JPS62163729A - Equipment for removing hydrogen chloride contained in exhaust gas - Google Patents

Abstract

PURPOSE:To increase the degree of removal for hydrogen chloride by providing a nozzle for blowing an alkali agent, a throttle part of a duct and a rotary type stirring mechanism to the inlet duct of an electrostatic precipitator and mixing the agent and exhaust gas efficiently. CONSTITUTION:An orifice 2 is provided near to a connection part of both the inlet duct 1 of an electrostatic precipitator 14 and a flue 13, and an alkali agent such as slaked lime is blown through a nozzle 20 provided slightly before the orifice 2 and the first-step mixing of the agent and exhaust gas is performed. Furthermore, a basket type stirring mechanism 3 is provided in the space to a gas rectification lattice 2a of the electrostatic precipitator 14 from the orifice 2, and rotated by a motor or the like and the second-step mixing is performed for the mixed stream of gas and the agent passed through the orifice 2. Thereafter exhaust gas is discharged via the electrostatic precipitator 14.

Description

[Detailed Description of the Invention] The invention relates to an apparatus for removing hydrogen chloride from exhaust gas, which removes 1 tfc of hydrogen chloride contained in exhaust gas from municipal waste incinerators, etc. The purpose is to provide a device that can remove the particles efficiently.

Industrial application field: Two spouts of alkaline chemicals for exhaust gas? Equipment that effectively removes gold hydrogen chloride through mixed contact.

BACKGROUND OF THE INVENTION Equipment for removing hydrogen chloride contained in exhaust gas from waste incinerators and the like has been known to use a dry method in which an alkaline agent such as slaked lime powder is injected into the exhaust gas. That is, this dry method is as shown in (2) below.

■ Blow into the flue using a nozzle.

As shown in FIG.
An alkaline agent 1 such as slaked lime stored in a silo 18 is applied to the flow of exhaust gas that is guided from the air to the electrostatic precipitator 14 and discharged into the atmosphere from the chimney 16 by the induction fan 15.
1 is mixed with air sucked in by a blower 17 and blown into the flue 13 from a nozzle 20 through a transport pipe 19.

■Reaction chamber blowing method.

As shown in FIG. 5, a reaction chamber 23 having a pentuary-type constriction part 21 is installed in the exhaust gas flue 13 as described above,
The alkaline chemical 11 is discharged from the nozzle 22 provided in the constriction part 21.
It is meant to instill.

Problems to be Solved by the Invention The conventional methods described above each have their own problems.

In other words, it is based on the method of ■, and it is Vi equipment V? - The hydrogen silica removal rate of simple products is low; for example, when the slaked lime 780 molar ratio is 1, it is about 40%, and even when this molar ratio is 2, it is as low as about 50%.

The method (2) above completely improves the poor mixing and contact between the chemicals and the exhaust gas compared to the method (2) above, so the hydrogen chloride removal method is approximately 50% at a molar ratio of heavy metal and slaked VHCl of 1. However, in 2, it can be increased by around 65%. However, this level is still far from being sufficient, and even if the total amount of the chemical is increased and the contact time between the chemical and the exhaust gas is extended by about 1-tn, it is not possible to hope for an improvement in the hydrogen chloride removal rate. On the other hand, forming the constricted portion 21 as described above in the flue brings with it a new problem of large pressure loss in the flow of the exhaust gas.

Means for Solving the Constituent Problems of the Invention In an apparatus in which exhaust gas is discharged through an electrostatic precipitator, an alkaline chemical injection nozzle is provided in the artificial duct of the electrostatic precipitator, and the alkaline chemical injection nozzle is This apparatus for removing hydrogen chloride from exhaust gas is characterized in that a constricted part of the duct is formed in the downstream part, and a rotary stirring mechanism is provided on the downstream side of the constricted part.

By providing an alkaline agent blowing nozzle in the duct of the working air dust collector and forming a constricted portion of the duct, the first stage of mixing of the alkaline agent into the exhaust gas is achieved. Subsequently, a second stage of mixing of the exhaust gas and the alkaline chemical is achieved by using a rotary stirring mechanism with a gold film, and the contact between the two through mixing brings about an accurate improvement in the hydrogen chloride removal rate.

EXAMPLE To further explain the present invention as described above, the present inventors have repeatedly studied how to solve the problems in the prior art as described above, and as a result, they have developed a method for removing hydrogen chloride by the dry method described above. The removal rate is determined by how efficiently the chemical and exhaust gas are brought into contact with each other.
The contact time between the two is not a very important factor in this type of plant where equipment is arranged in a limited space. In other words, even in the case of on-site application using method (2) described above, by installing a multi-cyclone (MC) behind the injection position, it is possible to increase the hydrogen chloride removal rate by several percentage points over the entire history, and this is due to the forced removal rate by MC. This is the effect of mixing. In short, 9 MC removes dust from the chemicals as well as the ducts in the exhaust gas, and even though the residence time of the exhaust gas in the MC is extremely short, the improvement in the removal rate is not achieved because of the concentration of chemicals in the exhaust gas. This shows that it is very important to increase the mixed contact gold.

Therefore, in the present invention, as shown in FIG. 1, an orifice 2 is provided near the connecting portion of the electrostatic precipitator 14 in FIG. An alkaline chemical is injected through the provided nozzle 20, thereby achieving first-stage mixing of the chemical and exhaust gas. That is, by such first-stage mixing, the hydrogen chloride removal rate can be increased to about t in accordance with the above-mentioned conventional method (2). In the space up to 2, an electric type stirring device 3 as shown in Fig. 2 is installed, which is rotated by a gold motor or the like. On the other hand, the second stage of mixing is performed.

In other words, Fig. 3 summarizes these results, and the three curves in the figure are those obtained by the conventional method (■), and the three curves in the figure are those obtained by the conventional method (■). However, while the conventional method (2) has a 5-curve shape, the method according to the present invention, which also performs second-stage mixing, has a C-curve shape. 91α When the molar ratio is 1, it is 60%, and when the molar ratio is 2, it is 80%.
It is possible to obtain a high hydrogen chloride removal rate reaching even

The specific operating conditions under which the C curve was obtained are summarized as follows.

Exhaust gas amount Average 3600 ONm”/h Exhaust gas temperature Average 300°C Hydrogen chloride concentration in exhaust gas Average 560 ppm (xz%0
2 conversion) Oriswis section exhaust gas flow velocity average 32m/se
c) Speed of drug injection and storage Average 2Q m/Sec Rotation speed of cage type stirring mechanism 11000rl) ``Effects of the invention'' When the present invention is used as explained above, a reaction chamber is not required as in the conventional method ① described above. So what kind of restrictions are there on the design of the flue? It is possible to effectively increase the removal rate of hydrogen chloride under conditions of low pressure loss and low pressure loss. Effects such as an increase in the gas rectification effect, which is extremely important for dust collectors, can be obtained, and in all these aspects, this invention is industrially very effective.

[Brief explanation of drawings]

The drawings show the technical details of the present invention, and Fig. 1 is a side view showing the main components of the invention, Fig. 2 is a perspective view of the electric type stirring mechanism, and Fig. 3 Illustration summarizing the relationship between the hydrogen chloride removal rate and the slaked lime/Hα molar ratio between the conventional method, comparative example, and the present invention. FIG. 5 is an explanatory view of a Venturi type aperture portion in another example of the prior art. In these drawings, 1 is an inlet duct, 2 is an orifice, 3 is an electric stirring mechanism, 10 is a waste incinerator, and 11 is an electric stirring mechanism.
is an alkaline chemical, 12 is a gas cooling equipment, 13 is a flue, 1
4 is an electric precipitator, 15 is an induction fan, and 16 is a chimney. Part 4 - Enki Ki Tojinki Part -? Picture No.,,rllk Stone Furnace CT Tunnel

Claims (1)

[Claims] In the apparatus in which exhaust gas is discharged through an electrostatic precipitator, an alkaline chemical injection nozzle is provided in the artificial duct of the electrostatic precipitator, and a constricted part of the duct is formed in a downstream part of the alkaline chemical injection nozzle. An apparatus for removing hydrogen chloride from exhaust gas, further comprising a rotary stirring mechanism provided on the downstream side of the throttle part.