Improving operation of fluidized bed reactors by optimizing temperature gradients via particle size distribution control
AssigneeCorner Star Limited
InventorsJia Wei Chew, Baisheng Zou
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Abstract
A method of improving the operation of polysilicon fluidized bed reactors is disclosed. The present disclosure is directed to the optimization of axial temperature gradients in gas-solid fluidized bed systems. Varying the width of the particle size distribution in the reactor alters the temperature gradient within the reactor, thereby providing a means of a better control of internal temperature profiles and hence better reactor performance.
Claims20
A method of improving the operation of a polysilicon fluidized bed reactor having a distributor plate and a core bed, the method comprising:
- adding polysilicon seeds having a pre-determined particle size distribution into the core bed of the fluidized bed reactor;
- measuring the width of the particle size distribution of granules in the bed, wherein the granules consist of a mixture of newly added seeds and previously added seeds, the previously added seeds having grown and/or shrunk in size;
- adjusting the frequency of seed addition into the reactor to change the width of the particle size distribution of the granules in the bed as determined from the ratio of standard deviation (σ) of mass-weighted particle size distribution to the Sauter mean diameter (dsm), seeds being added to the reactor from about every 60 minutes to about every 600 minutes;
- depositing silicon from a thermally decomposable compound onto the previously added and newly added seeds;
- and,
- withdrawing a polysilicon product from the bed.
A method of improving the operation of a polysilicon fluidized bed reactor having a distributor plate and a core bed, the method comprising:
- adding polysilicon seeds having a pre-determined particle size distribution into the core bed of the fluidized bed reactor, seeds being added to the reactor from about every 60 minutes to about every 600 minutes;
- measuring the width of the particle size distribution of granules in the bed, wherein the granules consist of a mixture of newly added seeds and previously added seeds, the previously added seeds having mown and/or shrunk in size;
- adjusting the pre-determined particle size distribution of the seeds to change the width of the particle size distribution of the granules in the bed as determined from the ratio of standard deviation (a) of mass-weighted particle size distribution to the Sauter mean diameter (dsm);
- depositing silicon from a thermally decomposable compound onto the previously added and newly added seeds;
- and,
- withdrawing a polysilicon product from the bed.
A method of improving the operation of a polysilicon fluidized bed reactor having a distributor plate and a core bed, the method comprising:
- adding polysilicon seeds having a pre-determined particle size distribution into the core bed of the fluidized bed reactor;
- measuring the width of the particle size distribution of granules in the bed, wherein the granules consist of a mixture of newly added seeds and previously added seeds, the previously added seeds having grown and/or shrunk in size;
- adjusting the frequency of seed addition into the reactor and adjusting the pre-determined particle size distribution of the seeds to change the width of the particle size distribution of the granules in the bed as determined from the ratio of standard deviation (a) of mass-weighted particle size distribution to the Sauter mean diameter (dsm), seeds being added to the reactor from about every 60 minutes to about every 600 minutes;
- depositing silicon from a thermally decomposable compound onto the previously added and newly added seeds;
- and,
- withdrawing a polysilicon product from the bed.
Dependencies are inferred from the claim text.