The utility model patent discloses a hollow blade dryer and a drying system for sludge drying, including a hollow heat shaft, a hollow blade, a dry air inlet, a wet air outlet, a hot medium outlet and a sludge outlet. The sludge is heated by the heat medium in the heat shaft and blade to achieve the appropriate humidity. The moisture in the sludge evaporates in the drying chamber to produce hot and humid air. The hot and humid air enters the heat pump heating system to change into dry air, and returns to the drying chamber through the fan to continue drying the wet sludge. The refrigerant in the heat pump system absorbs the heat of the hot and humid air through the evaporator, and then exchanges heat with the hot medium in the heat shaft and blade after compression to maintain a high temperature of the hot medium. The utility model patent mainly improves the drying efficiency of the drying process, greatly reduces the energy consumption of sludge drying and saves the consumption of energy by recovering all the waste heat of the steam tail gas produced in the process of sludge drying.

Technical field

The utility model patent belongs to the technical field of water-bearing sludge reduction and drying, in particular to a hollow blade drier and a drying system for sludge drying.

Background technique

After conventional treatment, the sludge in sewage treatment plants still has a large water content (about 80% water content), which is not conducive to sludge transportation and subsequent disposal work. To adopt a variety of sludge disposal methods such as agricultural use, landfill, incineration, building materials and other processes, the premise is that the moisture content of the sludge must meet the relevant requirements. Sludge drying can reduce the volume of sludge and make the transportation and subsequent treatment of sludge more convenient. The properties of dried sludge are relatively stable because it contains less moisture and contains fewer pathogenic microorganisms. Therefore, sludge drying is the key link to realize harmless, reductive and resource-based treatment and disposal of sludge, and is the premise of sludge resource-based utilization.

Traditional sludge drying process often directly uses primary energy, boiler flue gas waste heat, or directly electric heating drying. Its energy consumption is up to 4000 ~ 6000kJ/kg water and electric energy 45-90kW/t, also requiring complex additional equipment and high investment cost. And in sludge drying process, the residual heat is large, so direct discharge or simple treatment after direct discharge causes a large degree of energy waste and pollution. Conventional waste heat recovery can only be combined with the process itself to use tail gas or condensate water back into heating materials or cold media, and waste heat recovery amount is small. Therefore, sludge resource utilization and drying to avoid high energy consumption, and effective use of waste heat have become an important content of energy saving and environmental protection technology, which has important significance for the sustainable development of society.

Utility model patent content

According to the problems existing in the prior art, the utility model proposes a hollow blade drier and a drying system for sludge drying, which uses the high efficiency and high temperature heat pump energy saving technology to take air as the heat source and combines with the blade drying chamber to achieve the purpose of reducing energy consumption and avoiding pollution.

The technical scheme adopted by the utility model is as follows:

The utility model relates to a hollow blade drier, comprising a housing and a top cover. The housing is horizontally provided with two heat pipes arranged coaxial, and the two heat pipes rotate synchronously. A plurality of hollow blades are arranged on the outer heat pipe, and the adjacent hollow blades are interleaved. One end of the housing is provided with a hollow hot shaft steam inlet, and the other end is provided with a hollow hot shaft condensate outlet. The hollow hot shaft steam inlet and the hollow hot shaft condensation outlet through the heat pipe; one end of the top cover is provided with a wet sludge inlet; at the bottom of the housing away from the wet sludge inlet is provided with a dry sludge outlet. The bottom of the housing at the sludge inlet end is provided with a hot and humid air inlet, and the top cover at the sludge outlet end is provided with a hot and humid air outlet.

The inner heat pipe is the central flow channel, between the outer heat pipe and the inner heat pipe is the annular flow channel, the inner cavity of each hollow blade is communicated with the annular flow channel through the condensed water pipe, and the central flow channel is communicated with the inner cavity of the hollow blade through the steam pipe.

Further, the side of the hollow blade is made of two fan-shaped steel plates, and a closed cavity is formed between the fan-shaped steel plates.

Further, the hollow blade is provided with a rectangular stainless steel scraper along the radial outward, which is used to scrape up the sludge inside the casing to avoid deposition.

Further, the condensate outlet end of the hollow hot shaft is provided with a hollow hot shaft non-condensing steam exhaust valve.

Further, the shell can be attached to the wall and is provided with a steam jacket, the two ends of which are respectively connected with the hollow hot shaft steam inlet and the hollow hot shaft condensation outlet. The high temperature steam is fed along the inner wall of the shell, improving the internal temperature of the dryer.

The utility model patent relates to a drying system for sludge drying, which comprises a hollow blade dryer, a steam circulation channel and a hot and humid air circulation channel. The steam circulation channel comprises a condenser, the two ends of which are respectively connected with a hollow hot shaft steam inlet and a hollow hot shaft condensation outlet. The hot and humid air circulation passage comprises a dust collector, an evaporator and a fan connected in turn. The dust collector is connected with the hot and humid air outlet and the fan is connected with the hot and humid air inlet.

Further, the condenser and the evaporator are connected into a loop through the compressor, through which the heat transfer medium discharged from the evaporator is heated into the condenser and release heat to provide high temperature steam for the hollow blade dryer. After completing the heat release, the heat transfer medium flows into the evaporator as the refrigerant to cool the discharged wet air.

Further, The compressor can be configured with two stages.

The utility model has the following beneficial effects:

The equipment can recover all the residual heat of the steam tail gas produced in the sludge drying process, close the tail gas system in the blade drying chamber, and form a cycle. The exhaust gas at the exit of the drying chamber leads to the impeller drying chamber after passing through the evaporator of the heat pump. The low heat energy is used as one of the heat sources of the drying equipment, and the humidity of the air inlet is reduced to promote more water in the drying process, which saves the primary energy, improves the drying efficiency of the drying process and greatly reduces the energy consumption of sludge drying. It can also reduce the exhaust emissions of drying chamber, reduce the odor and other secondary pollution, and save the exhaust treatment equipment. The hollow blade dryer can effectively dry the sludge and make full use of the heat energy to heat and dry the sludge. R245fa working medium is used to increase the operating temperature provided by the heat pump to speed up the drying rate of the sludge drying process. Other high temperature working medium can also be used to replace it. By using air and exhaust gas of drying chamber as heat source, it combines with energy-saving technology of heat pump to achieve energy saving and low carbon, reduce the operation cost, and eliminate the pollution caused by heating equipment such as boilers.