阅读说明：本技术 一种蒸发器在线化学清洗方法 (Evaporator on-line chemical cleaning method ) 是由 卢森 邓道林 于 2021-08-17 设计创作，主要内容包括：本发明公开的一种蒸发器在线化学清洗方法,其特征在于,包括：S1,将MVR蒸发器启动运行,当MVR蒸发器达到蒸发出水的温度条件时,把MVR蒸发器内的压缩机停止运行；S2,当压缩机停止运行后,在MVR蒸发器内加入清洗液与MVR蒸发器内的高温原液混合,以使MVR蒸发器内原液PH值达到设定值；S3,将MVR蒸发器内的循环泵开启后,关闭排气阀门,开启回流阀,以形成闭合循环回路,以使清洗液与MVR蒸发器内的高温原液混合后的混合液通过循环泵与喷头喷淋至换热细管表面进行闪蒸,其蒸发后的蒸汽上升经回流阀循环冲洗蒸汽管束；S4,通过观察循环泵出口压力判断管束的清晰状况,当压力基本稳定不再下降后,则重新启动压缩机,正常运行。(The invention discloses an online chemical cleaning method for an evaporator, which is characterized by comprising the following steps: s1, starting the MVR evaporator to operate, and stopping the compressor in the MVR evaporator to operate when the MVR evaporator reaches the temperature condition of evaporated water; s2, after the compressor stops running, adding cleaning liquid into the MVR evaporator to mix with high-temperature stock solution in the MVR evaporator so that the pH value of the stock solution in the MVR evaporator reaches a set value; s3, after a circulating pump in the MVR evaporator is started, an exhaust valve is closed, a return valve is opened to form a closed circulating loop, so that a mixed liquid obtained by mixing a cleaning liquid and a high-temperature stock solution in the MVR evaporator is sprayed to the surface of a heat exchange thin tube through the circulating pump and a spray head to be subjected to flash evaporation, and evaporated steam rises and circularly washes a steam tube bundle through the return valve; and S4, judging the clear condition of the tube bundle by observing the outlet pressure of the circulating pump, and restarting the compressor to normally operate when the pressure is basically stable and does not drop any more.)

1. An on-line chemical cleaning method for an evaporator is characterized by comprising the following steps:

s1, starting the MVR evaporator to operate, and stopping the compressor in the MVR evaporator to operate when the MVR evaporator reaches the temperature condition of evaporated water;

s2, after the compressor stops running, adding cleaning liquid into the MVR evaporator to mix with high-temperature stock solution in the MVR evaporator so that the pH value of the stock solution in the MVR evaporator reaches a set value;

s3, after a circulating pump in the MVR evaporator is started, an exhaust valve is closed, a return valve is opened to form a closed circulating loop, so that a mixed liquid obtained by mixing a cleaning liquid and a high-temperature stock solution in the MVR evaporator is sprayed to the surface of a heat exchange thin tube through the circulating pump and a spray head to be subjected to flash evaporation, and evaporated steam rises and circularly washes a steam tube bundle through the return valve;

and S4, judging the clear condition of the tube bundle by observing the outlet pressure of the circulating pump, and restarting the compressor to normally operate when the pressure is basically stable and does not drop any more.

2. An on-line chemical cleaning method for an evaporator according to claim 1, characterized in that: in the step S1, the temperature of the water evaporated by the MVR evaporator is above 102 ℃.

3. An on-line chemical cleaning method for an evaporator according to claim 1, characterized in that: in the step S2, the cleaning solution is sodium hydroxide or sulfuric acid.

4. An on-line chemical cleaning method for an evaporator according to claim 3, characterized in that: in the step S2, sulfuric acid is added to adjust the PH of the stock solution in the MVR evaporator to 5, or sodium hydroxide is added to adjust the PH of the stock solution in the MVR evaporator to 12.

5. An evaporator on-line chemical cleaning method as claimed in claims 1 to 4, characterized in that: and in the step S4, the device further comprises a pressure gauge arranged at the outlet of the circulating pump, and the pressure gauge is used for monitoring the outlet pressure of the circulating pump in real time.

6. An on-line chemical cleaning method for an evaporator according to claim 1, characterized in that: and in the step S2, the device further comprises a pH value automatic control feeding device for detecting the pH value of the stock solution in the MVR evaporator and automatically feeding the cleaning solution according to the setting.

Technical Field

The invention relates to an online chemical cleaning method for an evaporator.

Background

MVR is short for mechanical vapor recompression technology, and is an energy-saving technology for reusing secondary vapor generated by evaporation so as to reduce the requirement on external energy.

The specific working principle of MVR is as follows: the incoming liquid passes through the heat exchanger, the exhaust condenser performs heat exchange twice, the temperature of the incoming liquid is heated to be nearly 100 ℃, then the incoming liquid enters the hot well of the main body, the incoming liquid is sprayed onto the surface of the heat exchange tubules in the main body through the circulating pump of the main body to perform heat exchange evaporation, the incoming liquid which is not evaporated falls back into the hot well and is filtered through the scraper filter, then the incoming liquid is discharged through the concentrated liquid pump, the evaporated steam is recompressed through the acting of the compressor, the effect of increasing the temperature and the pressure is achieved, the incoming liquid enters the tubules in the main body to perform heat exchange and condensation, the generated non-condensable gas is discharged through the exhaust condenser in a heat exchange manner, and the condensed distilled water is discharged to the heat exchanger through the distilled water tank to perform heat exchange treatment and then is discharged to obtain qualified normal-temperature distilled water. Latent heat is recovered through heat exchange, and heat utilization efficiency is improved.

Since calcium, magnesium and the like in the evaporated stock solution are adsorbed onto the evaporated tube bundle during the long-term operation of the evaporation equipment, resulting in the reduction of the evaporation capacity, the tube bundle of the evaporation equipment needs to be cleaned periodically.

Disclosure of Invention

Aiming at the defects in the prior art, the technical problems to be solved by the invention are as follows: compared with the traditional method for cleaning evaporation main body equipment, the method greatly saves the cleaning time and has better cleaning effect.

An on-line chemical cleaning method for an evaporator comprises the following steps:

s1, starting the MVR evaporator to operate, and stopping the compressor in the MVR evaporator to operate when the MVR evaporator reaches the temperature condition of evaporated water;

s2, after the compressor stops running, adding cleaning liquid into the MVR evaporator to mix with high-temperature stock solution in the MVR evaporator so that the pH value of the stock solution in the MVR evaporator reaches a set value;

s3, after a circulating pump in the MVR evaporator is started, an exhaust valve is closed, a return valve is opened to form a closed circulating loop, so that a mixed liquid obtained by mixing a cleaning liquid and a high-temperature stock solution in the MVR evaporator is sprayed to the surface of a heat exchange thin tube through the circulating pump and a spray head to be subjected to flash evaporation, and evaporated steam rises and circularly washes a steam tube bundle through the return valve;

and S4, judging the clear condition of the tube bundle by observing the outlet pressure of the circulating pump, and restarting the compressor to normally operate when the pressure is basically stable and does not drop any more.

Further, in the step S1, the temperature of the water evaporated by the MVR evaporator is above 102 ℃.

Further, in the step S2, the cleaning solution is sodium hydroxide or sulfuric acid.

Further, in the step S2, sulfuric acid is added to adjust the PH of the stock solution in the MVR evaporator to 5, or sodium hydroxide is added to adjust the PH of the stock solution in the MVR evaporator to 12.

Preferably, in the step S4, a pressure gauge is further included, and the pressure gauge is used for monitoring the outlet pressure of the circulation pump in real time.

Preferably, in the step S2, a PH automatic control feeding device is further included to detect a PH of the stock solution in the MVR evaporator and automatically feed the cleaning solution according to a setting.

In summary, compared with the prior art, the invention has the beneficial effects that:

the invention has simple structure, directly adds the cleaning liquid into the evaporation equipment under the condition of reaching the temperature of the evaporated water through the MVR evaporator, directly mixes the cleaning liquid with the high-temperature stock solution in the evaporation equipment, and achieves the effect of cleaning the tube bundle through the circulating flushing of the main circulating pump.

Drawings

FIG. 1 shows an on-line chemical cleaning method for an evaporator according to an embodiment of the present invention.

Detailed Description

The invention will be further described with reference to the following description and embodiments in conjunction with the accompanying drawings:

as shown in fig. 1, the embodiment of the present invention preferably provides an on-line chemical cleaning method for an evaporator, comprising:

s1, starting the MVR evaporator to operate, and stopping the operation of the vapor compressor 10 in the MVR evaporator when the MVR evaporator reaches the temperature condition of evaporated water;

s2, after the steam compressor 10 stops running, adding cleaning liquid into the MVR evaporator to mix with the high-temperature stock solution in the MVR evaporator so that the pH value of the stock solution in the MVR evaporator reaches a set value;

s3, after a circulating pump 17 in the MVR evaporator is started, closing an exhaust valve 10 and opening a return valve 9 to form a closed circulating loop, so that a mixed solution obtained by mixing cleaning solution and high-temperature stock solution in the MVR evaporator is sprayed to the surface of a heat exchange thin tube 12 through the circulating pump 17 and a spray head to be subjected to flash evaporation, and evaporated steam rises and circularly washes a steam tube bundle through the return valve 9;

and S4, judging the clear condition of the tube bundle by observing the outlet pressure of the circulating pump, and restarting the compressor to normally operate when the pressure is basically stable and does not drop any more.

Specifically, as shown in fig. 1, the system comprises a heat exchanger, an exhaust condenser 1, an evaporation chamber 26 and a distilled water tank 4; the heat exchangers are provided with a first heat exchanger 5 and a second heat exchanger 6 respectively, the input end of the first heat exchanger 5 and the input end of the second heat exchanger 6 are connected with a liquid inlet pipe 7 in parallel, and the output end of the first heat exchanger 5 and the output end of the second heat exchanger 6 are connected with the input end of the exhaust condenser 1 in parallel through a first pipeline 8; the evaporation chamber 26 is communicated with a pipeline III 9 between the upper part and the lower part of the evaporation chamber, a vapor compressor 10 is arranged on the pipeline III 9, a spraying device 11, a heat exchange tubule 12 and a hot well 13 are sequentially arranged in an inner cavity of the pipeline III from top to bottom, a pipeline IV 14 is communicated between the output end of the hot well 13 and the input end of the heat exchanger I5, a concentrated liquid pump 15 is arranged on the pipeline IV 14, a pipeline V16 is communicated between the output end of the hot well 13 and the input end of the spraying device 11, and a circulating pump 17 is arranged on the pipeline V16; the spraying device 11, the heat exchange tubule 12 and the hot well 13 in the evaporation chamber 26 mainly evaporate incoming liquid to separate water vapor and concentrated liquid, then the vapor compressor 10 does work to compress and pressurize the vapor evaporated in the evaporation chamber 26, the vapor with higher pressure and temperature is sent back to the evaporation chamber 26 to exchange heat with the incoming liquid to be evaporated, the liquid is evaporated, and the vapor is finally condensed into water; the heat exchanger mainly comprises a distilled water plate exchanger and a concentrated solution plate exchanger, wherein the distilled water plate exchanger mainly exchanges heat between the qualified distilled water after treatment and the coming solution, and the distilled water plate exchanger mainly exchanges heat between the concentrated solution obtained by performing sewage evaporation separation on an evaporation main body and the coming solution; a second pipeline 18 is communicated with the input end of the lower part of the evaporation chamber 26, a sixth pipeline 19 is communicated between the output end of the exhaust condenser 1 and the input end of the hot well 13, a seventh pipeline 20 is communicated between the output end of the exhaust condenser and the input end of the distilled water tank 4, and an eighth pipeline 21 is communicated between the input end of the exhaust condenser and the lower part of the evaporation chamber 26; the exhaust condenser 1 exchanges heat between the non-condensable gas discharged from the main body and the incoming liquid, and the temperature of the incoming liquid is raised to about one hundred degrees, and the incoming liquid enters the inner cavity of the evaporation chamber 26 to be evaporated and separated.

According to the MVR structure, the specific working principle is as follows: incoming liquid passes through the heat exchanger, the exhaust condenser 1 performs heat exchange twice, the temperature of the incoming liquid is heated to be nearly 100 ℃, then the incoming liquid enters the hot well 13 of the main body, the incoming liquid is sprayed onto the surface of the heat exchange tubule 12 in the main body through the circulating pump 17 of the main body to perform heat exchange evaporation, the incoming liquid which is not evaporated falls back into the hot well 13 and is filtered through a scraper filter (not shown in the figure), then the incoming liquid is discharged through the concentrated liquid pump 15, the evaporated steam is recompressed through the acting of the steam compressor 10, the effect of increasing the temperature and increasing the pressure is achieved, the incoming liquid enters the heat exchange tubule 12 of the main body to perform heat exchange and condensation, the generated non-condensable gas is discharged out through the exhaust condenser 1 for heat exchange, and the condensed distilled water is discharged to the heat exchanger 1 through the distilled water tank 4 for heat exchange treatment and then is discharged out qualified normal-temperature distilled water.

When the evaporation capacity is reduced and the steam tube bundle needs to be cleaned, the MVR evaporator is operated until the temperature condition of evaporated water is reached, then the steam compressor 10 is stopped to operate, cleaning liquid is added into the MVR evaporator to be mixed with high-temperature stock solution in the MVR evaporator so that the pH value of the stock solution in the MVR evaporator reaches a set value, a circulating pump 17 in the MVR evaporator is opened, an exhaust valve 10 is closed, a reflux valve 9 is opened to form a closed circulating loop, so that mixed liquid obtained by mixing the cleaning liquid and the high-temperature stock solution in the MVR evaporator is sprayed to the surface of a heat exchange tubule 12 through the circulating pump 17 and a spray head to carry out flash evaporation, evaporated steam rises and circularly washes the steam through the tube bundle reflux valve 9, calcium and magnesium ions and the like on the steam tube bundle are cleaned, the cleaning time is greatly saved, the cleaning effect is better, an operator observes the outlet pressure of the circulating pump 17 to judge the cleaning condition of the tube bundle, when the pressure is basically stable and does not drop any more, the compressor can be restarted to normally operate.

In the step S1, the temperature of the water evaporated by the MVR evaporator is above 102 ℃.

In the step S2, the cleaning solution is sodium hydroxide or sulfuric acid.

In the step S2, sulfuric acid is added to adjust the PH of the stock solution in the MVR evaporator to 5, or sodium hydroxide is added to adjust the PH of the stock solution in the MVR evaporator to 12.

And in the step S4, the device further comprises a pressure gauge arranged at the outlet of the circulating pump, and the pressure gauge is used for monitoring the outlet pressure of the circulating pump in real time.

And in the step S2, the device further comprises a pH value automatic control feeding device for detecting the pH value of the stock solution in the MVR evaporator and automatically feeding the cleaning solution according to the setting. Specifically, the PH automatic control feeding device adopts the prior art, which is not described in detail herein, and refer to the related art disclosed in chinese patent No. CN206676357U for details.

While there have been shown and described the fundamental principles and principal features of the invention and advantages thereof, it will be understood by those skilled in the art that the invention is not limited by the embodiments described above, which are given by way of illustration of the principles of the invention, but is susceptible to various changes and modifications without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.