Abstract: A method for producing reduced iron comprises agglomerating a raw material mixture containing a carbonaceous reducing agent and an iron oxide-containing material into small agglomerates, heating the agglomerate within a heat reduction furnace, thereby solid reducing the iron oxide in the agglomerate to produce solid reduced iron, or further heating the solid reduced iron, melting the metallic iron produced by the reduction, and coagulating the molten metallic iron while separating the slag component contained in the small agglomerates to provide granular metallic iron, which is characterized by using a agglomerate having a particle size of 10 mm or less or 3-7 mm, preferably less than 6 mm, more preferably 3 mm or more and less than 6 mm as the small agglomerates.

Abstract: Raw materials, including a metal oxide and a carbonaceous material, are supplied into a rotary hearth furnace. Then, the raw materials are heated and reduced by burners, which are arranged to cause a strong stirring action for an atmosphere around the raw materials, in an early reducing period that is defined as a period during which 70-80% of a total amount of a flammable gas generated from the raw materials is generated. In a latter period subsequent to the early reducing period, the raw materials are heated and reduced by burners arranged to cause a weak stirring action for an atmosphere around the raw materials, whereby a metal is manufactured. With the present invention, productivity can be improved and the fuel consumption per unit product can be reduced.

Abstract: A method of producing reduced iron agglomerates capable of preventing oxidation in the surface layer of the agglomerates and obtaining reduced iron agglomerates having a high degree of metallization, by blowing a methane or methane-containing gas to the reduced iron oxide agglomerates incorporated with carbonaceous material at a surface temperature of 1150° C. or higher during movement in a moving hearth heating type furnace at the end of reduction as the final stage of the stagnation period of the agglomerates in the heating furnace.

Abstract: A moving hearth is formed by providing a layer of hearth material primarily composed of iron oxide on a base refractory in a reducing furnace and then sintering the hearth material so that the sintered moving hearth is not melted at an operational temperature in a reducing step. The moving hearth is more easily constructed compared to providing a shaped or amorphous refractory on the base refractory, has high durability, and can maintain surface flatness during operation.

Abstract: A moving hearth reducing furnace is operated, while a gap is provided between a discharging apparatus for discharging reduced iron agglomerates from the moving hearth reducing furnace and the surface of the moving hearth. The gap prevents squeezing metallic iron powder formed by reduction of powder included in iron oxide agglomerates into the surface of the moving hearth and the formation of an iron sheet. An iron oxide layer formed on the moving hearth during the operation can be periodically scraped off without shutdown of the furnace.

Abstract: Iron oxide agglomerates incorporated with the carbonaceous material having a particle size within a range of about 10 to 30 nm are prepared upon production of reduced iron agglomerates. Then, the iron oxides agglomerates incorporated with the carbonaceous material were laid thinly at a laying density of less than 1.4 kg/m.sup.2 /mm or lower on a hearth of a moving hearth furnace. Subsequently, the iron oxide agglomerates are heated rapidly such that the surface temperature of the iron oxide agglomerates reaches 1200.degree. C. or higher within one-third of the retention period of time of the iron oxide agglomerates in the moving hearth furnace. Then, the iron oxide agglomerates are reduced till the metallization ratio thereof reaches 85% or higher to form reduced iron agglomerates and then the reduced iron agglomerates are discharged out of the moving hearth furnace. With the procedures, reduced iron agglomerates of a high average quality can be obtained at a high productivity.

Abstract: An image pickup apparatus has an adjusting mechanism for zoom lens unit so that the apparatus is made compactly. The zoom lens unit is constituted by a first group having a negative refracting power, a second group having a positive refracting power, a stop, a third group having a positive refracting power and a fourth group having a negative refracting power which are sequentially arranged from the object side to be substantially symmetrical about the stop. An image forming magnification is changed by moving whole system and moving the second and third groups on an optical axis thereof while a distance between an object and the image is kept constant. Image formation characteristics of the overall lens system are adjusted by moving and/or decentering the first group and/or the fourth group on/from the optical axis.

Abstract: A method for the production of polytetramethylene ether glycol wherein polymerization of tetrahydrofuran in the presence of fluorosulfonic acid is followed by hydrolysis of the resulting polymer, characterized by(1) using the fluorosulfonic acid at 0.007-0.3 molar equivalents with respect to the tetrahydrofuran;(2) using in combination therewith fuming sulfuric acid which contains free sulfur trioxide at 0.05-1.0 molar equivalent with respect to the fluorosulfonic acid; and(3) adding said fuming sulfuric acid to the tetrahydrofuran prior to adding the fluorosulfonic acid thereto.According to the method, high quality polytetramethylene ether glycol with a low fluorine content may be obtained at a high yield without lowering the polymerization temperature. For example, PTMG may be obtained with 3 or fewer, and preferably 2 or fewer terminal fluorines per 2,000 termini of the resulting PTMG.

Abstract: An image forming apparatus including at least first and second developing devices for developing latent images formed on an image bearing member. The first and second developing devices contain developers of different colors, respectively. The second developing device contains a developer of a predetermined color and is fixedly mounted in the image forming apparatus. The first developing device contains a developer of a color other than the predetermined color and is detachably mountable in the image forming apparatus. Only the first developing device is exchangeable.

Abstract: An image forming apparatus comprising a first body and a second body which are openable or separable from each other. The apparatus contains a plurality of developing devices, each of which is movable between its developing position for developing a latent image on an image bearing member of the image forming apparatus and a retracted position where the developing device is retracted from the developing position. At least the developing device that is located at its developing position when the apparatus is closed, is moved away from the image bearing member in response to an operation for opening the second body relative to the first body.

Abstract: A double-sided image forming apparatus having first and second input devices respectively for entering function data for desired image formation functions and for entering the number of copies to be formed. A memory is provided to store the function data, and a storage compartment is provided to store sheets during duplex copying. An image forming device is arranged to operate in two procedures: a first procedure in which image formation is effected on the sheet's first side in accordance with first function data, and a second procedure in which image formation is effected on the other side in accordance with a second, different, function data. A controller controls the image forming device so that entry of number data and function data is permitted before the first procedure begins, but so that entry of only function data and not number data is permitted after completion of the first procedure.

Abstract: An image forming apparatus capable of effecting plural image forming operations on one transfer sheet includes an image transfer device for transferring an image on the transfer sheet, an image magnification changing mechanism for changing the magnification of the image to be transferred onto the transfer sheet, and a control device for controlling the magnification changing mechanism in accordance with deformation of the transfer sheet caused by an image forming operation on the transfer sheet, after a first image is formed on the transfer sheet and before a second image is formed on the same transfer sheet, whereby those images are correctly registered.

Abstract: The invention relates to a method and apparatus for forming images on both sides or surfaces of sheets corresponding to images on two-side originals.In a method for two-side image formation for forming images on both sides of sheets from images formed on two-side originals, a first-side image formation cycle is continuously performed for a required number of sets of sheets, the first-side image formation cycle including sequential operations for forming images on the first sides of the originals on the first sides of the sheets and for storing the one-side copied sheets in an intermediate storing portion, and thereafter a second-side image formation cycle is performed by sequentially forming images of the second sides of the originals on the second sides of the corresponding sheets. The invention also relates to an apparatus adopting this method.

Abstract: A both-side recording apparatus in which sheets having a first image recorded on a first side thereof are temporally contained in a relay tray and subsequently a second image is recorded on a second side of the sheets has a first side recording compensation mode in which if a deficiency occurs in the number of sheets during the sheet first side recording operation, recording is continuedly effect on sheets corresponding to the number of deficient sheets, a second side recording compensation mode in which if a deficiency occurs in the number of sheets during the sheet second side recording operation, the second image is continuedly recorded on the first side of sheets corresponding to the number of deficient sheets after the recording of the second image on the second side of the sheets from the relay tray has been terminated, whereafter the first image is recorded on the second side of said sheets, and a device for changing over a transportation path so that where the image recorded on the second side of the

Abstract: A double-side image forming apparatus has input unit for entering the number of desired image formation for forming images on both faces of a sheet-shaped image bearing member and a storage section for storing said image bearing member after image formation on a first face thereof. The apparatus is adapted, when the image formation on the first face of said image bearing members is interrupted before the completion of said desired number of image formations, to conduct in continuation the image formation on the second face of the image bearing members stored in said storage section.

Abstract: The present invention relates to an electrostatic charging process for uniformly charging an image holding member such as a photoconductive or insulating drum. In an image forming apparatus in which such image holding member is driven both at a first speed and at a second speed different from said first speed, there results a phenomenon of uneven charging due to the difference between the start-up characteristic of charging performance of the charging means and the actual speed at the speed change-over of the image holding member. This drawback is prevented by the present invention in which the speed change-over time of the image holding member is selected different from the charging start time of the charging means in such a manner that the charging is initiated after the speed change-over.

Abstract: An air flow line system is disclosed which is operative effectively and advantageously in such type of image forming apparatus in which the photosensitive medium is in the form of a screen having therein a great number of fine openings. The air flow line system comprises first and second air flow channels or circuits. To switch over the direction of air flow, there is provided a switching device. In accordance with the operating condition of the apparatus, an air flow is directed selectively to the first channel or to the second channel through the switching device. The first channel includes therein the switching device and is defined by an air flow line extending between the vicinity of the screen type photosensitive medium and a pumping device functioning as an air blower or fan. The second channel the switching device and is defined by an air flow line extending between an air using mechanism operative with air flow and the pumping device.

Abstract: This specification discloses an invention relating to the relationship between a latent image bearing member such as screen-like photosensitive medium and a corona discharger used to form a latent image on the latent image bearing member. More particularly, the corona discharger is divided into a plurality of dischargers so that when the sum of the length of the corona discharger for the formation of the latent image and the length of the latent image bearing member is greater than the length in the direction of movement of an endless support member supporting the latent image bearing member, the plurality of dischargers may selectively discharge corona in accordance with the rotational position of the latent image bearing member. By this, the latent image bearing member may be prevented from being dually charged and the length of the latent image bearing member may be minimized to contribute to reduction in size of the image formation apparatus.

Abstract: The disclosure describes a variable magnification optical mechanism in an image forming apparatus in which a varied image at a selected magnification of an original image is formed. A photosensitive body on which the varied image is exposed is moved at a definite speed (v) irrespective of the selected magnification (m) and optical means for transmitting the image of the original to the photosensitive body is driven at a speed ratio of v/m. The pre-running length (l) of the optical means is changed in accordance with the selected magnification (m) at a ratio of l/m so that coincidence of the original image and the variation image formed therefrom may be attained every time.

Abstract: An electrophotographic copying apparatus for forming on a photosensitive medium electrostatic images corresponding to an original image and for providing copies thereof, comprises an original carriage for carrying thereon the original image, optical scanning means having a plurality of reciprocally movable scanning units for scanning the original image on the carriage, a photosensitive medium, and means for forming on the photosensitive medium electrostatic images corresponding to the original image. The optical scanning units of the optical scanning means are operable to successively scan the original image.