Molding apparatus and method with heat recovery

Abstract

Apparatus and method for recapturing and reusing heat provided in the course of fabricating a molded product.

1 . Apparatus for pre-heating moldable materials prior to molding using heat recovered from the molding process comprising:
 a) molding apparatus having an interior surface defining a molding chamber, and at least one fluid flow channel passing through the apparatus and being thermally coupled to the molding chamber;   b) a heat exchanger;   c) said fluid flow channel communicating with the molding apparatus and the heat exchanger for fluid circulation between the molding apparatus and the heat exchange apparatus to transfer heat from a molded product and parts of the molding apparatus adjacent thereto within the molding apparatus to the heat exchanger; and   d) a container housing raw materials for molding into a molded product the container interior being in fluid communication with the heat exchanger such that a second fluid transfers heat from the heat exchanger to the container raw material contents so as to heat the raw materials prior to molding.   
   
   
       2 . Apparatus of  claim 1  wherein the molding apparatus and the heat exchanger are in fluid communication by way of one or more fluid channels. 
   
   
       3 . Apparatus of  claim 2  wherein the fluid channels form a continuous loop between the molding apparatus and the heat exchanger. 
   
   
       4 . Apparatus of  claim 1  wherein the fluid is transferred from the molding apparatus to the heat exchanger by convective currents. 
   
   
       5 . Apparatus of  claim 1  wherein the molding apparatus is selected from the group consisting of a stretch blow-molding apparatus, injection molding apparatus, compression molding apparatus, thermomolding apparatus, thermoforming apparatus, vacuum forming apparatus, transfer molding apparatus, extrusion molding apparatus, and rotational molding apparatus. 
   
   
       6 . Apparatus of  claim 1  where is the first fluid is selected from the group consisting of water, air, thermal oil, refrigerant, and combinations thereof. 
   
   
       7 . Apparatus of  claim 1  wherein the first fluid is circulated between the molding apparatus and the heat exchanger using a turbulent flow. 
   
   
       8 . Apparatus of  claim 1  wherein the heat exchanger comprises a shell-tube heat exchanger. 
   
   
       9 . Apparatus of  claim 8  wherein the shell-tube heat exchanger is selected from the group consisting of parallel-flow heat exchangers, counterflow heat exchangers, cross-flow heat exchangers. 
   
   
       10 . Apparatus of  claim 1  wherein the heat exchanger is selected from the group consisting of plate heat exchangers, regenerative heat exchangers, adiabatic wheel heat exchanger, fluid heat exchangers, dynamic scraped surface heat exchanger, phase-change heat exchangers, multi-phase heat exchangers and spiral heat exchangers. 
   
   
       11 . Apparatus of  claim 1  wherein the container is in fluid communication with the heat exchanger by way of at least one fluid channel. 
   
   
       12 . Apparatus of  claim 11  wherein at least one fluid channel extending from the heat exchanger is coupled to an orifice contained on an underside of the container. 
   
   
       13 . Apparatus of  claim 1  wherein the second fluid is air. 
   
   
       14 . Apparatus of  claim 1  wherein the second fluid is circulated between the heat exchanger and the container. 
   
   
       15 . Apparatus of  claim 1  wherein the raw material is resin for producing plastics. 
   
   
       16 . A method for pre-heating raw material using a heat exchanger comprising:
 a) providing a circulation loop between a molding apparatus and a heat exchanger;   b) circulating a first fluid through the circulation loop such that heat captured by the first fluid from the molding apparatus is directed to the heat exchanger;   c) transferring heat captured by the first fluid to a second fluid within the heat exchanger;   d) redirecting the second fluid from the heat exchanger to a container housing raw material for processing in the molding apparatus; and   e) transferring heat of the second fluid to the raw material so as to heat the raw material prior to processing in the molding apparatus.   
   
   
       17 . The method of  claim 16  wherein the circulation loop, the molding apparatus and the heat exchanger provide a continuous unidirectional loop therebetween such that the first fluid is heated in the molding apparatus and cooled in the heat exchanger. 
   
   
       18 . The method of  claim 16  wherein heat is transferred from the first fluid to the second fluid by a convective current created by the second fluid such that heat is transferred without mixing the first fluid and the second fluid. 
   
   
       19 . The method of  claim 16  further comprising circulating the second fluid through a circulation loop between the heat exchanger and the container such that the circulation loop provides a continuous unidirectional loop therebetween such that the second fluid is heated in the heat exchanger and cooled in the container. 
   
   
       20 . The method of  claim 16  wherein the raw materials are comprised of resin used for producing plastics. 
   
   
       21 . A method for pre-heating plastic resin using a heat exchanger comprising:
 a) providing a first circulation loop between at least one fluid channel of a molding apparatus and a heat exchanger;   b) providing a second circulation loop between the heat exchanger and a container housing raw materials for molding in the molding apparatus;   c) circulating a first fluid through the first circulation loop such that heat captured by the first fluid within at least one fluid channel of the molding apparatus is directed to the heat exchanger; and   d) circulating a second fluid through the second circulation loop such that heat transferred from the first fluid to the second fluid within the heat exchanger is directed to an interior of the container housing plastic resin for processing in the molding apparatus wherein the plastic resin is heated prior to processing in the molding apparatus.