Eastman-Kodak Company

Brian L Simpson

Kevin M Logsdon

Jeffrey R Hennenkamp

Paul C Drake

Theodore E Walker

William J Gamble

Andrius A Naujokas

Bruce R DeBruin

Stephen Michael Popham

Walter E Toot, Jr

Gerald Douglas Knight

Gary Michael Distefano

John W Crevelling

Ralph H Pelto

Donald Charles Reid

Mark Louis Quadrini

Richard Arthur Tietz

Golf practice target system

Herein is disclosed a continuous process for manufacturing purified silver nitrate solutions comprising the steps of:

Continuous method of removing impurities from crude silver nitrate

An improved system (10) conveys comminuted material from a source (12) to a vessel (14), especially for continuously conveying chopped poly(ethyleneterephthalate), or PET, into a methanolysis recovery reactor without entrainment of air into the reactor and without frequent jamming of the apparatus. A single rotary vane valve (36) is provided in the conveyance path at an inlet (38) to the vessel. The valve has clearances between the vanes (44) and the housing (48) larger than the smallest dimension of the comminuted material to prevent jamming of the rotor by PET flakes. The internal spaces (52, 47) in the valve are continuously purged with nitrogen at sufficient volume and pressure such that gases and fumes in the vessel are substantially prevented from passing upward through the valve. Nitrogen also flows from the valve countercurrently through the supply ducts (26, 30) to strip entrained air from the incoming material. Preferably, additional nitrogen is introduced into the supply duct (30) ahead of the valve to assist in air removal from the material. Internal valve surfaces (64) are heated to prevent condensation of gases and fumes from the vessel, thereby preventing sticking and clogging of the comminuted material within the valve. A slide (28) for entry of material into the valve is provided at a 40.degree. angle to assure uniform flow of material. The comminuted material is conveyed from the source by high-velocity air (17) and can be humidified (66) as needed to prevent sticking or clumping in the conveyance path.

Method and apparatus for feeding chopped polyester scrap

A method of removing dimethyl terephthalate (DMT) from a vapor stream. The vapor stream includes dimethyl terephthalate (DMT), methylhydroxyethyl terephthalate (MHET), glycols and methanol. A distillation column is held under an elevated pressure of 100 to 500 kPag and at a temperature of at least 85.degree. C. It has (i) a plurality of distillation trays; (ii) methanol liquid sprays between the trays; (iii) a main spray zone below the trays and (iv) a liquid pool of methanol in the bottom of the column. The vapor stream is directed into the distillation column, above the liquid pool and below the main spray zone, thereby forming a stream of liquid and vapor. The stream of liquid is directed away from the distillation column walls and into the liquid pool at the bottom of the column. Concurrently, a portion of the liquid in the bottom of the column is (i) recycled back into the distillation column as a spray in the column above the vapor stream inlet, thereby preventing build up of solid DMT on column surfaces and (ii) removed from the column to enable DMT removal.

Removal of dimethylterephthalate from a methanolysis vapor stream

A process is disclosed for forming compacted silver nitrate bodies. A feed silver nitrate solution is introduced into an evaporative crystallizer (10). Steam is provided to a steam jacket (30) to heat the solution in the crystallizer (10) and form a slurry comprising silver nitrate crystals. The crystallizer (10) has an agitator (20) to mix the slurry and promote crystal growth. Slurry density is maintained within a desired range by controlling the rate of steam flow to the steam jacket (30) via a control valve (34). Slurry containing silver nitrate crystals is withdrawn from the crystallizer (10) and introduced to a centrifuge separator (78), for separating and drying the crystals. The separated, dried crystals are further dried by contact with an airstream and fall into a hopper (88). The crystals flow from the hopper into a translucent feed tube (96) and then into a roll compactor (100) that compacts the crystals to form the compacted silver nitrate bodies.

Process for compacting silver nitrate

Silver nitrate crystals comprising a substantially non-platelet crystal morphology are disclosed. The non-platelet silver nitrate crystals have an aspect ratio in the range of from about 1:2:3 to about 1:1:1. FIGS. 4 and 5.

Silver nitrate produced by a continuous evaporative crystallization

A novel leaching process for separating extractable material from a particulate solid material that comprises extractable and non-extractable portions includes the steps of introducing the particulate solid material and a liquid solvent to an extraction zone; agitating the liquid solvent to a degree sufficient to suspend the particulate solid material and effect segregation of particles thereof in relation to their propensity to settle; maintaining contact between the liquid solvent and the particulate solid material for a time sufficient to leach extractable material therefrom; and selectively withdrawing particles of the solid material from the extraction zone. In a preferred embodiment, the leaching process is a multi-stage process in which the selectively withdrawn particles from each stage are introduced to the next successive stage of the series. A particularly important use for the novel leaching process is in the recovery of gelatin from bone, and specifically in that step of the gelatin manufacturing process in which granulated bone is demineralized by contact with a dilute acid solution which converts bone particles to particles of ossein by extracting the minerals from the bone.

Process for leaching particulate solid materials

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Hamlin, NY, United States of America

Brian L Simpson