protected function exportDownload()
    {
        $this->view->layout()->disableLayout();
        $this->_helper->viewRenderer->setNoRender(true);
        $batch = $this->loader->getTaskRunnerBatch('export_surveys');
        $file = $batch->getSessionVariable('file');
        foreach($file['headers'] as $header) {
            header($header);
        }
        while (ob_get_level()) {
            ob_end_clean();
        }
        readfile($file['file']);
        // Now clean up the file
        unlink($file['file']);

        exit;
    }