U3T

Runaway

A reaction that gives off heat faster than the cooling system can remove the heat is an example of which kind of reaction?

dust and dirt particles

Air filters in home air-conditioning systems remove much of the ________ from the air.

elements

All matter is composed of building blocks called ________.

To dilute reactants to a safe concentration

Besides being used to absorb excess heat, what is the function of a diluent such as nitrogen in a gas phase reactor?

Donning proper PPE

Besides following established procedures, what can minimize the process technician's potential for exposure during sampling?

rhodium

Catalytic converters in some cars use precious metals like ________ to help convert the pollutants in the combustion gases to less-toxic products.

collect and analyze samples

During normal operation, technicians routinely ________ during their shift.

the process system must be opened to change the filter media

Filtration systems can be very hazardous primarily because ________.

sand

Gravity filters, commonly used in water treatment plants, use a filter medium such as ________ to filter the liquid.

By diluting the raw materials in a solvent

How can plants slow the reaction down and limit the amount of heat generated by reactions that might proceed too quickly and generate heat too rapidly?

By regularly inspecting the furnace system and identifying and correcting potential issues as quickly as possible

How do process technicians ensure the safe operation of furnace system equipment?

Through chemical reactions

How do processing units convert raw materials into new products with more desirable properties?

They require more monitoring and sampling.

How does continuous reactor startup compare with normal operations?

By adjusting the firing rate of the burners

How is the outlet temperature of the process fluid (usually some type of hydrocarbon) maintained in a fired heater?

air registers

Ideally , a fired heater will have automatic excess O2 control that adjusts ________ that control airflow to maintain the target O2.

coils

If excessive heating or cooling is expected due to the endothermic (heat absorbing) or exothermic (heat releasing) nature of the reaction, cooling water or steam can be circulated through a jacket on the outside of the vessel or through ________ on the inside of the reactor vessel to help control the temperature of the reaction.

exothermic

In ________ continuous-flow reactions, redundant (backup) temperature and pressure instruments are required for safety.

Too-low temperatures

In a filtration system, what may cause some process materials to "thicken," resulting in problems with strainers and/or filters?

Reactants

In a typical chemical equation, what is listed on the left-hand side of the equation?

A substance formed as a result of a chemical reaction

In batch operations, what is the product?

Monitoring outside equipment

In performing which of the following tasks might a process technician notice leaks or spills?

Batch reactors

In which reactors are reactants carefully measured and controlled, added to the reactor, reacted, and then removed as a single load?

highly exothermic reactions

It is very important not to add reagents too quickly in ________.

circular

Most batch reactors are ________ in shape.

Either a pipe spool piece or a Y or basket-type strainer

Once the system has been operating for a specific period, what is used to replace the conical strainer for permanent operation?

wear proper PPE at all times

One important requirement is that process technicians ________.

light off

Per our book over five decades of heater incidents show that about 70 percent of the explosions and 90 percent of fatalities occur during _____________

on both the upstream and downstream sides

Process technicians must monitor the pressure of a strainer/filter ________ as well as the flow through it

tubular reactors

Reactors in which reactants enter a hollow tube or pipe and react as they flow through the tube before coming out the other end as product are referred to as ________.

Endothermic

Reforming is an example of which kind of reaction?

A consistent product stream composition

Steady temperature, pressure, level, and feed flow in a continuous reactor during normal operation should produce what result?

target outlet temperature

The key variable for a furnace system is the ________ of the process fluid for a given target process fluid flow rate.

flame impingement

The most common cause of fluids being released from a process tube is prolonged ________.

much different from

The recipes, operating conditions, and sizes of continuous reactors are ________ laboratory experiments.

react hydrocarbons inside their process tubes

Two common reactors are reformers and cracking furnaces , both of which ________.

the smaller the pore size

Typically, ________, the greater the pressure drop across a filter

is very expensive

Using hydrogen (H2) as fuel ________.

Chemical changes in which one or more new substances are formed

What are chemical reactions?

Reacting liquids

What are continuously stirred tank reactors (CSTR) best suited for?

Flammability issues

What are possible hazards related to the process technician's filtration system task of preparing for maintenance and overseeing activities?

Vessels in which controlled chemical reactions are initiated and sustained

What are reactors?

Nitric oxide (NO) and nitrogen dioxide (NO2)

What are the two primary environmental concerns in fired heaters?

An increase in temperature and potential overpressurizing

What can be the result of hot spots in some exothermic reactions?

Sound

What can be used as an important diagnostic tool to help determine when something is wrong?

A runaway reaction

What can occur in a continuous reactor when unreacted raw material concentration rises above a safe level?

A filter

What device is used to remove unwanted solids from systems both to protect equipment and to ensure product quality?

Collect and analyze reactor samples.

What do process technicians in a continuous reactor operation do routinely during their shift?

Agitators

What do stirred tank reactors use to facilitate the mixing of reactants?

Rectangular -shaped base

What is a characteristic of a cabin heater?

The material that actually does the filtering in the filter unit

What is a filter medium?

Excessive flame lengths

What is a possible consequence of low draft in furnace operations?

High CO pollution emissions

What is a possible consequence of low excess O2 in furnace exhaust gas?

Digesters

What is a type of continuous reactor used by wastewater plants to remove harmful products before discharging clean water?

Huffing

What is commonly used term for the potential furnace problem of heater pulsation?

Energy must be added, and the molecules must collide.

What is required to break existing chemical bonds?

Exceeding the cooling system's capacity to absorb the heat produced by the reaction

What is the biggest concern for highly exothermic reactions?

The stack damper

What is the primary device used to control furnace draft in a natural draft heater?

Stoichiometric

What is the term for a reaction where there is exactly the right balance of fuel and oxygen?

Continuous reactor

What is the term for a reactor that accepts a steady flow of raw materials, solvents, catalysts, and recycle streams?

Compounds

What is the term for substances formed by joining two or more elements?

Relief system

What is the term for the collection of piping and equipment designed to prevent the overpressurization or underpressurization (vacuum) of a vessel or system?

Reactants

What is the term used for the raw materials that a facility adds to the reactor in a batch operation?

Reaction rate

What key variable in reactor operation represents the speed at which a chemical reaction proceeds?

A loss of heating

What may cause reaction material to crystallize in an endothermic (heat-absorbing) reaction?

The reaction may stop.

What may happen if the reactor cools off or depressurizes?

Performance may degrade.

What may result if catalyst ages and deactivates over time?

They may be corrosive

What may result when raw materials are at high concentrations?

Tubular

What type of reactor is a furnace?

It is recovered and recycled.

When a product stream contains unreacted raw material along with product, what happens to the unreacted material?

When starting up or cooling down a reactor

When is the potential for pooling highest?

When adding a gas

When may a sparger or distribution plate be used to improve contact with reactants or catalysts?

a load cell (strain gauge)

When precise measurements are needed, each reactant is measured by mass or volume as it is added using either ________ or a flow totalizer.

AB + CD → AD + CB

Which format represents a double displacement reaction?

Slips and falls from spills/leaks

Which is a possible hazard related to the process technician's filtration system task of monitoring outside equipment?

AB + C → AC + B

Which of the following equation formats represents a single displacement reaction?

Overseeing isolation activities

Which of the following is a task associated with the process technician's responsibilities for preparation for maintenance?

Digestion of food

Which of the following is an example of a chemical change?

Performing pressure testing (looking for leaks)

Which of the following is one of the tasks associated with the process technician's startup of the filtration system responsibilities?

AB → A + B

Which of the following is the format for a decomposition reaction equation?

A + B → AB

Which of the following is the format representing a combination reaction equation?

Extraction

Which of the following might be used separate liquid-liquid mixtures?

Heat is released.

Which of the following occurs in an exothermic reaction?

Startup of the filtration system

Which of the following process technician filtration system responsibilities can involve checking status of equipment and instrumentation?

Switching or backwashing equipment, making valve lineups

Which of the following process technician filtration system responsibilities can involve switching lineups to provide continuous flows through filters to other systems as needed?

Taking samples

Which of the following process technician tasks can present burn hazards?

Adding proper amounts of reagents

Which of the following process technician tasks is sometimes done by the distributed control system (DCS)?

A 30 mesh screen

Which of the following screens has the largest diameter holes?

Cleaning the reactor (if needed)

Which of the following tasks falls within the process technician's responsibilities for preparing the batch reactor?

Emptying the reactor contents

Which of the following tasks falls within the process technician's responsibilities for shutting down the batch reactor?

Condenser

Which of the following would be used to separate gas-vapor mixtures?

A premix burner

Which type of burner mixes some , if not all , of the fuel and combustion air inside the burner?

Forced draft (FD)

Which type of heater is sometimes referred to as an assisted draft or mechanical draft furnace?

Highly exothermic reactions

Which types of activities carry concerns about overheating?

The DCS control operator

Who should be notified by radio before field technicians begin working at a furnace?

Because they require a higher pressure drop

Why are filters located for the most part on the high-pressure/discharge side of the pump?

To keep the heat inside and to keep the outside cool

Why are the walls of furnaces refractory -lined?

To dilute the reaction mixture and limit the heat released

Why does the solvent ratio start out relatively high during startup?

To make sure any residual material is strained out

Why is a conical strainer (temporary strainer) is normally used in initial startup of a filtration system?

Solids would remain in the engine and damage its moving parts.

Without the automobile oil filter, what would happen to the car?

The computer's control system

________ adjusts heating and cooling utility fluids, as well as outlet product low, to maintain steady reactor conditions.