Send many transactions rapidly from an account

sendManyTransactions.js

var Tx = require('ethereumjs-tx');
var Web3 = require('web3');
var util = require('ethereumjs-util');
var stripHexPrefix= require('strip-hex-prefix');


// connect to  node
const web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));

function getTransactionReceiptMined(txHash, interval,callback) {
    const self = web3.eth;
    const transactionReceiptAsync = function(resolve, reject) {
        self.getTransactionReceipt(txHash, (error, receipt) => {
            if (error) {
                reject(error);
            } else if (receipt == null) {
                setTimeout(
                    () => transactionReceiptAsync(resolve, reject),
                    interval ? interval : 500);
            } else {
                if(stripHexPrefix(receipt.status) === '1'){
                    return callback({
                        receipt: receipt,
                        txStatus: 1
                    });
                }
                else{
                    return callback({
                        txStatus: 0
                    })
                }
            }
        });
    };

    if (Array.isArray(txHash)) {
        return Promise.all(txHash.map(
            oneTxHash => self.getTransactionReceiptMined(oneTxHash, interval)));
    } else if (typeof txHash === "string") {
        return new Promise(transactionReceiptAsync);
    } else {
        throw new Error("Invalid Type: " + txHash);
    }
};

const addressFrom = 'address'
var key = 'secret_key';
var privateKey = new Buffer(key, 'hex');
const addressTo = 'address'
var count = web3.eth.getTransactionCount(addressFrom);
console.log(count);
var j = 1;
for(let i = 0; i < 500; i++){  
    var rawTx = {
        nonce: web3.toHex(count+i),
		    gasLimit: web3.toHex(51334),
	    	gasPrice: web3.toHex(10),
    		to: addressTo,
    		from: addressFrom,
    		value: 0x1,
        data: 0x0
      }
      console.log("nonce: ",count+i)
    var tx = new Tx(rawTx);
    tx.sign(privateKey);

    var serializedTx = tx.serialize();

    // console.log(serializedTx);

    // console.log(`Attempting to send signed tx:  ${serializedTx.toString('hex')}\n------------------------`);
    // var receipt = await web3.eth.sendSignedTransaction('0x' + serializedTx.toString('hex'));

    // console.log(`Receipt info: \n${JSON.stringify(receipt, null, '\t')}\n------------------------`);
    //   try{
        web3.eth.sendRawTransaction('0x' + serializedTx.toString('hex'), function (err, hash) {
            // console.log("hash:",hash)
            
            if (!err){
                getTransactionReceiptMined(hash,10,function(txHash){
                    if(txHash.txStatus === 0){
                    console.log("exception thrown by contract",j)
                    j++;
                    }
                    if(txHash.txStatus === 1){
                        console.log('Done: ',j);
                        j++;
                    }
                })
            }
            else{
                console.log("error",err)
            }
            /*var receipt=web3.eth.getTransactionReceipt(trHash);
            if(receipt ! = 1){
                var receipt=web3.eth.getTransactionReceipt(trHash);
            }
            else{
                console.log("Transaction mined");
            }*/
        });
    // }
    //  catch(exception e){
    //     console.log(e)
    //  }

}