(i) Basic characteristics of biogas The biogas is a combustible gas. Its main components are methane (CH4), carbon dioxide (CO2), and a small amount of hydrogen (H2), carbon monoxide (CO), and hydrogen sulfide (H2S). )Wait. The nature of the gas is determined by the nature of the gas that composes it and its relative content, with methane and carbon dioxide having the greatest impact on the nature of the biogas. For example, if the volume of methane in a biogas is 60% and the volume of carbon dioxide is 39%, for example, the methane weight percentage is 35.35%, the carbon dioxide weight percentage is 64.07%, the biogas capacity is 1.22 kg/m3, and the biogas has a specific gravity of 0.943; The calorific value of biogas is 21,528 kJ/cm3 (5142 kcal/m3); the theoretical air volume of biogas combustion is 5.38/m3; the combustion range of biogas is: the upper limit is 24.44%, and the lower limit is 8.8%.
(2) Conditions for preparation of biogas Biogas is produced by bacteria that ferment and decompose organic matter under certain conditions. The more appropriate the conditions for the preparation of biogas, the more vigorous the life of the bacteria and the more methane produced. Therefore, in the production of biogas, requiring high gas production, it is necessary to make biogas microorganisms have more vigorous life activities under anaerobic conditions. Therefore, creating a good environment is the key to the production of biogas. Here are the conditions that must be met to prepare biogas.
1. Strict anaerobic environment Decomposition of organic substances Microorganisms producing biogas are anaerobic bacteria, and their entire life activities do not require air (anaerobic). On the contrary, the oxygen in the air has damage to them. Therefore, the construction of a watertight, airtight biogas digester is not only necessary for the loading and storage of gas, but more importantly it is to ensure that the bacteria live under anaerobic conditions so that they can achieve very high gas production.
2. The process of anaerobic decomposition of inoculum to produce methane is accomplished by a variety of biogas microorganisms. Therefore, in the biogas fermentation, it is extremely important to add enough required microorganisms as inoculants (also known as strains). There is no inoculum determines the success or failure of biogas fermentation, and the active ingredient in the inoculum is directly related to the activity of the fermentation process is good or bad. The active ingredient in the inoculum is a living biogas microbial population. Different sources of inoculants, the activity is different. Therefore, when choosing an inoculum, not only the inoculum that accounts for 20%-30% of the input amount but also the active inoculant should be selected.
3. Adequate raw materials for fermentation Biogas microorganisms require a certain amount of nutritive conditions besides the strict anaerobic environment, mainly carbon, nitrogen, moisture, and minerals.
Various organic substances, such as humans, animal excrement, crop straw, domestic sewage, and industrial wastes containing organic substances, can be used as raw materials for fermentation of biogas digesters, that is, nutrients required for the growth of biogas microorganisms. However, microorganisms have a certain ratio of carbon and nitrogen requirements in nutrients. According to measurements, the ratio of carbon to nitrogen is 25:1. People and livestock excreta have a large proportion of nitrogen, and straw, weeds, and other fibers have a high carbon content. Because, in order to maintain a certain carbon-nitrogen ratio, biogas digesters need not only to replenish enough raw materials for fermentation, but also to pay attention to the rational combination of various raw materials, so that comprehensive production can produce more gas.
4. Proper temperature Fermentation temperature is an important factor affecting biogas fermentation. In a certain temperature range, the decomposition and digestion rate of fermentation raw materials increases with the increase of temperature, that is, the amount of gas production increases with the increase of temperature, but it is not so much higher.
At present, household biogas digesters in rural areas are fermented at natural temperatures (that is, at room temperature for 13 minutes, and are kept at 0°C-30°C; over 30°C, they cannot be fermented normally. However, below 10°C, the fermentation effect is not satisfactory.
5, the appropriate pH is also an important factor affecting the biogas fermentation. The pH here refers to the pH of the fermentation broth instead of the raw material. The appropriate pH for the biogas fermentation (PH value) is between 6.5-7.5 (as measured by pH test paper), which can affect the smooth progress of biogas fermentation.
During the start-up phase of biogas fermentation, if the feed concentration is too high or the proportion of carbon in the raw material is too large, the accumulation of organic acids is too fast and the pH drops to 6; the activity of methanogens will be severely inhibited, and most of the gases will be generated. It is carbon dioxide. Therefore, the new pool start, the feed concentration is rather low, do not be too strong. When the biogas fermentation proceeds normally, appropriate amount of raw materials is gradually added.
If the fermentation broth is found to be acidic (pH is less than 6.5), an appropriate amount of lime or wood ash can be added to the fermentation broth; if the fermentation broth (pH greater than 7.5), some fresh grass, water grass, leaves and water should be added, pH Can be gradually adjusted.
6. Mastering the ratio of raw materials for fermentation to water The raw materials that produce biogas must have the right amount of water to be beneficial to gas production. This is because biogas bacteria need suitable moisture to absorb nutrients, excrete waste, and perform other life activities. If the amount of water is too small, the fermentation broth is too concentrated, and it is easy to accumulate a large amount of organic acid, which impairs the fermentation effect and affects the gas production. If the amount of water is too much, the dry matter content in the fermentation broth is small, and the amount of gas produced per unit volume is small.
The moisture content of the fermentation broth is suitable for 90%-94% (dry matter 6%-10%). In this range, it can be diluted in summer and thick in winter. If the ratio of raw materials and water in the digesters is difficult to estimate, it would rather be slightly dilute and not too strong.
Table 1 shows the moisture content of several biogas fermentation raw materials (%)
Table 1 Moisture content of biogas fermentation raw materials Original name Human feces Pig feces Pig urine Horse dung Dry straw Cow manure Dry air Manure Moisture content % 80 About 82 96 76 10-20 83 30-40
Dry matter content % 20 18 4 24 80-90 17 60-70
Knowing the moisture content of the fermentation material, you can determine the mix ratio of raw materials and water. Dry matter concentration and water addition can be calculated by the following formula:
D= 100%
Where: D - dry matter content of mixed materials, unit%;
T—Dry matter content of various raw materials, in kilograms;
X—weight of various raw materials, in kilograms;
W—weight of added water, in kilograms;
Example 1: Build a 6 cubic meter digester, feed 2,300 kilograms of pig manure, and set the dry matter concentration of the fermentation broth to 8%. How many kilograms of water need to be added?
Known: D=8%
T = Lookup Table 1 pig manure water content 82%, dry matter quality 18%
X = weight of pig manure added to 2300 kg according to the formula: 8% =
= 2875 (kg)
Example 2: Build a 6 cubic meter digester, feed 800 kilograms of pig manure, 400 kilograms of cow dung, 120 kilograms of straw, and add 3,780 kilograms of water. What is the dry matter concentration of the fermentation broth?
According to the company:
D= 100%
=6%
A: The dry matter concentration in the fermentation broth is 6%.
Second, the rational use of biogas products The use of biogas is very extensive, for farmers, the main purpose is to cook fuel and direct lighting lighting. Therefore, whether the correct selection and use of biogas supporting products is the key to whether the biogas benefits can be fully utilized. and so. We should master the correct and reasonable use of methods in order to achieve a multiplier effect.
Products commonly used for biogas include biogas stoves, biogas lamps, biogas pressure gauges, biogas switches, direct-flow, three-way, and gas pipelines. In addition, there are biogas igniters, biogas gas-water separators, Biogas desulfurizers, biogas water heaters, biogas rice cookers, etc.
The following describes the rational use of biogas products.
(1) Gas pipelines Gas pipelines are used to ensure that the biogas generated by the biogas digesters can be smoothly sent to the biogas stoves or biogas lamps for combustion. The main quality requirements for biogas gas pipelines are that they can withstand pressures of 10 kPa (1000 mmH2O) without leakage, ageing resistance, and tensile resistance. Therefore, the use of biogas gas pipeline should be selected qualified plastic gas pipeline.
Before installation, check whether the gas pipe leaks, especially the buried gas pipe must be checked.
Inspection method: Put the tube in water, block one end of the nozzle, use a pump to inflate or inflate the other end, and observe whether there are any bubbles around the tube. If there is no air bubble, the gas pipe will not leak. The leak is made when it is issued.
The size of the inner diameter of the gas pipeline depends on the volume of the digester, the gas distance and the application. For example, if the volume of the biogas digester is large, the gas volume is large, and the gas distance is long, the internal diameter of the gas pipeline should be larger. The biogas digester used by general farmers should have an internal diameter of 8-10 mm. Internal diameter less than 8 mm cannot be used. For large biogas tanks used for power, due to the large gas consumption, the internal diameter of gas pipelines should be more than 20 mm.
Plastic (or rubber) air ducts exposed outdoors are subject to ageing and cracking due to long periods of exposure to the sun and rain. Placing a plastic pipe (or bamboo pipe) on the outside of the gas pipe can extend the service life. The buried gas pipelines can also be sheathed with plastic pipes, iron pipes or brick trenches.
The gas pipeline should be reasonable. If there is a slope, tilt 0.05% toward the direction of the biogas, and the best length is shorter, the longer the tube is cut off, do not circle, hang on the wall or other places, this is equal to the growth of the pipeline distance and the pressure of the biogas The loss increases.
Recycled plastic tubes are not permitted as gas lines.
(b) The function of the switch is to open or close the biogas transmission channel, and at the same time, the biogas flow rate can be adjusted. It is an important part of the gas pipeline. It must be sturdy, tight, fast, flexible, and easily accessible. Switch material is divided into two major categories of plastic and metal.
The plastic switch usually adopts the compression degree of the pressure gas pipeline to control the biogas flow, completely deflate the gas pipeline, is in a closed state, the gas pipeline is fully loosened, is in the open state, and is also the state with the largest amount of biogas transportation. Because biogas gas pipelines are not easily compacted, latex tubes are usually used. However, latex tubes are not resistant to corrosion and are prone to ageing. After several months of use, cracking, blocking, etc. may occur, and there may be leaks and insecurity. Plastic switches also have the following problems:
1. Easy to wear, 2. Seal not 3. Good, 4. Cause leak
5. The processing is relatively coarse, the inner hole is often turbulent, 6. The pressure loss of the biogas increases, 7. The flow rate decreases;
8. The switch handle is too tight, 9. Not 10. Easy to operate.
Due to the above reasons, plastic switches have gradually been replaced by metal switches. Metal switches can be made of steel, copper, aluminum and other materials. The opening and closing is performed by using the rotation of the cone or core with the open hole, and the operation is simple and the action is rapid. In the selection of these switches, the cock diameter should be greater than 6 mm. At the same time, the cock hole is required to be concentric with the inlet and outlet. When the switch is opened, the hand sensing is flexible.
It is reasonable and safe to install a switch in front of each stove or lamp. Some users installed the main switch behind the air duct and installed switches at the bifurcation of the pipeline. This is completely unnecessary. Each switch installed more than one, not only more money, but also the more switches and gas pipe joints, the more chance of gas pipe leakage, the same time, the greater the pressure loss of biogas, easily lead to the pressure of the biogas stove can not reach the stove The design requirements will affect the ignition, reduce the thermal efficiency and heat flow of the cooker, and fail to achieve the intended use of biogas.
(3) Gauge pressure gauges are indicator instruments for observing the number of biogas in a biogas digester. At present, most of the pressure gauges used by farmers are U-glass tube type liquid level pressure gauges. The pressure gauge has a simple structure and is highly sensitive to use. The price is low, but the glass tube is easily broken during transportation. After a period of use, the indication value is inaccurate due to temperature change, and the scale is fuzzy and difficult to read. When the pressure of the biogas tank increases rapidly, the U-type pressure gauge liquid will be If you don't deal with it in time, it is prone to safety accidents. Membrane-type pressure gauges that have been used gradually have rapidly replaced U-type pressure gauges due to their small size, beautiful appearance, light weight, and high sensitivity. At the same time, a new type of glass straight-tube pressure gauge has been introduced to the market. The tube pressure gauge is small, corrosion resistant and intuitive.
The main function of the pressure gauge is to check whether the digester and the gas pipeline are leaky. Another function is to adjust the flow according to the pressure when the gas is used, so that the stove can work under the optimal conditions, but the inspection of the digester can only leak gas. Capsule pressure gauges cannot be used with U-type gauges.
The correct installation position of the pressure gauge should be between the pre-hood switch and the biogas stove on the gas pipeline (see Figure 2). In this way, the switch is opened, the pressure rises, the switch is turned off, and the pressure drops. This facilitates the monitoring of the working condition of the cooker. At the same time, when using, it is necessary to control the cooking pressure of the cooking appliance as much as possible to make it in the design pressure, in particular, it should not be excessively overpressured, so as to avoid too much pressure, the artillery out of the pot, waste of biogas.
Note: When there is a large amount of biogas in the biogas digester, the pressure gauge indicates that the pressure limit is 10kpa. At this time, the biogas should be used as soon as possible to protect the pressure gauge and the biogas digester, to prevent the table from being damaged or the biogas tank seal cover being washed away, and the pressure collapse tank. Wall incident.
(4) Gravity gas-water separators are currently used for gas-water separators. The principle of the separator is that the biogas produced by the biogas digester is imported into the tube by a gas-water separator. After entering the tube body, the cross-sectional area of ​​the instrument body is much larger than the cross-sectional area of ​​the inlet tube, resulting in a sudden drop in the biogas flow rate due to the lack of specific gravity of water and gas. In the same way, the falling speed of the water drop is greater than the rising speed of the air flow, and the water sinks to the bottom of the device and the biogas rises to be output from the outlet pipe.
If there is no gas-water separator, there will be blisters in the gas pipeline when the gas stove is burning, and the flame of the gas stove will be rushed down quickly. Like gasping, the gas lamp often flashes. The reason for these conditions is that the water vapor in the biogas accumulates in the tube or causes negative pressure during large discharge. The water in the pressure gauge is poured into the gas pipeline. In serious cases, the stove and the lighting fixture will not ignite. If a gas-water separator is installed, this problem can be solved. The gas-water separator should be installed at the lowest point of the gas pipeline.
(5) Desulfurizer Biogas contains a certain amount of hydrogen sulfide. Hydrogen sulfide is an acid gas. It is corrosive to pipelines, switches, valves, and other equipment. It also has a corrosive effect on household appliances. In order to ensure normal gas supply and extend the service life of the equipment, desulfurizers must be installed in the gas pipelines.
There are two methods of desulfurization: wet and dry desulfurization. Dry desulfurization has the advantages of simple process, mature and reliable, low cost, and can achieve good purification effect. Current home biogas desulfurizers basically use this method.
Dry desulfurizers include activated carbon, zinc oxide, manganese oxide, molecular sieves, and iron oxides. Considering the operating time, temperature, pollution, price, and other factors, the most commonly used desulfurizer is iron oxide (Fe2O3).
After the desulfurizer has been used for a period of time, the desulfurizer in the desulfurizer will turn black, lose its activity, reduce the desulfurization effect, and may also cause compaction and increase the biogas transmission resistance. In severe cases, the biogas will be blocked and cannot pass. At this point, the desulfurizer must be regenerated. The regeneration method is to remove the deactivated desulfurizing agent and evenly and loosely deposit it on a flat, clean, back-yang, ventilated site, often turning the desulfurizing agent so that it is in full contact with the air to oxidize and regenerate. When the moisture content of the desulfurizer is low, the dilute alkaline solution can be uniformly sprayed to accelerate the regeneration speed and shorten the regeneration time. Generally, after about one month, the desulfurizer can be loaded into a desulfurizer and used continuously. Desulfurizer can be regenerated 1 or 2 times. Note that when the digester is refueled, the switch in front of the desulfurizer must be closed to prevent the air from passing through the desulfurizer because when the digester is refueled, the gas passing through the gas pipe to the desulfurizer is not biogas but oxygen-containing gas. Once the desulfurizer is directly introduced into the desulfurizer, the desulfurizer undergoes a chemical reaction and the temperature rises sharply, which can damage the plastic housing of the desulfurizer and cause the desulfurizer to be unusable.
(VI) Biogas stove
1. The composition of the biogas stove The biogas stove we use is an atmospheric combustion type of biogas stove. The atmospheric biogas stove is mainly composed of five parts: the nozzle, the assembly, the air conditioning plate, the ejector and the combustion head.
The role of the nozzle is to deliver the biogas needed for combustion and control the biogas flow (ie load). The caliber of the nozzle gradually shrinks from large to small. It is a key part of converting the static pressure of the biogas into kinetic energy, and it also brings in air at the same time as the biogas is ejected. The nozzle is generally made of copper, and the machining accuracy is high. The nozzle design and processing technology directly affect the burner performance and use effect. The nozzle is usually fixed on the assembly.
The function of the assembly is to operate the opening and closing of the biogas, control the flow of the biogas, the transfer of pressure and size, and the assembly is equipped with an automatic ignition device, which is an important part of ignition and flow regulation.
The shell of the assembly is generally aluminum casting, the center has a copper cone, the cone has two holes, a Φ5, Φ0.5, when the knob to drive the cone to rotate to block the big hole, the biogas can only Through the small hole into the head of the burning that is the center of small fire burning, the normal use of small fire or fire at the same time burning.
The function of the air conditioning plate is to adjust the primary air volume (primary air factor a?) according to the flow rate of biogas, the pressure change, and the size of the biogas calorific value. During use, the air conditioning plate must not be closed, otherwise, atmospheric combustion It becomes diffused combustion (primary air coefficient a? = 0) diffusion combustion has the following disadvantages:
(1) The combustion is incomplete and the CO content in the combustion flue gas is high. It not only wastes biogas, pollutes the environment, but also harms human health.
(2) The combustion temperature is very low, the flame temperature is generally only 300 °C -400 °C, and the atmospheric combustion temperature can reach more than 1000 °C.
(3) Flaming, light and powerless like burning firewood. It seems that the flames are very large and very high, but in fact they are some of the flames that are not high in temperature and flutter outside the pot and lose a lot of heat.
(4) Low thermal efficiency. According to measurements, the thermal efficiency of diffusional combustion is only 50% or even lower.
The role of the ejector is to rely on the amount of air injected by the biogas emitted from the nozzle, and the biogas and the air are evenly mixed, and the mixed gas is formed in the outlet hole of the burner head to maintain the necessary speed to ensure stable combustion. .
The role of the combustion head is to evenly distribute the mixed gas of methane and air to each fire hole for stable and complete combustion.
2, the choice of biogas stove Choose home cooking things, be sure to buy the product quality inspection structure inspection qualified products, do not buy unexperienced stove or unqualified stove. At the same time, we should also consider the heat flow, thermal efficiency, and use pressure of the stove in conjunction with the family.
The heat flow of the stove refers to the amount of heat released by the biogas stove in accordance with the design pressure during the 1 hour. She stated that the heating capacity of the stove is in the unit of kilowatts, which is one of the main technical indicators of the biogas stove.
The national standards for household gas stoves stipulate that the heat flow rate is set at 2.33 kilowatts, 2.79 kilowatts and 3.26 kilowatts. If the calorific value per cubic meter of methane is lower than the calorific value of 21,000 kilojoules, it is equivalent to 0.4-0.56 standard cubic meters of methane gas consumed per hour. Farmers can determine the heat flow of stoves according to the number of their families, their standard of living, and their gas use standards.
3. Use of biogas stove Before using the biogas stove, you should read the instructions and the nameplate on the stove to understand the performance of the biogas stove's rated pressure and heat flow.
When used, adjust the pressure before the stove to make it equal to the rated pressure of the biogas stove. In order to achieve the thermal efficiency of the gas stove.
Because of the different feed quantities, raw material types, tank temperatures, and design pressures for each biogas digester, the methane content of the produced biogas and the biogas pressure are also different, so the calorific value and pressure of biogas are also different. Biogas combustion requires 5-6 times more air, so the degree of opening of the air-conditioning panel (behind the front panel of the biogas stove) should be adjusted with the amount of methane in the biogas. When the methane content is high, the air-conditioning plate can be opened to make the biogas burn completely to obtain high heat efficiency. If the air deflector is opened too much and too much air is blown in, the phenomenon of falling flame or even off-fire will occur (that is, when the pot is not released, the fire is not burned above the combustion head and is not connected with the combustion head fire hole); Part of the heat taken away by the flue gas will also reduce the thermal efficiency of the cooker. When the methane content is low, the wind deflector can be turned off slightly, but the wind deflector must not be shut down, so that the flame seems long and weak. After the wind deflector dies, no air enters the stove, and once the air is equal to zero, a diffused combustion is formed. As a result, the flame temperature is low, combustion is incomplete, and excess carbon monoxide is generated, affecting human health.
Therefore, when using a biogas stove, it is necessary to adjust the size of the damper by correctly grasping the color and length of the flame. Learning to use the air conditioning plate is an important part of whether the farmer can use the biogas stove correctly.
Some farmers prefer to use the stove on the stove. If the time of use is long, the oven will reach the thermal equilibrium with the stove after heating. This will continue to be used, which will increase the thermal efficiency of the stove. However, if the use time is short, the heat efficiency of the cooker will be reduced due to the heat absorption from the furnace wall. So whether the stove is placed in the furnace is beneficial, depending on the circumstances. In addition, the furnace must be well-ventilated and can quickly remove the fumes, which can meet the needs of the cooking appliances to use the secondary air supply. Therefore, the hearth and stove doors should be properly increased. It is recommended that you do not use the gas stove in the furnace.
4. Biogas stove electric ignition For ease of use, biogas stoves are equipped with electronic or pulse ignition. When the ignition is on, press the switch button and hold it for 3-6 seconds. Turn it to the “ON†position and make sure that the stove is turned on before you let go. If you leave the stove and the fire goes out, repeat the above ignition method. The frequency of electrical ignition problems is relatively high. On the one hand, the quality of the electrical ignition device of the product is defective, and on the other hand, the conditions of use are not suitable. If methane is less than 50% methane, the pressure in front of the stove is too high, the amount of battery is not enough, and moisture may not be on fire. Under normal circumstances (after deducting the quality of the cooking stove ignition device), the pressure before the stove is controlled and the ignition should be no problem.
(VII) Biogas Lamps
1. Composition of biogas lamps Biogas lamps are a type of combustion device that converts the chemical energy of biogas into light energy. It is a device that utilizes the light that occurs when the gauze cover is used in the high-temperature combustion of biogas.
Biogas is composed of nozzles, ejectors, mud heads, gauze covers, reflectors, glass shades and other components. The role of nozzles and ejectors is the same as that of biogas stoves. To simplify the structure, the ejector is made of a straight cylinder. The pipe is directly connected with the nozzle thread. The ejector can rotate freely on the nozzle. In the ejector not far from the nozzle, two elliptical holes are split, as a primary air inlet, the amount of primary air intake can be adjusted by adjusting the size of the air inlet or rotating the air inlet cover like a burning appliance damper. The ejector regulates the distance between the nozzle and the primary air port.
Mud head: It corresponds to the head of the burner and the yarn cover is installed on it. It is made of refractory material, with many small holes at the end, which can evenly distribute the mixture and buffer pressure. It is screwed to the ejector for replacement in case of damage.
Yarn cover: It is a light-emitting element, which is made of ramie, vegetable fiber, and rayon mixed into a desired mask shape, and then soaked in an alkaline solution of yttrium nitrate so that the fiber is filled with yttrium nitrate and then dried.
Reflectors, also known as condensers, collect light. Generally made of white enamel.
Glass shades are made of high-temperature resistant glass that protects against wind, insects and gauze.
2. Use of Biogas Lamps Biogas lamps should be burned with a new gauze before use. The burning of the new gauze can directly affect the illuminance and luminous efficiency of the biogas lamp. Therefore, whether farmers properly burn new gauze is the key to using biogas lights.
Farmers can choose the gauze according to the size of the biogas lamp's rated pressure. Biogas lamps with a rated pressure of 800 Pa are equipped with 200 yarn screens, and biogas lamps with a rated pressure of 1600 Pa and 2400 Pa are equipped with 150 yarn screens.
First straighten the yarn cover. Loosely open and set it on the head of the biogas lamp and tie it evenly. Cut the end of the yarn cover evenly and cut off the long wire. Turn on the switch and turn on the biogas to ignite the lamp. After the yarn cover is all on fire and red, slowly raise or move the nozzle or open the large throttle to adjust the amount of air entering the air, so that the biogas and air are properly matched and violently burned under high temperature. The yarn shroud will naturally shrink. It's best to make a pong sound and emit white light. When the gauze is burned, the pressure of the biogas must be sufficient, and the gauze that was burned is full of white light.
After the burned yarn cover is mainly protected, avoid collisions and vibrations, and do not touch it with your hands. After the yarn cover burns, the man-made fiber is burned out. The rest is a layer of silica-white mesh. Dioxanthellae is a harmful white powder that breaks once it touches.
(8) Biogas water heaters Biogas water heaters are much more complicated than biogas stoves and biogas lamps because of the large air-consumption of gas-fired water heaters, which are commonly used by users of centralized gas-supply projects, and some also use solvent-based water heaters to supply warm water for winter aquaculture products. There are few users of water heaters in biogas tanks, as long as there is enough biogas and safety at the same time, biogas water heaters can also be used.
1. Composition of biogas water heaters Biogas water heaters consist of water system, gas system, heat exchange system and flue gas removal system.
The main components:
The main burner, water and gas linkage valve, lead or burn it, solenoid valve, heat exchanger, combustion chamber, exhaust chamber and other components.
2. Matters needing attention when using biogas water heaters:
If the biogas water heater fails, it must be repaired by a professional; therefore, the working principle of the components of the biogas water heater is not introduced. However, due to the large amount of gas consumed per unit time, the water heater needs more fresh gas to be added, and it is the first place in safety when it is used.
1 The water heater should be installed in a place close to the gas pipeline and the water pipe and able to ventilate (it can supply the water heater with sufficient oxygen for combustion). The connection between the water pipe and the gas pipe must be buckled and fastened so as not to lose the gas or water pressure. Air hoses or hoses flush open.
2 Out of hot water From the “Ignition Viewing Holeâ€, after confirming that the fire is lit, open the cold water valve, the fire will burn, and the water will flow out from the hot water outlet. After a few seconds, hot water can be used.
3 water temperature adjustment water heater water temperature is determined by the size of the fire and the size of the water. When the size of the fire is adjusted, the temperature of the outlet water is adjusted by the "water temperature adjustment knob", the water is opened and the outlet water temperature is low, the water is opened small, and the outlet water temperature is high (never adjust the hot water temperature higher than 60 °C, In case of heat exchanger fouling). When the size of the water is adjusted, the temperature of the outlet water is regulated by the “gas adjustment knobâ€, the fire is opened, the outlet water temperature is high, the fire is small, and the outlet water temperature is low.
4 Suspended Use When the water heater is suspended, just turn off the "cold water method door", that is, no hot water flows out. The fire will be extinguished automatically (but the fire is still burning). If you need to use hot water again, open the cold water method door and the fire will burn automatically. Hot water means Come.
5 stop using the first close the "gas valve" and then close the "cold water valve" to confirm that the water vapor is off after people can leave.
(9) Biogas rice cookers Biogas rice cookers are similar to rice cookers and can cook 2.5 kilograms of rice at a time, which is economical and convenient.
1. The composition of biogas rice cooker The biogas rice cooker consists of a temperature sensor, a juice receiver, a main fuel switch, and an insulation switch. There are also lids, inner pots, hoods and other components.
2. Use of biogas rice cooker 1 The rice cooker should be placed in a smooth and ventilated place, 10 cm away from the wall, 50 cm above the height, and not near other flammable and explosive materials.
2 care to use the inner pot, do not make it deformed.
3 When installing, insert the gas hose of Φ9.5 into the air inlet of the rice cooker and secure it with the pipe clamp.
4 First, bring the main combustion and heat preservation switch to the upper end, and then press the switch. When the ignition is fired, lift the windshield and re-ignite it. After confirming that the fire has been normal, place the windshield within the hood and leave it.
5 Lightly press down the main burning insulation switch, and the pulse-ignited rice cooker will emit continuous firing sound for about 5 seconds. (Electronic ignition fired rice cooker should be pressed after reaching the end point, stay for 1-2 seconds and then press rotation Twist and give out a fear. The fire ignites.
6 Sometimes, because there is air in the pipeline and it doesn't ignite, it can be turned on and off repeatedly until it catches fire.
7 After the rice is cooked, the main burner is automatically turned off and enters the keep-warm state. After the insulation is completed, the heat-insulated switch must be referred to the upper-end home position to turn off the gas switch.
8 pulse ignition rice cooker, install a section of the 5th battery prior to activation.
Third, the common failure of biogas products and troubleshooting methods (a) biogas stove
1. In the case of normal gas production, the pressure indicated on the pressure gauge (kilopascals) is relatively high, but the stove power is not strong.
The reasons are as follows: 1 Partial blockage of the vent hole in the nozzle or assembly of the biogas stove results in the biogas flow being too small. 2 Biogas stove head fire hole partially blocked. 3 switch aperture size. 4 Gas pipelines are too thin, too long or bend when the pipeline turns, resulting in biogas flow. 5 There is water accumulation in the gas pipeline, and the blockage is occupied so that the biogas cannot pass smoothly. 6 gas pipeline leakage.
Remedy: 1 First check whether there is a bend in the turning of the gas pipe. If there is a need to enlarge the turning angle, it is generally greater than 120 degrees. 2 Check whether there is water in the gas pipeline, turn off the gas switch of the digester and the switch in front of the gas stove, shake off the water in the tube or use a bicycle gas pump to pump gas out. 3 Check whether the outdoor air pipe is damaged or the three-way connection is loose (because of the aging of the air pipe), replace or cut off the aging damaged section and reconnect it. 4 Clean the nozzle of the biogas stove and the fire hole in the head. Fine iron wire or sewing needle can be used as a cleaning tool. The nozzle and the fire hole are not effective after cleaning. The assembly should be folded down. The impurities in the vent hole should be clear and clean, so as to keep the size of the original fire hole. It is difficult to disassemble the assembly, and it is best to ask the professional maintenance personnel to take apart and wash. 5 replace the switch (aperture not less than 6 mm). 6 If necessary, replace the pipe (the inside diameter of the pipe is not less than 8 mm).
2. When the stove burns, when the firepower is strong or weak, there is a fire on the top, and the fluctuation of the pressure gauge is mainly caused by water in the gas pipeline.
The main reason is that the accumulated water in the gas pipeline is eliminated, and the water in the gas-water separator is drained.
3. The flame is too fierce, the combustion sound is loud, and the flame is easy to blow off. Cause: The primary air is too much. Exclusion method: Turn off the air deflector and reduce the air once.
11. Flames are long and 12. Weak, 13. Causes of yellowing: Mainly an air shortage, or the head fire cover is not installed. Remedy: Open the air deflector plate and increase the air once. Flatten the head cover.
5. The size of the flame on the surface of the cooker is uneven or fluctuates: The fire hole on the lid is clogged. Removal method: The fire hole of the lid must be cleaned regularly. Turn the stove upside down to see a pin on the back of the combustion head. Pull it out and the burner head can be removed. Clearly contaminate the inside of the burner head and the ejector tube. When installing, first push the burner head toward the assembly and push the fixed head of the burner into the mounting bracket of the burner.
14. Biogas stoves do not fire. 15. Spirit, 16. The causes of low fire rates are:
1 Newly folded, flattened, and blocked pipes;
2 There is air in the gas pipeline;
3 Battery voltage is not 17. Foot, 18. or battery contact is not 19. Good;
4 Ignition switch contact oxidation, 20. Contact not 21. Good 5 discharge gap too far or too close;
6 fire pilot nozzle clogging;
The inclination angle of the flame of the 7 electrode and the axis of the ignition nozzle is not 22.
8 The pressure of biogas is too high;
9 Methane content in biogas is too low.
Method of exclusion:
1 Correct or replace the gas pipe 2 repeatedly 23. Fight the fire, 24. Exclude the air in the pipe;
3 replace the new battery;
4 move some of the negative pole reeds, 25. Use sandpaper to sand a few times;
5 Adjust the discharge gap, 26. Adjust the distance between the electrode and bracket to 3-4mm
6 Use φ 0.04 mm fine needle to open the pilot nozzle;
7 Adjust the angle of inclination between the flame plate and the ignition nozzle axis with needle-nose pliers. 27. After experimentation, 28. The inclination angle is 20 degrees.
KN95 Mask Earband Single Spot Welder(Single Point)
Kn95 Corona Mask Machine,Kn95 Filters Respirator Machine,Kn95 Protective Face Mask Machine,Kn95 Covid 19 Face Mask Machine
Ningbo Dokee Mask Machine Co., Ltd. , https://www.autrendsmac.com