A sealed rotary feeder

Abstract: An object of this invention is to provide a sealed rotary feeder for use in an apparatus which continuously processes chips made of synthetic resin with a coating under high pressure and temperature without degrading its material strength. The sealed rotary feeder according to this invention consists of a cylindrical casing (13a) having a chip inlet (13a1) on the upper side of said cylindrical casing and a chip outlet (13a2) on the low side of said cylindrical casing (13a), a rotor (13b) in said cylindrical casing (13a), plural blades (13k) which are movably inserted into channels radially formed around said rotor, and divide said cylindrical casing into plural baskets, pressing means which press said plural blades (13k) against the inner surface of said cylindrical casing (13a), and walls which form said channels are extended at the vicinity of the inner surface of said cylindrical casing.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed rotary feeder, according to the preamble of claims 1 and 2. 2. Description of the Prior Art Recently it has become necessary to reuse waste parts made of synthetic resin, for environmental reasons, and it is general practice to separate waste parts and reuse them as material for new products. It is, furthermore, general practice to coat products with a thermosetting coating to add to the beauty of the products. In the case of liquefying waste parts with a coating, the thermosetting coating is not decomposed. Therefore, the strength of the material is degraded when synthetic resins containing un-decomposed coatings are reused. For instance, in cold districts, the strength of bumpers made of synthetic resins containing un-decomposed coatings is lower than that of bumpers made of synthetic resin without the coatings included. The degradation of material strength can be avoided if the coating is removed, but perfect removal of coating is too difficult. Although coating can be mechanically removed by shotblasting etc., it not only takes a long time but is impossible to perfectly remove the coating when parts have complicated shapes. Mechanical removal, therefore, is unsuitable for mass recycling. Although removal of the coating with organic acid has been proposed, it causes environmental pollution. To solve the above-mentioned problem, the present applicant has already proposed a method for recycling synthetic resin parts, that is, the coating thereof is hydrolyzed and kneaded into synthetic resin chips (See Japanese Patent Application No. 3-192431). The above-mentioned method is a so-called batch process, and is not suitable for continuous recycle. To hydrolyze synthetic resin chips, it is necessary to continuously supply chips to a hydrolyzing vessel, in which the temperature and pressure thereof are maintained at suitable levels. Prior art of an apparatus enabling a continuous supply of chips under pressure is disclosed in Japanese Unexamined Utility Model Application (Kokai) 55-117438. In this Prior Art, sealing blades of a rotary feeder are pressed against an inner wall of its casing by springs. It is necessary, therefore, that the more the pressure difference between the inlet and the outlet of the rotary feeder is increased, the more the spring force to press the sealing blades against the inner wall is increased. This causes the more damage to the sealing blades. Then the life of the blades may be reduced and frequent maintenance and inspection may be required. The sealing blades in the Prior Art, furthermore, are only inserted into channel arranged on a rotor. Then when the supplied chips go into the clearance between the sealing blades and the channel, the sealing effect may be lost. Document US-A-3 151 784 discloses a sealed rotary feeder corresponding to the ones according to the entering clause of claim 1 or claim 2 having a rotor with walls which are directed towards the cylindrical casing and which have channels for receiving the blades. These plates are pressed outwards by means of a pressing means comprising springs providing an outward directed force. Document US-3 052 383 shows a rotary feeder comprising a one-piece rotor having channels forming side walls for receiving the rotor blades. In these documents no indication is given how the clearance between side walls forming channels and the rotor blades may be sealed. The object underlying the invention is to provide a sealed rotary feeder having a rotor comprising a plurality of blades, wherein the sealing characteristics between said blades and the body of the rotor are improved. This object is solved by features of independent claims 1 and 2. According to claim 1, each of these plural blades has a slit on its top and a spring accomodated in that slit which spreads the blade to seal a clearance between the walls of the rotor and said blade. By spreading the top of the blade, a possible clearance between the side walls of the rotor and the blade can be sealed. According to claim 2, these blades comprise two springs, wherein one spring is arranged at one side of the upper part of that blade and the other spring is arranged on the other side of the lower part of that blade. By the action of these two springs, the blades are tilted and therefore the clearances of both sides of the blades between the side walls of the rotor and the blades is effectively sealed. The common inventive concept underlying the invention as claimed in claims 1 and 2 is to urge at least a part of the blade against the side wall of the channels formed in the body of the rotor. The further claims describe further developments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be more clearly understood from the description set forth below with reference to the accompanying drawings. Fig. 1 is an axial structural drawing of the first embodiment. Fig. 2 is a view of a rotor of the sealed rotary feeder. Fig. 3 is an enlarged sectional drawing of the first embodiment of a seal blade. Fig. 4 is an enlarged sectional drawing of the second embodiment of a seal blade. Description of the preferred embodiments Fig. 1 shows an axial sectional drawing of the rotary feeder. The rotary feeder consists of a cylindrical casing 13a having a chip inlet 13a1 at its top and a chip outlet 13a2 at its bottom, eight blades 13k, and a rotor 13b having eight baskets 13ℓ. And at least three blades 13k are pressed against the inner wall of the casing 13a. Fig. 2 shows a view of the rotor 13b with alternately arranged blades 13k and baskets 13ℓ. Chips supplied from the chip inlet 13a1 are stored in the basket 13ℓ, transported to the chip outlet 13a2, and delivered quantitatively from the chip outlet 13a2. Note, the axial length of the basket is equal to that of the chip inlet and the chip outlet in order to improve efficiency. It is necessary to install a sealing mechanism on the side of the rotor (X in Fig. 2) and the circumference (Y in Fig. 2) of the rotor to seal between the upstream and the downstream of the seal rotary feeder. To seal the side of the rotor 13b, sealant 13m is installed at the edge of the side plate 13n. Further, to seal the circumference of the rotor channels 13p the, same length as the rotor 13b, are cut on its circumference, and blades 13k and springs 13q are inserted into the channels. As the blades are pressed against the inner wall of the casing 13a by the springs 13q, steam flow around the circumference of rotor 13b is prevented. Note, the force of each spring 13q is set in order to keep the blades touching against the inner wall when high pressure is applied to the blades 13k. Note, the diameter of the rotor 13b is determined so as to have a clearance H between the casing 13a even when the casing 13a is deformed by thermal expansion. It is necessary, furthermore, to stop steam flowing through the clearance between the blades 13k and channels 13p. Fig. 3 shows the first method to stop steam flowing through the clearance (a) between each blade 13k and the corresponding channel 13p. Blades 13k are supported by supporters 13r and movably installed. At the bottom of the channel 13p, springs 13q are installed, and the blades 13k connected to the supporters 13r are pressed against the inner wall of the casing 13a. Each blade 13k has a longitudinal slit 13k1 and a spring 13k2 in the slit 13k1 to spread it, and both sides of blade 13k touch to the channel 13p for sealing. Note, in Fig. 3 the spread of the blade is exaggerated. Fig. 4 shows the second method of sealing, where two springs 13k3 and 13k4 are arranged on both sides of each blade 13k so that the blade 13k is slanted in the channel 13p. In the second method, each blade 13k is slanted by the two springs 13k3 and 13k4, and touched at the top of the channel (a) and the inner wall of the channel (b). Note, in Fig. 4 the inclination of the blade is exaggerated.

Claims: A sealed rotary feeder, comprising a cylindrical casing (13a) having an inner surface, a chip inlet (13a1) on the upper side of said cylindrical casing and a chip outlet (13a2) on the low side of said cylindrical casing (13a), a rotor (13b) in said cylindrical casing (13a), a plurality of blades (13k) which are movably inserted into channels (13p) radially formed around said rotor, and divide said cylindrical casing into plural baskets, pressing means which press said plural blades (13k) against the inner surface of said cylindrical casing (13a), wherein said channels (13p) are formed in walls (13b1) of said rotor (13b) extending radially to the inner surface of said cylindrical casing (13a) characterized in that each of said plural blades (13k) has a slit (13k1) on its top opposite to the inner surface of said cylindrical casing, and a spring (13k2) in said slit (13k1) which spreads each of said plural blades (13k) to seal a clearance between said walls (13b1) and each of said plural blades (13k). A sealed rotary feeder, comprising a cylindrical casing (13a) having an inner surface, a chip inlet (13a1) on the upper side of said cylindrical casing (13a) and a chip outlet (13a2) on the low side of said cylindrical casing (13a), a rotor (13b) in said cylindrical casing (13a), a plurality of blades (13k) which are movably inserted into channels (13p) radially formed around said rotor (13b), and divide said cylindrical casing (13a) into plural baskets (13), pressing means which press said plural blades (13k) against the inner surface of said cylindrical casing (13a), wherein said channels (13p) are formed in walls (13b1) of said rotor (13b) extending radially to the inner surface of said cylindrical casing (13a), characterized in that each of said plural blades (13k) has one spring (13k3) arranged on a first side of the upper part of said blades (13k) facing a side wall of said channels and another spring (13k4) arranged on a second side of the lower part of said each of said plural blades (13k) opposite to said first side to seal a clearance between said walls (13b1) and each of said plural blades (13k). A sealed rotary feeder according to claim 1 or claim 2, characterized in that said pressing means for pressing said plural blades (13k) comprises springs (13q) acting upon said blades (13k). A sealed rotary feeder according to claim 3, characterized in that said blades (13k) are supported by supporters (13r). A sealed rotary feeder according to claim 4, characterized in that said springs (13q) are installed at the bottom of said channels (13p), wherein the blades (13k) are connected to the supporters (13r).

Inventors: IKEDA SADAO, KITO MAKOTO, IKEDA, SADAO, KITO, MAKOTO
Applicants: TOYOTA MOTOR CO LTD, TOYOTA JIDOSHA KABUSHIKI KAISHA
Application year: 1993
Main classification: B65G53
IPC codes: B65G53, B29B17