SOLAR AND THERMAL ENERGY INTEGRATED SLUDGE DRYING SYSTEM AND METHOD

Abstract

The invention relates to a system and method that combines solar and thermal drying technologies in a sequential and integrated manner for drying domestic and industrial waste sludge. The main objective of the invention is to overcome the decreasing evaporation rate and space occupied by individual solar systems as the drying process progresses, and to eliminate the mechanical problems caused by the "sticky phase" encountered in thermal systems, as well as the need for "back-mixing," which leads to system complexity and capacity loss. Furthermore, it aims to achieve thermal energy savings through pre-drying of the sludge in the solar drying system. In the system and method, the waste sludge is first pre-dried in the solar drying unit (A) until it falls below the sticky phase zone, then it is conveyed to the thermal drying unit (B) via a transfer line (2) to reach the final dryness level. The flue gas or waste heat from the thermal drying unit (B) is fed back to the solar drying unit (A) directly or indirectly via a heat recovery line (4), increasing the pre-drying performance and system capacity. Thanks to this integration, there is no need for backmixing processes that require additional equipment investment, space requirements are optimized, total thermal efficiency is increased, and carbon emissions and operating costs are minimized.

Description

1 TARIFF SOLAR AND THERMAL ENERGY INTEGRATED SLUDGE DRYING SYSTEM AND METHOD TECHNICAL FIELD This invention relates to the processes of drying domestic and industrial waste sludge. The invention specifically relates to solar drying and thermal drying. systems that are used sequentially and in an integrated manner, encountered in industry a system focused on reducing challenges, high efficiency and energy recovery, and these 10 It relates to how the system works. STATE OF THE ART In current technology, waste sludge drying processes are generally either solar drying or other methods. in systems, or thermal drying systems, independently of each other 15 This is being implemented. Solar systems have low operating costs. However, it requires very large areas and depends on air temperature and sunlight. The drying process cannot be controlled depending on the duration. Furthermore, solar sludge... In drying systems, the drying rate of the sludge decreases as the drying process progresses. This shows the trend (see Figure 1 for example). Especially in the initial stages 20 The high rate of moisture evaporation leads to a decrease in the moisture content of the mud. It slows down significantly. Therefore, the sludge is dried in a solar drying unit. Keeping it until it reaches its final dryness level, for freshly fed wet mud. the usable areas being occupied by semi-dried mud and This causes a decrease in system capacity. 25 Thermal drying systems provide fast drying but require high energy. It has high energy consumption and operating costs. Solar sludge drying systems Just as the rate of evaporation decreases as the days go by, thermal sludge drying The higher the moisture content of the sludge fed into the systems, the more 30 is consumed. The demand for thermal energy is increasing so much. 2 Furthermore, a significant technical problem with thermal sludge drying systems is the sludge... as the "sticky phase" before any pre-drying This is the stage called thermal mud. In this stage, the mud is in a sticky state. Irregularities and inefficiencies in the feeding and drying processes of drying systems This is causing a decline. 5 In the current state of the art, to overcome this sticky phase problem... The 'back-mixing' method is commonly used. This In this method, a portion of the dried product is mixed back with wet clay to reduce its moisture content. It is artificially reduced in volume and then fed back into the thermal drying system. Back mixing. The process requires additional conveying, dosing, and mixing equipment. This situation, 10 both additional equipment investment and operational control points (system This leads to an increase in complexity and also ensures complete mixing homogeneity. Because this cannot be achieved, it reduces drying efficiency. However, dry Re-feeding a portion of the sludge back into the thermal sludge drying system, thermal This leads to a loss of capacity in the sludge drying system. 15 Also, for energy recovery from flue gas emissions in existing thermal systems. Even when economizer-like systems are used, this gain is generally limited. And energy loss continues to occur. Technical Problems That the Invention Aims to Solve 20 The main objective of the invention is to integrate solar and thermal drying technologies into a single unit. The goal is to eliminate the disadvantages of these systems. The technical solutions targeted by the invention are as follows: The adhesive phase gap of the mud is solar, without any mechanical stress. The moisture content exceeds 25 in the drying unit and beyond this phase in the thermal drying unit. Ensuring a homogeneous product feed with consistent content. This wet phase, which has the highest energy consumption range for thermal drying systems, Saving money with the help of solar energy. Back-mixing systems are expensive and complex. eliminating the need. 30 The flue gas or waste heat from the thermal drying unit is recycled back to the solar unit. by feeding the solar unit, the seasonal and weather-related efficiency loss 3 minimizing and increasing the drying speed and capacity in solar drying systems increasing energy efficiency. In this way, solar drying systems It reduces the space it occupies. Increasing overall energy and process efficiency to reduce the carbon footprint. Explanation of the Figures Figure 1. Evaporated Moisture – Time Graph in Solar Sludge Drying Systems. (Example) Figure 2. Overall flow diagram of the integrated sludge drying system. Reference Explanations; A: Solar sludge drying unit B: Thermal sludge drying unit 1: Feeding the waste sludge into the solar drying unit. 2: Feeding the pre-dried sludge into the thermal drying unit 15 3: The dried sludge, having reached the desired dryness, exits the system. 4: Recycling waste heat from the thermal drying system to the solar drying system. It shows his diet. Detailed Description of the Invention 20 The system described in the invention consists of at least one solar drying unit (A) and this unit It consists of at least one integrated thermal drying unit (B). In the system, the waste sludge is initially fed into the solar drying unit (A). In the solar drying unit, the sludge is dried using solar energy, ambient air, and thermal drying. 25 subjected to pre-drying with the help of waste heat (4) recovered from unit (B). is being held. Thanks to this pre-drying process, the moisture content of the mud is reduced and preferably lowering the mud below the sticky phase region This is provided. In addition, with this pre-drying process, in the thermal drying unit... By reducing the total amount of moisture that needs to be evaporated, the thermal energy requirement is reduced by 30%. and system efficiency is being increased. 4 Pre-dried sludge in solar drying unit (A), pre-dried sludge transfer It is conveyed to the thermal drying unit (B) via line (2). Thermal drying unit (B); belt type, rotary drum type, pedal type, high-speed pneumatic type, thin film type, It can be either a disc type or a fluidized bed type dryer. The mud is brought to its final dryness level in the thermal drying unit (B). 5 One of the important elements of the system is the heat recovery line (4), thermal drying Flue gas or waste heat from unit (B) to solar drying unit (A) It provides guidance. The energy transfer in question; 10 By direct hot air transfer, Or, through a heat exchanger, hot water, hot oil, steam, or a similar carrier This can be done via fluid. Thanks to this integration, the products coming out of the thermal drying unit and under normal conditions Waste energy that would otherwise be released into the atmosphere is being recycled within the system, 15 Pre-drying performance is improved by increasing the temperature of the solar drying unit. is being increased. This reduces energy losses in the system and increases the total thermal output. Productivity is being increased. One of the important advantages of the invention is that 20 are fed into the thermal drying unit (B). This means the mud has already passed the sticky phase region. This allows for thermal absorption. Back-mixing (dry sludge recirculation) is commonly used in drying systems. and the need for mixing systems is eliminated. Thus the system; 25 It is becoming mechanically simpler, Equipment requirements are decreasing, Operating and maintenance costs are decreasing. The continuity and efficiency of the drying process are increased. How the invention can be applied to industry. The invention is suitable for wastewater treatment plants of all sizes and industrial sewage sludge. It can be implemented in management centers. Thermal insulation can be added to existing solar systems. adapting to the industry by adding modules or installing new hybrid plants It can be done. 10 20 30

Claims

6 REQUESTS 1. The invention describes solar and thermal drying units for drying waste sludge. It is an integrating system whose characteristic is; - at least one solar sludge that enables the pre-drying of waste sludge. Drying unit (A), 5 - the final pre-dried sludge coming out of the aforementioned solar drying unit (A) at least one thermal sludge drying unit (B) where the drying process is carried out, - the waste heat released in the aforementioned thermal sludge drying unit (B) or at least one heat recovery unit that transfers flue gas to the solar sludge drying unit (A) gain line (4), 10 - pre-dried sludge coming from the aforementioned solar sludge drying unit (A) The sludge is sent to the thermal sludge drying unit (B) for the final drying process. It includes a mud conveying line (2) which enables it to be transported.

2. Solar and thermal sludge drying units for drying waste sludge. It is a method that works in an integrated way, and its characteristic is; - waste sludge is first processed in a solar sludge drying unit (A) subjected to drying, - after pre-drying process, the mud is transferred to a transfer line (2) and the thermal mud 20 - the final dryness level of the sludge in the thermal sludge drying unit (B) delivery, - heat recovery of waste heat generated during thermal sludge drying process. steps of conveying to the solar sludge drying unit (A) via line (4) It includes. 25

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