Patent GB-1124744-A (GB)
Title: Improvements in or relating to apparatus for the continuous treatment of castings
Inventor: MACMILLAN WILLIAM ROBERTSON
IPC: B22D29/00
Filed: 1965-08-27
Abstract: 1,124,744. Blasting. TILGHMAN WHEELABRATOR Ltd. 15 Aug., 1966 [27 Aug., 1965], No. 36853/65. Heading B3D. Apparatus for the continuous treatment of castings comprises: (a) Blasting means arranged to blast particulate magnetizable abrasive material at said castings; (b) Conveying means arranged to present continuously the castings to the abrasive material; (c) Magnetic separating means for separating the spent abrasive material from non- magnetizable contaminants; and (d) Feed means for automatically feeding the abrasive material free from contaminants to the blasting means. Castings, covered with contaminants such as sand, gits, wire, flash &c., are carried continuously by an endless overhead conveyer 7 through a blasting chamber 4 in which are located six impeller wheels 6 fed with steel abrasive from a hopper 5. During travel of the castings along the lead-in portion 8 some of the contaminants fall into hoppers 13 and are passed by a conveyer 19 and a vibratory feeder 21 on to a vibratory conveyer 18. Spent abrasive and contaminants removed by the blasting fall into hoppers 10, 11, 12 and on the vibratory conveyer 18. Abrasive and contaminants pass along the vibratory conveyer 18 into a bucket elevator 23; larger contaminants are sieved out on the conveyer and collected in a wheeled bin 37. The elevator passes the abrasive and smaller contaminants into a head box 24 from which they are metered out to four separators 25, each having a rotary sieve 33 and a magnetic drum 34. In the separators, gits, wire, flashes &c. which have escaped the previous sieving are removed by the rotary sieve. The magnetizable steel abrasive is substantially separated from the sand by the magnetic drum. The magnetizable portion is passed into a pneumatic portion of the separator, the re-usable abrasive being there separated from the unusable material. The re-usable abrasive passes via conveyers 28, 29, shoots 35, 35 and bucket elevators 36, 36 to the hopper 5. The non- magnetizable portion consisting essentially of sand with.a small amount of small steel particles adhering thereto is passed from the separators 25 by conveyer 30 to separator 31 having magnetic drum 32 for removing the small steel particles. The sand is discharged for re-use in sand moulds. Castings leaving the blasting chamber 4 pass through a spotting room 17 where an operator manually blasts any portions which have not been properly cleaned in the chamber. Any abrasive and contaminants remaining after passage through the chamber. 4 fall into hoppers 11, 12, 14 and thence (in the case of the hoppers 14 via conveyer 20 and vibratory feeder 22) to the vibratory conveyer 18.  The magnetic separators may be of the single or multi-pole type operated by a permanent or electromagnet. The conveyer for the castings may be a belt conveyer, gravity roller conveyer, driven roller conveyer, chain conveyer, twisted roller conveyer, diabolo roller conveyer, overhead monorail conveyer, tumbling barrel or circular overhead conveyer.