Study of briquette properties at their long-time storage

Abstract

ABSTRACT:The paper presents the results of laboratory tests aimed at the study of storage place, storage manner and storage time in relation to mechanical properties of briquettes made from spruce shavings. A BrikStar 50 briquetting press with a pressure chamber 65 mm in diameter of the Briklis firm was used for the briquette production. All briquettes were made at the constant adjustment of all parameters of the briquetting press. The briquette properties were evaluated by determination of their density and rupture force. Moreover, mechanical durability, gross calorific value, total mois ture and ash content were determined. It follows from the results of tests that at briquette storage in a well closed plastic bag neither place nor storage time influenced significantly their life time. At briquette storage in a net plastic bag various intensive damage to briquettes occurred, mainly depending on their storage place and storage time.Keywords: spruce shavings; gross calorific value; density; rupture force; moisture content Briquetting is a relatively old technology. The first mentions of their use were published in the first half of the 18 th century. Otto's Encyclopaedic Dictionary describes relatively lengthily the basis and the use of briquetting and of briquettes in practice. The mention of briquetting technology and of briquettes can be found in practice in all older as well in new domestic (Stehlík et al. 1966) and foreign encyclopaedias.In the Czech Republic the briquetting technology has also been used in the field of metallic and nonmetallic processing in the last twenty years. The basis of this method is the effect of a high pressure on fine-grained material. Briquettes, most often of cylindrical form and various diameter and length, are the final product. But briquettes can be of various shape, e.g. of cuboid with rounded corners, of hexagonal cuboid etc., according to the design of the press chamber of the used briquetting press. The use of briquetting technology can bring about substantial savings. The waste pressed from flammable materials, e.g. from wood waste (chips, sawdust), straw, coal, paper, cellulose, tobacco etc., is mostly utilized energetically (by combustion) (Basore 1929;Sheridan, Berte 1959;Plíštil et al. 2004;Brožek 2011;Brožek et al. 2012). After its compression the waste from combustible materials, e.g. dust collected on air filters, abrasion dust (Brožek 2007) or chips from the cutting of metals and their alloys [ČSN 42 1331[ČSN 42 (1991; ČSN 42 0030 (1994); Brožek 2009; Brožek, Nováková 2010] is better usable. After compression the waste volume strongly decreases. This makes its handling easy and decreases costs of transport or storage on a waste disposal site. MATERIAL AND METHODSBriquettes from wood waste designed for combustion should meet a number of requirements which are defined in relevant national directives. In the Czech Republic the requirements on briquette properties are laid down by Directive No. 14-2009 of Ministry of Environment of the Czech Republic: Briquettes f...

The Effect of Moisture of the Raw Material on the Properties Briquettes for Energy Use

“…Tripathi et al (1998) recommends the same moisture value. Brožek (2013) proved that the moisture of over a long period stored briquettes changes namely in dependence on the storage conditions. From the above mentioned information it follows that the majority of authors has experiences about briquetting of materials of moisture between 9 % and 18 %.…”

“…The requirements on the briquettes strength are included in none of above mentioned directives. But it is very important that briquettes were of adequate cohesiveness in order that at common handling neither crumbling nor falling apart occur (Brožek, 2001a;2001b;2013;Brožek and Nováková, 2009).…”

Evaluation of selected properties of briquettes from recovered paper and board

“…They influence expressively for instance the storage ability. The author experimentally proved that at storage, the briquettes mechanical properties decrease Brožek 2013b). The decrease depends above all on the storage conditions and storage time.…”

“…But they engage in other materials than paper waste, primarily in briquettes made from wood waste (Basore 1929;Sheridan, Berte 1959;Brožek et al 2012;Brožek 2013b), from energy plants (Plíštil et al 2004(Plíštil et al , 2005Kakitis et al 2010), or from alternative fuels (Kolářová 2011). Their authors concentrate primarily on energy properties, but not on mechanical properties.…”

Factors affecting the utilization of lignocellulosic biomass; compaction, handling and storage, and monetary value – a review.

“…Storage and handling conditions of pellets profoundly affect both performance of pellets and safety to personnel. According to Brožek (2013) Directive No. 14-2009 of the Ministry of Environment of the Czech Republic: Briquettes from Wood Waste requires that Briquettes from wood waste must guarantee a minimum 9 months storability.…”