AN OPTIMAL DESIGN OF HAZARDOUS (BIOMEDICAL) WASTE INCINERATION PLANT

International Journal of Industrial Engineering & Technology (IJIET) ISSN 2277-4769 Vol. 3, Issue 1, Mar 2013, 51-62 TJPRC Pvt. Ltd. AN OPTIMAL DESIGN OF HAZARDOUS (BIOMEDICAL) WASTE INCINERATION PLANT S. S. WAHID Mechanical Power Engineering & Energy Department, Faculty of Engineering, Minia University, Egypt ABSTRACT This research investigates an efficient and optimal Egyptian design of hazardous waste incineration plant for hospitals with a capacity of 100kg/h. This incinerator was designed according to the standard specifications guidelines, and rules of "Egyptian Environmental Affairs Agency (EEAA)" according to Law No. 94/1994 & Executed Regulations No. 338/1995". These incineration plants were built as a prototype in ten hospitals of Minia Governorate cities, Egypt". These incinerators are inline twin combustion chamber, fixed hearth, pyrolytic and controlled air (starved-air) incinerators. From this investigation it is worth to note that this hazardous waste incineration plant for hospitals operates efficiently at the designed parameters levels and has a full compliance with standard specification and rules of (EEAA), and their laws. So, this efficient design of this controlled-air incineration plant is the most accepted proper disposal method for the hazard (biomedical) wastes. KEYWORDS: Design Criteria, Starved-Air Incineration Plant, Air-Pollution Control System INTRODUCTION Based on the principal stated that the better understanding of the composition of hospital waste is fundamental in order to choose the best disposition alternative, Altin [2] made a research study to evaluate the physical and elemental composition of waste in four hospitals in Sivas, Turkey. The results of their investigation indicated that combustible waste constituted 92% of total mass of hospital waste. On the basis of their results, they decided that, the proper disposal method is incineration. However, individual incineration for each hospital does not seem to be economic. Therefore, one common incinerator should be designed for the four hospitals in Sivas. Also, Surjit Katoch [3] studied the classification, management, treatment, and disposal methods of biomedical waste, and health care waste generated from some hospitals in India. He stated that, incineration used to be the method of choice for most hazardous health care wastes and is still widely used. As well as, the use of proper air pollution control device (APCDs) during incineration would significantly reduce the carcinogenic potencies. Shaaban [4] investigated the development of the process engineering design of an integrated unit, which is technically and economically capable for incinerating medical wastes and treatment of combustion gases. Such unit consists of an incineration unit having an operating temperature of 1100 C at 300% excess air, combustion-gases cooler generating 35 m 3 /h & hot water at 75 C, dust filter capable of reducing particulates to 10 20 mg/nm 3, gas scrubbers for removing acidic gases, a multi-tube fixed bed catalytic converter to maintain the level of dioxins and furans below 0.1 ng/nm 3, and an induced-draft suction fan system that can handle 6500 Nm 3 /h at 250 C. The residence time of combustion gases in the ignition, mixing and combustion chambers was found to be 2s, 0.25s and 0.75s, respectively. This will ensure both thorough homogenization of combustion gases and complete destruction of harmful constituents of the refuse. The adequate engineering design of individual process equipment results in competitive fixed and operating investments. His

52 S. S. Wahid incineration unit has proved its high operating efficiency through the measurements of different pollutant-levels vented to the open atmosphere, which was found to be in conformity with the maximum allowable limits as specified in the law number 4/1994 issued by the Egyptian Environmental Affairs Agency (EEAA) and the European standards. Reis [5] made study interested with the hazardous clinical solid waste incinerator. His solid waste incinerators were industrial facilities, based on sustained high-temperature combustion processes and intended to treat these wastes, so as to reduce its volume and hazardousness, capture, concentrate, and destroy potentially harmful substances, and, as of more recently, recover energy from the combustion of the waste for disposal. He stated that, incineration is increasingly used in waste management, in an effort to counter the problem of growing waste production, consequentially increasing human exposure to the most critical pollutants potentially emitted by these facilities. However, emissions of pollutants under standard operating conditions have been substantially reduced by technological advances and increasingly stringent regulations. The term incinerate, means to burn something until nothing is left but ashes. An incinerator is a unit or facility used to burn trash and other types of waste until it is reduced to ash. Incineration of wastes has many advantages, such as: incinerators require relatively small plots of land as compared to sanitary landfills; it can usually be located in residential and collection areas. Also, incineration's operation is not interrupted by inclement weather, and it can operate for a range up to 24 hours a day to accommodate the variations in refuse generation. The waste is completely destroyed, the waste is not recognizable, waste volume and weight are significantly reduced (>95%), as well as the ash residues from an incinerator is generally stable nearly inorganic, and its volume not exceed than 4 5% from its capacity. Large quantities of waste can be treated, toxic emissions are reduced, suitable for all types of waste, micro-organisms are completely destroyed, so it has high disinfection efficiency, all types of organic waste (liquid and solid) are destroyed. Moreover, no shredding of waste is necessary prior to charging it into incinerator, low fly ash carry over, and low operational costs. It is worth noting that, the incinerator can be less expensive than sanitary landfill, and it can burn practically any kind of refuse. The incineration process is represented a controlled high efficiency combustion process, which leads to high thermal efficiency. But, there are some disadvantages of using the incinerators, such as: the high initial cost of an incinerator facility. Even though long-term landfill cost has been reported to be as much or more expensive than incineration cost. Operation, maintenance and repair costs may be high, because of the high temperatures necessary for the burning and damaging nature of the refuse and residue. Although the number of employees required to run an incineration plant may be smaller than other methods of disposal, the salary for the skilled employees who operate, maintain, and repair an incinerator are higher, for instance, than for men who work on a landfill. [6,7 and 8]. So, the most common treatment method of the hazard (biomedical) waste is incineration. In general, the using of incinerator is more safety, than the using of landfill, because the incineration destroyed the wastes completely and change it into ash. The high temperature of incinerator has a capability of destroying all kinds and types of viruses and diseases, that present in medical wastes and crematory, while, the landfill has a dangerous effect on the pollution of underground water. The present research is one of a series of researches interested with the studies leads to get an advanced, modified, and efficient Egyptian design for hazardous (biomedical) waste incineration plant for hospitals, a case study in general hospitals of Minia Governorate cities, Egypt. These groups of researches were supported by private company in Minia, Egypt which is interested in the field of incineration process as safe, proper and suitable disposal method for hazardous (biomedical) wastes. The hazardous (biomedical) wastes produced from the hospitals are used as the working medium for incinerators. So, the average quantities and physicochemical compositions of the hazardous (biomedical) wastes are the basis on which the design of incinerator is built. Therefore, the average quantities, compositions, and properties of the

An Optimal Desin of Hazardous (Biomedical) Waste Incineration Plant 53 mixture of hazardous waste categories generated from hospitals of Minia Governorate cities were determined in the first paper of these series. The design criteria for incinerators which would be got an advanced and modified efficient Egyptian design for hazardous (biomedical) waste incineration plant for hospitals, as a second study. The design of this incineration plant is based on some concepts, such as: the system must be simple in construction, easy to operate and low cost, and where most of the maintenance work can be done by local workers using local available material. The design criteria can be summarized as follows:-- Design criteria for the hazardous waste incinerator for hospitals Incineration plant DESIGN CRITERIA FOR THE HAZARDOUS WASTE INCINERATION PLANT FOR HOSPITALS The estimated properties for the mixture of the hazardous waste categories generated in "Minia General Hospitaly, Egypt", is illustrated in Table (1&2) [1&9]. Table 1: The Average Physical Properties of the Mixture of the Hazardous Waste Categories Produced from "General Hospital of Minia City, Egypt" [9] Table (1-A): Physical Characteristics Item % Sum% tissues 10.50% Combustible textile 17.00% matter, (%) plastics 52.00% 79.50% Moisture (body fluid, salt solution, glucose) 20.50% Total 100% 100% Table (1-B): Physical Composition Item % Sum% Combustible matter, (%) Volatile Matter, % 68.13 71.54% Fixed Carbon, % 3.41 Non-Combustible matter, % 2.06 2.06 Moisture from waste 5.9 Total Moisture, % composition, % Moisture from body fluid salt 20.50% 26.40% solution, glucose Total 100% 100% Table (1-C): Physical Properties Property Item Molecular weight of the mixture 58.622 kg/mole of hazardous waste categories Average density 872.4kg/m 3 Volume of 100kg waste 0.115 m 3 Heating value of the mixture of 28,910.615 kj/kg hazardous waste categories Table(1-A) shows the physical characteristics of this mixture of the hazardous waste categories are; 79.5% combustible matter (10.5% tissues, 17.0% textile, 52.0% plastics), and (20.5%) moisture (body fluid, salt solution,

54 S. S. Wahid glucose). The physical composition of the hazardous waste mixture is shown in Table (1-B). While the average values of molecular weight, density and heating value of the mixture of the hazardous waste categories are 58.622 kg/mol, 872.4kg/m 3, and 28,910.615kJ/kg respectively are shown in Table (1-C). Table (2) illustrates the chemical composition of the hazardous waste mixture. The main design parameters for the hazardous (biomedical) waste incinerator for hospitals, of a capacity of (100kg/h) are shown in Table (1&2). The calculation of the design of this incinerator based on the actual percentage of the constituents of hazardous waste mixture estimated from the hospital, as illustrated in this Table (1&2). The design of the incinerator was based on total mass of hazardous waste mixture, i.e. Capacity of Incinerator = m ) Waste = 100kg/h. It is worth noting to state that our incinerators are designed to burn many types of wastes, including Type IV pathological waste and infectious and contaminated "red bag," surgical dressings, plastic test devices and other wastes. Table 2: The Average Chemical Composition of the Mixture of the Hazardous Waste Categories Produced from "General Hospital of Minia City, Egypt" [9] Item % Sum% Carbon 57.96 Combustible matter, % Hydrogen 9.2 68.19% (Tissues, Textile, and Plastics) Sulphur 0.106 Chlorine 0.9 79.5 Oxygen 9.35 Non-Combustible matter, % Nitrogen 1.68 11.31% Ash 0.256 Moisture (body fluid, salt solution, glucose) 20.50% 20.50% 20.50% Total 100% 100% 100% INCINERATION PLANT There are three main types of incinerators are used; controlled air (starved-air), excess air, and rotary kiln. The majority of the hazard waste incinerators (>95 percent) are controlled air units, a small percentage (<2 percent) are excess air, and less than one percent were identified as rotary kiln. The rotary kiln units tend to be larger. It is recommended that all the incinerators typically are equipped with air pollution control devices [9]. Of the three types of incinerators, the controlled-air (starved-air) unit is currently the most widely accepted system for the incineration of biomedical waste [8]. The design of this incinerator is based on "controlled-air" incineration principle (i.e. starved air incinerator), as particulate matter emission is low in such incinerator. Incinerator means furnaces or combustion chambers, each incinerator must be associated with an air pollution control system (exhaust treatment unit), and electric control panel, and the assembly of these three parts assembly is called incineration plant. Figure 1, illustrates the block diagram for the incineration plant, including all its components and the air pollution control process. The incineration plant under investigation consists of three main parts: Incinerator (Combustion Chamber) Air Pollution Control System Electrical Control Panel

An Optimal Desin of Hazardous (Biomedical) Waste Incineration Plant 55 Controlled Air (Starved-Air) Incinerator (Combustion Chamber) The incinerator consists of double incineration furnaces, (double combustion chambers). The first combustion chamber is the primary combustion chamber (PCC), which is the main combustion chamber. It is preferred to call it, incineration chamber (IC). It has a volume 3.16m 3, with hearth area of 1.74m 2, includes charging door of (600 x 600mm) and ash removal door of (200 x 300 mm). The second combustion chamber is the secondary combustion chamber (SCC), which represented a thermal oxidation chamber or after burner chamber. The secondary combustion chamber (SCC) includes one door with a dimension of (500 X 500mm.), for maintenance operation. These two combustion chambers are inline and adjacent to each other. Both the two combustion chambers are separated from each other by a refractory (fire brick) wall. Both of the two combustion chambers are made of heavy welded steel sheet (6mm thickness), and painted externally with heat resistant paint. They are lined with special refractory material (fire bricks of 42% Al 2 O 3,). Also, they have a layer of insulating material (Asbestos), which keeps the outer surface of the incinerator body at a temperature not exceeds than (15-20 C) above room temperature, to protect the incinerator's operators. Air Caustic soda solution Exhaust Incinerator (Combustion chambers) Air Pollution Control System (APCS) Barometric Damper Waste +Fuel +Air Primary Combustion Chamber 800±50 C Secondary Burner Secondary Combustion Chamber at 1150±50 C Air Box Venturi Wet Scrubber Lower Liquid Separation Chamber Higher Liquid Separation Chamber Absorption Caustic Soda Tray Tower Scrubber Chimney Clean Air Caustic Soda Solution Tank Primary Burner Additional Combustion Air Blower Pumps Figure 1: Block Diagram for Incineration Plant The incinerator furnaces designed with stationary hearth, which is usually a refractory floor to the furnace. The additional primary combustion air does not admitted through openings beneath the stationary hearth, but it admitted under slight pressure through ports along the sides of the furnace, and combustion proceeds in the same, surface-burning manner as in a bonfire, but with improved conditions due to the re-radiation of heat from the surrounding furnace walls and roof. The refractory surface of the secondary chamber should be heated over a minimum period of 15 minutes, prior to turn-on

56 S. S. Wahid the primary oil-burner, to ensure optimum conditions for the destruction of micro-organisms [9]. To prevent leakage of gaseous emissions from the doors of combustion chambers, all of these doors are sealed; also, the incinerator is designed to operate continuously under minimum draft negative pressure in primary combustion chamber [12]. Each combustion chamber is equipped with a separated auxiliary oil-burner, the heat input capacity of each burner is sufficient to raise the temperature in the primary and secondary combustion chambers to the required temperature as 800±50 C and 1150±50 C respectively. The two auxiliary oil-burners operated by a two separated shield thermocouples (type-k). These two thermocouples are connected to two digital controllable thermostats, used in continuous monitoring and, controlling the operating temperature for both the two combustion chambers. The function of the secondary combustion chamber (SCC) is to oxidize the continuously generated pyrolysis off-gases coming from the incineration process in primary combustion chamber (PCC) with the additional secondary combustion excess air (rich oxygen i.e. more than stoichiometric). This is to ensure complete combustion of these pyrolysis off-gases before, allowing the product combustion gas to exit through the air pollution control system. So, the thermal oxidation in (SCC) is the most efficient, as well as the most flexible combustion technique for controlling high concentration of flammable emission and odours. Also, the high temperature of the (SCC) burns completely the toxic and carcinogenic substances (i.e. decompose the dioxin, and furan to its chlorine halogen.). Table (3), shows the specification of this incinerator. Table 3: Specifications of Incinerator (Capacity of 100kg/h) Incinerator outer Dimensions L = 3000, W =1800, H = 2800 mm Volume of primary combustion chamber V (PCC) V (PCC) = 3.16 m 3 Volume of secondary combustion chamber V (SCC) V (SCC) = 1.55m 3 Hearth area of primary combustion chamber A (PCC) = 1.74 m 2 Capacity of auxiliary primary oil-burner 180-220kW Capacity of auxiliary secondary oil-burner 280-300kW Charging Door dimensions 600 X 600 mm Ash Door dimensions 200 X 300 mm Oxidation Room Door dimensions 500 X 500 mm The incineration plant has a chimney of diameter (D=700 mm.) which is large enough to prevent the restriction of the flow of flue gases. Also, according to the rules of the "Egyptian Environmental Affairs Agency"(EEAA), the height of the chimney is taller with 3.5meter than any buildings in a circle of 50 meter diameter around the chimney. Air Pollution Control System (APCS) The air pollution control system (APCS) that installed in this incineration plant is wet-scrubbers type (wet scrubber exhaust treatment unit). This wet scrubber air pollution control system (Wet-APCS), consists of a sequential separated unites to ensure the removal of environmental pollutants It comprises; caustic soda solution tank, two stainless steel pumps, venturi wet-scrubber, caustic soda absorption tray tower-scrubber, two liquid separation chambers, tall chimney (stack), and blower (ID fan). This unite is used to clean the contaminated gases emitted from both combustion chambers (furnaces), [10,14, and 15]. Electrical Control Panel (ECP) The incineration plant is supplied with an electrical control panel (ECP) contains, indictors, switches protector, and controllers for all the components of the incinerator and air pollution control system (exhaust treatment unit). The automatic control system is divided in two parts: temperature control and timing control.

An Optimal Desin of Hazardous (Biomedical) Waste Incineration Plant 57 EXPERIMENTAL WORK The new designed hazardous (biomedical) wastes incineration plant for hospital (with a capacity of 100kg/h) was built in "General Hospital of Minia City, Egypt". The specifications, design details, manufacturing, installation and operation of this hazardous (biomedical) wastes incineration plant had been reviewed, inspected, and checked by the engineering receipt committee of the hospital. The incinerator was charged with about 105kg (red bags) of hazardous waste, which composed from a mixture of pathological tissues, textile and plastics. Hence the incineration plant had been started the incineration process. All the components of incineration plant were investigated and observed, before operation, during operation (incineration process), and during its cooling period. The hazardous (biomedical) wastes, and ash produced at the end of runs were weighed Also, the operating parameters, effectiveness of destroying the wastes, volume reduction, concentration of emission from the chimney,for this incineration plant was observed and recorded. RESULTS AND DISCUSSIONS This investigated hazardous (biomedical) waste incineration plant was operated successfully, and the operation conditions of it was observed and recorded in the following tables and figures. Table (4) shows the operating parameters of the incineration plant, while Table (5) shows the concentration of the exhaust gases emitted from the chimney of the incineration plant. Table 4: Operating Parameter of Incineration Plant Incinerator Capacity ( kg/h) 100kg Charge weight. 105kg Ash weight. 4.3kg Ash percentage. 4% Destruction efficiency 96% Standard range of Temp of Primary Combustion Chamber = 800±50 C Temperature of Primary Comb. Chamber. 830 C Standard range of Temp of Secondary Combustion Chamber = 1150±50 C Temperature of Secondary Comb. Chamber. 1120 C Standard range of Temp of outer surface of incinerator body < Room Temp + 20 C Temperature of outer surface of Comb. Chambers body 39 C Room Temperature. 25 C Temp of Exhaust gases rising from chimney 120 C From Table (4) the average measured values of the temperature of both primary and secondary combustion chambers were (830 C and 1120 C respectively), so it is met the designed level (800±50 C and 1150±50 C) respectively, as shown in Fig.2. Also, the average measured value of the temperature of the outer surface of the incinerator body was (39 C), which is met the design level (20 C above room temperature), at ambient temperature of 25 C. As well as, it operates safety with rapid, complete destruction, and clean disposal of hazard (biomedical) wastes. There are no odours or smokes leakage from incinerator's doors to the incinerating plant's room, also, no appearance of black smoke from chimney.

58 S. S. Wahid Temperature, C 1400 1200 1000 800 600 400 200 1200 1200 1100 1120 1100 850 830 850 750 750 0 Tp Figure 2: The Higher, Lower and Average Measured Temperatures of Primary and Secondary Combustion Chamber Ts The ash represents 4% of the capacity of the incinerator which gives destruction efficiency of 96%. It is observed that the ash is composed mainly of a fine grain, which is proved that the completeness of the incineration process and the combustion. Moreover, rapid cooling of the flue gases in wet scrubber air pollution control system, minimise the risk of reformation of dioxins. Also, the fully automatic control system (electric control panel), reducing the need for operating personnel and securing 100% controlled incineration process complying with any applied emission requirements. As shown in Table (5) and Fig.3, the measured values of the species concentration of carbon monoxide, sulphuric dioxide, and nitrogen oxides rising from the chimney of our incineration plant, were less than the standard levels of "Egyptian Environment Rules". Table 5: Concentration of Emissions from Incineration Plant No. Description Standard Law 4/1994 Measured Values (mg/m 3 ) 1- Carbon Monoxide 100 87 2- Sulphuric Dioxide 50 26.5 3- Nitrogen Oxides 200 91 Egyptian Environmental Affairs Agency, "Law No.4/1994 & Executed Regulations No. 338/1995". Emission Concentration, mg/m 3 200 100 0 (S)=Standard (M)=Measured 100 CO(S) 87 CO(M) 50 SO2(S) 26.5 SO2(M) Figure 3: Comparison between Standard and Measured Values of the Gaseous Emissions from the Hazardous Waste Incinerator for Hospital 200 NOx (S) 91 NOx (M)

An Optimal Desin of Hazardous (Biomedical) Waste Incineration Plant 59 Figure 4 shows the variation of the temperature of both primary and secondary combustion chambers with the time, and the higher and lower limits of their temperatures. This figure represents one run of operation, including three periods; preheating-period, incineration-period and cooling-period. It can be expanded the incineration period to several hours to overcome several numbers of operating runs. From Fig.4 at the beginning of the incineration (burning) process the operation of primary auxiliary oil-burner has been delayed for about 10-15 minutes even all the components of the incineration plant have been reached to their stabilized state (i.e. the temperature of the secondary combustion chamber reaches to 1150±50 C, to ensure the oxidation of the pyrolysis off-gases, also the air pollution control system (APCS) is filled with the circulated treatment caustic soda solution). The incineration processes in the primary combustion chamber are achieved on "controlled-air" incineration principle (starved air incinerator), i.e. with additional air less than the stoichiometric. In starved air incinerator, the waste in primary combustion chamber will be gasified and partially burnt using a support heat (from the primary auxiliary oilburner). So, the thermal reactions occurring in the primary combustion chamber (PCC) are a combination of combustion and pyrolysis. As primary (incineration) auxiliary oil-burner began to operate the combustible materials are ignited, after some minutes. At temperature between 100-300 C, the drying and degassing processes were occurred (evolution of volatile contents e.g. hydrocarbons and water). The drying and degassing process do not require any oxidizing agent and are only dependent on the supplied heat from the primary auxiliary oil-burner. While at temperature between 250 700 C the pyrolysis process began. 1400 Preheating period Incineration (burning) period Cooling period Temperature, C 1200 1200 1200 1100 1100 1000 800 600 400 200 0 850 850 750 ) ) ) ) ) 750 ) ) T PCC T SCC ) ) ) ) ) ) ) ) ) ) ) ) 0 20 40 60 80 100 120 140 160 180 Time, minutes Figure4: The Higher, Lower Values and Variation of Temperatures of Primary and Secondary Combustion Chambers with Time The additional primary air supply was sufficient to incinerate the carbon-rich (organic) residues by the pyrolysis process. Thereby, the necessary heat for the decomposition of organic substances in the absence of an oxidizing agent was

60 S. S. Wahid generated. Also, at the same time of pyrolysis process, gasification of the carbonaceous residues was achieved by the reaction of the residues with water vapour and CO2 at temperatures around 500 C. Hot exhaust gases seep upwards through the combustible material, heating it and causing it to decompose into small volatile molecules. Depending on the type of waste, the interval is varied from 10-15 minutes. The heat stored in the refractory material speeds up the pyrolysis process. Thus, solid organic matter is transferred to the gaseous phase. In addition to the temperature, water, steam and oxygen support this reaction. Keeping the temperature of the incineration chamber (PCC) at 800±50 C confirms and ensures the continuity of pyrolysis process. The products of the pyrolysis reaction, in primary combustion chamber, are typically hydrocarbon gases (mainly methane), carbon monoxide and water vapour off-gases, and unburned carbon. These product gases from the pyrolysis and incineration process in the incineration chamber (at around 800±50 C) are taken off to the secondary combustion chamber (SCC) (thermal oxidation chamber) through a refractory lined smoke gas flue, in which the secondary auxiliary oil-burner with the additional secondary combustion excess air supply is built, to complete their combustion (oxidation), and ensure optimum conditions for the destruction of micro-organisms, and the oxidation of the pyrolysis off-gases [16]. After the end of the incineration period, the primary and secondary auxiliary oil-burners were turn off. The air blowers were remained in working to cool the components of incineration plant specially the combustion chambers, even the temperature of the secondary combustion chamber was reached to about 50 C. The cooling period was taken about 2 hours. This cooling period may be exceeded to more than 2 hours, whenever the incineration period increased. Finally, this incineration plant under investigation has a high carefully disposal effect of highly infectious hazard (biomedical) waste, composed of many types of wastes, including Type 4 (pathological waste). From these experimental results that have been got from this incineration plant under investigation, it has been confirmed that the incineration process is the most accepted proper disposal method of hazard (biomedical) wastes. So, this represented an optimal and efficient design for a controlled-air (starved-air) incineration plant which is complied to the rules of EEAA Moreover, it is worth to note that, there were another nine incineration plants for hospitals (with a capacity of 100kg/h), which had been built in nine hospitals of nine cities of Minia governorate. All of these incineration plants were subjected to the same receipt protocol and strategy that mentioned previously. CONCLUSIONS This investigated hazardous waste incineration plant for hospitals operates efficiently at the designed parameters levels and has a full compliance with standard specification and rules of "Egyptian Environmental Affairs Agency (EEAA)", according to Law No. 94/1994 & Executed Regulations No. 338/1995". The operating parameters of temperatures of combustion chambers, and outer surface body of incinerator are within the standard levels. Also, the measured values of the gaseous emission from chimney are less than the standard values. As well as, it operates safety with rapid complete destruction, and clean disposal of hazard (biomedical) wastes. There are no odours or smokes leakage from incinerator's doors, also, no appearance of black smoke from chimney. Moreover, the residues ash is 4-5% of the incinerator capacity. This ash is composed mainly of a fine grains, which is proved that the completeness of the incineration process and the combustion. This incineration plant is simple in construction, easy to operate and low cost compared with the imported incinerators, and most of the maintenance work can be done by local workers using local available material.

An Optimal Desin of Hazardous (Biomedical) Waste Incineration Plant 61 Therefore, it is worth noting to state that, the design of this investigated incineration plant is considered to be an efficient design for hazardous waste incinerator for hospitals. So, this efficient design of this controlled-air incineration plant is the most accepted proper disposal method for the incineration of hazard (biomedical) wastes. Future Recommendation For saving operational costs, it is recommended that, this incineration plant may be combined with energy recovery systems for various purposes (e.g. heating, steam production, etc.). NOMENCLATURE [Q ] APS Air pollution control system A (PCC) Area of hearth of primary combustion chamber EEAA Egyptian Environmental Affair Agency ECP Electrical control panel IC Incineration chamber mg/nm 3 Milligram per normal cubic meter ng/nm 3 Nano gram per normal cubic meter m ) Waste Mass of waste PCC Primary combustion chamber Heat release rate per unite area of hearth of the primary combustion chamber A(Hearth) [Q ] V(PCC) Heat release rate per unite volume of primary combustion chamber SCC Secondary combustion chamber Tpcc Temperature of primary comb. chamber Tscc Temperature of secondary combustion chamber TOX Thermal oxidizer V (PCC) Volume of primary combustion chamber Volume of secondary combustion chamber V (SCC) REFERENCES 1. S.S.Wahid, "Design Criteria for the Hazardous (Biomedical) Waste Incinerator for Hospitals", (submitted to publication), bulletin of faculty of engineering, Minia University. 2. S. Altin, A. Altin, B. Elevli, O. Cerit " Determination of Hospital Waste Composition and Disposal Methods: a Case Study", Polish Journal of Environmental Studies Vol. 12, No. 2 (2003), 251-255 3. Surjit S. Katoch, "Biomedical Waste Classification, and Prevailing Management Strategies", Proceedings of the "Proceedings of International Conference on Sustainable Solid Waste Management", 5-7, September, 2007. Chennai, India. pp. 169-175. 4. A.F. Shaaban, " Process engineering design of pathological waste incinerator with an integrated combustion gases treatment unit", Journal of Hazardous Materials, Volume 145, Issues 1 2, 25 June 2007, Pages 195 202 5. M.F. Reis," Solid Waste Incinerators: Health Impacts", Encyclopaedia of Environmental Health, 23 February 2011, Pages 162 217 6. International Committee of the Red Cross (ICRC) "Medical Waste Management", 19 avenue de la Paix, 1202, Geneva, Switzerland, November 2011 7. Catalogue of Envikraft A/S Topstykket 18 DK-3460 Birkerød Denmark 8. Catalogue of Nika, Engineers Private Limited, India, 2010

62 S. S. Wahid 9. S.S.Wahid, "Assessment of Physiochemical Properties of Hazardous (Biomedical) Waste Categories, As a Working Medium for the Incinerators, A Case Study in (General Hospitals of Minia Governorate Cities, Egypt)", (submitted to publication ), bulletin of faculty of engineering, Minia University. 10. "Guidance For Incinerator Design and Operation", Volume 1, General, December 1988, Ontario, Ministry of Environment and Energy. 11. Walter R. Niessen, "Combustion and Incineration Processes", Third Edition, 2002, Revised and Expanded, Marcel Dekker, Inc. New York, Basel 12. "AP42, Fifth Edition, Volume I", "Section 2.3, Medical Waste Incineration", 1June 2005 13. Edward M. Voelker, " Incinerator Standards", Journal of the Air Pollution Control Association, Technical Committee, Incinerator Institute of America (IIA), New York, USA, October 1962 / Volume 12, No. 10, page487-491 14. Howard S. Peavy, Donald R. Rowe, and George Tchobanoglous "Enviromental Engineering", McGraw-Hill, 1986 15. Robert M Bethea, P.E., Ph.D, " Air Pollution Control Technology, An Engineering Analysis Point of View", Van Nostrand Reinhold Environmental Engineering Series, Van Nostrand Reinhold Company, NewYork, 1978. 16. European Commission, "Integrated Pollution Prevention and Control, Reference Document on the Best Available Techniques for Waste Incineration", August 2006 :ىبرعصخلم تايفشتسمللةرطخلاتايافنلا ) ديمرت ( قرحةطحمللثمأميمصت ديحوميهاربإدعسقيدص دقو (100kg/h). ةعسب تايفشتسمللةرطخلاتايافنلا (ديمرت) قرحةطحمللضفأولاعفىرصمميمصتققحيثحبلااذه نوناقللاقبطو (EEAA) يرصملاةئيبلانوئشزاهجلةيسايقلادعاوقلاو تاهيجوتلاوتافصاوملل اقفوةقرحملاهذهتممص تايفشتسمةرشعيف ( prototype )يلوأجذومنك قراحملاهذهتينبدقو.(338/1995) مقرهلةذفنملاحئاوللاو ) (94/1994 مقر (hearth) دقومتاذودحاوطخ ىلعنيتيلاتتمقارتحإللنيتجودزمنيتفرغنمضتتقراحملاهذهو.رصم اينملاةظفاحمندمب تايافنلا (ديمرت) قرحةطحمنأىلإةراشإلاردجت ثحبلااذهنم.ءاوهلاىف (ةردن) مكحتلاعمىرارحلاللحتلابلمعتوتباث دعاوقلا و تافصاوملا عمامامت ةقباطتم اهنأ و ميمصتلا تاريغتم تايوتسم ىلع ةءافكب لمعتهذه تايفشتسملل ةرطخلا لمعت ىتلا (ديمرتلا) قرحلا ةطحمل لاعفلا ميمصتلا اذه نإف كلذل.هنيناوقو ىرصملا ةئيبلا نوئش زاهجل ةيسايقلا تايافنلا (ديمرت) قرحل ميلسلا نما لا صلختلل ةقيرطك الوبق رثكألا وه ءاوهلا ىف (ةردن) مكحتلا و ىرارحلا للحتلاب.ةرطخلا (ةيويحلاةيبطلا)