A 1.5D model of a complex geometry laboratory scale fuidized bed clc equipment

The awareness of the climate changes has resulted in the development of new technologies allowing to increase the effectiveness and to lower the costs of CO2 separation from the flue gas. One of the most promised combustion technology of fossil fuels is Chemical Looping Combustion (CLC). The technology is considered to be one of the cheapest techniques for CO2 capture (1). Since it is still an emerging technology and the complexity of processes are still not sufficiently recognized, the development of a simple model of CLC equipment is of practical significance. The paper presents a 1.5D model of the laboratory-scale fluidized bed CLC equipment for Innovative Idea for Combustion of Solid Fuels via Chemical Looping Technology – NewLoop. The idea combines two technologies making them complementary: Chemical looping with Oxygen Uncoupling (CLOU) and In-situ Gasification Chemical Looping (iG-CLC). Experimental studies, calculations and model validation were performed for the CLC unit (Fig. 1). The unit constitutes two cycles: the main cycle and internal cycle with Air Reactor (AR) and Fuel Reactor (FR). Smooth glass microspheres with the Sauter mean diameter of particles of 141 µm and the density of 2450 kg/m3 were used during the investigation. Since the model is in the development stage the study was conducted for the cold tests at which the unit operated stably and smoothly. The model is performed by the use of Comprehensive Simulator of Fluidized and Moving Bed equipment (CeSFaMB). The CeSFaMB has its first successful version completed in 1987. Since then, various versions have been developed and validated for a wide range of cases (2). The first operational results with this CLC unit, i.e. fluidization dynamics are discussed, since the geometry of the system is rather complex. Pressure drops, void fractions, bubble diameter and rising velocity are determined. The results show good agreement between calculated and experimental parameters. On the matter of fluidization dynamics, CeSFaMB produces the parameters as function of vertical coordinate. As an example, the void fractions as well as bubble diameter and rising velocity in the dense region of the Air Reactor are illustrated in Fig 2. Please click Additional Files below to see the full abstract

Simple, handy and effective purifying water station for people and for household purpose

Przedstawiono niektóre istotne problemy związane z uzdatnianiem wód powierzchniowych i podziemnych zanieczyszczonych np. w czasie powodzi. Przeprowadzono badania nad usuwaniem zanieczyszczeń mineralnych (jony żelaza i manganu) i organicznych przy zastosowaniu kolumn adsorpcyjnych oraz zaproponowano sposób eliminowania mikroorganizmów przy użyciu specjalistycznych filtrów. Na podstawie uzyskanych wyników badań wykonano model użytkowy oczyszczalnika, opracowano i zweryfikowano procedurę wykonania prototypu oraz jego powielania. Opracowano procedury obsługi serwisowej oczyszczalnika.In this paper certain important issues concerning purifying underground and ground water sources contaminated as a result of, for example, a flood are presented. Studies of techniques used to remove mineral (iron and manganese ions) and organic contaminants with the use of adsorption columns were conducted. Also a way of eliminating microorganisms with the use of specialist filters is proposed. Based on the study results a utility model of the purifier has been created as well as a procedure of its creation and duplication has been designed and verified. Support service procedures for the purifier have also been prepared

Primary structure of the connecting ring of ammonoids and its preservation

The most distinctive and important element of the hydrostatic organ of ammonoids and nautiloids is the siphuncular tube. It consists of mineral and organic segments (so−called connecting rings). The connecting ring of ammonites never preserves its original organic matter in the mineralized state, usually having undergone diagenetic phosphatisation, more rarely, calcification, or even complete loss. Our knowledge about its original ultrastructure is based upon comparison with Recent Nautilus and phosphatised or calcified ammonite fossils. We show that depending on the taphonomic history, both calcium phosphate and calcite can participate in the diagenesis of the connecting ring wall. Under standard light microscopy, the phosphatised elements are indistinguishable from the calcified ones. Both are dark brown in colour, due to an excess of carbon. The structure of the phosphatised siphuncle does not closely replicate the structure of its organic elements. This casts doubts on conclusions of other authors who described a complex porous structure in ammonite siphuncles, which is completely dissimilar to the siphuncular structure of Recent Nautilus and suggests that this organ functioned differently in ammonites. SEM observations using a BSE detector on the calcified parts of the walls of connecting rings revealed a multilayered structure with perpendicular elements connecting particular layers, resembling the structure of a stacked nacreous layer

Precursory siphuncular membranes in the body chamber of Phyllopachyceras and comparisons with other ammonoids

Organic membranes preserved in the rear part of the body chamber of the Late Cretaceous phylloceratid ammonite Phyllopachyceras ezoense were examined with scanning electron microscopy (SEM) on the basis of well−preserved specimens from Hokkaido, Japan. SEM observations revealed that the membranes are continuous with the siphuncular tube wall in the phragmocone and consist of two layers, both of which are made of a dark, primarily conchiolin material; namely, a thinner inner homogeneous layer and a thicker outer layer with gently inclined pillar−like units. Hence, they are interpreted as the precursory siphuncular membranes. The precursory siphuncular membranes are not associated with any other organic components such as the siphuncular sheets reported in some Paleozoic and Mesozoic ammonoids. Unlike the tube−like condition in the phragmocone, the precursory siphuncular membranes in the body chamber of the specimens examined do not form a tube shape; on the ventral side the membranes are truncated and directly contact the outer shell wall. These observations suggest that the inner and outer layers of the precursory siphuncular membranes in the body chamber were respectively formed by the siphuncular epithelium from the inner side and by the invaginated septal epithelium from the outer side. It is also postulated that at the initial stage of septal formation, the rear part of the body moved slowly forward, developing a circumsiphonal invagination of the septal epithelium. Because similar conchiolin membranes are occasionally preserved in the body chambers of other phylloceratids, the above morphogenetic process applies to all members of the Phylloceratina. The tube−shaped structure in the rear part of the body chamber of desmoceratid Damesites consists only of nacreous layer. We interpret it as a pathologically overgrown prochoanitic septal neck

Dorsal shell wall in ammonoids

In ammonoids, a soft body organ (possibly a supracephalicmantle fold), extending from the conch aperture secreted aragonitic wrinkles, forming a layer on the surface of the preceding whorl. The dorsal shell wall consists of the outer and inner components which were deposited sequentially, beginning at the aperture of the living chamber inwards. The dorsal wall attains its full thickness near the last septum. The outer component is visible in the apertural region and is smooth or wrinkled; it is called the wrinkled layer in the latter case. The wrinkles may be continuous, interrupted, or form isolated patches arranged in rows. The wrinkles are usually triangular in cross section. A further stage of dorsal wall development involves filling in the space between the apices of triangles, and then adding one or more inner prismatic layers from the inside of the living chamber. This pattern occurs at least in the postembryonic stage of all genera studied, belonging to five suborders of Ammonoidea ranging from Late Carboniferousto Late Cretaceous. In many genera, the outer component of the dorsal shell wall exhibits remarkable ontogenetic change in its ultrastructure and microornament. It may be compared with the black film of Recent Nautilus shells with respect to place of formation. The outer component of the ammonoid dorsal shell wall is regarded as a product of organic secretion and carbonate precipitation in the area of the supracephalic mantle fold.U planispiralnie skręconych amonoidów, u których ścianka grzbietowa styka się bezpośrednio ze ścianką poprzedniego skrętu, mamy do czynienia z modyfikacją strukturalną ścianki grzbietowej w obszarze styku obu ścianek. Wymienione modyfikacje dotyczą w głównej mierze zewnętrznego składnika ścianki grzbietowej tzw. wrinkle-layer, położonego bezpośrednio na peryostrakum poprzedniego skrętu. Strefa zmarszczek (wrinkle-layer) znana była początkowo jedynie u amonoidów paleozoicznych, dopiero Senior (1971) i Kulicki (1979) odnotowali jej występowanie u amonoidów mezozoicznych. Na podstawie przebadanego materiału obejmującego 12 rodzajów należących do pięciu podrzędów Ammonoidea i występujących od późnego paleozoiku do późnej kredy nie stwierdzono występowania strefy zmarszczek poza ścianką grzbietową. Podobne suuktury, obserwowane u paleozoicznych amonoidów w ściankach bocznej i brzusznej nosza nazwę „Ritzstreifen” i nie są homologiczne do zmarszczek „wrinkle-layer”. Typowa zmarszczka „wrinkle-layer” w przekroju podłuznym zbudowana jest z elementu centralnego, organicznego lub organo-mineralnego, oraz pryzmatycznych warstewek, w których długie osie pryzm są prostopadłe do boków trójkąta skierowanych do wnętrza komory mieszkalnej. Obok typowych elementów strefy zmarszczek, opisano tzw. elementy dwurożne o zarysie okrągłym, lub owalnym u triasowych rodzajów Subolenekites i Sibirites, a także u wczesnokredowego Aconeceras. Te elementy były błędnie interpretowane (Doguzhaeva & Mutvei 1986) jako pory związane z przyczepami miękkich tkanek płaszcza do muszli. Typowa strefa zmarszczek wytwarzana przez fałd nadgłowowy płaszcza, została stwierdzona we wszystkich badanych podrzędach za wyjątkiem Phylloceratina. W wymienionym rzędzie opisano powszechnie występujące rytmiczne modyfikacje peryostrakum wbudowywane do ścianki grzbietowej. We wczesnych stadiach rozwojowych modyfikacje te mogą przypominać elementy strefy zmarszczek, lecz ich pochodzenie i budowa są różne