Effects of microwave irradiation on the moisture content of various wood chip fractions obtained from different tree species

Abstract

The paper proposes the use of microwave irradiation to lower the initial moisture content of wood chips. The study involved willow and fir chips fractionated by means of a sieve separator and unfractionated ash chips. The wood chips were exposed to a constant microwave power of 800 W for 30 s, 60 s, 120 s and 180 s. The chips were weighed before and after irradiation to measure loss of moisture. It was found that the decline in moisture content increased with wood chip size for a given irradiation time and microwave power. The initial moisture content of wood chips was not found to significantly affect loss of moisture as the drying rates of wood chips with higher and lower moisture content exposed to microwaves were not statistically different. The results showed that irradiation intensity increased with the time of exposure to microwaves and unit radiant energy per unit of evaporated moisture decreased with increasing wood chip size in the 3.15–31.50 mm range.

Modernization of an existing microwave installation for microwave processing of biological substrates

“…Technological processes for microwave processing of materials and products are widespread in the polymer materials industry: microwave drying of dyed cashmere fibers [1], microwave processing of polymers [2], microwave absorption by multilayer structures [3], in the forestry and woodworking industries: vacuum microwave drying of round bamboo [ 4], microwave irradiation of various fractions of chips of various types of wood [5], drying of wood shavings [6], in agriculture: microwave drying of rice [7], microwave drying of farm products [8], convection combined microwave drying of essential oils [9] , in medicine: composites with improved microwave absorption characteristics [10], polymerization of alkyls, aldehydes and amines in a microwave oven [11], development of a lightweight composite for controlled absorption of microwave radiation [12], in the food industry: thermal sterilization of products in a microwave oven [ 13], sterilization of mashed potatoes in a microwave oven [14].…”

Technical and economic aspects of designing a hybrid microwave electrotechnological installation for processing biological substrates and plant raw materials

“…In recent years, attention has been drawn to research and publications in the field of the use of microwave energy in various industries: microwave processing of lumber [8,16], microwave drying of agricultural products [10,12], disinfestation of food products with microwave energy [13], microwave drying food products [9,11], microwave drying of wood [1,15], the effect of microwave radiation on the properties of polymers [5,18], mathematical modeling of technological processes in a microwave electromagnetic field [7,17], design of microwave electrical technological installations with working chambers hybrid type [15].…”

Hybrid microwave electrotechnological installation for processing biological substrates and plant material

“…The use of microwave electromagnetic energy for thermal processing of materials is covered in sufficient detail in the world literature: in agriculture: microwave processing of materials at agricultural facilities [1], microwave drying of farm products [8], microwave drying of various varieties of rice [7], the influence of microwave processing on disinfection and stimulation of seed germination [14]; food industry: microwave disinfection of food products [15], the influence of microwave heat treatment on the nutritional characteristics of flatbreads with the addition of potato powder [20], microwave processing of watermelon [21], microwave processing of lemon cordial [22], microwave drying of essential oils [9], microwave processing of wheat grain and its flour [23], the effect of microwave stabilization on the properties of whole grain flour [24]; woodworking industry: microwave processing of lumber [11,12], microwave drying of bamboo in a vacuum [5], the effect of microwave radiation on the moisture content of various types of wood [6], drying of wood chips [10]; in construction: the influence of microwave radiation on the properties of geopolymers [17], microwave processing of carbon fiber polymer composites [18], the effect of microwave irradiation on materials [19].…”