System for demolding materials obtained by means of the freeze-casting technique

Patent metadata

Field	Value
Publication number	US-12186936-B2
Application number	US-202217901114-A
Country	US
Kind code	B2
Filing date	Sep 1, 2022
Priority date	Sep 1, 2021
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

A linear actuator is used to remove solid-state parts in low-temperature condition from the containers used as a mold for manufacturing parts using freeze-casting. The device allows pressure to be applied to the material to be removed, resulting in ejection. The displacement of the material is performed with controlled displacement speed, providing the achievement of defect-free materials. The system performing the ejection includes a source of compressed air, a pressure regulator filter coupled with a manometer, a directional valve, the linear actuator, a baton, a flow regulating valve, a fastening means, a metallic support and a chamber for receiving the cooled material.

First claim

The invention claimed is:

1. A system for demolding materials obtained by freeze-casting the system comprising:
a source of compressed air;
a pressure regulator filter fluidically coupled to the source of compressed air;
a manometer coupled to the pressure regulator filter;
a directional valve fluidically coupled to the source of compressed air by the regulator filter, the directional valve configured to direct compressed air to an end user;
a linear actuator fluidically coupled to the directional valve, the directional valve configured to control the linear actuator;
a baton coupled to and arranged to be axially moved by the linear actuator;
a flow regulating valve fluidically coupled to the linear actuator, the flow regulator valve configured to regulate an actuation speed of the linear actuator;
a fastening means coupled to the linear actuator;
a mold assembly comprising an outer mold and an inner mold disposed within the outer mold, wherein the outer mold is configured to freeze a material disposed between the inner mold and the outer mold while the inner mold remains at a temperature that is about room temperature, the outer mold and the inner mold configured to define a temperature gradient allowing freezing in a radial direction from the outer mold to the inner mold;
a metallic support arranged to support the fastening means, the metallic support comprising an intermediate platform configured to position the mold assembly after the material has been frozen within the mold assembly; and
a chamber arranged to receive the frozen material from the mold.

2. The system according to claim 1 , wherein, after an outlet of the source of compressed air, compressed air is carried through air transmission lines comprising resistant, elastic material.

3. The system of claim 1 , wherein the flow regulating valve is coupled to an outlet of a lower chamber of the linear actuator.

4. The system of claim 3 , wherein the flow regulating valve controls a flow rate of pressurized air from the lower chamber of the linear actuator, controlling a displacement speed of the baton and the frozen material slipping out of the mold.

5. The system of claim 3 , wherein the linear actuator comprises a front head, a rear head, and four tie rods supporting the front head and the rear head.

6. The system of claim 5 , wherein the front head and the rear head each define holes configured to receive a hose to carry compressed air and access to an upper and the lower chambers.

7. The system of claim 1 , further comprising a seal comprising a set of sealing rings positioned on a piston coupled to and aligned with the baton.

8. The system of claim 7 , wherein the piston is surrounded by a skirt of anodized aluminum.

9. The system of claim 1 , wherein compressed air is routed to the pressure regulator filter coupled with the manometer.

10. The system of claim 1 , wherein the pressure regulating filter comprises a valve that opens and closes to regulate the source of compressed air.

11. The system of claim 1 , wherein the directional valve is a 5/2-way type, having one port for inlet, two ports for exhaust, and two ports for work.

12. The system of claim 1 , further comprising an actuator configured to advance or withdrawal of the baton, the actuator being installed in the directional valve.

13. The system of claim 1 , in exhaust ports, pneumatic filters to attenuate sound produced by an exit of the compressed air and to prevent an entry of solid impurities.

14. The system of claim 1 , wherein the compressed air is conducted to the linear actuator, which is fastened to the metallic support by a fastening means.

15. The system of claim 1 , characterized in that the metallic support comprises carbon steel.

16. The system of claim 1 , wherein the support comprises:
an upper base configured to position the linear actuator; and
a foundation configured to stabilize the system on a flat surface and support pillars.

17. The system of claim 16 , wherein the upper base of the support defines holes configured to support the fastening means.

18. The system of claim 1 , wherein the baton, configured to eject the frozen material, is coupled to a metallic rod of the linear actuator, and both the baton and the metallic rod are configured to move in a linear direction.

19. The system of claim 1 , the baton comprises a thermal insulating material.

20. The system of claim 16 , wherein the system comprises a front fastening flange configure to fasten the linear actuator on the upper base of the metallic support with holes on the upper base to aid the fastening by screws.

21. The system of claim 1 , wherein the intermediate platform defines a central hole configured to receive a lower part of the mold.

22. The system of claim 1 , wherein the intermediate platform defines an edge in an arc shape configured to fasten a side flap of the mold, the intermediate platform further defining a frontal cut configured to allow access to the mold to a fitting point of the edge, for fastening a mold support ring.

23. The system of claim 22 , wherein a juxtaposition between the support ring of the mold and the edge of the intermediate platform is configured to delay a transfer of heat between the mold and the intermediate platform.

24. The system of claim 22 , wherein a ring comprising thermal insulating material is positioned on the edge of the intermediate platform.

25. The system of claim 1 , wherein, after ejection, the frozen material is conducted to the chamber with controlled temperature to receive a cooled material.

26. The system of claim 16 , wherein the mold remains immobilized on the intermediate platform, while the linear actuator exerts pressure inside the mold by the baton.

27. The system of claim 15 , wherein the metallic support comprises carbon steel.

28. The system of claim 19 , wherein the thermal insulating material comprises polyamide or acrylic.

29. The system of claim 24 , wherein the ring of thermal insulating material comprises rubber.

30. The system of claim 2 , wherein the resistant, elastic material comprises polyurethane, polyamide, or polyethylene.

31. The system of claim 1 , wherein the pressure regulator filter and the manometer are fluidically between the source of compressed air and the directional valve.

32. The system of claim 31 , wherein the manometer is fluidically between the pressure regulator filter and the directional valve.

Assignees

• Petroleo Brasileiro S A —Petrobras
• Univ Federal De Minas Gerais—Ufmg

Inventors

• Vasconcelos Wander Luiz
• Da Silva Reis Alan Marcos
• Ferreira Do Nascimento Jailton
• Cristh Fonseca Alves Priscila
• Cordeiro Leite Vasconcelos Daniela
• Guimarães Da Silva Débora

Classifications

• B28B1/007 Primary

  by freezing the material · CPC title

• B28B17/0081

  Process control · CPC title

• B28B13/06

  Removing the shaped articles from moulds (by means incorporated in, or carried by, the moulds B28B7/10) · CPC title

• B28B7/12 Primary

  by fluid pressure {, e.g. acting through flexible wall parts or linings of the moulds} · CPC title