comprises the following steps: Waste acid is injected into the waste acid distribution plate from the liquid inlet, and the waste acid is distributed through the herringbone-shaped flow channel, the inverted herringbone-shaped flow channel and the distribution channel, the rotating shaft is rotated to make the two heating plates close to the waste acid distribution plate, the heating pipes are close to the herringbone-shaped flow channel, the inverted herringbone-shaped flow channel and the distribution channel at a suitable distance to preheat the waste acid, and the preheated waste acid is discharged from the liquid outlet to enter the next process.

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