目前，VOCs治理还保存许多灾点，如排放源小而散，涉及众多行业；而各行业排放的VOCs种类繁多、身分庞大，纵然同一行业，如果原料组成和生产工艺差别，排放的VOCs种类、性质和浓度也不尽相同。因此，所需技术路线也纷歧样。

我国对挥发性有机废气的处理历程主要分为4个阶段：

第一阶段，2000年前，处理局部刺激性或有接纳价值废气，仅对刺激性废气通过水喷淋吸收处理；

第二阶段，2001～2005年，将废气集中收集处理后以有组织形式排放，废气主要处理要领为水、碱喷淋两级吸收处理；

第三阶段，2005年以后，增强源头控制，完善废气集中收集，在第二阶段基础上再经活性炭吸附强化处理；

第四阶段，2007年以后，开始逐步对挥发性有机废气进行全历程处理。

现阶段，我国对工业挥发性有机废气的氧化治理技术主要包括：光催化氧化、直接燃烧法、催化燃烧技术及RTO等。

其中，在燃烧法的基础上生长出来的RTO技术，由于操作简单，运行维护较少，对挥发性有机物的去除效率较高，一般在95%以上，成为目前我国有机废气治理的主要技术之一。

RTO，全称RegenerativeThermal Oxidizer，中文译“蓄热式热氧化燃烧”，听着很庞大，是不是
？不着急，且听小柏慢慢道来，首先我们从名字中可以提炼三个焦点信息——蓄热、热氧化、燃烧，可以嗣魅这就是RTO事情原理的净化浓缩。

热氧化、燃烧很好理解，有机物（VOCs）在一定温度下与氧气爆发反应，生成CO2和H2O，并放出一定热量的氧化反应历程，学过化学的同学们看到此一定是秒懂的，要害什么是“蓄热”呢
？如何蓄热
？

这个神秘的蓄热源，得益于RTO中的蓄热体。如果蓄热体热接纳率越高，说明其蓄积的热量越高，那么氧化废气所需要的热量就相应较低，在处理历程中就可以消耗很少的燃料或不必耗燃料，在浓度更高时甚至还可向外输出热量进行二次热接纳利用。

所以热接纳率成为这里边的要害指标之一，它随着蓄热体材质及造型的变革而变革。

早前，低阶版的蓄热，就是江湖中的TO（气体燃烧炉），其空气预热器为板式或管式，热接纳率国产约50%，德国最大为85%。

现在，进阶版的蓄热，就是RTO，其空气预热器换成了陶瓷填充床，把废气加热到700℃以上，使废气中的VOC氧化剖析为CO2和H2O，氧化爆发的高温气体流经陶瓷蓄热体，使之升温、蓄热，并用来预热后续进入的有机废气，从而节省废气升温燃料消耗的处理技术。

搞懂了RTO事情原理，接下来了解RTO的家族群，也就简单多了。目前处理VOCs的常见形式有：二室RTO、三室RTO和旋转RTO，凭据需求可设计成五室RTO、七室RTO等结构形式。

N室RTO以二室RTO、三室为例，以此类推：

二室RTO事情原理

在开工时先将新鲜空气取代有机废气，借燃烧器将蓄热室加热到一定温度。由于蓄热体具有极高的储热性能，所以从一个冷的RTO加热到一定高的温度，并且还要抵达正常温度漫衍，需要一定的时间。

正常事情时，其中一个蓄热室已在前一个操作循环中存储了热量，有机废气首先从底部进入该蓄热室，废气通过蓄热体床层被预热到接近燃烧时温度，而蓄热体同时逐渐被冷却。

预热后的废气进入顶部燃烧室，在燃烧室中有机物被氧化后，即作为高温净化气进入另一个蓄热室；此时，净化气的热量传给蓄热体，蓄热体床层逐渐被加热，而净化气则被冷却后排出。当被冷却的蓄热体冷却到尚可允许的温度水平时，就应切换气流的偏向，即完成第一个循环。

切换流向后，有机废气进入已被加热过的蓄热室，反应后的净化气则将热量传给上一循环被冷却的蓄热室，如上所述，完成第二个循环。

三室RTO事情原理

三室RTO的蓄热室同时进行操作：当第一台蓄热室处于被冷却而废气被预热的阶段时（冷周期），第二台蓄热室正处于被净化气加热的历程（热周期），而第三台蓄热室则在冲洗（清洗周期）。因此，当一个循环后，废气始终进入到在上一循环时排出净化气的蓄热室，而原来进入废气的蓄热室则用净化气（或空气）冲洗，并将残留的未反应废气送回到反应室进行氧化，然后与净化气一起从冲洗过的蓄热室排出。

在旋转RTO中，革新的焦点部位仍然是蓄热体。旋转式RTO主要由燃烧室、陶瓷填充床和旋转阀等组成。旋转RTO的蓄热体中设置分格板，将蓄热体床层分为几个独立的扇形区。废气从底部经进气分派器进入预热区，使气体温度预热到一定温度后进入顶部的燃烧室，并完全氧化。

净化后的高温气体离开氧化室，进入冷却区，将热量传给蓄热体而气体被冷却，并通过气体分派器排出。而冷却区的陶瓷蓄热体吸热，贮存大宗的热量（用于下个循环加热废气）。

为避免未反应的废气随蓄热体的旋转进入净化气出口去，当蓄热体旋转到净化器出口区之前，设有一扇形区作为冲洗区。

通过蓄热体的旋转，蓄热体被周期性的冷却和加热，同时废气被预热和净化器冷却。如此不绝地交替进行。

At present, there are still many difficulties in VOCs governance. For example, the emission sources are small and scattered, involving many industries. The VOCs emitted by various industries are various in variety and complex. Even in the same industry, if the raw material composition and production process are different, the types and properties of VOCs emitted are different. And the concentration is not the same. Therefore, the required technical route is different.

China's treatment of volatile organic waste gas is mainly divided into four stages:

The first stage, 2000 years ago, the treatment of local irritating or recycled value of exhaust gas, only the irritating exhaust gas through the water spray absorption treatment;

In the second stage, from 2001 to 2005, the exhaust gas was collected and treated in an organized manner, and the main treatment method of the exhaust gas was water and alkali spray two-stage absorption treatment;

The third stage, after 2005, strengthen the source control, improve the centralized collection of exhaust gas, and then strengthen the treatment by activated carbon adsorption on the basis of the second stage;

In the fourth stage, after 2007, the whole process of volatile organic waste gas is gradually processed.

At this stage, China's oxidation control technology for industrial volatile organic waste gases mainly includes: photocatalytic oxidation, direct combustion, catalytic combustion technology and RTO.

Among them, the RTO technology developed on the basis of the combustion method, because of simple operation, less operation and maintenance, high removal efficiency of volatile organic compounds, generally more than 95%, has become one of the main technologies of organic waste gas treatment in China. .

RTO, the full name RegenerativeThermal Oxidizer, Chinese translation "regenerative thermal oxidation combustion", listening is very complicated, isn't it? Don't worry, and listen to Xiaobai slowly. First of all, we can extract three core information from the name - heat storage, thermal oxidation, and combustion. It can be said that this is the purification and concentration of RTO working principle.

Thermal oxidation and combustion are well understood. Organic compounds (VOCs) react with oxygen at a certain temperature to form CO2 and H2O, and emit a certain amount of heat in the oxidation reaction process. Students who have studied chemistry can see this in seconds. What is the key to "heat storage"? How to store heat?

This mysterious heat storage source benefits from the regenerator in the RTO. If the heat recovery rate of the regenerator is higher, indicating that the higher the heat accumulated, the heat required to oxidize the exhaust gas is correspondingly lower, and the fuel can be consumed with little or no fuel during the treatment, and the concentration is higher. It is even possible to export heat to the secondary heat recovery.

Therefore, the heat recovery rate is one of the key indicators here, and it changes with the material and shape of the regenerator.

Earlier, the low-order version of the heat storage was the TO (gas incinerator) in the rivers and lakes. The air preheater was plate or tube type, the heat recovery rate was about 50% domestically, and the largest in Germany was 85%.

Now, the advanced version of the heat storage is RTO, and the air preheater is replaced by a ceramic packed bed, which heats the exhaust gas to above 700 °C, so that the VOC in the exhaust gas is oxidized and decomposed into CO2 and H2O, and the high temperature gas flow generated by oxidation. The ceramic regenerator is used to heat up and store heat, and is used to preheat the organic exhaust gas that is subsequently entered, thereby saving the treatment technology of exhaust gas heating fuel consumption.

Understand the working principle of RTO, and then understand the family of RTO, it is much simpler. The current common forms of processing VOCs are: two-room RTO, three-chamber RTO and rotating RTO, which can be designed into five-room RTO, seven-room RTO and other structural forms according to requirements.

The N-room RTO uses the two-room RTO and three rooms as an example, and so on:

The working principle of two-room RTO

Fresh air is used to replace the organic exhaust gas at the start of the work, and the regenerator is heated to a certain temperature by the burner. Since the regenerator has an extremely high heat storage property, it takes a certain time to heat from a cold RTO to a certain high temperature and to reach a normal temperature distribution.

In normal operation, one of the regenerators has stored heat in the previous operating cycle, and the organic exhaust gas first enters the regenerator from the bottom, and the exhaust gas is preheated through the regenerator bed to near the combustion temperature, while the heat storage is performed. The body is gradually cooled at the same time.

The preheated exhaust gas enters the top combustion chamber, and after the organic matter is oxidized in the combustion chamber, it enters the other regenerator as a high-temperature purification gas; at this time, the heat of the purified gas is transmitted to the regenerator, and the regenerator bed gradually It is heated, and the purified gas is cooled and discharged. When the cooled regenerator is cooled to an acceptable temperature level, the direction of the airflow should be switched, ie the first cycle is completed.

After switching the flow, the organic waste gas enters the regenerative chamber that has been heated, and the purified gas after the reaction transfers the heat to the regenerator that was cooled in the previous cycle, as described above, completing the second cycle.

Three-room RTO working principle

The regenerator of the three-chamber RTO operates simultaneously: when the first regenerator is in a stage where it is cooled and the exhaust gas is preheated (cold cycle), the second regenerator is in the process of being heated by the purified gas (thermal cycle) ), while the third regenerator is flushing (washing cycle). Therefore, after one cycle, the exhaust gas always enters the regenerator that discharges the purified gas in the previous cycle, and the regenerator that originally entered the exhaust gas is flushed with the purified gas (or air), and the residual unreacted exhaust gas is sent. It is returned to the reaction chamber for oxidation and then discharged together with the purge gas from the rinsed regenerator.

In rotating RTO, the improved core is still the regenerator. The rotary RTO is mainly composed of a combustion chamber, a ceramic packed bed and a rotary valve. A filter plate is arranged in the regenerator of the rotating RTO, and the regenerator bed is divided into several separate sectors. The exhaust gas enters the preheating zone from the bottom through the air inlet distributor, so that the gas temperature is preheated to a certain temperature and then enters the top combustion chamber and is completely oxidized.

The purified high temperature gas leaves the oxidation chamber, enters the cooling zone, transfers heat to the regenerator, and the gas is cooled and discharged through the gas distributor. The ceramic regenerator in the cooling zone absorbs heat and stores a large amount of heat (used to heat the exhaust gas in the next cycle).

In order to prevent unreacted exhaust gas from entering the purifying gas outlet with the rotation of the regenerator, a sector is provided as a flushing zone before the regenerator is rotated to the purifier outlet zone.

By the rotation of the regenerator, the regenerator is periodically cooled and heated while the exhaust gas is preheated and cooled by the purifier. This is constantly alternating.