On the morning of May 27, Lu Chen got up and washed up while thinking about what he could do today.

"First of all, the building materials of the shelter are gone, and it will take a month for the vegetables to mature for the time being, so you have to go outside to find out if there are any sand, gravel and cement these things, the city has been vigorously developing construction in recent years, and the official is also collecting these materials, after a few days it is estimated that the collection is almost, I can go to see if there are any fish that have slipped through the net, and high-energy batteries have to start research as soon as possible, and go out to collect materials, if only one pickup truck is estimated to be not enough, but also to make an external compartment to load materials, and the boom that I prepared before can also be manufactured and installed, as well as the main device of the mechanical skeleton, oh yes, I have to prepare a small cart, and I have to prepare a lot of things,"

Then Lu Chen looked at the time, as of ten o'clock in the morning, the nano core had accumulated 350 points of energy, and then Lu Chen used 100 points and 200kg of steel and 10kg of rubber to make a tractor compartment, but it was four wheels, and the load was estimated to be about 3 tons, and then he took out 50 points of energy to form a crane arm directly in the back compartment of the pickup truck, and then according to the previous design, spent 100 points of energy to make the exoskeleton mechanical booster device using the nano core. Finally, I put the folding cart of the shelter in the compartment, took a bucket of oil (the 20-liter kind) and set off.

......

The streets of Tingcheng were empty, and there was a faint black smoke in the distance that did not disperse, it was the result of the meteorite impact, Lu Chen's shelter was in a position between the southern city of Tingcheng and the town below, plus there were no vehicles on the road, so Lu Chen took twenty minutes to get to Nancheng District, there was a big crater not far away, and the surrounding communities were staggered by the meteorite impact, Lu Chen also saw that several buildings on the side had fallen next to the buildings next to them, and some vehicles parked on the side were damaged, At this time, the meteorites in the pit have been officially transported away, leaving only a big pit, Lu Chen looked at this big pit, it has destroyed the surrounding roads, and has no choice but to detour, but thanks to the development of the southern urban area in recent years, the road is built in all directions, and the detour has no effect, Lu Chen found a community under construction around, there is no one in it, Lu Chen drove the car into the construction site, and found that most of the equipment and materials on the construction site have been transported away, leaving only some unfinished buildings.

After Lu Chen parked the car, he searched the surrounding open space for a while, and found two bags of cement, some steel bars, and some sand and gravel, but there were not many, only some remnants on the ground, Lu Chen took a shovel and shoveled it up, found a bag and put it up.

After Lu Chen put these things in the car, he went to search for a building next to him, and after more than an hour of searching, he found 5 bags of cement piled in the corner of the building, but he didn't find much steel bar, and there was no sand and gravel.

Lu Chen got in the car first and walked around the construction site, and found that the community behind it had been built, and it seemed that there were also residents decorating, Lu Chen felt that there should be a harvest here.

Then Lu Chen parked the car under a building, went upstairs to see, after searching layer by layer, Lu Chen found that there were ten households in this building being renovated, and the doors were open, and then Lu Chen went in and found that almost every house had materials like sand and gravel cement, but the sand was piled together, Lu Chen found the remaining cement bags and packed them up, and finally after nearly two hours of busyness, he finally moved the building materials to the car, Lu Chen counted it, there was nearly a ton of sand, and about 500kg of cement, There were only a few steel bars that he had found in the open space before, and Lu Chen thought about it and found that what he needed was not steel bars but steel, so Lu Chen threw away the steel bars directly, and then drove to the steel factory, after all, there was still a lot of steel over there.

According to the map, Lu Chen found a steel company, and found that the door was open, which should have been collected by the official, and Lu Chen drove in to try his luck.

After entering, Lu Chen found that there was also a small construction site in the innermost part of the steel plant, but the equipment inside was also dismantled, Lu Chen came to the workshop and found that the workshop was empty, and all the equipment inside had been transported away, as for where it was transported, there was no need to guess that Lu Chen also knew that it was transported to the official shelter, after all, even if he went to the shelter, he would not just wait for the disaster to pass, and he would definitely have to produce, otherwise many materials would not be enough for all people to use.

The workshop of the steel factory is still very large, Lu Chen came to look inside for a while and found a bunch of scattered iron ingots, it is estimated that he didn't care about him when he saw that they were all scattered, Lu Chen thought that it was just cheap for me, and then Lu Chen drove the car in, put the iron ingots in, and estimated that there were 500kg, and then Lu Chen found another workshop, and there was no harvest in this workshop.

Subsequently, Lu Chen drove the car to the small construction site inside, and found that there was a small room on the side, and near the window, he saw a bunch of iron ingots inside.

In fact, Lu Chen was lucky, the steel plant was going to build another small warehouse, but after the news of the meteorite came, the construction site was stopped, and there was a batch of iron ingots before there was no place to live, so a small room was temporarily set up to pile it up.

Lu Chen immediately transported the iron ingots inside and loaded them into the car, and when he saw that the car couldn't fit it, he drove to the shelter, which could be said to be a full load.

......

Two hours later, Lu Chen sat on the sofa in the living room of the shelter to rest, and began to think about how to use this harvest, an hour ago Lu Chen returned to the shelter and spent an hour to transport the materials of this harvest into the shelter, and now he can feel more tired than before, not that his body is not good, but that his oxygen intake is insufficient, so he has to consider solving this problem first.

"I was going to fence off the house, but now let's raise the oxygen level of the shelter first, or I won't know if I'll suffocate in my sleep one day."

After more than an hour of searching, Lu Chen summarized several methods of oxygen production, not to mention the chemical ones, there are too many methods and need to use a lot of chemicals, the cost is too high, there are two physical methods, one is to separate liquid air, the other is the adsorption method, the separation of liquid air is to use the boiling point of nitrogen and oxygen is different, first compress and liquefy the air and then evaporate, give priority to the nitrogen discharge, the rest is the liquid air with a relatively high oxygen concentration, The adsorption method is similar, the difference is that nitrogen atoms are adsorbed with special materials, and the rest is also a gas with a relatively high oxygen concentration, and there is a biological oxygen production method, which is to cultivate cyanobacteria to produce oxygen through photosynthesis.

Lu Chen thought about it for a while and felt that he could use the method of separating liquid air to produce oxygen, after all, he had to go out later, and at that time, the protective clothing needed to be equipped with an oxygen device, and if the oxygen production facility in the shelter could directly produce liquid oxygen, then he would not need to build another liquid oxygen production equipment.

Then Lu Chen began to design an oxygen concentrator in the nanocore, and was preparing to design a large-scale oxygen concentrator with pipes connecting all the rooms in the shelter, so as to ensure that all places in the shelter had sufficient oxygen.

Then Lu Chen transformed it according to the industrial oxygen concentrator found on the Internet and the corresponding program, designed an oxygen concentrator, and also designed two interfaces on the side of the oxygen concentrator, which can be used to connect gas cylinders to fill liquid oxygen, and then Lu Chen got this set of data

......

Sky III oxygen concentrator

Manufacturing requirements: energy 200 points, steel 300kg

Manufacturing time: 30 minutes

Unfolding time: 1 hour

Description: A large oxygen concentrator transformed from ordinary oxygen concentrators, with built-in automation programs, added pipelines and monitoring systems, which can monitor the oxygen concentration in the air, set the corresponding concentration requirements, and can recompress excess oxygen into a liquid state and store it.

......

Lu Chen took a look and found that he couldn't make this oxygen concentrator today, and it was only about five o'clock in the afternoon, and the nano core had only 170 points of energy after this period of accumulation, and he had to wait for 3 hours, but it was already five o'clock, so he could eat first, and it would be almost enough to have fun for a while after eating.

......

Three hours later, Lu Chen started the nano core, saw that the energy reached 200 points, and immediately chose to make it, after half an hour, a nano worm nest was spit out, Lu Chen took the nano worm nest to a utility room, the things inside have been cleaned out, and the space is enough, after starting the nano core, the oxygen generator began to form slowly, Lu Chen waited for an hour, and the oxygen generator was deployed.

I saw that the height of the entire oxygen concentrator was about two meters, and it was extended to various places in the shelter by many pipes, and then the width and length were about the same, from about one meter to five, there were many cylindrical tanks inside the oxygen concentrator, and then there was a computer embedded in the outer wall of the oxygen concentrator, after Lu Chen started the oxygen concentrator, the computer was opened, and Lu Chen began to operate.

After Lu Chen operated for a while, he found that the oxygen concentrator had been connected to the ventilation system inside the shelter, when the oxygen concentrator was started, it would absorb air from the outside and compress it, and then release the oxygen into the shelter after liquid separation.

Subsequently, Lu Chen set the oxygen concentration, started the machine, and waited for about ten minutes, Lu Chen found that the air suddenly became fresh, no longer the dull feeling before, and the air in the bedroom and living room felt much better than other places.

Subsequently. Lu Chen came to the workshop, ready to produce ten small oxygen cylinders, connected to the 3D printer, entered the drawings of the small oxygen cylinders, put in the materials to start production, exactly 100kg of material can produce ten oxygen cylinders.

After Lu Chen set it, seeing that the time was not early, he took a bath and went to bed, and Lu Chen slept exceptionally soundly this night.