Phosphoric acid activated carbon activating furnace waste-heat utilization and tail-gas absorption device

Abstract

The invention discloses a phosphoric acid activated carbon activating furnace waste-heat utilization and tail-gas absorption device. Heat exchange pipes are connected with hot water outlet headers; a hoisting hole is located between each hot water outlet header and each cold water outlet header; the cold water outlet headers are connected with the heat exchange pipes; a top insulating layer is located above the heat exchange pipes; support hooks are each located on the upper end of the heat exchange pipe. The device breaks traditional concepts of the conventional activated carbon activating furnace waste-heat utilization and tail gas absorption device field, so as to achieve the purpose of the waste-heat utilization; and at present, because of use of the waste-heat utilization device, the flue gas temperature is dropping, a humidification cooling tower can be supplemented, effects can be reached by direct use of a tail gas absorbing spray tower, and moreover, investment and operation costs of a tail gas absorbing system are saved.

Description

technical field [0001] The invention relates to the design and modification of waste heat utilization and tail gas absorption of a wood activated carbon activation furnace, in particular to waste heat utilization and tail gas absorption equipment of a phosphoric acid activated carbon activation furnace. Background technique [0002] With the progress of society, people's requirements for quality of life continue to increase. As a wood-based activated carbon for decontamination and detoxification, the demand is increasing and the scope of use is becoming more and more extensive. For example, medicine, sugar, food, cosmetics, urban water supply, tobacco, alcohol, chemical industry, automobile exhaust treatment and other industries need to be used, and the demand for activated carbon in the military is increasing and there is no substitute, so the product is economical. The prospects are very good. Wood activated carbon The main raw material of activated carbon products is was...

AI Technical Summary

Problems solved by technology

At present, there are many problems in domestic chemical activated carbon production, such as large consumption of phosphoric acid, high energy consumption, serious smoke pollution, low degree of mechanization, and high labor intensity.

In the phosphoric acid production process, the most important equipment is a horizontal activation furnace, which uses a horizontal converter to carbonize and activate wood chips. Most of the manufacturers’ horizontal activation furnace exhausts the flue gas directly, and the large amount of heat in the flue gas cannot Recycling, this has caused a series of problems: one, the outlet gas temperature of the horizontal converter of the phosphoric acid process production process must be controlled so that the product quality can reach the standard. Taking the horizontal converter with a length of 35 meters and a diameter of 1.8 meters as an example, the production capacity is 6 tons / Calculated in a day, the outlet flue gas volume will reach 15000Nm3 / h, and the outlet flue gas temperature must be controlled at 180°C~200°C, and this part of heat energy cannot be recovered and directly emptied, resulting in a large amount of heat energy loss

2. The phosphoric acid production process needs a lot of hot water in the recovery and rinsing process. Generally, each ton of charcoal needs to consume about 8 tons of hot water at 70°C~80°C. This part of hot water needs to be solved by adding a boiler. On the one hand Heat energy is wasted. On the other hand, heat energy is urgently needed in the production process. It is extremely unreasonable not to use heat energy effectively.

3. The entrainment of phosphoric acid mist in the tail gas at the outlet of the horizontal converter is large, so that the phosphoric acid consumption of the product increases. The phosphoric acid consumption per ton of carbon is generally greater than 0.3, and this part of phosphoric acid cannot be recovered.

At the same time, this part of the exhaust gas is not absorbed, which also causes a certain amount of air pollution.

4. The exhaust gas temperature at the outlet of the horizontal converter is high, resulting in a large flue gas volume flow rate, which puts forward higher requirements for the exhaust gas of the horizontal converter, the height and diameter of the chimney. If the exhaust gas at the outlet of the horizontal converter is blocked, this also Indirectly affect product quality and production capacity

At present, some manufacturers try to solve the problems and existing problems: 1. Install a heat exchanger in the outlet flue of the horizontal converter or install a heat exchange coil in the horizontal direction to achieve the purpose of using waste heat to produce hot water. This solution can achieve a certain level in the early stage. However, smoke and wood tar will quickly block the heat exchange tubes, which will cause poor heat exchange and blockage of the flue, which will eventually make it difficult to continue production, and it is very inconvenient to clean the heat exchange tubes and flue. This solution is obviously not ideal

2. Set up a stainless steel flue, and build a heat exchange hot water pool outside the flue. The heat exchange efficiency of this solution is extremely low, and a large amount of heat cannot be effectively used. In addition, the cost of this solution is extremely high, and the stainless steel flue needs to be cleaned regularly. This solution is obviously not good. ideal

3. Install more than two sets of heat exchange tubes in the outlet flue of the horizontal converter. The heat exchange medium is changed from water to dilute phosphoric acid. By exchanging and recovering the heat energy of activated carbon kiln exhaust gas, the normal temperature dilute phosphoric acid in the heat exchange tubes is heated to dilute phosphoric acid. The next step is to concentrate and recycle. This plan is extremely expensive. First, it is necessary to build a phosphoric acid concentration and recovery system in the process flow. On the other hand, it does not solve the problem of cleaning heat exchange tubes and flue blockages. This plan is obviously not ideal.

4. Add a tail suction spray tower at the outlet of the horizontal converter to achieve the purpose of recovering phosphoric acid in the tail gas, and the recovered phosphoric acid is returned to the system for recycling, which achieves the purpose of recovering phosphoric acid, but this plan does not consider the utilization of waste heat problem, the solution is obviously still lacking

None of the above methods are suitable for satisfactorily solving the problem

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