Process for the mechanical cleaning of foundry used sand
AssigneeKGT Giessereitechnik GmbH
InventorVolker Godderidge
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Abstract
The invention relates to a process for the mechanical cleaning of foundry used sand by means of thermomechanical regenerations, in which the sand is blown pneumatically against a deflection hood and the mechanical-pneumatic cleaning is performed batchwise in a separate container. The process can be used both as pre-cleaning and as after-cleaning. In the case of pre-cleaning there is a simultaneous drying, preheating, pre-cleaning and sifting, whereas with after-cleaning there is a simultaneous cooling, after-cleaning and sifting. As a result of the batchwise operation, all the quartz particles are exposed roughly to the same friction treatment and consequently, in conjunction with a simple control of the cleaning process, reduced grain destruction is achieved.
Claims12
A process for the cleaning of used foundry sand, comprising the steps of, in sequence:
- (a) heating and mechanically pre-cleaning the sand in a batchwise manner in a pre-cleaning container by repeatedly pneumatically blowing the sand through a vertically positioned blast pipe with hot air against a deflection hood until an adequate cleaning level is achieved, the cleaning level being measured as a function of two or more in combination of the degree of contamination, degree of moisture and temperature in the preheating container, and
- (b) thermally regenerating the sand in a regeneration container.
A process for the cleaning of used foundry sand comprising quartz fines and organic matter, comprising the steps of, in sequence:
- (a) heating and mechanically pre-cleaning the sand in a batchwise manner in a pre-cleaning container by pneumatically blowing the sand with hot air against a deflection hood, while simultaneously drawing off the quartz fines and organic matter through an opening in an upper area of the pre-cleaning container for use in green sand preparation until the proportion of quartz fines to organic matter increases to a certain value where efficient reclamation of the quartz fines becomes possible, and
- (b) thermally regenerating the sand in a regeneration container.
A process for the cleaning of used foundry sand, comprising the steps of, in sequence:
- (a) pre-heating the sand in a pre-cleaning container by fluidizing the sand with hot air,
- (b) heating and mechanically pre-cleaning the sand in a batchwise manner in the pre-cleaning container by pneumatically blowing the sand with hot air against a deflection hood, and
- (c) thermally regenerating the sand in a regeneration container.
Dependencies are inferred from the claim text.