Police Detective

"Even if the room is resealed, there is still air leakage. If some kind of flammable gas was introduced a few days ago, it will be scattered anyway." Bai Song said: "Yao's personal situation must rule out suicide. To be honest, there is no such thing as a gas tank in his house, so if he wants to have enough explosives, he must have enough flammable gases or particles."

"If you talk about pellets, this house is just for accommodation, there is no flour or anything like that." Wang Huadong said.

"Yeah", Bai Song took out a pen and started analyzing on the paper.

The room has a volume of more than 30 cubic meters. Even if gas is not required to fill every part of the room, the amount of flammable gas required is at least five times that of those hydrogen balloons.

"Is it possible that the balloon is not filled with hydrogen?" Wang Liang asked: "Will other gases have lower explosion limits?"

"It's impossible." Wang Huadong shook his head: "There's only so much gas that can float in a balloon, and it's impossible to do this."

"That means there are other gases." After Bai Song finished speaking, he continued: "Or they are particles."

"Will the cake be full of flour?" Wang Liang suddenly thought again.

"If you take a bag of flour at home, you can't even light it. The flour must be evenly distributed in the air, and the cake also has debris, so there's no problem." Bai Song looked at the photo carefully: "Rule out all possibilities , there is only one possibility, the balloons are in these bottles, wine bottles."

"The child was murdered?" Everyone became a little excited.

"The problem is in the bottle? How to do this?" Liu Shuyuan frowned.

"I have a way!" Bai Song suddenly thought of something.

"Say it quickly, don't show off!" Four people surrounded him.

"I thought of something called butene." Bai Song said: "The explosive limit of this thing is very low, within 2%. If two bottles of liquid butene are all volatilized into gas, it may reach in this situation."

"Butene? Where can I get this stuff?" Everyone was a little confused.

"There is this thing in liquefied petroleum gas." Bai Song said: "When I was a child, I used liquefied petroleum gas at home. Sometimes the gas could not come out in the winter because the butene and butane in it could not be vaporized. The gasification of butene The temperature should be about minus six degrees."

"At minus six degrees, it vaporized soon after it was in the bottle? How can we wait until Yao returns?"

"This is the key." Bai Song thought for a while: "It is not difficult to obtain butene. Just buy liquefied gas and then find a way to fractionate it. You can learn how to do this online. In this, we cannot forget one issue, which is butene. Although the boiling point of alkene is minus six degrees Celsius, it is at one atmospheric pressure. If the bottle is sealed to a certain extent and the internal pressure is maintained at more than one atmosphere, there will be no problem."

"It makes sense!" Liu Shuyuan's eyes lit up: "This seal does not need to be too good. The outdoor temperature is only about ten degrees now. It is enough to make the seal just enough to maintain this pressure. Once Yao returns home, turn on the air conditioner With the heat function, when the temperature rises, the seal will break due to the increase in internal air pressure, and then the butene inside will quickly vaporize.”

"Yes!" Wang Huadong also feels that this method is feasible: "And because butene gas has a low density, it will quickly float to the roof and permeate the room. If it reaches a certain concentration, it may explode quickly because there are candles in the room. exist."

"Yes!" Sun Jie nodded: "This plan is feasible. However, specific calculations are needed."

Wang Liang looked confused, looked at everyone, and nodded pretending to be profound: "It makes sense."

Seeing that everyone ignored him, Wang Liang was a little depressed. Then, he suddenly thought of something and said directly: "There is a problem. Isn't the air conditioner turned on, and the air in the room is always exhausted? How could this happen?"

"What are you thinking?" Sun Jie complained: "The outdoor unit of a household air conditioner is not used for exhaust at all. It is used to exchange heat out of things like Freon in the pipe. The air conditioner and the outdoor unit The tubes in between are not ventilated.”

"Oh" Wang Liang pinched his fingers and said nothing.

"Let me do the math." Bai Song used his mobile phone to check the specific physical and chemical properties of charbutene.

Assume that one of the daughters or sons brings butene, then the two bottles add up to one liter, a total of 630 grams, which is about 1 cubic meter after it becomes gaseous.

It can already meet the B-explosion lower limit of 1.6% butene!

"I C, I solved the case and arrested his son and daughter." Wang Liang was very excited.

"There are still problems," Liu Shuyuan said after getting excited, "This state is too ideal."

"Yes", Bai Song expressed his approval: "The most critical difficulty lies in obtaining butene. Although it can be fractionated, the main components of liquefied petroleum gas are propylene, propane, butene, and butane. The first two have relatively low boiling points. , it is easy to fractionate, and the last two are only a few degrees Celsius apart. Without professional equipment, they are likely to stay together. Butane’s B-explosion limit is as high as 19%. The most important thing is, because butene is used in industry More broadly, there may be more butane in LPG.”

"Ah?" When everyone heard what Bai Song said, they were all discouraged.

"So, that's not the case?" Wang Liang started to worry about gain and loss again: "Otherwise, the murderer had special professional channels to obtain this butene."

"If Yao's children were murdered, it would be difficult to obtain the so-called purer butene." Bai Song said: "However, although it may not be achieved, there is still a remedy, and that is to deflagrate the hydrogen balloon, thus This causes the air in a certain area of ​​the room to be squeezed, causing butene and butane that cannot reach the explosive concentration to ignite at once."

"Is it so troublesome?" Wang Huadong was confused: "Then how to make the hydrogen balloon explode? It is impossible to put the hydrogen balloon on the candle, right?"

"The problem lies with the fruit." Bai Song thought for a while, "Fruit can burst the balloon."

"What does this mean?" Wang Liang didn't understand at all.

"Yao's daughter Yao Xin bought oranges for Yao, and it can be seen from the final scene that Yao Xin ate some oranges. Oranges, especially fresh oranges, have flavonoids and limonene in their peels. Can react with rubber. When peeling an orange peel, the liquid from the orange peel splashes onto the balloon, and the balloon will burst. Once the balloon bursts, it can reach the explosion limit in a small area nearby for a moment, and then be ignited by a candle. Then all the other balloons burst, and then triggered a chain reaction, igniting the butene and butane that filled the room, which achieved this effect."

"If you follow what you said, then you can put butene gas in the balloon. The density of this thing is lighter than air." Wang Huadong corrected.

"No, the density of air is 1.2kg per cubic meter. Although butene is 0.6, butane is as high as 2.4. Under the premise that the murderer cannot obtain pure butene, the density of the mixture of butene and butane obtained is higher than that of air. "Bai Song said: "And the hydrogen balloons were bought casually on the road. From the time analysis, the murderer didn't have time to fill them with other gases."

After saying that, Bai Song immediately said: "If this reasoning is true, my daughter is the murderer. Ignore other things and bring her back tonight."