Carlos A. Teixeira

Racionalização do uso de força motriz em fábrica de ração

A falta de investimento no setor energetico, aliada a sazonalidade de recursos naturais necessarios para a geracao de energia hidroeletrica, faz da racionalizacao do uso de energia eletrica uma ferramenta de apoio imprescindivel para o crescimento do Pais. A racao animal pode representar entre 70 e 80% do custo de producao da criacao de animais. Sendo assim, e importante o estudo da racionalizacao do uso de energia em processos que utilizam intensivamente forca motriz, tais como as fabricas de racao. Na fabrica de racao estudada, os motores eletricos sao utilizados principalmente para moagem e mistura de granulados e transporte. Com o objetivo de racionalizar o uso da energia eletrica, foi realizado estudo de adequacao de forca motriz dos equipamentos da fabrica de racao da Industria Pif Paf Alimentos. O indice de carregamento medio dos motores eletricos estudados foi de 48,6%. O potencial estimado total de economia com energia eletrica anual, utilizando-se sempre da melhor opcao de adequacao de forca motriz foi de R

Uso de motores monofásicos acoplados mecanicamente em série, em irrigação por pivô central

24.426,50 ao ano (23,9%). Para que essas medidas sejam efetivadas, devem-se adequar tambem: (i) as exigencias eletricas do circuito, como ajuste de reles e escolha de fusiveis; (ii) o horario de funcionamento, e (iii) necessidade de implantacao de sistema de armazenamento de racao.

CONSUMO ESPECÍFICO DE ENERGIA NO PROCESSAMENTO DE MADEIRA EM CAVACOS DE UM PICADOR (ESTUDO DE CASO)

The utilization of central pivot irrigation system requires in most cases high electric power which imply in high initial investment. Most of the Brazilian farms are electrified in the single phase electrical system, due to the fact that their implementation requires only about 40% of the initial investment as compared to three phase system. In Brazilian market the highest available power of single phase motors is 9.2 kW (12.5 hp). To supply power demand above this limit with single phase system one could couple mechanically the single phase motors in series. The objective of this work was to estimate the efficiency of such coupling system and to evaluate the economic and technical feasibility compared with other forms of energy supply such as diesel and three phase electrical system.

Energy Management of Pumping Systems in Irrigation Districts

The objective of this work was to evaluate a wood chopper. Electrical energy use, energy used for wood processing, wood chip processing capacity and the specific energy consumption were evaluated. The initial moisture content of the wood was 16.5% w.b. The processing capacity of the equipment was 1,550 kg/h and the specific energy consumption was 3.8%, meaning that 3.8% of the energy contained in the wood was used in the form of electrical energy. Under the conditions in which the wood chipper was tested (initial wood moisture content and manual feeding), it was considered viable to use the chipper for wood processing.

Methodology for Matching Electric Motors to Agricultural Processes

Several energy saving strategies were investigated to decrease production costs and to optimize the use of electrical energy by small farmers that are participants of irrigation districts. The research was carried out at the Miroros Irrigation District, located in Ibipeba, Bahia State, Brazil. This energy management study of pumping systems in irrigation districts focus on two objectives. The first objective was to resize water pumping systems by matching the hydraulic and electrical characteristics of pump and motors to the demand. For the motors, five possibilities were studied to choose the one that provided the required power with minimum cost. The possibilities of studied were: (i) the current motor, standard type, (ii) an alternative standard type motor, that kept the load index as high as possible, (iii) high efficient type of motor with same power rating, (iv) high efficient motor but with power adequate to the demand, (v) a motor efficient type sized based on the number of hours of operation. The second objective was to investigate the districts water management plan to minimize energy costs considering both electrical energy and demand costs. A study of water usage by the participant farmers was conducted, to determine how multiple users potentially using the system simultaneously affect water costs. Reduction of the amount of electrical energy used for irrigation has potential to bring significant benefits to small farmers in the form of reduced cost through increased energy efficiency with potential savings of around 31% of costs.

Balanço energético de uma cultura de tomate

Rational use of electricity could save energy and improve profitability. Electric motors are used extensively in the production of animal feed. The objectives of this research were: (i) to propose a methodology for adequate use of electric traction in feeding industry; (ii) to apply the proposed methodology to a commercial animal feed industry; (iii) to compare the sizing using the present motor with the sizing based on the manufacturer’s literature. This research was based on all the motor-load combinations of a feed mill located in the Minas Gerais State, Brazil. For each motorload combination, each of the following was compared energetically and economically: (1) the current motor, (2) an alternative motor that kept the load index as high as possible, (3) a more efficient motor with same power rating, (4) a more efficient and adequate motor, and (5) a motor sized according to the technical literature. The main conclusions were: (i) the potential economic savings in electrical energy used by motors was around 23%. These savings were in demand and energy costs; (ii) the average load index for the motors in the industry audited were 48.6% which was considered to be too low. Only 23.3% of the total number of motors that were analyzed had a load index higher than 81.0%; (iii) as much as possible, it is advisable to study the possibility to optimize the number of functioning hours in order to save with the electrical demand bill; (iv) more restricted security factors are needed for dimensioning electrical motors.