JP2020169257A - Detergents for aluminum fins of industrial air conditioners and methods of using the same - Google Patents

Abstract

To provide two types of safe detergents for food processing factories and metal processing factories, which can improve the safety of workers and reduce the burden on the global environment, and to provide a method for using the same.SOLUTION: Cleaning agents that chemically generate microbubbles by blending raw materials. In recent years, research on fine bubbles (microbubbles) has progressed, and it has become clear that they are very effective in cleaning. Two types of detergents have been invented for cleaning aluminum fins of industrial air conditioners. The cleaning power of the cleaning agents are equal to or higher than that of commercially available detergents containing caustic soda, and the cost of manufacturing of the cleaning agents is low.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cleaning agent for aluminum fins of an air conditioner for the industrial field and a method of using the cleaning agent.

Air conditioners, air conditioners, etc. have become widespread as social infrastructure for each home, each workplace, and each factory, and have become indispensable to the world. If an air conditioner, air conditioner, etc. is used, the aluminum fins will become dirty, causing problems such as deterioration of thermal efficiency (that is, increase in power consumption) and mold contamination sources, so appropriate regular maintenance is required. ing. FIG. 1 is an image diagram of business fields and objects for cleaning aluminum fins of various types of air conditioners, air conditioners, and the like.

The business fields covered by the present invention are air conditioners, unit coolers, industrial floor-standing air conditioners, oil coolers, spot coolers, air-cooled chillers, etc. installed in a food processing factory, b metal processing factory, etc. shown in FIG. Heat exchanger Aluminum fins (hereinafter abbreviated as aluminum fins) cleaning agents and their usage methods.

The performance required for aluminum fin cleaning agents in the relevant industrial field is high work standards such as those that allow workers to work safely and those in which the waste liquid after cleaning complies with the Water Pollution Control Law for public water areas of the Basic Environment Law. There is a request. However, there was no safe aluminum fin cleaning agent that could be used.

The maintenance work of industrial air conditioners is to regularly clean the plastic filters or disposable non-woven fabric filters installed on the front (suction surface) of the air conditioner aluminum fins. In some factories, etc., the dust adhering to the aluminum fins is blown off with a blower, but cleaning of the aluminum fins at the end of the filter is not controlled. It is common for the work environment to be replaced with a new air conditioner after using it for about 10 years.

Air conditioners that are heavily soiled are generally cleaned by diverting an aluminum fin cleaning agent containing sodium hydroxide as the main component, which is used for consumer use.
Certainly, the cleaning agent containing sodium hydroxide has a detergency enough to dissolve aluminum fins, but the waste liquid treatment after cleaning is waste liquid treated as specially controlled industrial waste with ph = 12.5 or more, and the waste liquid is specialized for taking home. Outsource the treatment to an industrial waste treatment company. Alternatively, after confirming the neutralization treatment with a neutralizing agent (acidic liquid), it is necessary to pour it into a sewer or devise a waste liquid treatment shown in Patent Document 1.

Since indoor units such as air conditioners and air conditioners are located in high places, the waste liquid can be collected by devising a vinyl curing tool (hopper) that wraps the entire indoor unit so that the waste liquid can be completely collected in the cleaning work process. It is in a state.
However, when cleaning the outdoor unit, there are many environments where the outdoor unit is installed directly on the ground or on the roof, so to collect the waste liquid after cleaning the aluminum fins, suck and collect it with a large vacuum truck. Other than that, it is in a state of dripping and it is actually difficult to collect the waste liquid. Therefore, it has been desired to develop an aluminum fin cleaning agent for an outdoor unit that is safe even if the waste liquid after cleaning is drained.

JP-A-2015-066550

The conventional cleaning method using a strongly alkaline cleaning solution containing caustic soda certainly has detergency, but has the following problems that impose a heavy load on workers and the global environment.
Problem 1: There is a risk of blindness if the caustic soda solution gets into the eyes of the operator. It is essential to wear goggles and non-permeable rubber gloves to protect the eyes, as they cause inflammation when they adhere to the skin.
Problem 2: The strongly alkaline caustic soda solution is a dangerous substance (treated as a deleterious substance) that cannot be poured into the sewage ditch according to the environmental standard for water pollution of the Basic Environment Law. Since it is necessary to outsource the treatment of waste liquid to an industrial waste business operator approved by the prefectural governor, the treatment cost will be increased accordingly.
Problem 3: The use of such a dangerous cleaning agent in a food processing factory itself is a great risk. In the unlikely event that the trouble is mixed with the ingredients, it can be predicted that a very expensive price will be paid.

As a result of intensive research to achieve the solution of the above problem, the present inventors contribute to the solution of the problem by utilizing the microbubble technology and the cleaning agent that generates microbubbles (called macrobubbles) by chemical means. Based on this finding, the present invention was made.

That is, the present invention is as follows.
The invention according to claim 1 is a cleaning agent corresponding to aluminum fins in a food processing factory, which is a cleaning method using alkaline (indicated as agent D in FIG. 1) and acidic (indicated as agent B in FIG. 1). ..
The concentrations of Agent D and Agent B are formulated so that the concentration neutralized by the same volume volume of one cap of the bottle and the chemical equivalent of the hydrogen ion concentration are the same.
Put 1 cap (about 10 g mass) of each of D agent and B agent in 2 buckets of 10 liters, dilute to about 1 mass% with 1 liter of tap water, and spray each on aluminum fins in sequence. .. After that, it is washed with a high pressure washer (water pressure 5 to 10 megapascals) until it becomes fresh water.
At the site, the amount of agent D and agent B used is estimated according to the size of the aluminum fin and the degree of dirt. It is important to maintain the neutralization treatment by using the same volume volume of Agent D and Agent B.

The invention according to claim 2 clarifies the composition of the contents of the agent D (alkaline agent) and the agent B (acidic agent). The component of the agent D is a mixture of sodium percarbonate (2NaCO3.3H2O2), 25 to 75% by mass, and sodium hydrogen carbonate (NaHCO3), 25 to 75% by mass. The component of Agent B is 100% by mass of CH2 (COOH) C (OH) (COOH) CH2 (COOH) citrate.

The invention according to claim 3 is a cleaning agent for aluminum fins in a metal processing factory (indicated as agent E in FIG. 1), a stain on mineral oil during metal processing, an oil cooler attached to a machine tool, and a spot. It cleans aluminum fins of air conditioners and outdoor units.
The composition of the E agent is sodium percarbonate (2NaCO3.3H2O2), 20 to 50% by mass, sodium hydrogen carbonate (NaHCO3), 20 to 50% by mass, citric acid, 20 to 75% by mass, and% rate agent, 25 to 75% by mass. % (EDTA agent of Kirest Co., Ltd., etc.) is a mixture of at least 4 types. E agent, 1 cap (about 10 g mass) is put in a 10 liter bucket, diluted with 1 liter of tap water, and sprayed on aluminum fins. After that, it is washed with a high pressure washer until it becomes fresh water.

In claim 1 of the present invention, by spraying the alkaline cleaning agent D onto the aluminum fins, acidic stains (sebum dirt, higher fatty acid stains such as vegetable oil, etc.) are peeled off, and then the acidic cleaning agent B is sprayed. This makes it possible to remove both alkaline stains (water stains, soap scum, urine, etc.). This is a cleaning method in which the neutralization treatment is completed as a result of collecting all the waste liquid in a bucket by using the same amount of the alkaline cleaning agent and the acidic cleaning agent.

Since there is a correlation between dirt and bad odor, and bad odor is also a mixed substance of acidic odor and alkaline odor, cleaning with both an acidic solution and an alkaline solution has the effect of removing the bad odor at the same time.

In claim 2, it is a component of a cleaning agent in which a powdered cleaning agent, a powdered mixture of sodium percarbonate and sodium hydrogencarbonate, and a powder of citric acid are used instead of a solution of a dangerous cleaning agent containing caustic soda.
The ingredients of the three types of drugs are used in large quantities in various fields in the world, and they are safe drugs and inexpensive. Sodium percarbonate is used as a safe bleaching agent, and sodium carbonate and citric acid are used in large quantities as raw materials for cider and lemon water. In addition, sodium hydrogen carbonate and citric acid are food additives and are safe chemicals used in large amounts in food factories and the like.

Details will be described later, but when these cleaning agents are dissolved in water (preferably hot water of 40 ° C or higher), carbon dioxide gas CO2 of fine bubbles (called microbubbles) with a thickness of hair (about 100 μm) or less , Or oxygen gas O2 is generated. Therefore, when stored in a closed container in liquid form, the container bursts due to the pressure of the microbubbles, so it is safe and best to transport it in powder form and dilute it with water or hot water on site. ..

When cleaning the aluminum fins of an outdoor unit or the like installed outdoors using the cleaning agents D and B shown in claim 2, the waste liquids of the D and B agents are finally mixed and medium. Since it is treated in Japanese, it is not necessary to collect the waste liquid. Compared to conventional cleaning agents containing caustic soda, it is a highly safe cleaning agent that is friendly to workers and the environment.

A third aspect of the present invention is a cleaning agent developed exclusively for lubricating oil (mineral oil) stains in metal processing factories, particularly aluminum fins of an oil cooler attached to a machine tool. The detergency was insufficient with the cleaning agents for food factories and the diversion of the above D and B agents. By mixing a chelating agent that blocks metal ions, it becomes a cleaning agent that removes mineral oil stains.
Further, the agent E is prepared with an acidic agent, citric acid (powder), for the purpose of promoting foaming and neutralizing. When the agent E is dissolved in tap water, microbubbles are generated and at the same time, the liquidity of the aqueous solution becomes neutral.
At the time of cleaning, put a cap (about 10 g) of E agent in a 10 liter bucket, dilute with 1 liter of tap water, spray on aluminum fins, and then wash off the mineral oil stains peeled off with a high pressure washer. is there.
The waste liquid (mineral oil) after cleaning is designated as a specially controlled industrial waste, and is stored in a drum can and the treatment is outsourced to a specialized industrial waste treatment company.

Further, the agent E is also effective for cleaning the aluminum fins of air-cooled outdoor units such as air conditioners and refrigerators that are contaminated with exhaust gas, which is a petroleum-based stain. Since the waste liquid after cleaning is blended so as to be neutralized with a mixture of four types of cleaning agents, it is safe even if it drips onto the ground.

It is an image diagram of the business field and the object of aluminum fin cleaning of each type of air conditioner, air conditioner, etc. It is a temperature characteristic of the volume (volume, ml) of oxygen O2 generated when 10 g of sodium percarbonate is dissolved in 200 ml of hot water. (Source: Papers by 5 other than Yoko Gushiken, 2013, J.FAC.EDC.SAGA.UNIV.VOL.18, NO1) The verification inspection data of the cleaning agent of the present invention and the cleaning power of the D agent are inspected for oil stains in the kitchen. It is a state (photograph) of the change of oil stain when the agent D of the present invention was put into the gristrap of the ramen shop where the verification inspection data of FIG. 3 was carried out. It is a monitoring result by 7 subjects comparing the product of the present invention, the cleaning agent D and the cleaning agent E with a commercially available aluminum fin cleaning agent (product mixed with caustic soda). Elucidation of the cleaning effect of microbubbles, data on the mechanism by which negatively charged microbubbles exfoliate positively charged vegetable oil stains. (Source: Hideki Tsuge's paper, Journal of the Seawater Society of Japan, Vol. 64, No. 1, 2010)

The details of the examples of the present invention will be described below.
The mechanism by which the three types of cleaning agents (D agent, B agent, and E agent) according to claims 2 and 3 generate microbubbles will be described by a chemical formula.

The generation of carbon dioxide CO2 and the generation of oxygen gas O2 when water is added to the cleaning agents D and B for air conditioner aluminum fins in a food processing factory will be described.

(1) The chemical change when an aqueous solution of citric acid is added to sodium hydrogen carbonate is given by the following equation. Microbubbles of citrate, water and carbon dioxide CO2 are generated.

CH2-COOH CH2-COONa
｜ ｜
C (OH) COOH + 3NaHCO3 → C (OH) COONa + 3H2O + 3CO2
｜ ｜
CH2-COOH CH2-COONa

(2) Next, the chemical reaction when sodium percarbonate reacts with water is given by the following equation.
As a result of the reaction, microbubbles of sodium carbonate, water and oxygen gas O2 are generated.

2NACO3 ・ 3H2O2 → 2NACO3 + 3H2O2
2H2O2 → 2H2O + O2

Figure 2 shows the amount of oxygen gas O2 (volume V) when hot water is added to sodium percarbonate, specifically by Gushiken et al. (5 outside Gushiken Sonoko, 2013, J.FAC.EDC.SAGA.UNIV.VOL) This is the data measured by .18, NO1). It can be understood that the higher the temperature of the hot water, the faster it generates a large amount of oxygen gas O2.

The inventors have observed that a large amount of white microbubbles are generated when the D agent is put in a cup and hot water at 60 ° C. is poured. It has been observed that when this is placed in a PET bottle and the cap is tightened tightly, the PET bottle swells due to the gas pressure of carbon dioxide gas CO2 and oxygen O2 and bursts.
Also, if you put the D agent in a cup, leave the D agent dissolved in hot water for 24 hours, and then irradiate the aqueous solution with the white microbubble bubbles disappeared with a red laser beam, you can observe the linear trajectory of the laser beam brilliantly. I'm checking. It is presumed that microbubbles or nanobubble bubbles remain and that the laser beam is diffusely reflected.
Similarly, it has been confirmed that even if tap water is irradiated with a laser beam, the trajectory of the laser beam cannot be found in the cup.

The inventors have verified and verified the cleaning effect of the D agent on oxygen O2 gas, generation of microbubbles and oil stains by the following three methods.
The first verification method will be described.
FIG. 3 shows data verified at two locations, a ramen shop and a bakery shop (bakery shop). The D agent (600 g) was put into the gristrap that collects the wastewater from each kitchen, and the change in water quality (normal hexane extract and biochemical oxygen demand BOD value) after 24 hours was inspected. The container containing the two solutions before and after the addition of the D agent was sent to the Chiba Prefectural Pharmacist Inspection Center and requested to be inspected.
The test data at the two locations showed the same tendency, and both the normal hexane extract and BOD decreased.
The value of normal hexane extract from ramen shops decreased to 1/13 of that before the introduction. The value of the bakery shop decreased to 1/5. The ramen shop was more oily than the bakery shop, and the amount of oil was 1.5 times more. We also visually observe that the ramen shop has a large amount of oil stains.
The value of biochemical oxygen demand BOD decreased to 1/3 at the same rate in both places. It can be understood that the decrease in the normal hexane extract material reduces the oil stains, and the decrease in the BOD value indicates that a large amount of oxygen O2 is supplied to the wastewater.

The result of the second verification method is shown in FIG.
The D agent (1 bottle, 600 g) was put into the gristrap of a ramen shop, and the change in the tank was observed 24 hours later. The sewage expanded due to the generation of microbubbles of the D agent, and the sewage overflowed from the gristrap tank. You can see how it is.

The result of the third verification method is shown in FIG.
FIG. 5 compares the detergency of the D and E agents with a commercially available cleaning agent containing caustic soda, and is the result of monitoring by seven test subjects. ■ Mark is a commercially available aluminum fin cleaning agent containing caustic soda, ◎ mark is E agent, and ▲ mark is D agent.
Five out of seven people judged that the detergency of ◎ E agent was the best, ■ mark (commercially available product with caustic soda) was second, and ▲ mark (D agent) was third.
The cleaning power test method is to attach it to the ventilation fan of the kitchen and use it, then cut a black-stained non-woven fabric filter into strips of the same size and soak them in each cleaning solution for 24 hours to determine the degree of oil stain removal. It was visually compared and ranked by 7 subjects.
Based on the above judgment results, the difference between the three types of detergency is small, and the three detergency have practical detergency.

Figure 6 shows the data published in a paper explaining the mechanism of cleaning by microbubbles (Hideki Tsuge, Journal of the Seawater Society of Japan, Vol. 64, No. 1, 2010).
Microbubbles of 100 μm or less have a negative charge (zeta potential) in the alkaline region of the solution, and have the effect of largely removing positively charged acidic stains (sebum dirt, higher fatty acid stains such as vegetable oil, etc.). is there.
In the acidic region, it has a positive charge and has the effect of removing alkaline stains (water stains, soap scum, urine, etc.).
FIG. 6 shows the zeta potential measured by generating microbubbles with distilled water, and the zeta potential corresponding to Ph was measured by adjusting the pH of the aqueous solution with hydrochloric acid and caustic soda.
In a general environment, there are many positively charged stains, and as shown in the characteristics of Fig. 6, the zeta potential is also generated as the Ph increases. Therefore, in the region where the cleaning effect by microbubbles is remarkably exhibited. I can understand that there is.

Aluminum fins for industrial heat exchangers are applied to devices that generate heat, such as compressors and dehumidifiers, in addition to air conditioners and refrigerators. Further, it is applied to cleaning machinery of a metal processing factory, indoor walls, floors and outdoor walls of a factory building.

Claims (3)

After diluting each of the two types of cleaning agents, alkaline and acidic, for the air conditioner aluminum fins of food processing factories with water, each of them is sprayed sequentially on the air conditioner aluminum fins to remove dirt adhering to the aluminum fins. The method of floating and cleaning with the water pressure of a high pressure washer, and the alkaline solution and the acidic solution are prepared so that they have the same chemical equivalent, and when each cleaning agent is mixed in the same volume volume, it is neutralized and the hydrogen ion concentration is neutral. A cleaning agent for aluminum fins for food processing factories, which is characterized by becoming an area, and how to use it. The component of the alkaline cleaning agent according to claim 1 is a mixture of at least two kinds of sodium percarbonate (2NaCO3 / 3H2O2), 25-75% by mass and sodium hydrogencarbonate (NaHCO3), 25-75% by mass, and acidic. The components of the cleaning agent are 100% by mass of citric acid CH2 (COOH) C (OH) (COOH) CH2 (COOH), each cleaning agent is diluted with water, and carbon dioxide CO2 and oxygen O2 microbubbles generated are aluminum. The cleaning agent according to claim 1, which is characterized by removing vegetable oil stains adhering to fins, and a method for using the cleaning agent. Cleaning agent for oil coolers attached to machine tools installed in metal processing factories, the components of the cleaning agent are sodium percarbonate (2NaCO3.3H2O2), 20-50% by mass and sodium hydrogen carbonate (NaHCO3), 20- A mixture containing at least 4 types of 50% by mass, CH2 (COOH) C (OH) (COOH) CH2 (COOH) 20 to 75% by mass and a chelating agent, 20 to 75% by mass, and the cleaning agent. The aluminum fins of the oil cooler are sprayed, and the fine bubbles of carbon dioxide CO2 and oxygen O2 generated are used to remove dirt from the lubricating oil or exhaust gas that has adhered to the aluminum fins. Cleaning agents for outdoor units, etc. and how to use them