Now the quality of tap water is getting worse and worse, and it is a strange smell to boil it directly to drink, and it is simply impossible to live without a water purifier!

This ultrafiltration water purifier was used for 4 or 5 years, when it took 360 oceans, the peculiar smell in the water can be effectively removed, but the difference between boiled and unboiled drinking is quite obvious, obviously it cannot be drunk directly, and scale can not be removed, every two weeks to clear scale, has been unbearable.

Considering changing the pure water machine, I originally planned to buy the finished product directly, and I looked at many brands, all of which are computer controlled and need to be plugged in. I had no socket in my cupboard and no space on the wall, so I had to use one without plugging in, so I decided to assemble one.

Let’s try it with a pumpless water purifier, this is the schematic

The pre-filtration adopts a three-stage 10-inch palletized one, which is more compact

Three-stage filter element: PP cotton, UDF granular activated carbon, CTO precision activated carbon

Transparent bottle selection for pre-filtration for easy inspection of the filter element. It is rare to see light in the cabinet, and it should not be moldy due to light.

Wastewater than with adjustable, make a fixed frame

Wastewater ratio and flushometer as a unit

Wastewater ratio and installation location of flushometers

A 3-point switch is installed between pre-filtration and reverse osmosis

After the pre-filtration, there is a water outlet for washing vegetables and dishes. The new activated carbon filter element has scattered toner, after changing the filter element, first turn off the 3-point switch, turn on the faucet to rinse the toner, and then open the 3-point switch to let the water without toner enter the RO filter element.

Install a water pressure gauge to monitor the water pressure

400G low pressure reverse osmosis RO membrane

It is said that 2 kg of water pressure can be used normally

Fill the membrane housing

Install the membrane shell retention mechanism on the pallet, the holes reserved for the pallet are not suitable, and the holes are punched separately

Install the RO filter

The necessary parts of the pumpless pure water machine – four-sided valve

The flow direction of the four-sided valve water flow

This is a check valve, also called a check valve, which is marked with the direction of water flow

Connect the water pipes

The water inlet and outlet of the membrane housing are 3 points, and the interface of the four-sided valve is 2 points, which requires several reducing joints

Change the angle

At the top is the small T33 post-activated carbon filter

Try it in the bathroom, first turn off the 3-minute switch and rinse the toner

The water pressure is average, not high

Start draining the water, adjust the wastewater ratio so that the flow rate is about 1:1, and then tighten the lock nut

Close the outlet valve, and the wastewater flow gradually decreases

Finally, the wastewater also stopped flowing out, proving that the four-sided valve was working properly

Tap water TDS is 124

At first, the TDS for water purification was 51

After a period of time, the TDS of the purified water dropped to 13, and after drinking it, it felt no different from cold boiled water

The standard pressure barrel of the water purifier is too large, try to replace it with an empty filter bottle, and one end of the filter bottle is closed.

The filter bottle is inverted and the water is pressed out using the pressure generated by the compression of the original air inside

The water output is obviously much larger, but the water in the inverted filter bottle returns to a small flow state after flowing.

The original installation method of the water pressure gauge makes the replacement of the RO membrane inconvenient, adjust it

Installed in the cabinet, the pallet is screwed to the wall, and the front filter bottle is 3cm from the ground, so that the filter bottle can be directly unscrewed to change the filter element.

Wastewater outlet

Install the water purification faucet, try the water outlet, the flow is quite small, it seems that the pumpless pure water machine does not have a pressure barrel or not, the pressure barrel is like a cache in the computer.

It is feasible to replace the pressure barrel with an inverted filter bottle, but one filter bottle does not store much water, and the electric kettle is 1.5 liters, and two filter bottles are required.

Two filter bottles connected in series, with a 2-point connection at one end

The other end is plugged

It doesn’t take much to put it in a cupboard

The water outlet effect is much better

Try the kettle water, no scale. It’s been more than two months now, and there’s no scale at all.

By now, a pumpless pure water machine has been completed, and the cost is not large, a total of more than three hundred. After a few days, I pondered and tossed again, installed a water pump to try, the 400G water pump is quite large, can only make a shelf to install aside

The installation drawing of the water pump has not changed much on the basis of the original

6 18650 lithium batteries for water pump power supply, wiring diagram

Replace manual flushometers with 18-second automatic flushometers

Plus two sensors, high-voltage switch (open when water pressure is high, turn on when water pressure is low)

Low pressure switch (open when water pressure is low, turn on when water pressure is high)

Connection to the interface of the water pump

Add a water pressure gauge to the water inlet of the RO membrane shell, and install a high-voltage switch at the water purification outlet

A TDS detector is installed at the RO membrane shell water purification outlet, which can detect water quality in real time

The high-voltage switch has an adjustment screw that adjusts the on/off at what pressure

Water pump hoisting

Make a small circuit board, use a relay to control the water pump, plus the battery power display board, and press the touch switch to display the power

6 series 18650 quasi-power battery, 15A with balanced protection board

There is no heat shrink sleeve, wrapped with electrical tape

The low-pressure switch is installed at the inlet of the water pump, eliminating the pressure barrel made of filter bottles

Water output is ok

Real-time detection of TDS

After using it for a few days, I found that there was a problem, when the water purifier was idle for a period of time and then released water, the TDS value was very high (up to more than 200), and then gradually decreased, Du Niang said that it was because of mutual penetration. When there is a pressure barrel, the water in the barrel dilutes the TDS value, and the performance is not obvious. The finished water purifier basically does not consider this problem.

Tried a few methods and thought this one was good.

The red box in the figure is the last added part, the principle is: when the water is discharged, the water inlet solenoid valve opens, when the water purification faucet is closed, due to the existence of the filter bottle, the water flows into the filter bottle, the water pressure rises slowly, when the water pressure reaches a certain value, the high pressure switch is disconnected, the water pump stops, the water inlet solenoid valve is closed, at this time the water pressure of the filter bottle is greater than the water pressure of the water inlet, the water in the filter bottle (TDS value is small) flows into the RO membrane shell, replacing the original water with high TDS value, in the case of mutual penetration, the water TDS value of the outlet is not high.

After a period of use, the TDS value in the first few seconds of water release is about 50, and the disadvantage is that there is more waste water than the original.

The inlet solenoid valve is directional, in order to prevent high reverse water pressure, a check valve is connected at the water outlet

When the inlet solenoid valve is closed, the amount of water in the filter bottle and the water level are marked with adhesive tape

Gradually replace the water in the membrane housing

The replacement is complete

This water purifier was completed before the Spring Festival, and it feels good to use it now, the battery is charged once a week (2200mAH), and about 5 liters of water is purified every day, and the battery can also produce water without electricity, but the amount of water is small.

Compared with those with computer boards, it is relatively troublesome in terms of maintenance, such as regular flushing has to be artificially controlled, but with computer boards there must be sockets, connecting sockets is too troublesome, concealed installation to gouge the wall, open installation is not safe, think or forget it!

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Source: Digital House