“According to the material, the water tank is divided into six types: glass fiber reinforced plastic water tank, stainless steel water tank, stainless steel inner tank glass fiber reinforced plastic water tank, sea water glass fiber reinforced plastic water tank, enamel water tank, and galvanized steel water tank. The water tank is generally equipped with a HYFI remote liquid level electric valve, a water level monitoring system, an automatic cleaning system and a self-cleaning sterilizer. The overflow pipe of the water tank is connected to the drain pipe valve of the water tank and an insect-proof net is installed. The water tank should have two different heights. A ventilation pipe (fortification insect net), the water tank is equipped with an internal and external ladder; the water tank generally has a water inlet pipe, a water outlet pipe (living water outlet pipe, fire water outlet pipe), an overflow pipe, and a drain pipe. The water tank is divided into living water tank and fire water tank according to different functions. , production water tank,
According to the material, the water tank is divided into six types: glass fiber reinforced plastic water tank, stainless steel water tank, stainless steel inner tank glass fiber reinforced plastic water tank, sea water glass fiber reinforced plastic water tank, enamel water tank, and galvanized steel water tank. The water tank is generally equipped with a HYFI remote liquid level electric valve, a water level monitoring system, an automatic cleaning system and a self-cleaning sterilizer. The overflow pipe of the water tank is connected to the drain pipe valve of the water tank and an insect-proof net is installed. The water tank should have two different heights. A ventilation pipe (fortification insect net), the water tank is equipped with an internal and external ladder; the water tank generally has a water inlet pipe, a water outlet pipe (living water outlet pipe, fire water outlet pipe), an overflow pipe, and a drain pipe. The water tank is divided into living water tank and fire water tank according to different functions. , production water tank, human waterproof tank, household water tower five kinds, strictly speaking, toilet flushing water tank and car water tank are not water tanks.
Water tank accessories:
Water inlet pipe: The water inlet pipe of the water tank is generally connected from the side wall, and can also be accessed from the bottom or top. When the water tank uses the pressure of the pipe network to enter the water, a floating ball valve or a hydraulic valve should be installed at the outlet of the water inlet pipe. Generally, there are no less than 2 float valves. The diameter of the float valve is the same as that of the water inlet pipe, and an inspection valve should be installed in front of each float valve.
Outlet pipe: The water outlet pipe of the water tank can be connected from the side wall or the bottom. The inner bottom of the water outlet pipe connected from the side wall or the top surface of the water outlet pipe mouth when connected from the bottom should be 50 mm higher than the bottom of the water tank. A gate valve should be installed at the outlet of the water outlet. The inlet and outlet pipes of the water tank should be set separately. When the inlet and outlet pipes are the same pipeline, a check valve should be installed on the outlet pipe. When a check valve needs to be installed, a swing check valve with less resistance should be used instead of the lift check valve, and the elevation should be more than 1m below the minimum water level of the water tank. When living and fire fighting share the same water tank, the check valve on the fire outlet pipe should be lower than the top of the domestic outlet siphon (when it is lower than the top of the pipe, the vacuum of the living siphon will be destroyed, only to ensure that water flows out of the fire outlet) at least 2m, so that it has a certain pressure to push the check valve. When a fire occurs, the fire reserve water can really play a role.
Overflow pipe: The overflow pipe of the water tank can be connected from the side wall or the bottom. The diameter of the pipe is determined according to the maximum inflow of the discharge tank, and should be 1 to 2 larger than the water inlet pipe. No valve shall be installed on the overflow pipe. The overflow pipe shall not be directly connected to the drainage system, and indirect drainage must be used. The overflow pipe shall have measures to prevent the entry of dust, insects, mosquitoes, etc., such as water seals and filters.
Drain pipe: The tank drain pipe should be connected from the lowest point at the bottom. Drain pipe Figure 2-2n Fire and living bench water tanks are equipped with gate valves (no interception valves should be installed), which can be connected to overflow pipes, but must not be directly connected to the drainage system. The diameter of the drain pipe is generally DN50 unless there are special requirements.
Ventilation pipe: The water tank for drinking water should be provided with a sealed box cover, and the tank cover should be provided with access holes and ventilation pipes. The ventilation pipe can be extended indoors or outdoors, but should not be extended to the place where harmful gas is located. The nozzle should be equipped with a filter screen to prevent dust, insects and mosquitoes from entering. Generally, the nozzle should be set downward. Valves, water seals and other devices that hinder ventilation shall not be installed on the ventilation pipe. Air pipes must not be connected to drainage systems and ventilation ducts. The ventilation pipe generally adopts the pipe diameter of DN50.
Liquid level gauge: Generally, a glass liquid level gauge should be installed on the side wall of the water tank to indicate the water level on the spot. When the length of one level gauge is not enough, two or more level gauges can be installed up and down. The overlapping part of two adjacent liquid level gauges should not be less than 70 mm, see Figure 2-22. If there is no liquid level signal timer installed in the water tank, a signal pipe can be set to give an overflow signal. The signal pipe is generally connected from the side wall of the water tank, and its height should be such that the inner bottom of the pipe is flush with the bottom of the overflow pipe or the overflow water surface of the bell mouth. The pipe diameter generally adopts DNl5 signal pipe, which can be connected to the washbasin and washbasin in the room that is often on duty. If the liquid level of the water tank is interlocked with the water pump, install a liquid level relay or signal device on the side wall or top cover of the water tank. Commonly used liquid level relays or signal devices include float type, rod type, capacitive type and floating type. The high and low electric water levels of the water tank where the water is fed by the pump pressure should be considered to maintain a certain safe volume. The maximum electric control water level at the moment of stopping the pump should be 100 mm lower than the overflow water level, and the minimum electric control water level at the moment of opening the pump should be higher than the design. The minimum water level is 20mm to avoid overflow or emptying due to errors.
There have been many applications of UV disinfection in water treatment. Due to the slight degree of water pollution in the water tank, the application of medium-pressure UV rays has advantages. This article mainly combines some foreign cases of ultraviolet application in water tank disinfection, introduces the matters that should be paid attention to in the application of ultraviolet disinfection technology in the water tank circulating water treatment system, and emphasizes that medium-pressure ultraviolet disinfection technology should be used in the water tank circulating water treatment system.
1. Classification of UV lamps UV light sources are generated by mercury discharge lamps. According to the pressure of mercury in the lamp tube, the UV lamps on the market are mostly low-pressure lamps, low-pressure high-intensity lamps and medium-pressure lamps.
2. Comparison of low-pressure and medium-pressure ultraviolet rays In terms of sterilization intensity, because the photoelectric conversion rate of low-pressure ultraviolet lamps is higher than that of medium-pressure ultraviolet technology, low-pressure ultraviolet technology is mostly used in some industrial water treatment. But for tank water disinfection, medium pressure UV has its special advantages:
(1) The low-voltage UV lamp has the highest sterilization efficiency at a wavelength of 253.7 nm, but it is only a single spectrum with a single straight line output; while the medium-voltage external lamp has a wide wavelength range and can kill many bacteria. The slightly polluted water body of the load is enough to satisfy the bactericidal effect.
(2) The low-pressure ultraviolet lamp has no obvious effect on chloramine degradation; while the medium-pressure high-intensity ultraviolet lamp has a wide output wavelength range (230-400 nm), which contains 245 nm, 297 nm and 340 nm required for the degradation of chloramine. wavelength. It can effectively promote the decomposition of chloramines and other organic substances through photo-oxidation.
(3) Effectively improve the UV penetration rate of water tank water quality. The penetration rate is one of the criteria for evaluating water quality. The penetration rate is not exactly the same as the turbidity. The turbidity is only a representation of the suspended matter in the water, and does not represent the dissolved substances in the water. The structure of substances that can cause water turbidity, combined with filtration processes, can improve the penetration rate of water quality. According to related reports, medium-pressure UV light can increase the penetration rate of water quality from 75% to over 97%.
(4) The influence of temperature on the sterilization effect. Generally, the water temperature of the water tank is 26-28°C or higher, which is higher than the effect evaluation temperature of general disinfectants and disinfection methods (generally tap water and sewage are lower than this temperature).See the curve of the amount of ultraviolet light that is affected by temperature
It can be seen that the generation efficiency of low pressure UV lamps is greatly affected by temperature, while the generation efficiency of medium pressure UV lamps is basically not affected by temperature.
Finally, I recommend a UV detector used in the disinfection of UV water in the water tank, that is, the UV detector introduced by Xiaobian from abroad – GUVC-T11GC-3LWLO1.1, which is a very excellent UV detector with Strong sterilization and disinfection ability, single power supply voltage, analog voltage output. Widely used in UV power detection, UV lamp monitoring, UV lamp sterilization and other fields.